AREA
User's    Manual
                FOR  MICROSOFT WINDOWS™
   CO
   CD
   CD

   CO
   OJ

   o_
   UJ
EPA550-CB-92-007
*
(
X
     U.S. ENVIRONMENTAL
#g& 5  PROTECTION AGENCY

OCTOBER 1992

      NATIONAL OCEANIC
      AND ATMOSPHERIC
      ADMINISTRATION
                    Chemical Emergency Preparedness
                            and Prevention Office
                           Washington. D.C. 2O46O

                       Hazardous Materials Response
                          and Assessment Division
                          seanie. Washington 98115

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 Terms and Conditions for
 ALOHA™ for Macintosh and DOS Computers



 The recipient agrees to the following conditions:

 Use and Distribution Restrictions
 CAMEO™ (and ALOHA™, when sold separately) is available on a not-
 for-profit basis from the National Safety Council to those individuals and
 organizations involved in the safe handling of chemicals.

 The recipient may make sufficient backup copies to protect his site or
 organization against loss of the information. The recipient may use the
 information, by copying of disks or by installation on a local area network
 or mainframe, at one site and within one organization. For purposes of
 this restriction, a "site" means anyone street address, and includes mobile
 response units  assigned to that site over which the recipient is respon-
 sible.

 Temporary classroom installation of no more than 25 copies is allowed for
 a period not to exceed the normal course of instruction. The recipient shall
 not distribute, electronically or by any other means, any portion of CAMEO
 to individuals other than those included in the site or organization restric-
 tions defined above or to any other organizations not part of the recipient
 organization.

 The recipient shall honor  all disclaimers and other limits of liability
 associated with those organizations that have provided data in the com-
 pilation of the ALOHA™ chemical database.

 Limitation of Liability
 The United States Government has used its best efforts to deliver complete
 data incorporated into CAMEO™ and ALOHA™. Nevertheless, the United
 States Government and the National Safety Council do not warrant accu-
 racy or completeness,  are not responsible for errors and omissions, and
 are not liable for any direct, indirect, or consequential damages flowing
 from the recipient's use of ALOHA™.

The CAMEO and ALOHA software  are being distributed "as is" and
neither the United States Government nor the National Safety Council

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Licenses and Trademarks
 makes any warranty claims, either expressed or implied, with respect to the CAMEO
 or ALOHA  software, their quality, accuracy, completeness, performance, mer-
 chantability, or fitness for any intended purpose.

 Indemnification
 The recipient shall indemnify and save harmless the United States and the National
 Safety Council and their agents and employees against any and all loss, damage,
 claim, or liability whatsoever,  due to  personal injury or death, or damage to
 property of others directly or indirectly due to the use by the recipient of CAMEO
 and ALOHA, or any other act or omission of the recipient, including  failure to
 comply with the provisions of the National Safety Council order form.

 Editing
 Any unauthorized editing or alteration of CAMEO or ALOHA chemical data or
 information  provided by the National Safety Council as agent of the U.S. Govern-
 ment will result  in the  termination of the agreement between recipient and the
 National Safety Council and U.S. Government. Upon receipt of notice of termina-
 tion, the recipient shall immediately return all CAMEO and ALOHA information to
 the National Safety Council, including all documents and all copies of software
 containing CAMEO and ALOHA information.
Maintenance
Recipients should keep the National Safety Council informed of any address changes.
This information is necessary so that the U.S. Government or the National Safety
Council may notify users if any CAMEO or ALOHA program changes or updated
information become available.

ALOHA™ is a trademark of the U.S. Government. National Safety Council is a
nongovernmental, not-for-profit, public service organization. Apple® and Macin-
tosh™ are trademarks of Apple Computer, Inc. MacWrite and MacPaint are trade-
marks of Claris. Diamond Unpacking Code from Sextant Corporation was used to
compress ALOHA™ files. Microsoft, MS, and MS-DOS are registered trademarks,
and Windows and Windows/386 are trademarks of Microsoft Corp. Paintbrush is a
trademark of Zsoft Corp. 386 is a trademark of Intel Corp. PostScript is a registered
trademark of Adobe Systems, Inc., and HP is a registered trademark of Hewlett-
Packard Company. IBM is a trademark of International Business Machines. Pkware
was used to compress CAMEO™ DOS files.  Clipper is a trademark of Computer
Associates. GFX Screen Dump is a trademark of C Source, Inc. dBase and Turbo C
are trademarks of Borland International, Inc.

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 Your feedback is
 welcome...
 ...in fact, it's essential to helping us improve both the ALOHA
 program and the ALOHA manual. Please use the space on the next
 page to let us know your comments and suggestions (don't be
 bothered by the fact that we give you only  one page for your
 comments. We actually hope you'll have so many comments that
 you cover several sheets!)  Here are some questions to get you
 started:

 How can we make ALOHA better?
 Does ALOHA cover appropriate issues (heavy gas, etc.)?

 Which features do you think  need improvement? What would
 you like to see done?

 How can we make the manual better?
 Are things explained in a way that you can easily understand?

 Is the type easy to read?

 Is it organized so that you can find pretty much everything?

 Does the manual explain how to use ALOHA to its fullest advan-
 tage?

 Are there some things that the manual could do a better job of
explaining—or are there things that we spend too much time on?

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Your Comments
Please use the lined page for your comments; simply fold it, tape
it, and mail it to us. Thanks!

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                                                            Your Comments
ALOHA is thp best_thing that pypr iiapppned to me.

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OFFICIAL BUSINESS
PENALTY FOR PRIVATE USE, $300
                                                      POSTAGE AND FEES PAID
                                                   U.S. DEPARTMENT OF COMMERCE
                                                           COM-210
                                                          THIRD CLASS
                               The ALOHA Manager
                               NOAA/HAZMAT
                               7600 Sand Point Way N.E.
                               Seattle, Wash.  98115

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     Contents
                                              Page
 I    Overview	1-1
2    Introduction to Air Modeling	2-1
3    The File and Edit Menus	3-1
4    The SiteData Menu	4-1
5    The SetUp Menu	5-1
6    The Display Menu	6-1
7    Sharing	7-1
     Appendices
A       Examples
        I  A Tank Source	A-l-1
       2  Direct Input (Heavy Gas)	A-2-1
       3  A Pipe Source	A-3-1
       4  ALOHA, MARPLOT, and a PICT Map	A-4-1
       5  ALOHA and BitPlot	A-5-1
       6  ALOHA and a MARPLOT Map	A-6-1
B       Troubleshooting
          Macintosh	B-l
          Windows	B-9
C      AlohaSpy	C-l
D      BITPLOT	D-l
     Glossary	8-1
     References	9-1
     Index	10-1

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                      Chapter /

                      Overview
In this chapter...


File and Edit menus ..1-2
SiteData menu	1-2
SetUp menu	1-2
Display menu	1-3
Sharing menu	1-5
Installing ALOHA
  Macintosh	1-5
  Mac memory	1-8
  Windows	1-9
  Windows memory 1-11
Getting help	1-11
How to Use This Manual
This manual is divided into five chapters, beginning here in
Chapter 1 with a discussion of ALOHA's menus, hardware
requirements, and using on-line help.  So that you use the
model knowledgeably and interpret its output correctly, you
should read Chapter 2, Introduction to Air Modeling.


Following the discussion  of dispersion modeling  in
Chapter 2, each chapter addresses a specific feature of the
model. These chapters explain ALOHA's menus and provide
examples to help you move confidently through the menu
items.  Like the model itself, the manual moves successively
through the menubar,  File, Edit, SiteData, SetUp, and
Display, and their respective menu items.
         Rgure 1-1.
        Main ALOHA
            menus.
                                                                C*ncMitrati«n_.
                                                                MM
                                                                Sourc* StrongIb
                                                                       1-1

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 Chapter 1: Overview
 A glossary of air modeling terms and an index are included
 at the end of the manual. There are four appendices:
 O     Examples
 G     Troubleshooting
 G     AlohaSpy
 G     BitPlot

 File and Edit menus
 You'll benefit most from this manual if you are already famil-
 iar with some  basic Macintosh and Microsoft Windows™
 concepts, such as cutting and pasting, and using the File and
 Edit menus, and the Clipboard. PrintAll is an option that has
 been added to ALOHA's File menu; this permits you to print
 ail of the ALOHA output windows that you have open on
 your computer screen. (See Chapter 3, The File and Edit
 Menus, for more information.)

 SiteData menu
 The SiteData menu is where you establish the physical loca-
 tion of your spill source.  Here, you'll tell ALOHA the Loca-
 tion of your spill (in which city did it occur?),  the Building
 Type (what are the buildings like in the vicinity  of the spill?),
 and the Date and Time of the spill.

 SetUp menu
 The SetUp menu is where you give ALOHA the spill condi-
 tions necessary  for it to calculate the "footprint," starting
 with the Chemical that is involved. Next, you  establish the
 Atmospheric conditions present for your spill. You can enter
 this information in two different ways: 1) User Input (typing
 it in yourself), or 2)  having the data relayed by  a portable
 meteorological  station, known as  Station for Atmospheric
 Measurements (SAM Station).  The next information that
 you enter is related to the Source of the spill: was it from a
1-2

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                                   Chapter 1: Overview
puddle, tank, or pipe?  If you know the amount of vapor
entering the air, you may want to choose Direct

Finally, you select Computational to choose the type of dis-
persion computation that you wish ALOHA to use for calcu-
lating the spread and  duration of the chemical cloud. The
options are:

O Let model decide, which lets ALOHA choose the type of
   calculation, based on chemical properties and specifics of
   the release,
O Use Gaussian dispersion only,'or  •
O Use heavy gas dispersion only.

Also on this screen, you'll find the option Define dose. This
option allows you to vary the exponent ALOHA will use in its
dose calculation (dose is the  accumulated amount of the
chemical to which a person is exposed at a particular  loca-
tion).

Display  menu
The Display menu gives you several different choices for how
you'd like to see ALOHA's results displayed.  The first two
choices deal with how you wish the output displayed on your
screen.  Under Options, you must select a Level of Concern
concentration for the footprint to be displayed. Would you
like the shape of  the  chemical cloud at ground level (its
Footprint) plotted on a grid, or displayed with a scale that
you set yourself? What Output Units (English or metric units
of measure) would you like to use with the footprint graph?

Next, you decide what type of output you'd like ALOHA to
Display:
                                                  1-3

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Chapter 1: Overview
 Text Summary
 Footprint
Concentration
Dose
Source strength
Tile Windows
Stack Windows
recaps the options that you've chosen as you
move through the ALOHA menus, and sum-
marizes, in text form, the results of ALOHA's
calculations. This window is always visible.

calculates and  displays  the shape (when
viewed from above) of the chemical cloud at
your specified level of concern.

calculates the expected indoor and out-
door  concentration  levels at the speci-
fied location.  This  information is then
presented on a graph.

calculates the expected indoor and out-
door  dose  levels  at the specified loca-
tion.  This information is then presented
on a graph.

presents  a graph indicating the amount
of the chemical that is released into the
atmosphere over time.

simultaneously shows  you the output
from  all  of the windows that you have
open.

shows you the output, with the windows
stacked on top of each other so that only the
title bars are visible.
Calculate
Calculate Now
allows you to set when you would like
output windows updated.

updates all visible windows.

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                                                     Chapter I; Overview
                  Sharing Menu
                  The Sharing menu allows you to display an ALOHA foot-
                  print on a background map using MARPLOT, the CAMEO
                  mapping module.
    Load only one
 version of ALOHA;
   if you load both
 versions, you can
 run into problems
when you try to use
saved ALOHA files.
Installing ALOHA on your Macintosh
To install ALOHA, you will need to use only one of the two
disks provided (ALOHA™ math coprocessor version if your
Macintosh has a math coprocessor chip or ALOHA™ , if it
doesn't). An installer contained on each disk automatically
copies the files to your hard disk. Data are compressed on the
disks and so must be uncompressed into folders on your hard
drive. You'll receive two floppy disks with packed, or com-
pressed, ALOHA files:
      Figure 1-2.
   Packed ALOHA
           files.
                      ALOHA™ math cp
                               ALOHA™
     1 item
                      ALOHA Folder /
i 1 item
                             ALOHA Folder J
                                                                   1-5

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 Chapter 1: Overview
 To begin:
 O  Insert the floppy disk with the version of ALOHA  that is
    appropriate for your Macintosh (ALOHA™ math coprocessor
    version if your Macintosh has  a math coprocessor chip;
    ALOHA^ if it doesn't).
 O  Double-click on ALOHA Folder/.
 O  Click Drive until you see  your hard  drive's  name (in the
    example below, the  hard drive is named Athena).












(oRthena-H






Unpack as ...
HLOHfl Folder



0

i$i
tf:
;•:•:
;;;;
ijli
•iji!
*>




cs flthena
I 1

[ Desktop J

[ New Q ]

[ Cancel ]
(^Taue^j
* *
 G  Click Save.
 D  You'll see an Unpacking timeline that gives you an idea of how
    long (probably not more than one minute) it takes to extract the
    files that are compressed onto the disk. Notice that the names
    of the files currently being unpacked appear above the time-
    line.
 G  When unpacking is completed, choose Quit from the File
    menu.
1-6

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                                                   Chapter 1: Overview
After unpacking,
you should have
these files in the
 ALOHA Folder.
ALOHA Folder
                 ALOHA
                 ALOHA Helps
                 ALOHA Resources
                 AlohaSpy
                 CbemLib
                 ChemManager
                 CityLib
                     The ALOHA files will be copied into
                     the ALOHA Folder on your Macin-
                     tosh desktop; don't remove the files
                     from this folder. Your ALOHA folder
                     should contain the files shown at left.

                     If you stop before you finish unpack-
                     ing any disk, throw away the ALOHA
                     Folder that has  been partially filled
                     with the files unpacked so far. Start
over and insert the appropriate ALOHA disk, double-click
on ALOHA Folder J, and repeat the steps above.

Your new folders will include these files:
                        ALOHA: be sure that you load the correct version of
                        ALOHA for your machine. The coprocessor version
                        of ALOHA will not run on a Macintosh that does not
                have a math coprocessor chip. You can run the non-coproces-
                sor version of ALOHA on a machine with a math coprocessor
                chip, but each time you use ALOHA you will be warned that
                the other version will run faster on your machine.
                        ALOHA Resources has most of the resource infor-
                        mation that is needed to run ALOHA. Don't lock this
                        file.

                        ALOHA Helps is the database for the on-line help
                        available while you are using ALOHA.

                       ChemLib contains all of the available physical and
                       toxicological properties used by the air model for
                       over 700 chemicals. If you are using ChemManager,
                       unlock this file.
                                                                  1-7

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 Chapter 1: Overview
 ChemManager  allows you to modify or delete
 chemical data that is already present in the chemical
 library, or to add other chemicals for which you
 have the required physical property  information.
 To use  ChemManager, you must first unlock
 ChemLib

 City Lib contains the location data used in the SiteData
 menu. If you add or modify locations while running
 ALOHA, City Lib will be updated automatically. This
 file should not be locked.
 AlohaSpy lets you save the results of an ALOHA
 model run; a SPY file contains the information from
 the windows in ALOHA when you saved the file.
 A note about memory and speed
 ALOHA runs on an Apple Macintosh with at least one mega-
 byte of random access memory (RAM) and a hard drive. It
 will run much faster on a Macintosh with a math coprocessor
 chip. You must also have two megabytes of hard disk space
 available to load ALOHA. ALOHA will also work on com-
 puters that do not have the math coprocessor chip, although
 it will be slower and, in some cases, significantly so.

 ALOHA runs under either the Finder or MultiFinder, unless
 you are working on a Macintosh with only  one megabyte of
 RAM.

 Ask your Apple dealer for  information about  Macintosh
 models with and without coprocessor chips.
1-8

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                                    Chapter 1: Overview
Installing ALOHA Windows


O Place the disk containing the ALOHA Installer in either
   Drive A or B.


O Choose the Run option from the Program Manager's File
   menu.
O Type b:install (or a:install if you placed the diskette in
   Drive A) in the command line box and click OK.
O You'll see the following dialog box:
   Specify the drive and directory where you wish to install
   ALOHA,  and  click  OK.   The  default  directory  is
   C:\ALOHA; if  this is sufficient,  just click OK.   The
   installer will now decompress files and place them in the
   specified directory.
        Aloha Installer
   Please specify the directory for
   ALOHA to be installed in. If the
  directory does not exist. It will be
   created. Click 'OK' to continue.
  C:\ALOHA
      JOKj
Cancel
                                                   1-9

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Chapter 1: Overview
 O  When the installation is complete, you will be notified.
    Click OK.
                                   Aloha Installer
                              Aloha has been successfully
                                      Installed.
                             C:\ALOHA
D The installation process will create a group called ALOHA
   in the program manager, and will place all executable
   files in that group. You are ready to double-click your
   way into ALOHA.
                    Program Manager
  Die  Options  Window  Help
                                 Accessories
                                             a
                                   PfFEdfax    Temhal
          ChenManager  BftPtot    AtohaSpy  ALOHA
                         Catondar
    WordSetip Microsoft Wo
Rgure 1-3.
Installing ALOHA
Windows.

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                                                    Chapter 1; Overview
                 A note about memory and speed
                 ALOHA runs in Microsoft Windows™, version 3.0 or above.
                 It requires at least one megabyte of Random Access Memory
                 (RAM) and about 2.5 megabytes of space on your hard drive.
                 ALOHA requires a PC using at least an 80286 microprocessor.
                 The model must be run in either Standard or Enhanced mode.
                 ALOHA can be run with or without a math coprocessor; it
                 will run faster if a coprocessor is installed. We recommend
                 that you run ALOHA on a PC using' an 80386 microprocessor
                 or above, with a math coprocessor, and with at least two
                 megabytes of RAM.


                 Getting help
                 On-line help is available at any time in ALOHA.  If you're
                 using ALOHA for the Macintosh, select About ALOHA™
                 under the < menu to see a brief explanation of each menu
                 item and dialog  box in the air model (Figure 1-4). With
                 ALOHA Windows, you select About ALOHA™  from the
                 Control menu box; for both Macintosh and Windows, you can
                 also click the Help button  next to the option in question
                 (Figure 1-5).  Either of these approaches takes you to the same
                 Help information. Clicking Help, as in Figure 1-5, is a short-
                 cut that takes you directly to the topic of concern.
Selecting ALOHA    ^B File   Edit   SiteDato  SetUp  Display
         Help.         ——	
flbout flLOHfl™
                                                                 1-11

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 Chapter 1: Overview
              Infiltration Building Parameters
   Select building type or enter etichange parameter
      O Enclosed office building
      <§> Single storied building
1   Help   I
                    Figure 1*5.
                    ALOHA Help
                    button.
 The Help index you access from About ALOHA is arranged
 alphabetically (Figure 1*6). Under each topic there is a brief
 discussion of the option, instructions for how  to use  that
 option, any pertinent warnings or notes, and the range of
 allowable inputs if it is a numeric option.
                       ALOHA~5.1

                Developed jointly by NCAA end EPA.




                            Help Index
           About help
           Add chemical data
           Add location data
           Air temperature
           Ambient saturation concentration
           Amount of chemical (unknown state) in tank
           Amount of 909 in tank
           Amount of liquid In tank
                                      [  Cancel ]
                   Figure 1-6.
                   ALOHA Help index.
1-12

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                                                     Chapter 1: Overview
               When you've finished looking at the Help screen, click Top-
               ics to return to the Help index to select another topic, Print to
               print the Help screen, or click Cancel to return to the previous
               screen (Figure 1-7).
  Figure 1 -7.
Sample Help
    screen.
                  ABOUT HELP

DESCRIPTION
About ALOHA provides on-line information about the
CAMEO" oir model, ALOHA™. Each Help is organized
Into five categories:  Description, Instructions,
Warnings, Notes, and Allowable Input. Use the scroll
bar to locate the Information you need. To get
additional information about a topic, refer to the
ALOHA manual.
                 INSTRUCTIONS
                 [  Topics  ]
                    [  Print  ]
                                                                     1-13

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                     Chapter!
                     Introduction  to
                     Air Modeling
In this chapter..

Dispersion modeling 2-2
What is dispersion?...2-2
Use caution	2-8
ALOHA doesn't
  model	2-13
The Area! Locations of Hazardous Atmospheres (ALOHA)
model is a tool for estimating the movement and dispersion of
gases.  The air model estimates pollutant concentrations
downwind from the source of a spill, taking into consider-
ation the toxicological and physical characteristics of the
spilled material. ALOHA also considers the physical char-
acteristics of the spill site, the atmospheric conditions, and
the circumstances of the release. Like many computer appli-
cations, it can solve problems rapidly and provides results in
a graphic, easy-to-use format. This can be helpful during an
emergency response or planning for such a response. Keep in
mind that ALOHA is only a tool whose usefulness depends
on your accurate interpretation of the data.

ALOHA originated as an in-house tool to aid in response
situations. In its original format it was based on a very simple
approach used in  the Workbook  on  Atmospheric Dispersion
Estimates  (Turner 1974). It has evolved over the years into a
tool used for a wide range of response, planning, and aca-
demic purposes. However, you must still rely on your own
common  sense and experience when deciding how to re-
spond to a particular incident. There are some processes that
would be useful in a dispersion  model that have not been
included in ALOHA because of extensive input and compu-
tational time requirements (e.g., topography). These model
limitations will be discussed in this manual as they come up.
                                                                   2-1

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 Chapter 2: Introduction to Air Modeling
 Dispersion modeling
 There are a number of different types of air dispersion models,
 ranging from simple models that do not require a computer, to
 complex three-dimensional models that require massive amounts
 of input data and powerful computers. The type of model to be
 used depends a good deal on the scale of the problem, the level of
 detail available for input and required for output, the background
 of the  intended  user, and the turnaround time needed for an
 answer.

 ALOHA was designed with first responders in mind. The model
 is most helpful for estimating plume extent and concentration for
 short-duration chemical accidents. It is not intended for use with
 accidents involving radioactive chemicals. Nor is ALOHA in-
 tended to be used for permitting of stack gas or chronic, low-level
 ("fugitive") emissions. There are a number of other models avail-
 able that will address larger scale and/or air quality issues (Turner
 and Bender 1986).

 Since the first responder typically  does not have a dispersion
 modeling background, a guiding criterion in ALOHA's develop-
 ment was that the data  required for input be easily obtained or
 estimated on-scene.  ALOHA's extensive on-line help can assist
 you in making appropriate choices.
 What is dispersion?
 Dispersion is a term used in modeling to include advection (mov-
 ing) and diffusion (spreading). The cloud of dispersing vapor will
 generally move in a downwind direction and spread in a cross-
 wind and vertical direction (crosswind is the direction perpen-
 dicular to the wind).  A heavy gas can also spread upwind to a
 small extent. There are really two separate dispersion models in
 ALOHA: Gaussian and heavy gas.
2-2

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                                   Chapter 2: Introduction to Air Modeling
                 ALOHA uses a Gaussian dispersion model to describe the
                 movement and spreading of a gas that is neutrally buoyant
                 (approximately the same density as air). The Gaussian equa-
                 tion describes the bell-shaped curve that many teachers use in
                 grading. In this curve, there are always a few grades at the
                 high and low ends, but most are in the C range. This curve is
                 used to describe many other phenomena, including  how a
                 contaminant will be dispersed in the air from the source of a
                 spill.  Figures 2-1 and 2-2 show such a Gaussian distribution
                 produced by ALOHA.
     Figure 2-1.
      Gaussian
     dstrfcution.
                          Crosswind Distance
At the source of the spill,
the concentration of the
pollutant is very large and
the Gaussian distribution
looks like a spike or a tall
column  (Figure 2-1).  As
the pollutant drifts farther
downwind, it spreads out
and the "bell shape" gets
continually wider and
flatter (Figure 2-2).
     Figure 2-2.
Gaussian spread
                   Source of Spffl
                                                             CmnwM
                                                                    2-3

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 Chapter 2: Introduction to Air Modeling
 The model can produce a diagram that shows the top view of
 the plume, called the plume's "footprint."  This diagram
 connects all the points of the same concentration (for ex-
 ample, the Immediately Dangerous to Life and Health (IDLH)
 concentration). The area inside the footprint is the region that
 is predicted to have ground level concentrations above the
 limit you set during the model run. . Choosing this value
 (often called the level of concern or LOG) is discussed in the
 Options section of Chapter 5, The Display Menu.

 The heavy gas dispersion calculations that are used in ALOHA
 are those used in the DEC AD IS model (Spicer and Havens
 1989). This model was selected because of its general accep-
 tance and the extensive testing that was carried out by the
 authors.  In order to speed up the computational procedures
 and reduce the requirement for input data that  would typi-
 cally not be known  in an emergency spill scenario,  a few
 simplifications were introduced into ALOHA-DEGADIS,
 making it different from the initial model. These simplifica-
 tions include:

 O  the  initial momentum jet  model for elevated sources
    (OOMS) is not included. ALOHA-DEGADIS assumes that
    all spills originate at ground level;

 O  the  mathematical approximation procedures used for
    solving the model's equations are faster, but less accurate
    than those used in DEGADIS; and

 O  ALOHA-DEGADIS models sources for which the release
    rate changes over time as a series of short, steady releases
    rather than as a number of individual point source puffs.
2-4

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                 Chapter 2: Introduction to Air Modeling
Throughout the creation of ALOHA-DEGADIS, NOAA
worked closely with the original authors of DEGADIS to
ensure a faithful representation of DEGADIS model dynam-
ics.

ALOHA-DEGADIS was checked against DEGADIS to ensure
that only minor differences existed in results obtained from
both models.

Considering the  typical inaccuracies common to emergency
response, these errors are probably not significant.  In cases
where technical accuracy is required, you should obtain the
original DEGADIS model and use it to investigate  the sce-
narios of interest.

There are some instances, however,  when ALOHA's heavy
gas  calculations  may estimate that  the footprint is much
larger than its actual size. In order to speed calculation of a
heavy gas  footprint, each spill is treated as a continuous
release at the highest release  rate estimated for the scenario.

When the source strength is calculated, it is broken into five
steps which represent the average fate of release for each
segment of time. For the overall footprint estimate, ALOHA's
heavy gas calculations use the highest of the five steps, which
means that it uses the highest possible rate in its calculations.
However, when estimating the dose and concentration curves,
the  heavy  gas calculations use all  five varying time-
dependent rates.
                                                  2-5

-------
 Chapter 2: Introduction to Air Modeling
 These differences are particularly noticeable when you're
 working with large, time-dependent releases, such as those
 from pressurized tanks. For example, you may find that the
 concentration curve for a  location within the footprint is
 actually below the footprint level of concern. An estimate of
 source strength or footprint length is "conservative" if it is an
 overestimate. When release rate changes, ALOHA's heavy
 gas footprint will always be at least somewhat conservative,
 and sometimes,  too conservative. To get a more accurate
 picture of the computed concentrations, examine the concen-
 tration curves for a few locations within the footprint.

 When a gas that is heavier than air is released, it initially
 diffuses very differently than a neutrally buoyant gas. The
 heavy gas will first "slump," or sink, because it is heavier
 than the surrounding air. As the gas cloud moves downwind,
 gravity makes it  spread; this often causes some of the vapor
 to travel upwind of the source.  As the cloud becomes more
 diluted and its density approaches that of air, it begins behav-
 ing like a neutrally buoyant gas. This takes place when the
 concentration of heavy gas in the surrounding air drops
 below one percent.  For many small spills, this will occur in
 the first few tens of yards.  For large spills, this may happen
 much further downwind.
                           Wind
                                                  .*.
                                               .•.•.::••:?•..•••:
                                           •£••.:>{:•• "V- "
Rgu»2-3.
Plume spread as a
resut of gravity.
2-6

-------
                                      Chapter 2:  Introduction to Air Modeling
                     The classification of a gas as heavy is not always straightfor-
                     ward.  The molecular weight of air is approximately 29 and
                     the density of air is approximately 1.1 kilograms per cubic
                     meter. Gases that have molecular weights greater than that of
                     air will be heavy if enough is released. If the density of the
                     gas is substantially greater than the density of the air, ALOHA
                     considers the gas to be heavy.  Gases that are lighter than air
                     under  normal  conditions, but are being shipped in a cryo-
                     genic (low temperature) state, form a heavy gas cloud be-
                     cause they are very cold, and therefore dense, at the time of
                     their release (like anhydrous ammonia, for example).
                                                    * *   »
                     ALOHA  allows you to choose to always use the heavy gas
                     calculations, always use Gaussian calculations, or to let the
                     model decide.  Do this by choosing Computational from the
                     SetUp  menu (see Chapter 4).

                     There are instances when you may want to specify the calcu-
                     lation  method rather than letting the model choose.  Such
                     cases include:

DISPERSION CHOICES    G Heavy gas calculations can take longer to complete than
 ^"^"^"""^""^       Gaussian ones, especially if you are running ALOHA on
                        a computer without a math coprocessor chip. If a very fast
                        turnaround is required, you may wish to run the Gaussian
                        module first and the heavy gas module when time allows.

                     O In the case of a gas that may be heavy because of how it is
                        stored (e.g., cryogenic), ALOHA will warn you that the
                        selected chemical may flash boil and/or result in two-
                        phase flow.  In  this case, ALOHA may default to the
                        Gaussian calculation.  In such cases, you should re-run
                        ALOHA using the heavy gas calculations, and compare
                        the potential threat zones as represented by the two foot-
                        print estimates.

                                                                      2-7

-------
 Chapter 2: Introduction to Air Modeling
 O When used in a planning or training session or when time
    is not an issue, consider running some scenarios using
    both the heavy gas and Gaussian modules. This will give
    you a feel for how the models compare.
 Use Caution
 Be cautious when interpreting any model's results. Remem-
 ber that these results are only as good as the information
 you gave the model to work with. They reflect the amount of
 guesswork that went into your input. Any model requires
 accurate data from you in order to come up with valid esti-
 mates. For example, if you find that you don't know the exact
 wind  speed or temperature, and are instead doing a lot of
 guessing, the information that you give ALOHA to work with
 may not represent actual conditions. If this is the case, you
 can't expect ALOHA's output to reflect what is really going
 on.

 In addition, ALOHA's calculations become significantly less
 reliable in certain situations, even though you may be provid-
 ing accurate input.  In particular, pay careful attention to
 these situations:
ALOHA's results are only <
good as your input
 D  very low wind speeds
 O  very stable atmospheric conditions
 O  wind shifts and terrain steering effects
 G  concentration patchiness, particularly near the spill source.

 ALOHA doesn't take into account the effects of:
 O  fires or chemical reaction by-products
 G  particulates
 G  topography
CAUTION
ALOHA DOESNT
CONSDER
2-8

-------
                  Chapter!: Introduction to Air-Modeling
 Very low wind speeds
 As the wind speed decreases, the wind direction may become
 very inconsistent. ALOHA warns you in two ways that low
 wind speeds may lead to problems.

 First ALOHA does not allow you to enter a wind speed that
 is less than two knots (one meter per second). If you try to use
 a wind speed of less than two knots, ALOHA tells you that the
 wind speed  is too low and forces you to reset the speed to a
 minimum of two knots  before you can continue.

 Second, as the wind speed decreases towards two knots, the
 "confidence" or "uncertainty" lines drawn around the foot-
 print form a circle (see Footprint in Chapter 4, The  SetUp
 Menu), indicating that changes in wind direction may move
 the chemical cloud in any direction.

 Very stable atmospheric conditions
 Very stable atmospheric conditions intensify the uncertainties
 discussed above.  Under the most stable atmospheric  condi-
 tions, there will often be very little wind at all. This situation
 will  usually  occur late at night or during the early morning.
 In these conditions, there is almost no mixing of the pollutant
 into  the surrounding "clean" air; none of this air is entrained,
 or mixed, into the toxic cloud.

 In a  very stable atmosphere, the chemical cloud will spread
out in the same manner as cream poured into a coffee cup.
The cream will dilute and spread slowly into the coffee, but,
until you stir it, will take a very long time to mix completely
into  the coffee. In the same way, a cloud will spread slowly
under very stable  atmospheric conditions. Terrain features,
such as small valleys or depressions, may trap the gas until
wind and hence, mixing, is introduced.
                                                  2-9

-------
 Chapter 2: Introduction to Air Modeling
 These processes may lead to high concentrations of the gas
 remaining for a long period of time and/or remaining even at
 large distances from the spill source.  The Bhopal, India,
 accident involving the release of methyl isocyanate is an
 example of what can happen under very stable atmospheric
 conditions. Thousands of people died,-some of whom who
 were quite a distance from the release.

 For the first responder, a very stable atmosphere should send
 up a  flag: this is a dangerous situation where models are not
 very reliable. To counter this situation, think about whether
 the chemical will  behave as a heavy  gas; look for physical
 depressions and topographic features that may trap or steer
 the dispersing cloud.

 Wind shifts and terrain steering effects
 ALOHA allows you to enter only one wind speed and direc-
 tion; this may not accurately describe conditions  over the
 entire affected area. For example, areas with hills or valleys
 may  experience wind shifts where  the wind actually flows
 between the hills  or down  into the valleys, turning where
 these features turn. Since ALOHA does not account for shifts
 in wind direction, the footprint it calculates will not reflect
 these turns (Figure 2-4).
                                                           Rgue2-4.
                                                           Wind stilts
2-10

-------
                                     Chapter 2: Introduction to Air Modeling
        Figure 2-5.
Small-scale variations
    in wind direction.
                    Recognizing the probability of wind shifts over distance and
                    time, ALOHA has set limits on the duration of a release and
                    size of a footprint. Though ALOHA will not draw any plume
                    longer than 10 km (6.4 miles), as a general rule, you should
                    think that any footprint more than a few miles long may be
                    influenced by variations in the wind direction.  Similarly,
                    ALOHA only models the first 60 minutes of a release.  After
                    that time, meteorological conditions are likely  to  have
                    changed.

                    Another important limitation of the air model is that it does
                    not  resolve small-scale variations in the wind  caused by
                    obstacles (Figure 2-5).
                   Wind flowing around large obstacles will create eddies and
                   unstable wind shifts; these can significantly change a cloud's
                   shape. For example, in an urban area with high-rise build-
                   ings, the wind patterns at ground level are totally controlled
                   by the through streets. These streets may generate a "street
                   canyon" wind pattern. ALOHA's footprint will appear to go
                   right over, or through, obstacles like these. Remember these
                   limitations when you're interpreting model results.
                                                                      2-11

-------
 Chapter 2: Introduction to Air Modeling
 Concentration patchiness
 ALOHA doesn't accurately represent variations associated
 with near-field (close to the spill source) patchiness. In the
 case of a neutrally buoyant gas (which would be modeled
 using Gaussian calculations), the vapor cloud will move down-
 wind.   Very near the source, however, the cloud can be
 oriented in quite a different direction.

 This kind of movement is familiar to anyone who has tried to
 toast marshmallows over a campfire (you know—no matter
 where you sit, the smoke from the fire always seems to come
 straight towards you). In fact, what you see in a case like this
 is the effect of individual drifting eddies in the wind, pushing
 the cloud from side to side (Figure 2-6). These eddies, or
 small gusts, are also responsible for much of the mixing that
 makes  the cloud spread out. As the pollutant drifts down-
 wind from the spill source, these eddies shift and spread the
 cloud until it takes on the form of a Gaussian distribution.
                                                           Figure 2-6.
                                                           Concentration
                                                           pstchinsss doss to
                                                           the source.
2-12

-------
                             Chapter 2; Introduction to Air Modeling
            In the case of a  heavy gas, concentration patchiness still
            occurs, though it is combined with the slumping and spread-
            ing processes caused by gravity (see page 2-8).
            ALOHA does not model...
            ...fires or chemical reactions
            The smoke from a fire rises due to thermal energy, then moves
            downwind.  This rise is based on many factors which are not
            considered by ALOHA.  In addition, ALOHA does not ad-
            dress the by-products resulting from fires or chemical reac-
            tions.                          «•    •

WARNING    Be careful that  the chemical you select to model reflects the
            chemical that is actually being released to the air in your
            scenario. For example, when aluminum  phosphide comes in
            contact with water, it releases phosphine gas.  If you wish
            ALOHA to estimate a footprint associated with aluminum
            phosphide, you will need to know the reaction rate and how
            much phosphine is being generated.

            ~.particulates
            ALOHA does not include the  processes needed to model
            particulates.

            ...solutions and  mixtures
            At this time, the chemical database contains pure compounds
            only. If you know the chemical properties (e.g., vapor pres-
            sure, normal boiling point) for a mixture or solution, you may
            enter these data and use ALOHA.

            ...topography
            ALOHA does not consider the shape of the ground under the
            spill or in the area  affected by the pollutant.  This can be
            particularly  important if a liquid is spilled onto a sloping
            surface.

                                                             2-13

-------

-------
                    Chapters

                    The File and Edit Menus
In this chapter...

The File Menu	3-1
ALOHA Save Files	3-2
   AlohaSpy	3-2
The Edit Menu	3-4
introduction
With several Important exceptions, the File and Edit menus
in ALOHA work in the same way as in other applications.
These exceptions are described below.
                                       The File Menu
                                       New
                                       allows you to reset ALOHA before
                                       beginning a new scenario. When you
                                       choose this menu item, you will have
                                       the option to save your old scenario
                                       before resetting "ALOHA.
  New       96N
  Open...     9§0
  Close
  Saue
  Saue Rs...
98111
                      Page Setup...
                      Print...    36P
                      Printflll...
                      Quit
             96Q
                   Open...
                   allows you to open an ALOHA save
                   file which you previously created
                   using the Save As... menu item (see
                   below).
                    Close
                    closes ALOHA's front window.  You cannot close the Text
                    Summary window.
                                                                3-1

-------
 Chapter 3: The file and Edit Menus
 Save and Save As...
 allows you to create and save
 ALOHA save files and Spy
 window archive files.
                                      SOMB B« OpUom
                              Select MM* format   [  Holp  ]

                                      RLOHR cawa flla

                                       Urchin* windows to
                                       display from RlahaSpif
                                          Cancal
ALOHA save files
If you have information
about chemical storage facili-
ties in your area, you can pre-
pare in advance for a spill response by creating a set of ALOHA
save files. You can store some information about the characteris-
tics of a spill in such files, thereby saving time during an actual
incident.

Remember, though, that because these files are intended for use
in spill response, not all information about a scenario will be
saved into an ALOHA save file.  Information that is not expected
to change from day to day will be saved, including location,
chemical of concern, and dimensions of existing storage vessels
and containment areas. You'll still need to enter information
specific to a particular spill, including weather conditions and
size of the spill, when you use an ALOHA save file.

SPY files
You may also archive the results of an ALOHA model run as a SPY
file.  These  files will be useful to you whenever you wish to
document your results. A SPY file contains all the information
from the windows visible in ALOHA at the time the file was
saved.  SPY files can be viewed and printed from  ALOHA's
companion application, AlohaSpy (see Appendix C).
figure 3-1.
ALOHA Save options.
3-2

-------
                      Chapter 3: The File and Edit Menus
Creating new files
To create an ALOHA save file, choose Save As... from the File
menu, then choose ALOHA from the Save As Options dialog,
type in a file name, and click OK. Now, when you enter new
information about the scenario into ALOHA, you can simply
choose Save to update this file.

Before creating a SPY file, be sure that all windows you'd like
to archive are visible.  Then choose Save As... from the File
menu, choose SPY from the Save As Options dialog, type in a
file name, and click OK. You can use AlohaSpy to open, view,
and print the new SPY file.

Print...
prints the contents of the front ALOHA window.

PrintAII...
prints the contents of all visible ALOHA windows.

Quit (or Exit)
ALOHA saves your choice of location upon quitting the
application. Remember that if you wish to save the scenario
information for later use, select Save As... from the File menu
before quitting.
                                                 3-3

-------
 Chapter 3: The File and Edit Menus
Undo
tut
Copy
 The Edit Menu

 Copy
 allows you to copy pictures or selected
 text from the front window to the clip-
 board. This allows you to paste selected
 items into a word processing or graphics
 application.
 Note
 The Undo, Cut, Paste, and Clear menu items are not available
 in ALOHA.
3-4

-------
                     Chapter 4
                     The SiteData Menu
In this chapter.

Location	4-1
   Adding	4-3
   Modifying	4-6
   Deleting	4-7
Building Type	4-7
Dale & Time	4-9
The SiteData menu is the first menu in ALOHA where you
enter information. There are four items where you can give
ALOHA information about your spill situation:

O  geographic location;
O  the building type in the area of the spill; and
G  date and time of the spill.
           Figure 4-1.
    The SiteData menu.
  SiteData
                        Location...
                        Building Type..
                        Date & Time...
                      Location
                      Here, you tell ALOHA the actual geographic location of your
                      spill. Once you have selected Location, you can type in the
                      initial letter of the location and move to the first city begin-
                      ning with that letter, or you can scroll to the location. To
                      choose a location for the incident, double-click on the location
                      you wish, or click on it once and then click the Select button.
                      If the city or location you are interested in isn't on the list, you
                      can add it. We explain how to add a city later in this chapter.
                                                                      4-1

-------
Chapter 4: The SiteData Menu
 ALOHA currently uses location information to calculate:

 O  the angle of the sun (ALOHA looks at latitude, longitude, and
    time of day for this calculation), and
 O  the atmospheric pressure (ALOHA bases this on the location's
    elevation).

 The angle of the  sun becomes important when a chemical has
 formed a puddle on the ground.  ALOHA will calculate the
 amount of energy coming into the puddle from the atmosphere
 and from the ground. For example, if the sun is high in the sky, the
 amount of energy coming into the  puddle is greater than it would
 be in the early morning or late afternoon, when the sun is lower.
 The more energy coming in, the higher the evaporation rate.

 The model is not very sensitive to small errors in the location
 information. If you are in a situation where you must guess at this
 information, an estimate will be adequate if it is within one degree
 in latitude and longitude, and a few hundred feet in elevation, of
 the actual site.

 Let's run through an example in which you'll add, modify, and
 delete two cities, one in the U.S. and one outside the U.S. To begin,
 choose Location from the SiteDaU menu.  You see a scrolling
 index of locations (mostly U.S. cities and towns).
4-2

-------
                                               Chapter 4: The Sit eD at a Menu
   Figure 4-2.
Location index.
                      Location Information
                  HHIHUILN. MHKVLHND
                  ABILENE, TEXAS
                  RIKCN, SOUTH CAROLINA
                  HLAMEDft, CALIFORNIA
                  RLBRNY, NEW YORK
                  1LBRNV, OREGON
                  ALEXANDRIA BHV. NEW VORK
                  RLEHRNOfllfl, LOUISIANA
                  RLEHRNDRIfl. UIR6INIR
                  RILEN, TEHAS
                  RMBLER, PENNSVLUANIA
                  IMES, IOUIA
                  RMESBURV, MASSACHUSETTS
                  INACONOA, MONTflNR
                  RNRHEIM, CRLIFORNIR
                  RNN BBBOR, MICHIGAN
                  RHLEE, MONTANA
                  HBLINGTON. TEHHS	
                                                 f cancel
                                                    Rdd
                                                  Mortify
                                                 [  Oelete
                                                 [  Aelp
   Figure 4-3.
 Adding a U.S.
     location.
                 Adding a U.S. location
                 Since Jupiter, Florida is not included in this index, click Add.
                 Type in the city name,  its approximate  elevation, and its
                 latitude and longitude (Figure 4-3).
                        location Input
Enter full location name:
                   Location it  Jupiter
                   I* location In • U.S. stale or territory?
                    ® In U.S.    O Not In U.S.
                                    Select itate or territory
                  Enter approximate elevation
                   Elevation Is [so    ] ® ft Qm
                 Enter approHimot* location
                             deg.     mill.
                   Latitude   [26

                   Longitude  FflO
                         ®N OS

                         OE IU
RLRBRMR
ALASKA
ARIZONR
ARKRNSRS
CALIFORNIA
COLOARDO
CONNECTICUT
DELRUIRRE
OIST OF COLUMBIA
FLORIOB
£
i
I,
1
§
1
i
1
••0
                        L
           OK
J
Cancel
J     C
Help
J
                 Next, select Florida from the scrolling list of U.S. states and
                 trust territories.  ALOHA checks that the information you
                 have entered  is within the  range of reasonable values  for
                 Florida. (If you have entered a value that is not in the valid
                                                                          4-3

-------
Chapter 4:  The SiteData Menu
 range, ALOHA will tell you which value is out of range; you
 must correct this value before you can continue). Click OK.
 Provided all of your input was within the acceptable ranges
 for Florida, you return to the scrolling city index screen.

 Jupiter, Florida appears at the top of this screen. If you click
 Cancel at this point, the information you added on Jupiter
 will disappear and the city name will be removed.  To save
 this information, you must Select a location.
                      Location Information
  JUPIIEB. fLORIDR
  JKflLRMRZOO, MICHIGAN
  KAM
-------
                                                Chapter 4:  The SiteData Menu
         Figure 4-5.
Adding a non-US, city.
                     Adding a location outside the U.S.
                     We'll use Hamilton, Bermuda as our example here. To add a
                     city or town that is not located in the U.S., click Add and type
                     in the name of the location without its country (you'll be asked
                     for that next). Click Not in U.S. Notice that the scrolling list
                     of U.S. states and territories disappears from the right side of
                     the window (Figure 4-5). Enter the approximate elevation,
                     and latitude and longitude coordinates, and click OK.
                      Enter full location name:
                       Location It  Hamilton
                       I* location In • U.S. state or territory?
                       O I" U.S.    ® Not In U.S.
                      Inter approximate elevation
                      Eleuatloit is  fp     I ® f t O ">
                     Enter approximate location
                                dag.    mln.
                       Latitude  fiF~|  |Ti~"l ®N QS
                       Longitude [T5   1  f«   '
Cancel
                                                      ]     f
                    You should next see the Foreign Location Input dialog box
                    (Figure 4-6). Now, type in the name of the country and the
                    time difference between Greenwich Mean Time (GMT) and
                    the local standard time. The GMT offset must be entered with
                    a negative sign if the time difference is in hours behind GMT.
                    If you don't enter a sign, ALOHA assumes that  the  time
                    difference is positive.  Finally, decide whether the time that
                    you want ALOHA to use in its calculations here is Standard
                    Time or Daylight Savings Time.
                                                                        4-5

-------
Chapter 4: The SiteData Menu

Country name: [Bermuda

Offset from local STRNORRD lime to GMT: [2


hours

Is current model time standard or daylight savings
time?
O Standard Time © Daylight Sailings Time
| OK ^ [ Cancel ] [

Help ]


                                                           Figure *6.
                                                           Adding a foreign county.
Although ALOHA will automatically switch U.S. cities from
Standard to Daylight Savings Time (based on the date), the
time change for foreign locations will not be corrected auto-
matically .

When you click OK, you'll see that Hamilton, Bermuda has
been added to the location index:
WARNING
                                                           Rgu»4-7.
                                                           Location index with
                                                           foreign addtion.
Modifying a location
To  change information that  you've already entered for a
location, click Modify on the Location Information screen
(Figure 4-4). You will see the information that is currently in
CityLib.  Select the item that you wish to change and type in
the new value.
4-6

-------
                                           Chapter 4: The SiteData Menu
       Figure 4-8.
Cfty deletion caution.
     WARNING
                  Deleting a location
                  To remove a location from the index, select the location on the
                  list, and click Delete. ALOHA will ask you if you're sure that
                  you want to remove this location.  At this point, you can
                  change your mind by clicking Cancel, or proceed with re-
                  moving the location from the list by clicking OK.
                              Caution !
                     Vou are about to delete a city permanently
                     from  the city library, never to appear
                     again. Select OK if this is what you really
                     want to do. Otherwise cancel.
If you've made a mistake and deleted the wrong city, your
only option at this point is to click Cancel.  If you close the
Location dialog box and move on to the next menu item, the
city is permanently deleted.
                  Building Type
                  You can specify the type of buildings in the area of the spill.
                  ALOHA uses this information, together with data such as the
                  outside wind speed and temperature, to determine the rate at
                  which the chemical will infiltrate the buildings.

                  If you select a single or double-storied building, ALOHA will
                  use a  default value to calculate the number of air exchanges
                  per hour (Wilson 1987). If you select Enclosed office build-
                  ing, ALOHA assumes that the air exchange rate is controlled
                                                                  4-7

-------
Chapter 4: The SiteData Menu
 and sets a default value based on the number of air exchanges
 an average  enclosed building would, require  to keep the
 inside air from being "stuffy."
            Infiltration Building Parameters
  Select building type or enter eHchahge parameter
    O Enclosed office building
    <§> Single storied building
    O Double storied building
    O No. of air changes is
   1   Help   I
per hour
   Select building surroundings
    1   Help   I
    <§) Sheltered surroundings (trees, bushes, etc.)
    O Unsheltered surroundings
                                     Cancel
           J
                      figure**.
                      BuiUng parameters.
If you know the number of times per hour that the total air
volume within the building is replaced, enter this number
next to No. of air changes. You can use this to compare the
effects of different air exchange rates.

Unless you have specified the number of air changes or have
chosen Enclosed office building, you will need to tell ALOHA
whether the surrounding area is sheltered or unsheltered.
Sheltered surroundings will reduce the rate at which the
chemical can infiltrate the buildings. Below are some guide-
lines for choosing sheltered or unsheltered surroundings.
4-8

-------
                                        Chapter 4: The SiteData Menu
              If the buildings...
              ...are surrounded by trees or
               other buildings in the
               direction from which the
               chemical cloud will be coming
              ...are in an open space, with
               nothing near it
              ...if you are unsure
                              Clirk...
                              Sheltered surroundings
                              Unsheltered surroundings

                              Unsheltered surroundings.
              Date & Time
              Now enter the date and time of the spill. If you don't select
              Date & Time, ALOHA will use the time on your computer's
              internal clock to run your scenario.   If the time on your
              computer's clock is incorrect, reset the time on the Control
              Panel. This time may be important as some of the calculations
              ALOHA will do depend on the time of day.
 Figure 4-10.
Date and time
    options.
                Date and Time Options
Vou can either use the computer's internal clock for the
model's date and time or set a constant date and time.
     <§) Use internal clock    O Set constant time
                Internal Clock Time is:
                FriRprl? 13:27:41 1992
                  L
        OK
1   (   Cancel   ]
Help
                                                                4-9

-------
Chapter 4: The SiteData Menu
 Set constant time lets you specify when you want the sce-
 nario to begin.  This  is useful for contingency planning or
 training exercises because you can set up scenarios to run at
 different times of the day arid /or year (and therefore under
 different environmental and atmospheric conditions).  The
 computer's internal clock time will be automatically filled in
 when you choose this option.. You may then change any of the
 values.

                  Date and Time Options
You can either use the computer's Internal clock for the
model's date and time or set a constant date and time.
O Use internal clock (§> Set constant time
Input constant date and time
Month Day Year
4
(1-12)
I OK

27
(1-31)
I

|1990 |
(1900-...)
Hour
US j
(0-23)
[ 'Cancel ] (


Minute
(0-59)
Help


I

Figure 4-11.
Setting constant time.
4-10

-------
                      Chapters
In this chapter.
The SetUp Menu
Chemical	5-2
   Chemical data	5-3
   Adding	5-5

   Modifying	5-7    After you've entered the information under the SiteData
     anging ata	5-9    menu, you need to select a chemical, set the atmospheric
     ^ enc	        conditions, and specify the type of source in your spill see-
   User Input	5-12    nario These Options are found under the SctUp menu. In

         1  	 "      addition, you can specify the type of computations that you
 °urce	        want ALOHA to use to calculate dispersion and dose.
   Direct	5-31

                      You should select the menu  items in descending order.
    M  	        Although you can select the  Chemical and Atmospheric
     p  	 *      items at any time, the Source option cannot be selected until
Computational	5-46        .    ,.,,  , .  .,  „.    .   .   . .       .  .  ,
                      you have filled in the Chemical and Atmospheric data.
            Figure 5-1.
       The SetUp menu
                        Chemical...
                        atmospheric
                        Source
                 user input...
                 SRM Station.
                        Computational.
                                          OR
Chemical...
Rtmospherfc
Source
                              Computational.
               Direct...
               Puddle...
               Tank...
               Pipe...
                                                                       5-1

-------
 Chapter 5: The SetUp Menu
 Chemical
 Select Chemical from the SetUp menu to access a scrollable list of
 the chemicals included in ALOHA's chemical library, ChemLib
 (Figure 5-2). About 700 pure chemicals are included in the library.
 No chemical mixtures are included in ALOHA's library, nor are
 any chemicals with unstable structures, nor any chemicals of such
 low volatility that they don't represent air dispersion hazards
 (i.e., solids or liquids with very low vapor pressures). Chemicals
 may be added to  the library  or deleted from it, and property
 information about any chemical may be modified.
                      Chemical information
  ftCETHLDEHVDE
  RCETIC ACID
  flCFTIC flNHVDRIDE
  KETONE
  ACETONE CVflNOHYDBIN
  RCETONITRILE
  RCETVL BROMIDE
  HCETVL CHLORIDE
  ACETYLENE
  ACETYLENE TETRHBROMIDE
  RCETVL IODIDE
  ACETYL METHVL CARBINOL
  ACROLEIN
  RCRVLIC RCIO
  RCRVLONITIIILE
  RCRVLVL CHLORIDE
  ROIPIC RCIO
  ftOIPONITAILE	
[  CancH  ]
[ Modify j
                Figure 5-2.
                Chemical index.
 Selecting a Chemical
 Select a chemical by scrolling through the list until you find its
 name, clicking on the name, and choosing Select You can search
 rapidly through the list by typing in the first few letters of the
 chemical name.  Once you have selected a chemical, you'll see
 some of the most important properties of the chemical listed in the
 Text Summary window (Figure 5-4).
5-2

-------
                             Chapter 5: The SetUp Menu
 Chemical Data
 The chemical library includes information about the physical
 properties of each ALOHA chemical. The library also in-
 cludes values for the IDLH (Immediately Dangerous to Life
 and Health) and TLV-TWA (Threshold Limit Value - Time-
 Weighted Average) toxic thresholds.

 The ALOHA library contains information from two sources.
 When available, information was obtained from a chemical
 database compiled by the Design Institute for Physical Prop-
 erties Data (DIPPR), known as the DIPPR database (Daubert
 and Danner 1989). Additional property values were obtained
 from the chemical database included in the Computer-Aided
 Management of Emergency Operations (CAMEO™) hazard-
 ous chemical information system (National Oceanic  and
 Atmospheric Administration 1992).

 ALOHA uses information from the library to model the physi-
 cal behavior of  a chemical that you have selected.  For ex-
 ample, once ALOHA knows the temperature within a tank, it
 can use library information to estimate the vapor pressure,
 density, and other properties of the chemical stored in the
 tank.

 You need only  the name of a chemical  and its molecular
weight to run ALOHA, but you will be able to use only the
Direct source option and Gaussian dispersion module.  You
will need values for additional chemical properties to make
source  calculations using the Tank, Puddle, or Pipe source
options or to make heavy gas calculations.  Check Table 5-1
for the  properties necessary to use each option.
                                                 5-3

-------
 Chapter 5: The SetUp Menu
 Refer carefully to Table 5*1 before adding property informa-
 tion about a chemical. ALOHA's chemical library contains a
 few data fields for properties that the model either estimates
 itself or does not currently use (we anticipate that  these
 properties may be useful in a  future version of  ALOHA).
 Adding values for these properties will have no effect on
 source or dispersion calculations, and you won't need to add
 values for them to run any ALOHA calculation.
Gaussian H«avy Gas
»**«*
Ctumkal
name
Molecular
Wright
Nomal
boiling point
Critical
pmMire
Critical
temperature
Deaaityfeae)
Noraul
fleering point
Heat cap.  *
Q 
o * «> •>
0 <» * +

^ <>

* * *
* *

CMkTMpI P^MMMI TMIlJl Pt|MI
4& ^Ok •& 4J||

* ^ ^ 0
<» -> -> *
Q OS> C» C»
Q e» o» e»
* ^ * *
* >

* ^ + *
* *
4> c*> c* <*
Required propcrti** for rateriag A MW dMoucaU
Q Only needed If the Krarceli given ii
C» Either critical preuure ami critical t
lobeentoivd
i nail* of VOliKM

                                                            T«bb5>l.
                                                            Cn6fTHC
                                                            needed to use each
                                                            ALOHA source and
                                                            dspereion option.
5-4

-------
                                                                                       1
                                              Chapter 5: The SetUp Menu
                 These properties are:

                 O Critical molar volume
                 O Diffusivity (molecular and thermal)
                 O Heat of vaporization
                 O Density (liquid)
                 G Heat capacity (gas at constant volume)
                 G Kinematic viscosity (gas and liquid)

                 Adding a chemical
                 You may  add a chemical to the library either temporarily
                 (from within ALOHA) or permanently (using ALOHA's com-
                 panion application, ChemManager). You must know at least
                 the name  and molecular weight of each chemical that you
                 add.  You may add as many chemicals as you like to the
                 library.

                 Here's how to add an example chemical, argon, to the library
                 temporarily:

                 Choose Chemical from the SetUp menu, then click Add.
                 Type "ARGON" in the Chemical Name field.  Next, type in
                 39.95 in the molecular weight field (Figure 5-3).  To enter
                 additional property values, click on the name of the property
      Figure 5-3.
Adding a chemical
CMmltd NMM:
MMttirtw IMfkt:
   input *u«n«tl« i»fooi>«««» I
••SON
                            M.W
                                                  I""     I
                  •rn»t frmnnt h*m
                                            )Pra».:   IT
                  *«* C«f (a«»
                                                                   5-5

-------
 ChapterS:  The SetUp Menu
 in the scrolling list (or click on Next Field until the property

 name is highlighted). Enter property values in the appropri-

 ate data fields, and choose appropriate units from the corre-

 sponding popup menus.


 You must add a reference temperature and pressure for all
 properties which change their value when temperature or

 pressure change.  Click on Heat  Capacity (gas, constant

 pressure) and enter the value 520.3 J/kg K at 294 K and 1 atm

 pressure.


 Once you have entered all information about the new chemi-
 cal, click OK.  You'll be returned to the chemical index. Click

 Select to select the Chemical that you've just added.

 •*v
 Chemicals that you add from within ALOHA will be deleted

 from the  library when  you quit from the program.  Use
 ChemManager (see below) to add chemicals permanently to
 the library.


 Review the Text Summary screen for useful information about

 each chemical you've selected, added, or modified.  For ex-

 ample, when only the  name and molecular weight of argon

 have been added to the library, a note will appear on the Text

 Summary window: "Not enough chemical information to use

 the Heavy Gas option."  This note alerts you that, although
 SITE DRTB I        	
   location: POITUM), OHCOOH
   •ul Idino mi- EMftongoi Par
   Oat* ( TIM: Find at
 oenic*.
1W-TM: •wail-
Footprint Louol of Cancam
•oilinq Point: -3«. S3* F
UOPOF fmmn at (M>l*nt TMporatir*: or«atar ttm 1 •<•
tafclvnt Saturation Canev«lratl«n:  1,000,000 ppo or MO.M
not*: Mot «nouo> ehoBleal data to «OM Hoowy Oat option
                        Tent Summary
                  Hair: 1.94 c»ioltarod clnglo «torfod>
                     a. 1M2 t 1430 hem
                              floloeulor UoloM: 39. « bg/tuol
                              taut: -wMl I-
                         to b* Mt tofar* footprint Mloctlan
Rguti5-4.
Text Summaty
window.
5-6

-------
                                            Chapter 5: The SetUp Menu
               argon's molecular weight is heavier than 29 kg/kmol, the
               molecular weight of air, so that it may behave like a heavy
               gas, ALOHA will have to use Gaussian dispersion calcula-
               tions (unless you add additional property information).

               Also, when you select a chemical which has been identified as
               a confirmed, potential, or suspected carcinogen, a notation,
               "Note: Potential or suspected human carcinogen," will ap-
               pear on the Text Summary screen under the Chemical Infor-
               mation heading.

               Modifying a chemical
               You may modify information about a  chemical already in
               ALOHA's library, or about a chemical that you have previ-
               ously added. You can make either temporary (from within
               ALOHA) or permanent (using ChemManager) modifications.

               Here's how to temporarily modify information about argon,
               which you just added to the library. You'll add the properties
               necessary to run the heavy gas option.

               First, choose Chemical from the SetUp menu. Scroll through
               the chemical index until you  find "ARGON"  (or type the
               letters " AR" for a faster search). Select argon and click on the
               Modify button.
    Figure 5-5.
Chemical index.
Chemical Information
                RRSENIC TRICHIORIDE
                URSINE
                BENZRLOEHVDE
               Go through the same steps to modify a chemical property
               value that you used to add values for a new chemical. Click
               on the name of the property in the scrolling list (or click the
                                                                5-7

-------
 Chapter 5: The SetUp Menu
 Next Field  button until you've highlighted the property
 name). Enter property values in the appropriate data fields,
 or modify existing values, and choose appropriate units from
 the corresponding popup menus.

 The first property in the scrolling list is Normal Boiling
 Point  Click on this property name, then enter "87.28" into
 the empty data field, and choose Kelvin from the temperature
 units menu.  Next, click on Critical Temperature, and  enter
 the value 150.86 Kelvin. Click on Critical Pressure, and enter
 the value 4,898,100 Pa. Click on Density (gas) and enter the
 value 1.659 kg/m3at 294 K and 1 aim pressure.

 You cannot modify all property values for ALOHA chemicals
 already included in the library.  Values that you cannot
 modify, and their units, appear grayed-out. These are values
 that ALOHA calculates internally, using either values for the
 chemical's critical properties (molecular weight, boiling point,
 critical temperature, and critical pressure)  or information
 from the DIPPR database.  If you would like to use your own
 property values for an ALOHA chemical, add the chemical
 using a slightly different name (such as "CHLORINE-2"), and
 enter your own values in the new data fields.

 Modifications that you've made from within ALOHA will be
 deleted from the library when you quit from the program.
 Use ChemManager (see below) to permanently modify the
 library.

 Making permanent changes with ChemManager
 You can use  ChemManager to make permanent changes to
 ALOHA's chemical library. To use this application, first quit
 from ALOHA, then double-click on the ChemManager icon.
 You'll see a screen very like the one that appears when you
 choose  Chemical from ALOHA's SetUp menu.
Not al ALOHA cherrical
properties can be modified
5-8

-------
                             Chapter 5: The SetUp Menu
 To add a chemical to the library, click Add. Then follow the
 same steps used to temporarily add a chemical from within
 ALOHA.  First, type in the name of  the chemical and its
 molecular weight (you'll absolutely need these two pieces of
 information). Then add values for all other properties that
 you'll need to run ALOHA (check  Table 5-1  to see which
 properties are necessary for ALOHA's various source and
 dispersion options).  Be sure to  add  values  for reference
 temperature  and  pressure  when  these  are  needed
 (ChemManager will remind you if you don't).  When you're
 finished, click OK to make your new chemical a permanent
 part of ALOHA's library.  Click Cancel to avoid adding the
 chemical.

 To modify a chemical, select the chemical from the  scrolling
 list of chemical names, then click Modify. Follow the same
 steps used to make temporary modifications from within
 ALOHA; make modifications to existing information, or add
 new information to data fields. Remember that you cannot
 change information in any grayed-out data fields; this infor-
 mation is internally calculated by ALOHA.  When you're
 finished, click  OK to make  your permanent changes to
 ALOHA's library.   Click  Cancel to avoid making these
 changes.

 To delete a chemical,  select the chemical from the scrolling
 list of chemical names, then click Delete. Click OK  to delete
 the chemical  permanently from ALOHA's  library.  Click
 Cancel to avoid deleting this chemical.

 Remember that when you click OK within ChemManager,
 you're making a permanent change to the ALOHA chemical
 library. Be sure that you are entering accurate information.
To exit ChemManager without making permanent changes to
the library, click Cancel.
                                                 5-9

-------
 Chapter 5; The SetUp Menu
 Changes made to ALOHA's chemical library from within
 ALOHA will not be saved when you exit from ALOHA. Use
 ChemManager to make permanent changes to the library (see
 below). To save any changes you've made to an ALOHA
 chemical without making permanent changes to ALOHA's
 chemical library,  choose Save from the File menu
 (Figure 5-6), and save this scenario as an ALOHA  file (see
 Appendix C for more on saving files using AlohaSpy).  Any
 modifications you have made to your chemical will be saved
 in this file, which you can reopen from within ALOHA at any
 time.
                              Save fls Options
                     Select saue format   [  Help  ]
                              RLOHR sau« file
                              Archiue windows to
                              display from RlohaSpy
                                  Cancel
Figure 5-6.
Saving changes.
 When you reopen an ALOHA file, the model will use the
 modified chemical properties contained in the file to make
 source and dispersion calculations. However, if you again
 select (via the Chemical menu item) the chemical that you
 previously modified, then the changes you made will be
 replaced by information stored in the chemical library. Choose
 Open... from the File menu and reopen your saved ALOHA
 file whenever you want to run a scenario using the modified
 chemical information included in the file.
5-10

-------
                                             Chapters: The SetUp Menu
                 It is important to review the Text Summary screen.  In our
                 example, a note appears with the chemical information: Not
                 enough chemical data to use Heavy Gas option (Figure 5-4).
                 This tells you that, although the vapors may behave like a
                 heavy gas, the model will have to use the Gaussian calcula-
                 tions. You can also see from the text summary screen that the
                 substance is a gas (the boiling point is well below the air
                 temperature). Argon is a simple asphyxiant; no IDLH or TLV-
                 TWA value has been assigned to it.
                 Atmospheric
                 The processes that ALOHA considers to move and disperse a
                 pollutant cloud include atmospheric heating and mechanical
                 stirring, low-level inversions, wind speed and direction,
                 ground roughness, and air temperature.  Each of these pro-
                 cesses will be discussed in detail below.
      Figure 5-7.
Atmospheric menu.
SetUp
                    Chemical.
                    Htmospheric
                    Souix *>
                      User Input...
                  H  SRM Station..
                    Computational...
                 You can enter atmospheric data into ALOHA in two ways:

                 O  User Input..., which you use if you know weather and
                    wind conditions, or

                 O  SAM  Station..., which you use if you  want real-time
                    weather data fed directly to ALOHA from a Station for
                    Atmospheric Measurements (SAM).
                                                                 5-11

-------
 Chapter 5: The SetUp Menu
 User Inputs.
 Here, you enter information about the atmospheric environ-
 ment and the ground roughness at the spill site.  This in-
 cludes:

 O  stability class            O  ground roughness
 O  inversion height          O  cloud cover
 D  wind speed and direction  O  relative humidity
 G  air temperature

 1.  Stability class
 There are principally two processes, heating and mechanical
 stirring, that can affect mixing in the lower atmosphere.

ra)  Heating
 Heating the atmosphere near the ground leads to the most
 unstable conditions.  Think about what happens to a pan of
 water that you're heating on the stove. As heat is added to the
 bottom of the pan/ the bottom-heated water rises and mixes as
 it moves toward the  surface.  As the heating becomes more
 intense, so does the mixing.

 This same type of heating happens in the atmosphere. On hot
 summer days, the sun will heat up the ground and warm the
 lower atmosphere. The lower air rises as it warms, tumbling
 and mixing as it goes.  Remember  looking out over a dark
 parking lot on a hot summer day and seeing the air seem to
 shimmer?  This shimmer is caused  by thermal mixing.

 Just as air that is warmed rises if it  is warmer than the
 surrounding air, air that is cooled sinks, or stays trapped in
 the lower level of the atmosphere.  The opposite extreme of
 intense heating is intense cooling; rapid cooling of the ground
 leads to the most stable atmospheric conditions. Cooling of
5-12

-------
                              Chapter 5; The SetUp Menu
 the ground causes the lower layer of air to cool and become
 more dense, making it very stable with little tendency to mix.
 Clear, calm nights are a prime time for this type of intense
 cooling to take place; for example, weather conditions where
 you might expect a quick frost or low ground fog to develop.
 These very stable conditions make for a very large threat zone
 (see page 2-11). Very stable air is usually seen in the late night
 or early morning hours.

 b) Mechanical stirring
 The second factor affecting stability in the lower atmosphere
 is mechanical stirring caused by the wind. As the wind blows,
 the friction caused by the earth slows down the air movement
 closest to the surface.  Air layers near the ground tend to mix
 and tumble as they glide past each other at different speeds.
 The stronger the wind, the more effective this stirring mecha-
 nism becomes.

 Mechanical stirring not only mixes up the air, it also disturbs
 the temperature layers created by intense heating or cooling.
 This secondary effect of mechanical mixing causes what may
 at first seem like a contradiction: it mixes up very stable, cool,
 ground layers, making conditions less stable.  In the same
 way, it mixes up very unstable warm layers, making condi-
 tions more stable. The net effect of stirring mechanisms such
 as strong winds is that they reduce the possibility of either
 very stable or very unstable air so that all strong wind cases
 tend to be in the intermediate (neutral) range of stability.

 Meteorologists typically summarize atmospheric stability by
 specifying the stability class in terms of a letter, ranging from
 A to F. With A being the most unstable and F the most stable
 conditions, you will use the same letter code in the air model
 to specify the relationship of stability class, heating, and
wind speed at your spill site (Figure 5-8).
                                                   5-13

-------
 ChapterS:  The Setup Menu
                                        |   COOLING
                                       WfOUNO TRAPPING)
           In the very rare case, stability class F may have stronger winds.
                                                            Rgure5-8.
                                                            Stabifty class and
                                                            mixing of a poflutart
                                                            ctoud
 Stability class is the first atmospheric condition that you enter
 in ALOHA. You choose the single letter that best represents
 the weather conditions present at your spill site. Using our
 example from Figure 5-9 and Table 5-2 below,  you would
 choose C or D for your stability class because the wind speed
 is between 11  and 13 knots.  (You can see Table 5-2 while
 you're running ALOHA by clicking the Help button next to
 Stability Class on the Atmospheric Options screen or by
 looking at the Stability Class topic in the Help index.) ALOHA
 uses stability  class information to classify the amount of
 mixing occurring in the atmosphere. To dilute a cloud of toxic
 gas, unstable (lots of mixing) conditions give shorter threat
 distances than would stable (very little mixing) conditions.
 The cloud is diluted faster when conditions are unstable.

 2. Inversion height
 Under normal conditions, as you move up in the atmosphere,
 the  air gets  cooler. An inversion occurs when cooler air is at
 the ground  and warmer air is above. ALOHA needs to know
 whether there is a low-level inversion that could  trap the
 pollutant near the ground (Figure 5-10). This type of inver-
 sion is different from the inversion that causes smog. That
 type of inversion is  typically  thousands  of feet above the
 ground and therefore,  much too high  to affect a cloud of
 escaping chemical.
5-14

-------
                                                       Chapter 5: The SetUp Menu
         Figure 5-9.
 Atmospheric options.
                    Hlmospheric Option*
Mobility Clats It:  Q« O*"  OC  $0  QE  OF
                       Inversion Height Options era:   [    Help   I
                         ® No Inversion  O Inversion Present, Height is:
                       Wind Options an:
                                                 Qfatt
                                                 O Hatars
                   Help
J
                         Wind Speed is: \\2
                         tUind I* rrom :  [si
                     ® Knots  QMPH  OM«t«r«/$at.
                     Enter degrees true or tent (l.e. CSC)
                        Mir Temperature is: [«0    | negroes  $F  QC  t	Help
                       (round Roughness Is:   Q	
                         €> Open Country    .«_...        ...   i_ _   i O to
                                         OH  O Input roughness(2o):  15.0   I "r
                         O Urban or Forest                          '	' ®CBI
                                     OK
                    J
      c
                                                          Cancel
Table 5-2.
Stabiitydassand
wind speed
Surfwe Off lift**
(butt) fadMon OoudCncr

«
4-7
7-11
ll-U
>13
(Tkina
Stfoo| Madetsle SiRhl
A A-B B
A-B B C
B M C
C C-D D
C D D

E
e
D
0
0

197fl

Cloud Corer

F
F
E
D
D

                      ALOHA needs to know about the special situation where the
                      inversion is very near the surface  (one hundred feet or less
                      from the ground).  A common clue to this situation is a thin
                      layer of patchy ground fog or "sea smoke" over water. These
                      situations are relatively rare, but you should watch for low-
                      level inversions after clear nights with little or no wind.
                                                                               5-15

-------
 Chapter 5: The Setup Menu
 If there is an inversion present and you know its height, click
 Inversion Present and type in the appropriate number, being
 sure to select Feet or Meters.  If there is an inversion present
 but you don't know its height, click Inversion Present and
 estimate the height, making sure that the values you choose
 fall between 10 feet (about three meters) and 5,000 feet (about
 1,524 meters). If there isn't an inversion, click No Inversion.
 If the heavy gas computations are used, ALOHA will not
 factor in the inversion.
                                                             Rgue5-10.
                                                             Example of pollutant
                                                             Dispersion with and
                                                             without a bw level
                                                The heavy gas module doesrit
                                                account for aversions.
 3. Wind speed and direction
 ALOHA will next need information on wind speed and direc-
 tion. Since many hazardous vapors cannot be seen, imagine
 a pollutant cloud using your own experience in looking at a
 smoke stack or campfire.  If you've ever done this, you know
 how the wind's direction and speed will affect the movement
 of the cloud.
  '-%&&%&*&
  SV3J*** *  «*'« **** -I*-*—-
^^it-^ife.^
                                            i I  strong winds  I
                                                            Figure 5-11.
                                                            Effect of wind spood
                                                            and drecbon on
                                                            plume movement
5-16

-------
                                                      ChapterS:  The Set Up Menu
                     Obviously, the wind direction will determine which way a
                     cloud will drift. The wind speed also has a pronounced effect
                     on what the cloud will do. For example, low wind speeds may
                     allow the cloud to meander; high concentrations typically can
                     be found in puffs drifting away from the source. As the wind
                     speed picks up, meandering near the cloud's source decreases,
                     while small-scale mixing in the atmosphere usually increases.
                     The model will make sure that  the  wind speed and  atmo-
                     spheric stability class you set are consistent.

                     You can use  the table below to help you estimate the wind
                     speed. (Notice that you have the option of miles per hour,
                     knots, or meters per second; be sure to look in the proper
                     column on the table and type in the corresponding value on
                     your computer screen.  Since miles per hour and knots are
                     very close, Table 5-3 does not include both measures.)
         Table 5-3.
How to estimate wind
                      Meters per second     KaoB   description
                       SpeciiciacKa
                        Z-3
                        4-5
                        8-11
                        14-17
                        17-21
<1    Calm

1-3    Lighter

44    light bree*

7-10   GcDdebitoe

11-16   Moderate

17-21   Fieri)
                                    22-27
28-3)   Near gale
34-40   Gate
Calm; smoke roes rerocally

DirecDoo of *md shown by smoke drift
but ool by wind noes

Wind felt on bee. lent* nude; oniony
woe moved by wind

Lana and soul twigs in consul
motion; wind extends fight flat;

Raises dust, loose piper, soul
branches lie moved

Small (net in leaf begin to sway,
erased wxvdets km OB inlind water

Lane branches kt motion; whistling
heard in telegraph wires; umbidlai
used with dficnky

Tbole trees in motion-, incotnaiieDce
fee wil long agakist wind

Brealo nrifi off trees; seDenDy impedes
                                                                              5-17

-------
Chapter 5:  The SetUp Menu
 In our example we said that the wind was 12 knots; looking in
 the knots column, this means that we would expect to see
 small branches moving slightly, with only  dust and loose
 paper blown along the ground.

 Now, enter the direction/rom which the wind is blowing. You
 can enter this using letters (e.g., se, ne, sw) or in degrees true
 (176°, 210°, etc.).

 4. Air temperature
 The model uses the air temperature in a number of calcula-
 tions. This value is used to calculate the evaporation rate
 from a puddle surface (the higher the temperature, the higher
 the vapor pressure and the faster the substance evaporates).
 Elsewhere, especially when you  are entering information
 about the source, you can use air temperature as a value for
 ground, pipe, or tank temperature if these values are un-
 known. Because it may be used for so many calculations, you
 need to enter as accurate an air temperature as possible.

 5. Ground roughness
 Another process  that contributes to  mixing is the stirring
 caused  by  air  moving  over  "roughness  elements"
 (Figure 5-12). A roughness element is any surface feature that
 interrupts the flow of air. Depending on the size of the spill,
 roughness elements  may become  obstacles.  For example, a
 very  small spill on the railroad tracks in an urban area will
 only  experience the roughness of  the tracks and immediate
 surroundings.  If the nearest buildings are 500 yards away
 and the cloud doesn't travel that far,  the ground roughness
 may be open country (see below).  A cloud will generally be
 narrower and travel  further across open country than it will
 over  an urban or forest environment because of the relative
 lack of roughness elements to create turbulence or curtail the
 cloud's spread.
5-18

-------
                                                    ChapterS: The SetUp Menu
           Rgire5-12.
     Plume behavior over
different types of roughness
  elements and obstacles.
                       You must tell ALOHA the ground roughness in the area over
                       which the cloud will be moving.  You have three choices:
                       Open Country, Urban or Forest, or you may enter a roughness
                       (Z0) value.
                       D  Open Country means that there are no buildings or other
                          obstacles close by.

                       O  Urban or Forest means that there are many obstacles in
                          the area in which your spill has occurred. These obstacles
                          may take the form of skyscrapers, suburban homes, or
                          pine trees. Selecting an Urban or Forest ground rough-
                          ness will lead to more mixing and, hence, a shorter foot-
                          print.

                       Naturally/ you can characterize few environments  as totally
                       urban or totally open, so make your best guess by deciding
                       which type of ground roughness dominates the area where
                       the spill occurred.  For example, if the  spill occurred in a
                                                                         5-19

-------
 Chapter 5: The SetUp Menu
 downtown area with more tall buildings than open areas or
 parking lots, you'd choose Urban or Forest as your ground
 roughness.  However, if the spill occurred in an area with
 more open spaces than buildings, you'd choose Open Coun-
 try. If it's not clear which category your spill location falls in,
 run ALOHA twice, once for each category.  In determining
 the downwind distance to the given Level of Concern, you
 will find that Open Country is a more conservative choice
 than Urban or Forest.  That is, if you choose that option,
 ALOHA will estimate a longer threat distance.
 If you want to specify your own roughness length (Zo), you
 may find the following table helpful (Brutsaert 1982). As you
 can see from Table 5-4, choosing roughness length is more
 complicated than entering the height of the roughness ele-
 ments.
                Surface Description 	2o_£flDl
                Mud flats, ice                       0.001
                Smooth tarmac (airport runway)         0.002
                large water surfaces (average)          0.01-0.06
                Grass (lawn to 1 cm high)              0.1
                Grass (airport)                      0.45
                Grass (prairie)                      0.64
                Grass (artificial, 7.5 cm high)           1.0
                Grass (thick to 10 cm high)             2.3
                Grass (thin to 50 on)                 5.0
                Wheat stubble plain (18 on)            2.44
                Grass (with bushes, some trees)         4
                1-2 m high vegetation                20
                Trees (10-15 m high)                40-70
                Savannah scrub (trees, grass, sand)      40
                Large city (Tokyo)                  165
TebteS-4.
Z9 equivalences.
 When ALOHA uses the ground roughness in its calculations,
 it may readjust the value you have entered to be consistent
5-20

-------
                             Chapter 5:  The SetUp Menu
 with the requirements for the Gaussian and heavy gas mod-
 ules. In the Gaussian case, ALOHA only needs to know the
 roughness category (Urban or Forest or Open Country). If
 you enter a Zo, ALOHA will categorize your value into one of
 these two classes.

 If the heavy gas calculations are used, ALOHA will assign a
 value to the Urban or Forest or Open Country choice. If you
 have entered a ZQ ALOHA will use this value, if it falls within
 the range 0.05 cm to 10 cm.  Values greater than or less than
 these limits will be set to the nearest limiting value.

 After you've selected the appropriate atmospheric conditions
 and ground roughness,  and clicked OK, ALOHA requests
 information about the cloud cover and relative humidity in
 the vicinity of the spill.

 6. Cloud cover
 ALOHA uses information on cloud cover to help estimate the
 amount of incoming solar radiation at the time of the spill.
 With location, air temperature and your other atmospheric
 selections, this  information helps ALOHA to calculate the
 rate at which the spill will evaporate.  ALOHA gives you six
 options for cloud cover, ranging from complete cover to clear.
 The sixth option allows  you to describe cloud cover in the
 standard meteorological terminology of tenths. For example,
 if you called the National Weather Service, they might tell
 you that cloud cover that day was 5/10, in which case you'd
enter 5 as the value.
                                                  5-21

-------
 Chapter 5: The Setup Menu
                    Cloud Ceuer end Humidity
Select Cloud Cover
o o
complete
cower
9 O
pertly
cloudy
0,
O on
cleer
[ Help ]

O enter velue
(0-1 II
- -•
[5 |

                              Figure 5-13.
                              Cloud cover options.
 7. Humidity
 Relative humidity is another measure that ALOHA uses to
 help calculate the rate at which the spill will evaporate into
 the atmosphere.  As with cloud cover, ALOHA gives you six
 options for relative humidity, ranging from wet to dry. The
 sixth option allows you to describe humidity in the standard
 meteorological terminology of percentage.  For example, if
 you called the National Weather Service, they might tell you
 that  there was 50% humidity that day.
 Note that,  as you've entered more information, the Text
      o    o     ®     o
     wet        medium

       [ Help
O  BR  O enter value
dry
(0-100)
                                  Cancel
                                                            Figure 5-14.
                                                            Humkfty options.
 Summary window has continued to be updated (Figure 5-15).
 The window now includes information on the site, chemical,
 and atmospheric conditions for the spill scenario.
5-22

-------
                                                     ChapterS:  The Setup Menu
       Figure 5-15.
    Text summary.
                                            ' Tent Summc
SITE win
  Location JUPITER, FUMIM
  Building Air Cxcftanow Par Haw: 1.07 (Stialt
  Data ( Ti«>: Using cospuUr's intarnal clock
                                                   Stialtvad «ingla »tori«d>
  TLU-TUA: 29.00 ppa
  Footprint L«w«l of Canevrn: 500 DDB
  Boiling Point: -33.43* C
  Uapor Prw>w>« at fMivnt Tvevotw^: qrwtor than 1 ate
  Mblont Satiratlon Cancan trail an:  1,000,000 pp* or 100.01
                                                      ttalaculor Moigtil: 17.03 kg/kaol
                                                      iOLH: 900.00 pp»
RTHOSnCRIC INFOPJ«TIOH:
-------
 Chapter 5: The SetUp Menu
 A SAM transmits updated meteorological conditions every
 30 seconds. If ALOHA has finished the previous dispersion
 calculations and has drawn a footprint, the new SAM data
 will be used to update the dispersion calculations and draw a
 new footprint. If, on the other hand, ALOHA is still in the
 process of  calculating the dispersion when SAM data are
 received, the new data will be ignored. Not until the footprint
 has been drawn will ALOHA again begin acknowledging the
 SAM data and resume the process of calculating a new foot-
 print. Remember that the SAM can only update the data that
 it collects. You will need to update the inversion, cloud cover,
 and humidity conditions if these change during the incident.

 When you select SAM Station, ALOHA assumes that you are
 hooked into a SAM unit and are prepared to receive weather
 data through it (Figure 5-16).  ALOHA will alert you if it
 doesn't receive data from the SAM after several minutes.

 Windows users will need to specify  the serial port to which
 the SAM unit is connected.

 After you click OK, ALOHA asks you for additional informa-
 tion about atmospheric conditions in the vicinity of the SAM
 that cannot be measured by the station.

 t. fnvwifon Height Options
 Click No inversion if there is no inversion present.  If an
 inversion is present, click Inversion present and type in its
 height. Make sure that you choose whichever unit of measure
 is appropriate. (For more on inversion height, see pages 5-14
 to 5-15.)
                                                           WARNING
5-24

-------
                                                Chapter 5:  The Setup Menu
     Rgue5-17.
  Invoision bsignt
        options.
                   User Input far SUM Unit
inversion Height Option* ire:  [  Help
 ® No Inuerilon
 O Inversion present, Height Is:
                                                     ®feet
                                                     O meters
                  2.  Ground/toughness
                  Next, select  the appropriate Ground roughness category.
                  (See previous discussion of ground roughness.)
     Figure 5-18.
Ground roughness
 and time options.
                  User Input Tor SUM Unit
Inversion Height Options ere:  I  Heli
 ® No inversion
 O Inversion present, Height Is:
                                                     ®feet
                                                     O meters
Ground roughness is:
 ® Open country
 O Urban or Forest
                                             Help
                                            Input roughness (2o): 3.0
                                                  Oln
                                                  ® cm
                   NOTE: The model time will be teken from the computer's interne!
                   clock. Be sure It Is set correctly.
                                                   Concei
                  Make sure that your computer's internal clock is set to the
                  appropriate time for your spill; your SAM will run using this
                  time and ALOHA will use this time, along with the wind
                  speed and direction, to calculate the appropriate stability
                  class. After you click OK, ALOHA requests cloud cover and
                  humidity information  for the location where your spill oc-
                  curred.  (See previous discuss of cloud cover and humidity.)

                  If you save a scenario as an ALOHA file while the met station
                  is turned  on, ALOHA  won't automatically start receiving
                  data when  you reopen the file.  You must again select
                  Atmospheric and choose either User Input or SAM Station.
                                                                       5-25

-------
 Chapter 5: The SetUp Menu
 SAM Options
 After you click OK on the Cloud Cover and Humidity screen,
 notice that a new menu item, SAM Options, appears to the
 right of the Display menu. You can Archive the data received
 through SAM as ASCII characters in a text file, look at Raw or
 Processed data, or look at a Wind Rose displaying the last ten
 wind vectors that ALOHA received from your SAM.  You do
 not have to use any of these options for ALOHA to use the
 SAM data; they are truly "optional."
                                  SRM Options
                                   Rrchiue Data...
                                   Raw Data
                                   Processed Data
                                   Wind Rose
Met station sensors are scanned
every two seconds; the mean wind
speed, direction, and temperature
are based on five-minute running
averages of the scanned sensors.
Be  aware that the data received
through these sensors are specific
only to the area where you have
set up your SAM. Wind speed and direction for other areas
covered by the dispersing cloud may not be reflected (see
Wind shifts on pages 2-10 to 2-11). Further, since ALOHA
can only receive  data from one SAM at a time, footprint
calculations may be  invalid if  they are based on a SAM
located some distance from the spill source, and there is a lot
of variation in the terrain in between.

1, ArcMv* Data
You can save your processed meteorological data as a tab-
delimited text file for later referral.  Choose Archive Data
from the SAM Options menu, name the file in the dialog box,
and click Save. You can later open this file in a word process*
ing application. Since data may not be received every 30
seconds if ALOHA is doing time-intensive calculations, the
archived data will include the time of each transmission. This
time is taken from the computer's internal clock; please be
Figure 5-19.
SAM Options menu.
5-26

-------
                                            Chapter 5: The Setup Menu
                sure this time is accurate. You may change the time using the
                Control Panel on the Macintosh or the Control menu box on
                the IBM.
    Figure 5-20.
Archive SAM data
                             flLOHH
                     D flLOHfi Meips
                     <* fllOHH
                     D ChernLil)
                     D Citylib
                    Rrchiue SflM data as:
                    file name
           I
           iiii
                  Key West
                [  Saue   J
                  Cancei~)
                ALOHA places no  limit on the amount of data you may
                archive. The only limit will be the amount of space available
                on your hard drive (or floppy disk).

                2. Row Data
                This option allows you to view the string of data that the met
                station is sending to your computer. The data, separated by
                commas, are printed on a single line on your screen in the
                following format:
    Figure 5-21.
  Raw SAM data.
Raw Sam Data
                 0999,9.13,308.67,6.79,24.30,8.93,304.48,24.26,12.3,2929,
                                                                5-27

-------
 Chapter 5: The Setup Menu
 G met station identification number
 O mean wind speed (meters per second)
 O mean wind direction (in degrees true)
 O standard deviation of wind direction (in degrees)
 O mean temperature (in degrees Celsius)
 O instantaneous wind speed (meters per second)
 O instantaneous wind direction (degrees)
 O instantaneous temperature (again, in °C)
 O battery voltage of the field unit
 O the sum of the ASCII code of all the data sent (ALOHA
    uses this number to  trap bad  or incomplete transmis-
    sions).                                       '    * * -

 1. Proc*cs«d Data
 Here, you see SAM  data after ALOHA has processed and
 interpreted it (Figure 5-22).
                        Pr«c*if M Sam Data !
       rtttwvloglcal *tatl«n ID: «M
          4.4
 Ulnd direction: 97 i
  TMevoUn: M*
3 niMITE NMIINO
           Hind ttmue: 4.9
        Hind Direction. 62
                         tn*
           gjH ftata: 9.2 
-------
                                                 Chapter 5: The SetUp Menu
                    Theta is -1.00, SAM has not been transmitting for five min-
                    utes. ALOHA will not allow you to set the source or draw any
                    footprints until SAM has been running for at least five min-
                    utes.
                    4. Wind ROM
                    Selecting Wind Rose displays a diagram that summarizes the
                    direction and speed of the wind at a SAM's location.  This
                    window shows up to the last ten wind observations received.
                    Each observation appears as  a  line,  called a vector, that
                    indicates the wind direction by the angle at which each line is
                    drawn, and the wind speed, by the length of the line.  Each
                    vector represents a five-minute running average, rather than
                    an instantaneous measurement.
Figure 5-23.
SAM wind rose.
IDindRose
                       4.2 mph
                              The wind rose helps you to
                              visualize how much the
                              wind has been shifting. For
                              example, in low wind con-
                              ditions on a hot, sunny day,
                              you would expect fairly
                              unstable atmospheric con-
                              ditions.  The wind rose
                              would show vectors that
are widely scattered.  Conversely, under stable conditions,
the wind rose will show very little scatter; some of the vectors
may even be lying on top of one another. The last wind speed
received is displayed in the lower left corner. The vector
representing the last wind observation is drawn on the dia-
gram  with a darker line. Notice that the vectors are drawn
from the center of the circle towards the direction TO which
the wind  (and any cloud of chemical) is blowing.  Both
processed and  raw data will show the direction FROM which
the wind  is coming.  The wind rose will continue  to be
updated until you disconnect your SAM or close the window.
                                                  5-29

-------
 Chapters: The Setup Menu
 Source...
 The Source options let you tell ALOHA the amount and/or
 circumstances of the chemical release.
                     Chemical...
                     Htmospheric    >
                                          Direct...
                                          Puddle...
                    Computational... |   Tank...
                                          Pipe...
 ALOHA can estimate the duration of chemical releases last-
 ing from a minimum of 60 seconds to a maximum  of 60
 minutes.  After sixty minutes, atmospheric conditions are
 likely to have changed.  Remember, ALOHA uses constant
 atmospheric conditions. If the circumstances of the release
 lead to a spill that would last longer than 60 minutes, you will
 see that the concentration, source strength, and dose curves
 are truncated at 60 minutes. The text summary screen will say
 "Release Duration: ALOHA limited the duration to 1 hour."
 The 60-minute cutoff is a maximum; if conditions change
 dramatically before an hour has passed, ALOHA's output
 will not be valid. When this happens, reset the atmospheric
 and source input and let ALOHA calculate a new footprint.

 ALOHA reports two release rates. The maximum  computed
 release rate is the fastest release rate possible for your sce-
 nario. It may be very fast  in the case of a pressurized tank
 release. The maximum average release rate is averaged over at
 lest one minute. It will be considerably slower than the maxi-
 mum computed rate in the case of a  pressurized release.
 ALOHA uses a series of average rates to make its dispersion
 calculations.
                                                         Fgure5-24.
                                                         Source options.
5-30

-------
                              ChapterS: The SetUp Menu
 After you click OK, the source is calculated and you will be
 returned to the Text summary screen.  Review the informa-
 tion you have entered as it appears on this screen. The
 source strength information calculated by ALOHA includes
 an estimate of how long the release will last, the total amount
* released, and both the maximum computed and average re-
 lease rates. If a pressurized liquid was stored in the tank,
 ALOHA will indicate that the release was a two-phase flow.
 In such  cases,  liquid, as  a  fine aerosol mist, and gas are
 released  rapidly and simultaneously  from  the  tank. Two-
 phase mixtures are denser than the gas phase of the chemical,
 and often disperse as  a heavy gas.

 Choose the Source option that most closely resembles the
 spill scenario.

    Choose...    If...
 O  Direct      ...you can estimate the amount entering the
                atmosphere,
 ID Puddle      ...you can estimate the size of the puddle on
                the ground,
 a Tank        ...the substance is being released from a tank,
                or
 O Pipe         ...a gas is escaping from a broken or punc-
                tured pipe.
 Direct
 Choose Direct to enter your own estimate of how fast the
 pollutant is entering (or has entered) the atmosphere. Was
 the spill instantaneous (the entire amount escaped into the
 atmosphere in the first 60 seconds) or continuous (the con-
 tents are entering the atmosphere over time)? This estimate
 must be for the amount of pollutant entering the atmosphere as
 a gas. This may not equal the amount spilled, particularly if
                                                  5-31

-------
 ChapterS: The SetUp Menu
 the substance spilled is a liquid (in such a case, you'd need to
 estimate its evaporation rate).
                    User Input Source Strength
   Select source strength unlit of mass or volume:      [ Help ]
     O grams       O kHogroms ® pounds     Q tons(2,000 Us)
     O cubic motors  Qlltors     Q cubic foot   O9*U
-------
                                         Chapter 5: The SetUp Menu
 Figure 5-26.
Puddte input
             Puddle
             If the spill is a liquid that has formed a puddle on the ground,
             select Puddle, unless the source of the puddle is a tank that is
             still leaking (in which case you should select Tank).

             When you select Puddle, the first pieces of information that
             you must give ALOHA are how large an area the puddle
             covers, and how much of the chemical is contained in the
             puddle (Figure 5-26).
             Puddle Input
              Puddle area is:
       500    square ® feet  Q yards O meters
              Select one and enter appropriate data
                © Uolume of puddle
                O Average depth of puddle
                O Mass of puddle
                Uolume is:
               © gallons    Q liters
               O cubic feet O cubic meters
               (L
OK
J    (   Ca""l    1    [
Help
J
             O  Visually estimate the amount of ground the puddle covers
                (remember, for a square or rectangle shape, area = length
                times width; for a circle, area = 3.14 times the square of the
                radius).

             O  Estimate the amount of chemical contained in the puddle
                by typing in either the volume or mass of the chemical in
                the puddle. Otherwise, estimate the average depth of the
                puddle and ALOHA will calculate its mass.
                                                              5-33

-------
 Chapter 5: The SetUp Menu
 ALOHA now knows the puddle's surface area and the amount
 of the chemical available for evaporation.  The evaporation
 rate will depend on these factors, as well as:

 D incoming solar radiation (affected by location, time, cloud
    cover);
 O heat transfer with air (affected by air temperature, humid-
    ity, initial puddle temperature); and
 O heat transfer with ground (affected by ground temperature,
    ground type, initial puddle temperature).

 The ground conditions influence the amount of heat trans-
 ferred between the ground and the puddle (for example, the
 warmer the ground, the warmer the puddle; hence, there will
 be a higher vapor pressure, resulting in a higher evaporation
 rate).

 Choose ground type by selecting default, concrete, sandy, or
 moist.  (ALOHA doesn't assume any of the chemical is ab-
 sorbed into  the ground, but uses ground type information to
 help calculate energy transfer.)  In most cases, concrete will
 be the most conservative choice (it leads to the highest heat
 transfer). The default selection is equivalent  to unwetted
 ground not  covered by rock or concrete.  This choice will
 usually lead to evaporation rates that are somewhat  slower
 than those  resulting from concrete, but faster than if you
 chose sandy.

 You must next select a ground temperature; the air tempera-
 ture will be automatically filled in as an estimate of Ground
 temperature. You may use this as a default value or you may
 enter the ground temperature, if you know it. There may be
 a  large difference between air and ground temperatures in
 some situations, such as in a parking lot on a hot day late in
 the afternoon, or on a street during the early morning hours
5-34

-------
                                             ChtipterS: The Setllp Menu
                following a very cold  night. Be sure to estimate  air and
                ground temperatures carefully in such situations.

                The last piece of information ALOHA will need here is the
                initial puddle temperature. You may again elect to use either
                the air or ground temperature, or you may enter an initial
                puddle temperature, if you know it.
    Figure 5-27.
   Ground type,
temperature, and
    initial pudde
   temperature.
         Soil Type, Mr and Ground Temperature
Select ground type              [  Help   J
   ©Default   OConcrete  QSandy   OMoist
                  Input ground temperature
                               [   Help   ]
                     
-------
 Chapter 5: The SetUp Menu
 ALOHA doesn't take into account any changes in atmo-
 spheric conditions—such as changes in wind speed or air
 temperature— when calculating the rate of evaporation from
 a puddle. This is especially important to remember because
 wind speed and air temperature are very important  influ-
 ences on evaporation rate. If these conditions change  while
 ALOHA is  calculating the evaporation rate,  you'll need to
 enter the new values and re-run ALOHA.
                                                           WARNING
 Puddb ortook?
 Puddles may also be formed by leaks from tanks. If a tank is
 the source of the puddle, choosing Tank allows the puddle
 area to grow while the tank continues to leak.

 Tank-
 If the source of the spill was a tank rupture or tank valve leak,
 choose Tank. ALOHA will need to know what the tank looks
 like, how big it is, how much of a chemical, either liquid or
 gas, could be stored in the tank, and the storage temperature
 and/or pressure.

 '                  Tank Size and Orientation                  "
  Select tank type and
  orientation:
 Hdrlsontal cull
                    Uvtleal cull
 0
                           Enter two of three values:
    0         ) -r
                       diameter 113.0
length   [50
               ' ® feat  O meters
J
                       volume  lEEEEEBBJ® gallons Q cu. feet
                          Cancel
               [  Help
                                     Figure 5-28.
                                     Tank size and
                                     orientation.
5-36

-------
                                                   Chapter S: The SetUp Menu
                      Tank srz* and orientation
                      ALOHA considers three type of tanks: a horizontal cylinder,
                      a vertically oriented cylinder, or a sphere. As you choose the
                      tank type and orientation, the bottom of the tank input screen
                      will change to reflect whatever additional information  is
                      needed to help ALOHA determine the total volume of the
                      tank.
         Figure 5-29.
State and temperature of
      chemcal in tank.
If, for example, you select a cylinder, the model will request
that two of the following three values be entered: diameter,
length, or volume. If you select a sphere, ALOHA needs to
know either the  diameter of the container or the volume of
the tank. The model will fill in the calculated values for the
other input boxes as you enter the requested information.

Chemical state
Next, tell ALOHA the nature of the material in the tank and
the temperature at which it is stored.  You may tell ALOHA
that the tank contains liquid, the tank contains gas only, or
you don't know.

             Chemical State and Temperature
  Enter the state of the chemical:
    ©Tank contains liquid
    QTank contains gas only
    O Unknown
[   Help  ]
                       Enter the temperature within the tank:      [  Help  ]
                         O Chemical stored at ambient temperature
                                                      degrees   <§> r  O C
      Chemical stared at||32
                                                      Cancel   j
                                                                        5-37

-------
 Chapter 5:  The Setllp Menu
 Liquid in a tank
 If you choose liquid, ALOHA will determine how much of the
 chemical is in the tank once you have entered the mass or
 volume of the chemical, the percentage of the tank that is
 filled, or the liquid level in the tank. Remember that you have
 already specified the size of the tank, so the model already
 knows the maximum amount that may be in the tank (Figure
 5-30). ALOHA won't allow you to overfill the tank!
                        liquid MI«I or uoiurea
      Enter the mess OR volume of Me liquid
      Tfce mast of liquid Is:
Ooi
® tont(2.000 ibs)
OkHograim
      Enter uoiume OR liquid
                                 liquid
                              welume i*: I
              gaHons
            -|O cubic reet
            JQ liters
             O cubic meters
                                    > full by velume
                             Cancel   J
              Hal*
                             Figure 5-30.
                             Liquid in tank.
 Gat in a tank
 If you choose gas/ ALOHA will determine how much is in the
 tank by asking you to enter the tank pressure or amount of
 gas directly.
5-38

-------
                                            Chapter 5: The SetUp Menu
    Figure 5-31.
  amount of gas
      in a tank.
                                Moss or Pressure of Cos
 Enter either tank pressure OR amount of gas
                 The tank pressure is :  2
                                     OH
                  The amount of gas is :  0.095
                                                  O mm Hg.
                                                  ® fltnt.
                                                   OP".
                                 O pounds
                                 <8> tons(2,000 Ibs)
                                 O kilograms
                                 O Cu. Ft. at STP
                                 O Cu. M. at STP
                                   [  Cancel   j    [    Help   ]
                Unknown in a tank
                If you choose unknown, ALOHA will ask you to enter the
                mass of the chemical in the  tank.  The model   will then
                calculate  the state of the chemical based on tank volume,
                temperature,  and mass of the chemical in  the  tank
                (Figure 5-32).
    Figure 5-32.
Mass of unknown
 chemical in tank,
         Mass of Chemical In Tank
For a chemical of unknown state,
the chemical mass Is required
                  The amount of
                  chemical In
                          O pounds
                          
-------
 Chapter 5:  The SetUp Menu
 Ana and typ* of leak
 Now ALOHA will ask you about the opening from which the
 pollutant is escaping. You must decide if the opening is best
 described as a hole or a short pipe/valve leak, and what shape
 best describes the opening (Figure 5-33).
             Select the shope that best represents the shape of
             the opening through which the polluted! Is exiting
                O Circular opening    ® Rectangular opening
              Opening length:
                                          ® Inches
              Opening width:   H_
          O centimeters
          O meters
             is leek through e hole or short plpe/uelwe?
                O Hole             ® Short pipe/value
                  OK
Cancel   ]   |    Help
                              Area and type of leak.
 If you specify that the opening is rectangular in shape, ALOHA
 will ask you for the length and width of the hole.  If you
 specify a circular leak, you will need to provide a diameter.
 The last piece of information that you must give ALOHA
 about how the chemical is leaking out of the tank is whether
 the leak is through a hole or a short pipe/valve. A hole is any
 kind of break directly into the tank (e.g., a puncture or crack).

 If there is any liquid in the tank, you must next tell ALOHA
 where  the leak occurs on the tank (Figure  5-34).
5-40

-------
                                                Chapter 5:  The Setup Menu
      Figure 5-34.
Height of leak in tar*.
Height of the Tank Opening













	 liq. IM! 	


j[ OK ]|
	









5

I
1
fi




The bottom of the leak it:
jl.99 ] Ol». O«- Ocm.®m.
above the bottom of the tank
OR

50.0 | * of the way to the top of
the tonk
Cancel J [_ Help J
*
                   You may tell ALOHA where the leak is in one of three ways:

                   O  move the scroll bar up to the approximate height of the
                      bottom of the leak (notice that the liquid level is shown),

                   O  specify the distance from the bottom of the tank to the
                      bottom of the leak, or

                   O  specify the height of the leak as a percentage of the total
                      tank height (e.g., 0% means that the hole is at the bottom
                      of the tank; 90% means that the hole is 90% of the way to
                      the top of the tank).

                   If the leak is a gas, you will be returned to the Text Summary
                   screen when you click OK.  You will see a summary of the
                   information that you entered on the  tank, and the source
                   strength results calculated by ALOHA (Figure 5-35).
                                                                     5-41

-------
 Chapter 5:  The SetUp Menu
  IQrt:OWrtM. IFVUT Of
/«oe fro* 080* trua
«: 0
      IIC
  Ulnd: S Mti
  Stability Cl
  nalatlua
  Cloud Cower: 9 tantte

SOUCC STHDtJTH IWOMHIIOH:
  Oac look. fnjB hoi a in harlBontal cyl indrli

        i^r 3.672 gal lam
  Internal Taaparatw*: 99* F
  ChaBleal llaca In Tar*: 0.023 ton*
  Circular Opening DioMlar: 6 Inehw
  Halaava Ouratiqn: 1 atnuta
  nax Caapntad Halaava Kata: •-« pautd*/«a<
  HOB •juaraga Smtfllnod Halooca Nate: 0.337
    
  Total HMunt Ralaaaad: l« 6 pound*
No lnwar«lan MalgM
nlr ToKiaratm: 39* F
                                                      try
                                    I tank Ml«et«d
                                            39 foot


 If the chemical is stored as a non-pressurized liquid, a puddle
 may be formed, so ALOHA will ask you for information about
 the ground.  This information is similar to the information
 requested in the Puddle option.  There are, however, two
 differences.
                                                                   Figure 5-36.
                                                                   Text summary of gas
                                                                   teak from tank.
 First, ALOHA will have calculated the initial puddle tern-
 perature, based  on the temperature of the tank and flow
 considerations, so you will not have to enter this information.

 Second, you must let the model know whether the puddle is

 diked.

                         Puddle Parameters
        Select ground type
            'Default   O Concrete  O Sandy    O Moist
        Input ground temperature
                           Help ]
          <§) Use air temperature (select this If unknown)

          O Ground temperature Is [J80  ~~| deg.  ® F Q C
       Input maximum puddle diameter  (  Help  ]

          ® Unknown
          O Mauiroum diameter is |      ] ® ft  O ydt O meters
                                      [   Cancel   ]
                                                    Figure 5-36.
                                                    Pudde input
5-42

-------
                                                    ChajtterS:  The Setup Menu
                  ALOHA will ask you to enter the maximum puddle diameter.
                  If there are no barriers to prevent the liquid from flowing,
                  select unknown.  If there is a barrier to liquid flow (e.g., a
                  containment or diked area), then enter the approximate diam-
                  eter of that barrier as the maximum puddle diameter.  Re-
                  member to select the appropriate units, and click OK.
    Figure 5-37.
Text summary of
   Squid release
     from tank.
                        TeHt Summary
nTrtDSPtCAIC ltrCN*ITIOtt:
  Mind: 12 krwta from SE               Mo Inversion MeigM
  (tabilitg Clem:  D                  Air Teeparature: W* F
  ftelBtlue Huelditu.: SOI               Ground toughness: Open country
  Cloud Cover: 3 tenths

SOMX 9TRENOTH INFOWflTIW:
  Liquid iHk fro* hot* In horizontal cgllndrleal tank Ml acted
  TanH Diameter: 8 tat                Tank Lengtti: 20 feet
  To* Ualuo*: 7.320 gallon*
  Internal T«ap«ratur«: BO* F
  ChMleal na*« In Tank: 20 « tone        Tank I* 771 full
  Circular Opening OioMtor: B inehM
  Opening I*  I 80 f««t froo tank bet to*    SoH Tup*: Default
  Qround Teep: equal to orient          fXB Puddle Dlaeeter: UMutom
  H*l*a** Duration: 30 alnutec
  nax Ceaputed P*l*ac* Hot*: 710 poundc/oin
  nan Average Sustained n*l*ai* Rate: 716 pounds/Bin
    
  Total flBOunt Releaaed: 34,646 pound*
                  Now you can select Source from the Display menu to see a
                  plot of the source strength over time.


                  Pipe.
                  If the chemical is spilled from a leaking gas pipe, choose
                  Pipe.... (ALOHA does not allow for liquid pipe leaks.)  Here,
                  you tell ALOHA  the  inside diameter of the pipe, the pipe's
                  length, whether the pipe is connected to a tank (infinite tank
                  source) or shutoff valve (closed off), and  the pipe's rough-
                  ness.
                                                                            543

-------
 Chapter 5: The Setup Menu
                       Pipe input
   Input pipe diameter
                                    [  Help  ]
      Diameter Is
               1 2
Inches Ocm
   Input pipe length
      Pipe length Is  2400
                                    [Help  ]
                           ' ft  O yds  O meters
   The unbroken end of the pipe Is        [  Help  ]
      © connected to infinite tank source
      O closed off
Select pipe roughness
   
-------
                                         Chapter 5: The Setup Menu
             Next, tell ALOHA the pressure and temperature inside the
             pipe. You may enter a value for the size of the hole in a broken
             pipe if the pipe is closed off at its unbroken end. If, instead,
             the pipe is connected to a large reservoir, ALOHA will as-
             sume that the hole diameter equals the pipe diameter.
  Figure 5-39.
Pipe pressure'
   hole size.
          Pipe Pressure and Hole Size
               Input pipe pressure
                                      [  Help  )
                  Pressure is 110000
                           PSI
Input pipe temperature
   O Unknown (assume ambient)
   
-------
Chapter 5: The SetUp Menu
                         \ TeHt Summary
nuarriEnlC III UWIITIQn
 Hind: 9 MUrs/MC fro* 090* Iru*
 Stability Clan: 0
 talotlw* HuBldlty: TSf
 Cloud Cowar:  10 tantta
                                  TH)
                                    No Inversion Might
                                    Air TiHurntura: 95* F
                                    Orawtd RouanrMs: Opan country
       8TKHOTM INFOMMTIOH:
    Pip* DIOMtar:  12 InehM              PI(M length: MOO tot
    Pip* TMBV«tu>«: 99* f               Pkp« fr+is: WOOD lttt/ eorvMCitad to an Infinite Mure*
    Hainan Duration: ALOHA Haltad tn* duration to I hour
    no* Caaputtd miaaM toU: 268,000 poundt/»ln
    Itac ftuirag* Suitaliwd talaoM Kate: 200,000
      
    Total Aaount AtlaoMd: 19.960. KM pound*
                         I
                                                              ! i
Figure 5-40.
Text summary of gas
release from pipe.
Computational^.
Choose Computational to specify which type of calculations
you want ALOHA to use for estimating the dispersion. You
may choose to let ALOHA decide whether to  use the heavy
gas or Gaussian calculations, or you may force the model to
use one or the other. This option also allows you to specify a
dose exponent.
                   Computational Preferences
   Select spreading algorithm. If unsure, let
   model decide.
              t   Help   1
          © Let model decide (select this If unsure)
          O Use Gaussian dispersion only
          O Use Heauy Gas dispersion only
   Define dose:
              I   Help   I
            Dose - j c 
-------
                              Chapter 5: The SetUp Menu
 Let moo*/decide
 When you choose Let model decide and are running one of
 the Tank, Puddle, or Pipe source options, ALOHA will iden-
 tify chemicals that will behave as heavy gases. This is true
 even if a chemical's molecular weight is less than 29 kg/kmol
 (the "molecular weight" of air). However, if you chose Direct
 as your source option, ALOHA may not have enough infor-
 mation about the release to determine whether a heavy gas is
 formed when the molecular weight of  the chemical is less
 than 29 kg/kmol. In these cases, it will  default to the Gaus-
 sian calculations.

 Us* Gaussian dispersion onfy
 When you choose Use Gaussian dispersion only, ALOHA
 will calculate the spread of the chemical cloud  using  the
 Gaussian distribution discussed in Chapter 2. The Gaussian
 calculations may be quicker than the heavy gas calculations,
 particularly if you  are using a computer without a math
 coprocessor. In a response situation, you may elect to use the
 Gaussian dispersion option to obtain an initial footprint esti-
 mate. You may then recompute the footprint using Let model
 choose when time allows.

 A general  rule is that for unstable  atmospheres (stability
 classes A and B), the heavy gas  calculations will predict
 longer footprints; in stable atmospheres (stability classes E
 and F), the Gaussian footprints will be longer. Under neutral
 (C and D) conditions, the  computations will be approxi-
 mately the same.

 Us* Heavy Gas dupenion onfy
 When you choose Use Heavy Gas dispersion only, ALOHA
 will calculate the spread of the pollutant using the heavy gas
 computations discussed in Chapter 2.  These calculations may
be slower than the Gaussian calculations, particularly if you
are using a computer without a math coprocessor.  There are

                                                  547

-------
 ChapterS: The SetUp Menu
 some instances, such as when a chemical has been stored at a
 low temperature or under high pressure, when a chemical
 with a molecular weight less than that of air may behave like
 a heavy gas. ALOHA will warn you in some of the situations
 where this may happen.  If you think this may be true of a
 chemical, choose Use Heavy Gas dispersion only.
 Scientists disagree about the definition of "dose." ALOHA
 defines dose using the equation shown when you choose
 Computational. In this equation, C represents the concentra-
 tion of the chemical in the air, t represents the time period
 over which  the dose  is calculated, and n is the  exponent
 related to response (see below). When n is 1.0, you would
 read this equation as:
Define
dose:
r'n r—
Oose-J C"(T)(!T n- l.fl

1 OK 1 [


I Help 1



Cancel ]

Some chemicals w*h
molecular weights less
than that of air may
behave Ike heavy gases.
 dose =       concentration of the chemical multiplied by the time
             period it is present

 For example,
 dose =       concentration of the chemical (250 ppm)
             multiplied by time (four minutes)

 In our example, people at this location have been exposed to
 a total dose of 1,000 ppm-min.
548

-------
                             Chapter 5: The SetUp Menu
The default value for n is 1. You should retain this value
unless you are consulting with a specialist who understands
the dose formula and knows the appropriate exponent to be
used in the formula for the chemical in question.

S««ing t/i« calculated footprint
After selecting a computational preference, click OK. You are
now ready to move on to the Display menu, where you will
specify how you would like your data displayed.
                                                 S49

-------

-------
                      Diopter 6
                      The  Display Menu
In this chapter-.

Tile and Stack
  Windows	6-2
Options	6-3
Text Summary	6-6
Footprint	6-8
Concentration	6-8
Dose	6-12
Source Strength.......6-15
Calculate	6-17
Calculate Now	6-18
Once you've entered information about your scenario under
the SetUp menu, you can use the options on the Display menu
to look at various types of output. Qutput options are:   •

O text summary
O dispersion footprint
D graph of concentration over time at a given point (both in-
   and outdoors)
O graph of dose over time at a given point (both in-
   and outdoors)
O source strength (release rate over time).
     The Display menu.
                       Display
                        Tile Windows
                        Stack Windows
                        Options...
                        Tent Summary
                        Footprint
                        Concentration...
                        Pose
                        Source Strength
                        Calculate...
                        Calculate Now
                                                                        6-1

-------
 Chapter 6: The Display Menu
 When windows displaying this information are visible, you may
 organize them by selecting Tile Windows or Stack Windows.
 Tile and Stack Windows
 The Tile and Stack Windows options allow you to organize the
 information windows on your computer screen. Tile Windows
 displays the windows side by side, or one above the other; Stack
 Windows overlaps the windows one on top of the other, so that
 only the front window is visible; the title bars of the remaining
 windows are stacked behind. These windows can be expanded to
 fill your screen. Each of the windows may be sized or moved.
                •I—>
UMr ipMlflM UK: a*ml* IOLM CMOOO p*»
l»» UlTMt ZOM f«P LOC: LOC Ml MMT I
IteU: foeKrlnl Mn't «w> Meau
                                                              FiguB6-2.
                                                              Tie windows.
                             Co«c»iHr«»on UllnOm
                                                      M
               1,000

               2.000.
                              70
                                                      M
6-2

-------
                                           Chapter 6: The Display Menu
    Figure 6-3.
 Stack windows
       Footprint Windoui
                            Concentration Window
                                  TeHt Summary
                Options...
                You can ask ALOHA to calculate the shape of the footprint
                based on a given level of concern.  You then specify how the
                footprint should be displayed.
    Figure 6-4.
Display options.
                     Display Options
Select Level of Concern or Output Concentration:   [  Help   ]
     O'lHHnul
                      ® User specified cone, of
                                ®ppm
                                O milligromi/cubic meter
                 Select Footprint Output Option:               r  Help
                     ® Plat on grid and onto-scale to fit window. 	
                     O Use user specified scale.
                 Select Output Units:
                     ® English units
                     O Metric units
                                        Help
                                                    Cancel
               Level of Concern
               You must choose a level of concern before ALOHA can plot a
               footprint. The footprint will encompass the area within which,
               at some time during the hour after a spill begins, ground-level
               concentrations will reach or exceed your specified level of
               concern. There are two choices for specifying a level of con-
               cern.  IDLH  Concentration is the maximum concentration
               from which a healthy person could escape within 30 minutes
               without escape-impairing symptoms or  irreversible health
               effects (NIOSH 1990).

-------
 Chapter 6: The Display Menu
 The IDLH was not designed to be an appropriate measure of
 exposure levels for the general population. It doesn't take
 into account the greater sensitivity of children and the eld-
 erly. Although it is the most commonly used toxic threshold,
 it should be used with great care.

 Hence, you should be cautious when using this value for any
 type of evacuation decision. Make sure that you don't use
 this estimate to evaluate the relative toxicity of different
 chemicals, as a definitive way to identify safe or hazardous
 conditions, or without reference to length of exposure.

 When you select a chemical for your scenario, ALOHA au-
 tomatically checks to see if the IDLH value is available from
 the chemical library. If it is, ALOHA will set the default level
 of concern to this value.  If it is not available, IDLH Con-
 centration will be  grayed-out and you will not be  able to
 select this option.

 A preferred way to determine the level of concern to be used
 as an action criterion is through contingency planning. In this
 way, communities  can set  predetermined  levels of concern
 for chemicals or classes of chemicals common to their region.
 If such a value exists for the chemical you are using, enter that
 value next to User specified cone, making sure to click ppm
 or milligrams/cubic meter as appropriate. You may also use
 User specified cone, to obtain footprint estimates for a vari-
 ety of levels of concern.

 Footprint options
 Once you've chosen the level of concern that you want ALOHA
 to use for calculating the potential threat zone, decide how
 you want to view this information. If you click Plot on grid,
 ALOHA will draw the footprint  on  a  grid  and scale the
 drawing to fit on your computer screen.
                                                           WARNING
64

-------
                      Chapter 6
                      The  Display Menu
In this chapter^.

Tile and Slack
  Windows	6-2
Options	6-3
Text Summary	6-6
Footprint	6-8
Concentration	6-8
Dose	6-12
Source Strength	6-15
Calculate	6-17
Calculate Now	6-18
Once you've entered information about your scenario under
the SetUp menu, you can use the options on the Display menu
to look at various types of output. Output options are:

O text summary
O dispersion footprint
G graph of concentration over time at a given point (both in-
   and outdoors)
O graph of dose over time at a given point (both in-
   and outdoors)
O source strength (release rate over time).
           Figure 6-1.
     The Display menu.
 Display
                        Tile Windows
                        Stack Windows
                        Options...
                        Text Summary
                        Footprint
                        Concentration...
                        Dose
                        Source Strength
                        Calculate...
                        Calculate Now
                                                                        6-1

-------
 Chapter 6: The Display Menu
 When windows displaying this information are visible, you may
 organize them by selecting Tile Windows or Stack Windows.
 Tile and Stack Windows
 The Tile and Stack Windows options allow you to organize the
 information windows on your computer screen. Tile Windows
 displays the windows side by side, or tine above the other; Stack
 Windows overlaps the windows one on top of the other, so that
 only the front window is visible; the title bars of the remaining
 windows are stacked behind. These windows can be expanded to
 fill your screen.  Each of the windows may be sized or moved.
                                                            Figure 6-Z
                                                            Tie windows.
                            Co»iM»r»Hoi> u»iod«m
                toi
                                         40
                                                     M
               4.0

               9.000-
6-2

-------
                                           Chapter 6: The Display Menu
    Figure &3.
 Stack windows
       Footprint Window
                            Concentration Window
                                  Tent Summary
                Options...
                You can ask ALOHA to calculate the shape of the footprint
                based on a given level of concern.  You then specify how the
                footprint should be displayed.
    Figure 6-4.
Display options.
                     Display Options- I
Select level of Concern or Output Concentration:
     O IIHH not 4ii<»Dle
Help
                      ® User specified cone, of
                                ©ppm
                                O milligrams/cubic meter
                 Select Footprint Output Option:
                      ® Plot on grid and auto-scale to fit window.
                      O Use user specified scele.
                 Select Output Units:
                     ® English units
                     O Metric units
                                        Help
                                                    Cancel
               Level of Concern
               You must choose a level of concern before ALOHA can plot a
               footprint. The footprint will encompass the area within which,
               at some time during the hour after a spill begins, ground-level
               concentrations will reach or exceed your specified level of
               concern. There are two choices for specifying a level of con-
               cern.  IDLH  Concentration is the maximum concentration
               from which a healthy person could escape within 30 minutes
               without escape-impairing symptoms or  irreversible health
               effects (NIOSH 1990).
                                                                   6-3

-------
Chapter 6:  The Display Menu
 The IDLH was not designed to be an appropriate measure of
 exposure levels for the general population. It doesn't take
 into account the greater sensitivity of children and the eld-
 erly. Although it is the most commonly used toxic threshold,
 it should be used with greal: care.

 Hence, you should be cautious when using this value for any
 type of evacuation decision.  Make sure that you don't use
 this estimate to evaluate  the relative toxicity  of  different
 chemicals, as a  definitive way to identify safe or hazardous
 conditions, or without reference to length of exposure.

 When  you select a chemical for your scenario, ALOHA au-
 tomatically checks to see if the IDLH value is available from
 the chemical library.  If it is, ALOHA will set the default level
 of concern fo this value.  If it is not  available, IDLH Con*
 centration will be grayed-out and you will not be able  to
 select this option.

 A preferred way to determine the level of concern to be used
 as an action criterion is through contingency planning. In this
 way, communities can set predetermined levels of concern
 for chemicals or classes of chemicals common to their region.
 If such a value exists for the chemical you are using, enter that
 value next to User specified cone, making sure to click ppm
 or milligrams/cubic meter as appropriate. You may also use
 User specified cone  to obtain footprint estimates for a vari-
 ety of levels of concern.

 Footprint options
 Once you've chosen the level of concern that you want ALOHA
 to use  for calculating the potential threat zone, decide how
 you want to view this information. If you click Plot on grid,
 ALOHA will draw  the footprint  on a grid  and scale the
drawing to fit on your computer screen.
                                                          WARNING

-------
                                                  Chapter 6: The Display Menu
        Figure 6-5.
    Footprint dsplay
          options.
Select Footprint Output Oplton:
     ® Plot on grid and auto-scale to fit window.
     O U» u**r specified scale.
                           Help
                      Select Output Units:
                           ® English unitt
                           O Me trie units
                                          Help
                                                         f  Cancel J
        Figure 6-6.
Spedfyingascalefor
      footprint plot
                    If you select User specified scale, when you click OK, ALOHA
                    will ask what scale you wish to use. User specified scale is
                    useful if you want to print the footprint on a transparency and
                    overlay it on a map of known scale.
                  User Specified Plot Seal*
Please Input User Scale
         ®lnch
         Ocm
                      I screen
equals:
O inches  O miles
O f«et    O meters
O yards   @ kilometers
                                              Cancel
                                        (   Help
                    Select Output Units
                    ALOHA will use the units that you select to represent the
                    footprint distance and source rate information. The units that
                    you select will not affect the meteorological, chemical, and
                    source information that you entered using the SetUp menu
                    (i.e., your inputs will remain in the units that you used and
                    will appear on the Text Summary screen as such).
                                                                           6-5

-------
 Chapter 6: The Display Menu
 Text Summary
 Choose the Text Summary menu item to make the Text Sum-
 mary window the current front window.  This window dis-
 plays the options you've chosen as you've moved through the
 ALOHA menus. It also summarizes, in text form, the results
 of ALOHA's calculations, such as the length of the footprint
 and type of dispersion calculation used. When you first open
 ALOHA, you'll see short messages in the Text Summary
 window. These indicate that you haven't yet told ALOHA the
 location, chemical, or atmospheric conditions for your sce-
 nario.
pay careful attention
to this screen: make
sure that your input is
and note warnings or
messagos.
                    T»Ht Summary!
     OATH IIFONMTION:
    Location: •loan Ml act yav location
    Building: *wltar«d *lngl« •toriad
    Data 4 Tloa: Using Intarnal naelntoati clack
  CHOIICM. immmoH: - CMLECT ocnion.)
          IftrflMMTIttf: • fafLCTT
Figure 6-7.
Text summary window.
                      •
 Whenever you choose a menu item, enter information, and
 click OK, your choices are summarized in the Text Summary
 window. For example, when you choose a chemical, its name
 will appear next to CHEMICAL INFORMATION; when you
 enter atmospheric information, that information will appear
 under ATMOSPHERIC INFORMATION,  and so on. In the
 example above, only a Building type and  Date & Time have
 been specified.
 Footprint
 When viewed from above, ground-level concentrations of a
 dispersing chemical reach or exceed your specified level of
 concern within an area that forms a "footprint." This shape
 represents the spread of the gas cloud to the level of concern.
6-6

-------
                                               Chapter 6: The Display Menu
                   Dashed lines are drawn on either side of the footprint. These
                   lines reflect the uncertainty in the wind direction based on the
                   stability class that you (or the SAM station) have chosen. The
                   wind usually will not remain constant from any one direc-
                   tion; the lower the wind speed, the more likely it is that the
                   wind direction will vary, and thus, the wider the uncertainty
                   lines become.  These "uncertainty lines" give you an indica-
                   tion of how confident you can be of the direction of the
                   dispersing cloud.
     Figure 6*8.
ALOHA footprint
overhead view of gas cloud showing concentration 2 level of
concern
u. fa
0.25
0
0.25
0.75



~-
	


_• 	 '"
•*.

0.5
^.



IB,






^^j
*
1
	 	 +~
1 1.3 2
• i les
possible cloud movement based on uncertainty in the
wind direction
                                                                       6-7

-------
 Chapter 6: The Display Menu
 You can never be 100% certain that the wind direction will fall
 within the uncertainty limits unless you draw a circle (to
 indicate that it's possible for the wind  to come from any
 direction). The outer lines drawn by ALOHA are based on a
 95% confidence factor. This means that, 19 out of 20 times, the
 wind will be from a direction that  will keep the cloud  of
 pollutant between these lines. At very low wind speeds, you
 will notice that these lines will form  a circle.

 Be aware that, whenever source strength changes during a
 release or a release is very brief, a heavy gas footprint may
 overestimate the threat zone. This overestimate can be sub-
 stantial when source strength changes rapidly and drasti-
 cally. This happens because ALOHA makes simplified calcu-
 lations in order to produce a footprint plot in the short time
 available during an  emergency response. Except in  cases
 when release rate is constant, the model warns you of this by
 placing brief messages both on the heavy gas footprint plot
 (where you'll see the messages, "May be overestimate" and
 "Check concentration") and in the Text Summary window.

 When source strength is not constant for an hour, treat a
 heavy gas footprint as an initial screening estimate.  When
 you see ALOHA's warning messages, check concentrations,
 both at locations of concern and at a few points along the
 footprint centerline. This will give you a better idea of what
 ground-level concentrations may actually be downwind of
 the source. Unlike the footprint calculations, ALOHA's heavy
 gas concentration calculations are not simplified. Note that,
 in some cases, concentrations may be lower than your level of
 concern well within the footprint.
6-8

-------
                           Chapter 6: The Display Menu
Concentration
Besides examining ALOHA's footprint plot to see how far a
dispersing chemical cloud may spread, you may want to find
out about the concentration of chemical to which people at a
particular location within the affected area may be exposed.
This location could be a hospital, school, or large office build-
ing, as examples.

ALOHA displays a Concentration vs. Time graph showing
predicted concentrations for the first hour following the start
of a release, at a location that you have specified. You'll see
                       __      ^ •   •
two curves on the graph. The solid (red on a color monitor)
curve represents  the outdoor, ground-level concentration.
The dashed (blue on a color monitor) curve  represents con-
centration within a building of the type you selected using the
Building Type... menu item in the SiteData menu.

In reality, concentration of a dispersing chemical at a specific
point can fluctuate widely. The concentration values pre-
sented by ALOHA represent concentration values that have
been averaged for five minutes.

An example of a concentration graph is shown below. This
graph shows concentrations downwind of an evaporating
puddle of acrolein.  You can see that outdoor concentration
started to increase immediately after the spill began.  Inside
sheltered, single-story buildings (the type selected for this
scenario) it  took much longer for indoor concentration to
increase. Comparing indoor and outdoor curves on a Con-
centration vs. Time graph can be helpful in determining the
relative threats associated with remaining  indoors versus
leaving the area through a dispersing pollutant cloud.
                                                   6-9

-------
 Chapter 6: The Display Menu
                    Concentration Window
Figure 6-9.
Concentration vs. Time
graph for an evaporating
puddle.
 Designating a Location
 You may choose either of the following ways to designate a
 location for which you would like to see predicted concentra-
 tion. (You'll first need to have chosen a chemical and entered
 informatioxiunder the source option.)

 Choose Concentration from the Display menu.
 Then type in the coordinates of a location either in terms of its
 east-west and  north-south distances or its downwind and
 crosswind distances from the source. Once you have indi-
 cated a location and clicked OK, ALOHA will automatically
 calculate and display a concentration graph for that point.

 Choosing coordinates
 Your choice of coordinates will have important effects on the
 information that ALOHA will present  to you if the wind
 direction changes (whether you're using a SAM station, or
 you manually entered a new value).

 Using fixed (east-west and north-south) coord/notes
 Choose this method if you wish to know the concentration
 expected at a specific geographical location. This could be,
 for example, a school 100 yards to the west and 400 yards to
 the north of the spill  location. This is the best method to
 choose if you wish to monitor expected concentration at the
6-10

-------
                                            Chapter 6: The Display Menu
     Figure 6-10.
    Entering fixed
  coordinates for a
location of concern.
                 school, and you are using a SAM station to track wind speed
                 and direction in ALOHA. If the wind shifts direction, the
                 concentration graph displayed by ALOHA may change, de-
                 pending on whether or not the shift in wind direction moves
                 the cloud closer to the school or farther away from it.
IfaaBBsa-^^B Concentration and Dose Locotion fcjfa— — ^^^=
Specify the location at which yau want la eualuate the
concentration and dose ouer time.
f* Relatlue Coordinates
^ (OoiunwInd.Crof sivind)
N
_. FiHed Coordinetes *£*
w (East-West, North-South)
Input H, the east-west distance
from the source and V. the s*un» 0 	
north-south distance from the
source.

Input H: QEast Qwest JIOQ

Input V; ©North O South [400

I OK I [ Cancel ] [


Evrtuttan
P*M
I
Y
.J


© Verde
O Miles
O Meters
O Kilometers
Help

                 Using re/otrVe (downwind and crosswind) coordinates
                 Choose this method when you wish to know the concentra-
                 tion expected at a position that can best be described in terms
                 of its downwind and crosswind distance from the spill source.
                 For example, suppose that you have estimated the straight-
                 line distance between the site of a spill and a nearby hospital
                 to be a quarter-mile. At the moment, the wind is not blowing
                 the chemical cloud directly towards  the  hospital, but the
                 wind is variable in direction.

                 You wish to know the concentration you could expect if the
                 wind were  to shift and carry the cloud of escaping chemical
                 directly towards the hospital. You can find this out by using
                 ALOHA to obtain a concentration graph for a location a
                 quarter-mile downwind, with a crosswind distance of 0 miles.
                                                                    6-11

-------
 Chapter 6: The Display Menu
 When you use relative coordinates, ALOHA will remember
 the location of the point that you have specified in terms of its
 downwind and crosswind distance to the source. Therefore,
 the geographic location of the point that you have specified to
 ALOHA will move when the wind direction changes.
                                                           IMPORTANT
If^R^R^^a^^^Rl Concentration and
Dose Locetion •
vs^&sssh
Specify the locetion el which you want to eueluate the |
concentration and dose over time.
.- Relative Coordinates
™ (Downwind, Crosswind)
_ FiMcd Coordinates
u (Eost-Ulest.North-South)
Input H, the downwind distance
from the source and V, the
perpendicular distance from the
downwind BHIS.
Input H, the downwind distance:
Input V, the crosswind distance :

(OK H f Cancel


Ev«lMtfen
PoM
\*™
X
~s



i°-25 i 2

|o | u

^^ J I









Vards
Hllei
mmwi •
Kilometers
]

                                                           Figue6-11.
                                                           Entering wind-relative
                                                           coordinates for a location
                                                           of concent
 In the Footprint window, double-dick on the location of
 concern
 You are not restricted to choosing a point within the foot-
 print.  ALOHA will display a concentration graph for the
 point that you have indicated.

 ALOHA will use relative (downwind and crosswind) coordi-
 nates to remember your site's position. Remember that the
 geographic location of the point that you have specified to
 ALOHA will move when the wind direction changes.
6-12

-------
                                                Chapter 6: The Display Menu
         figure 6-12.
 Footprint plot showing a
 selected concentration
 location. Thecros$-hair
 symbol marte the port
where concentration has
      been evaluated.
      0
     no
                     Dose
                     There is no general agreement among toxicologists about the
                     proper definition of the term "dose." ALOHA defines dose as
                     the concentration of pollutant to which people are exposed,
                     taken to a power, multiplied by the period of time that it is
                     present. The exact equation used in ALOHA is
        WARNING:
where C is the concentration computed by ALOHA, t is the
period of exposure, and n is the dose exponent. Toxicologists
adjust the exponent n to account for the differing toxic effects
of hazardous chemicals. When n is 1.0, dose is equivalent to
what many people call "exposure."

Dose information is difficult to interpret because the effects
of most toxic chemicals on people are poorly understood. If
you  don't know the appropriate dose exponent to use for a
particular chemical, or if you can't consult with  a specialist
who can advise you on the correct exponent to use and help
you  to interpret ALOHA's results,  avoid using ALOHA's
dose calculations.  Instead, use information from ALOHA's
footprint and concentration plots and your own knowledge
of a chemical to make response decisions.
                                                                        6-13

-------
 Chapter 6: The Display Menu
 Using the dose exponent
 You can adjust ALOHA's dose exponent, n, by choosing
 Computational from the SetUpmenu. ALOHA will calculate
 dose by multiplying concentration, taken to the n-th power,
 by the exposure time. For example, if you set n to 1.0 and the
 concentration is predicted to remain at a constant 100 ppm for
 5 min at a particular location, ALOHA will predict that people
 there will be exposed to a dose of 500 ppm-min. If you change
 the exponent to 2.0, ALOHA will calculate dose as concentra-
 tion squared and multiplied by exposure time.  For the ex-
 ample above, ALOHA would predict dose to be 50,000 ppm2-
 min. (Note that the units of dose change when the exponent
 changes.)

 Obtaining a dose graph
 Once ALOHA has made concentration calculations for a loca-
 tion that you have specified, you may choose Dose from the
 Display menu  to see a Dose vs. Time graph for the same
 location. This graph will display indoor and outdoor dose
 predicted for the first hour after a release begins.  On the
 graph,  outdoor dose  is shown as a solid (red on a  color
 monitor) curve, and indoor dose as a dashed (blue on a color
 monitor) curve. In the Text Summary window, you'll see
 values for maximum indoor and outdoor dose at the end of
 ALOHA's one-hour scenario representation.
6-14

-------
                                                  Chapter 6: The Display Menu
          Fig ue 6-13.
 Dose and concentration
vs. time graphs for a time-
     dependent release.
                     Dote Window
  •0,000

e 40,000

  40,000-

I 20.000

     P
                        I
                                           20             40
                                                 •InuU*
                                                                      6O
                                         Concentration Window
                                           20             40
                                                 •irutM
                      Source Strength
                      You may choose Source Strength from the Display menu to
                      get an idea of how rapidly (or slowly) a spilled chemical is
                      escaping into the atmosphere. When you choose this menu
                      item, ALOHA will display a graph showing the rate of release
                      of your chemical (the "source strength") predicted for the
                      first hour after a spill begins.

                      ALOHA produces two main types of source strength  esti-
                      mates, depending on the type of release that you have chosen.
                      Source strength graphs for the two types of estimates differ in
                      appearance.
                                                                          6-15

-------
 Chapter 6: The Display Menu
 Release rate for a Direct source, whether it's instantaneous or
 continuous, will remain constant for the duration of the re-
 lease. ALOHA expects an instantaneous release to last for 1
 minute, and a continuous release to last for one hour. Graphs
 of either type of Direct release look like the plot shown below.
GBBBH^^Bi Sourte Strength (Meat e Rott) •O^MESBEl

1"
I*
i:






0 20 40 U
^






-------
                           Chapter 6: The Display Menu
 Source strength averaging
 ALOHA calculates source strength as a series of up to 150
 steps. These values must be averaged into fewer steps so that
 dispersion and concentration calculations can be made rap-
 idly. The averaged source strengths form a series of up to five
 steps, each of at  least one minute duration.  The highest
 release rate from each of the two series is reported on the Text
 Summary window.  The highest release rate from the first
 series is the maximum computed release rate.  The highest
 release rate from the averaged series is the maximum aver-
 aged release rate.  The series of averaged steps is shown on
 the Source Strength graph, since this is the information used
 to calculate the footprint.

 Calculate
 You can choose how often you would like the data in the
 windows  in ALOHA updated.  This is necessary because
 some of ALOHA's calculations, such as those for heavy gas,
 may take a few minutes. You have three options for deciding
 when to update ALOHA output windows:

 O  Automatically update all visible windows
 O  Automatically update only front window
 G  Manual update of all visible windows

 In all cases, ALOHA will not update any windows until new
data are available.  The first two options are self-explanatory;
 the last option means no window will be updated until you
select Calculate Now from the Display menu.  All visible
windows will then be updated.
                                                  6-17

-------
 Chapter 6: The Display Menu
   ToMkeanttple  Choose
   dangesbeforc    "Manual
                update of all
                visible
                windows*
            AlOHA wffi oriy Bpdae ifc windows wfeayoi
            Otherwise, dl risiNe viriois viD be piyed-0*
            to mind yon that their dtt be Mt jet ben
   TokaveyoBrdata  Choose       Wbeanreryon add data, iD of Ac windows wiB
                •Automatically  be updated to reflect your additions.  However,
                update afl     a^r data you ire receniif fro« the SAM static*
                visible       during d* update wffl be lost
                windows"
Choose       All of Ae other windows win be grayed-out, bat
"Automatically  yonondldkoaooeoftbebackwindotslo
update only     bringitibrvrdlobercalcniated(youcaaoair
front window"   choose (be nndowfrtwi (he Display
   To tare only
   ALOHA'S BOS
   •pdateiL
 Figure 6-16.
 Calculate options.
 Calculate Now
 You can only select Calculate
 Now if you've done two things:
 1) chosen Manual update  of
 all visible windows in the Cal-
 culate Options dialog box, and
 2) changed some of your infor-
 mation under the Setup menu.
 The windows remain grayed-
 out, indicating that they do not
 reflect current conditions.
 When you choose  Calculate
 Now, the output will  be recal-
 culated and the visible win-
 dows will be updated.
                    Display
                     Tile Windows
                     Stock Windows
                     Options...
                     TeHt Summary
                     Footprint
                     Concentration...
                     Dose
                     Source Strength
                     Calculate...
                     Calculate Now
Figure 6-17.
Calculate Now option.
6-18

-------
                    Chapter 7
                    The Sharing Menu
In this chapter...

Sharing Info in Windows
   BUPloi	7-1
   MARPLOT-DOS ...7-3

Sharing Info on the Mac
   MARPLOT	7-3
Introduction
ALOHA can communicate and share information with other
programs. Both in Windows and on a Macintosh, ALOHA can
share information with mapping applications so that a cur-
rent ALOHA footprint can be plotted on a map.


Sharing Information in Windows
When you're running ALOHA in Windows, you can choose
between two applications to plot an ALOHA footprint on an
electronic map of your city or community. ALOHA can share
information with two mapping programs, BitPlot and
MARPLOT-DOS. The program you choose depends  on the
type of map that you have.
                    BitPlot
                    BitPlot  is a Windows application that is installed in your
                    ALOHA directory when you install ALOHA.  It uses maps
                    which are in the Windows device-independent bitmap (.bmp)
                    format.  If BitPlot is present in your ALOHA directory, ALOHA
                    will display a Sharing menu for BitPlot
                                                                  7-1

-------
 Chapter 7: The Sharing Menu
                         Sharing
                          BitPlot
Go to map
                  Figure 7-1.
                  ALOHA Windows
                  Sharing menu.
 Select Go to Map from this menu to launch BitPlot or to bring
 it forward if it is already running. A step-by-step example
 describing  how to use ALOHA and  BitPlot together is in-
 cluded as Example 5 in Appendix A. Refer to the appendix
 describing BitPlot in this manual, or to BitPlot's on-line help
 topics, for additional information.
                                                            Figure 7-2.
                                                            An ALOHA footprint
                                                            plotted on a map in
                                                            BitPlot.
7-2

-------
                           Chapter 7: The Sharing Menu
MARPLOT-DOS
MARPLOT-DOS is the mapping module of the CAMEO-DOS
package.   To see your ALOHA footprint on a MARPLOT
map, you must run ALOHA and MARPLOT simultaneously
in Windows.  See your  MARPLOT documentation for addi-
tional information.

MARPLOT was designed to use special maps generated from
TIGER (Topologically Integrated Geographic  Encoding and
Referencing) files, prepared by the U.S. Census Bureau.  TI-
GER files are computer-readable geographic data bases for all
U.S. states, territories, and possessions. They include digital
descriptions of features such as political boundaries, water
bodies, transportation routes, and address ranges for street
segments.  MARPLOT-readable maps incorporating this TI-
GER information are available from the National Safety Coun-
cil  (1-800-621-7619,  extension 6900) and other sources.
MARPLOT cannot directly read TIGER files; however, you
may use MARPLOT to generate maps from TIGER files.


Sharing Information  on a Macintosh
When you're running ALOHA on a Macintosh, you can use
MARPLOT-Macintosh to plot an ALOHA footprint on an
electronic map of your city or community.
The Sharing menu
The programs that comprise the CAMEO package for the
Macintosh work together by means of the Sharing menu.
Any program that can communicate with ALOHA may install
a hierarchical  menu under ALOHA's Sharing menu. In the
example below, MARPLOT has installed a menu in ALOHA's
Sharing menu. In return, ALOHA installs a menu under the
Sharing menu in MARPLOT.
                                               7-3

-------
 Chapter 7; The Sharing Menu
 These menus will appear every time the two applications are
 run simultaneously. A menu installed by another application
 into the ALOHA Sharing menu belongs to the installing
 application.  Refer to the documentation from that program
 for a description of how those menu items operate.
               Sharing
                fiboutShared Menus
                Save Shared Menus...
                MRRPLOT
Go To Map I
                Figure 7-3.
                ALOHA's Sharing menu.
                inducing a menu installed
                bytheappScation
                'MARPLOT.
 Before you quit ALOHA, you may wish to save the menus that
 other applications have placed under ALOHA's Sharing
 menu. Do this by choosing Save Shared Men us and selecting
 those menus which you wish to be saved. These menus will
 automatically be placed under the Sharing menu the next
 time ALOHA is run. When you use a saved menu that belongs
 to an application that isn't currently running, ALOHA starts
 that application so that it can carry out the specified action.
 MARPLOT-Macintosh
 On a Macintosh, ALOHA relies on MARPLOT-Macintosh, the
 mapping module of the CAMEO-Macintosh package, to dis-
 play a footprint generated by ALOHA on a map. You must be
 using either MultiFinder in System 6 or System 7 to use
 MARPLOT with ALOHA. Like MARPLOT-DOS, it uses spe-
 cial maps generated from TIGER files. MARPLOT-Macintosh
 cannot  read TIGER files directly, and cannot be used to
 generate maps from TIGER files. Obtain MARPLOT-readable
 maps generated from TIGER files from the National Safety
 Council. MARPLOT also can use standard Macintosh PICT
 format files as background maps.
7-4

-------
                                              Chapter 7: The Sharing Menu
         figure 7-4.
  ALOHA menu items
installed n MARPLOTS
      Sharing menu.
                    In order to plot an ALOHA footprint on a background map,
                    you'll need to run ALOHA and MARPLOT simultaneously.
                    ALOHA will install a menu in MARPLOT'S Sharing menu
                    which will allow you to display an ALOHA footprint on a
                    MARPLOT map.  Choose from among the following items
                    contained in the MARPLOT menu:
flbout Shared Menus...
Saue Shared Menus...
                                            Set Source Point
                                            Set Cone 0- Dose Point
                                            Delete HLOHR Objects
                                            Go To RLOHH
                   Help...
                   Choose this item to see a help text describing ALOHA's menu
                   items in MARPLOT. When you're finished, click Cancel to be
                   returned to MARPLOT.

                   Set Source Point
                   Before choosing this item, click on the location of the spill on
                   your MARPLOT map.  Then choose Set Source Point to tell
                   ALOHA the source location. ALOHA will place a symbol at
                   that location. The footprint, confidence lines/ and concentra-
                   tion/dose  point will automatically be placed on  the map
                   when the necessary information is available in ALOHA.

                   Set Cone & Dose Point
                   Before choosing this item, click the location on your MARPLOT
                   map for which you'd like to see concentration and/or dose
                                                                   7-5

-------
 Chapter 7: The Sharing Menu
 information.  Then choose Set Cone & Dose Point to tell
 ALOHA the concentration/dose location. ALOHA will place
 a symbol at that location, then come forward to make concen-
 tration calculations and display the results.
 Delete ALOHA objects
 Choose this item to remove all objects placed on the map by
 ALOHA. ALOHA will then stop updating the map every time
 it generates new information.

 Go to ALOHA
 Choose this item to bring ALOHA forward.

 A step-by-step example describing how to use ALOHA and
 MARPLOT together is included in Appendix  A.  See your
 MARPLOT documentation, and  MARPLOT'S  on-line help
 topics for additional information.
ALOHA wi use fixed
(east-wast, north-south)
coorrfnates to remember
the point's position.
7-6

-------
Appendix A
 Examples
...a tank source

...direct input (heavy gas)

...a pipe source

...ALOHA, MARPLOT, and a PICT map

...BitPlot and ALOHA

...ALOHA and a MARPLOT map
Note:

Here are six examples which are designed to help you understand
ALOHA for both the Macintosh and Windows platforms. You may
get slightly different answers if you use a computer without a
coprocessor.

-------

-------
Example I
A Tank  Source
In a small industrial park outside of Baton Rouge, Louisiana, a 500-
gallon, four-foot diameter vertical tank contains liquid benzene.  On
August 20,1990 at 10:30 pm local time, a security guard discovers that
liquid is leaking out of the tank through a six-inch circular hole that is
10 inches from the bottom of the tank. He also notices that the liquid
appears to be flowing into a grassy field west of the industrial park.
The security guard trunks the tank had just been rilled that evening.

The on-scene weather is partly cloudy, 80°F, jvith wind from the east at
7 knots. There is more than 50% cloud cover and the humidity is
greater than 75%. There is no inversion.

The local emergency planning committee (LEPC) has indicated that the
level of concern (LOG) for this product is 10 ppm.  Using this scenario,
we'll determine the downwind distance to this LOG.
first...
      Double-click on ALOHA and, after reading the ALOHA caveats,
      click OK
Date!
> Time...
      Choose Location from the SiteData menu.
                            A-l-1

-------
       BflKEHSFIELD, CHLIFORNIN
       BRLTIMORE. MRHVLRND
       BRftNWEU. SOUTH CRROLINM
       BflRnOUl, CRLIFORNIH
       BATRUIR. ILLINOIS
       BRTRUIR, NCUI VOMC
                                                  ( tmncml
                                                    Modify
                                                  t  ••»  I
       Use the scroll bar or type the character "B" to find the city. Once
       you have located Baton Rouge, Louisiana, double-click on it or
       dick once and click Select
Second...  -

For this case, we will not enter information about the building type
because buildings are not described in the scenario.
I
       Choose Date & Time... from the SiteData menu.
      Select Set constant time and enter the month, day, year, hour
      and minute for this scenario. You may tab to each of the fields
      to enter the date.  Remember, the hour must be entered as a
      military time.
                               A-l-2

-------
                       Pete and Time Options
         You can either use the computer's Internet clock for the
         model's date end time or set e constant date end time.
             O Use Internal clock   © Set constant time
         Input constant date and time
            Month   Dey     Veer
                   |2D    | 11990
            (1-12)   (1-31)  (1900-...)
Minute
 tt-59)
                              Cancel   ]   [    Help   ]
3      Click OK.
      The next menu for data input is the SetUp menu.
Third...
I      Select Chemical... from the SetUp menu.
                         SetUp
                          Chemical...
                          Btmospheric
                          Souix P
                          Computational.

      Use the scroll bar or type the character "B" to find the chemical.
      Once you have found benzene, either double-click on the
      chemical or select the chemical and dick Select.
                              A-l-3

-------
                          I Cfttinlct.1 Information 1
      bENZRLDEHYDE
       liNZENE, MCHLOROMETHVU-4-NITRO-
       IENZENE PHOSPHORUS OICHLOHIDC
       IENZENE PHOSPHORUS THIODICHLORIDE
       IENZENE SULFONVL CHLORIDE
       ICN20NI1RILE
       IENZOTRI CHLORIDE
       BENZOVL CHLORIDE
       DCNZVl HLCOHM.
       BENZVL RHOMIDE
       BENZn CHLMIK
       BENZVLIDENE CHLORIDE
       BITOSCRNATE
       IORNCOL
       BORON TBIBROMIDE
       BORON TRICHLORIDE
       BORON IRIfLUORIDE	
[ Modify
Fourth...
       Select User Input., from the Atmospheric submenu under the
       SetUp menu.
| Chemical... I
HlmospheiK ^ User Input...
Source »| SAM Station ... |

Computational...

       Click the button for stability class E because the spill occurs at
       night, the winds are between 4 and 7 knots, and the cloud cover
       is greater than 50%. To help you make this choice, click Help
       and look at the table.  Nothing in the scenario indicates the
       presence of an inversion, therefore, the default setting, No
       Inversion, should not be changed.
                                A-l-4

-------
	] atmospheric Optlont	
Stability Clati It:  OR  OB  OC  O>  ®E  OF
Inuorslon Height Dplloni ere:   |    Help
                    Help   1
  ® No Inversion   O Inuenlon Present, Height Is:
Wind Optlont oro:
  Wind Speed Is: [7
  Wind Is from: fl
                                                  ®Feet
                                                  O Meters
Mr Tomperelure Is: [>0
Ground Roughness Is:
  ® Open Country
  O Urban or Forest
® Knots  OMPH  O Meters/Sec.
Entor degrees truo or tout (Lo. HE)
Degrees  ®F  QC  [  Help  J
                  c
      J
                  OK  O Input roughness(Zo):
                            Ota
                            ®em
                                   Cmtol
 After selecting the stability class, enter the wind speed and click
 the button next to knots. Enter either E or 90 for the wind
 direction.  Remember, the direction entered is the direction
 from which the wind is blowing. Enter 80 for the air
 temperature and select the units button for degrees F.
 Select the button for Open Country for the ground roughness
 because the leaking chemical is flowing into a nearby grassy
 field that is west of the industrial park. The wind direction is
 from the east and the general area that we would expect the
 benzene cloud to move is over the grassy field.  If the wind
 direction had been from the west, that Is blowing towards the
 industrial park, the Urban or Forest button should have been
 selected.
                          A-l-5

-------
                                     OR O«nt«r
                                           10-10)
        caiw
        Sttect NvmMIti:
                                 ft
          o
          llWt
               O    O
              medium
O  OR  ®«ntwralm
*•        10-100)
S     Click OK when you've filled in all of the data.
       The scenario describes the cloud cover as partly cloudy (greater
       than 50%) and not completely overcast, so click the button
       between complete cover and partly cloudy.
       Click the enter value button and enter 75 for the humidity.
8
dick OK.
      The information that you have entered into ALOHA will
      appear on the text summary screen. Remember that, for this
      scenario, we are not considering the infiltration rate into
      buildings so you should ignore the building exchange rate.
                              A-l-6

-------
                                TeHt Summary
   SITE MTR INFORHRTION:
     Location:  BATON ROUGE.  LOUISIRNA
     Building Rip Exchange*  Par Hour; 0.67 (Shaltarod slngl* *tarlod>
     Data ft TIM: Flxod at Rugust 20, 1900 t 2230 hours

   ocniCRL irrawRTiort:
     Chanieal NOM: BENZENE                   ttalocMlar Might: 7S.11 kg/to)
     TLW-TUH: O.lOppa                       IOLH: 3000.00 DOB
     Not*: Potential or confti-Md hu»an carclneowi.
     Footprint  Lawol of Cancom: 3000 ppo
     Boiling Point: 17*.IB*  f
     Uopor Pronur* at Roblont To^orati««: 0.13 ate
     Rofelont Satiratlon Cancan trot ion: 134,985 poo or 13.SB

   HTDOSFHEHIC imRnRTION:w
SI*
 Utl
o
 21
Fifth...


I       Select Tank... from the  Source submenu in the Setup menu.
                         Chemical...
                         Rtmosphflric
       Click Vertical Cylinder.
                          i Tonk size and Orientation
   Select tank  type and
   orlontatIon:
                            Uortleol Cyllnov
    Horlsontol Cyli
                                     Entor  tma at thr
                               diameter |H_
                               length    [5.32
                                                             O meters
                               iiolume   1500       |® gallont O en. feet


                                                    Help
[ Cancel ]
                                    A-l-7

-------
  Enter 500 gallons for the volume and 4 feet for the diameter of
  the tank. Be sure to select the correct buttons for the units.
  Once the volume and diameter are entered, the correct length is
  automatically calculated.
  Click OK.
  The scenario described the product stored in the tank as a
  liquid. Since we would expect benzene to be a liquid at ambient
  temperature (notice on the summary screen that it has a boiling
  point of 176.16T), we have no reason to suspect that the
  chemical is stored at a temperature other than ambient. Click
  Tank contains liquid and Chemical stored at ambient
  temperature.
              Chemical State and Temperature
   Enter the stele of the chemical:
     ® Tank contains liquid
     O Tank contains gas only
     O Unknown
[  Help
   Enter the temperature within the tank:      f~
     © Chemical stored et ambient temperature
   Help
     O Chemical stored et|J80      | degrees   © F Q C
                               [  Cancel  ]
dick OK.
                          A-l-8

-------

       The security guard thinks the tank was filled in the evening, so
       the most conservative estimate we can make is that the tank is
       100% full and contains 500 gallons of product  Either enter the
       liquid volume directly, 500, and select gallons for the units,
       enter 100% full by volume, or scroll the bar to the top for the
       liquid level.  After the liquid volume is entered, the mass of the
       liquid is automatically calculated.
      Enter tin mas* OR uolumo of the liquid
      The man mf liquid to:  11.82
                             ® 1ont(2.000 IBI)
                             O kilvgrauM
       Enter volume OR liquid level
                                 The liquid
                                 uolum* is: 1500
                                            ® galloni
                                          -] O cubic feet
                                          -JO Ht"r*
                                            O cubic meter*
                                [100  | % full by volume
                            {  Cancel   ]       (    Help    )
8
Click OK.
       Click Circular opening, enter 6 for the hole diameter, and select
       inches.
                                A-l-9

-------
 10    Click Hole.
Select the shape that best represents the shape of
the opening through which the pollutant Is OHlting

® Circular opening
Opening diameter:
1 Ivttlh
« ** »
O Rectengular epenlng
® inches
1 O centimeters
O meters
Is leak through a hole or short pipe/ualue?
© Mole O Short pipe/value
|"« 'l i
Cencel J [ Help ]
II
Click OK.
12    Enter 10 and select inches for the height that the bottom of the
       hole is from the bottom of the tank. ALOHA will automatically
       calculate the percent from the top of the tank.
             llq. !•*•!.
             OK
                       Height of the Tank Opening
                               The bottom of the leak is:
                                                   O cm* O m.
                               •bows in* bottom of ti» tenk
                                   	 911	
                               15.7
                              I % of the way to the top of
                              1 the lank
             J      I   Cence'   I       [    Help
13    Click OK.
                               A-l-10

-------
14    The product is flowing into a grassy field, but grass is not one of
      the choices.  For this scenario/ clicking Default for ground type
      is probably the best choice. You may wish to compare results
      using other ground types.

      "                  Puddle Parameter!
        Select ground type             [ Help ]
          ©Default  O Concrete  O Sandy    O Moist
        input ground temperature       [ Help ]
          © Use air temperature (select this If unknown)
          O Brbund temperature is [|BO    | deg.  ® F O
       Input maKimum puddle diameter  [ Help ]
          ® Unknown
          O Maximum diameter is |      | ® ft  O SJ<1« O meters
                    OK
[   Cancel   ]
15    The scenario does not give the ground temperature so the best
      choice is to click Use air temperature.

16    Because the product is flowing into a field, it is probably not
      contained by a dike. For input maximum puddle diameter,
      click Unknown.

17    Click OK.

      The source strength information that you have entered into
      ALOHA should appear on the Text Summary screen.  This
      screen contains a lot of information about the release.  For
      example,  you know that the release of vapor  into the
      atmosphere is estimated to last for approximately 33 minutes
      and the maximum amount of vapor released at any one time is
      estimated at 125 pounds/minute (maximum  computed release
      rate). In the case of the puddle, we would expect the maximum
                            A-M1

-------
        release rate to correspond to the time when the puddle surface

        is the greatest.
                            ' Text Summary
  SOURCE STMENOTH IHFOIVMT ION:
     Liquid look fro* tola In vortical cylindrical tank Mloetod
     Tar* DioMter: 4 f«*t                 Tank Langth: S.32 foot
     Tar* UolUM: 900 gal Ian*
     Internal T*»paratur«:  SO' F
     ChoBleal Haw in Tank:  I.S2 tan*        Tar* is 100* full
     Circular Opanlng OlOMlar: 6 Inch**
     Opanlng !• 10 Inch** froo tank bettoo    Soil Typo: Oafault
     Oround TOOB: oqual te aobiont          Max Puddlo OioBotar: Unknaan
     KalooM Duration: 33 Minutes
     Max Cooputed Naloasa Hate: 125 pounds/Bin
     (tax fWoraga Susteinad Ralaasa Hate: It4 pound*/• in
       
-------
Let's think about the release rate implications of our scenario and try
and determine where the model may not be accurately representing
what is actually occurring. We have a tank that has formed a puddle;
the puddle is undiked so it can grow quite large and thin. This would
lead to a large evaporation rate for a short period of time. What would
happen if the puddle were constrained by small depressions in the
grass?

The puddle would not be able to spread out as far because the liquid
flowing away from the tank would fill up the depressions in the grass.
The puddle would  then be smaller and deeper. This would make the
evaporation rate  lower and it would take much longer for the puddle
to completely evaporate.

The release rate calculated by ALOHA in our scenario assumes that the
puddle gets  large;  therefore,  ALOHA would  predict  the  most
                                       ' *   •
conservative (worst-case) downwind distance  to the level of concern
and, in  this instance, the  duration of the  release rate may be
underestimated.

                    Source Strength (Release Rate)
       200-
     : ISO-
     'S 100-
     I so-
                     10
                                 20
                               • InutM
30
If the terrain contains any features (e.g., ditch or ground depression)
that may constrain the puddle from spreading, we can try to estimate
the effective diked area and enter this as the maximum puddle area.
In this scenario, no other information was given.
                             A-I-13

-------
Seventh...
 I    Select Computational... from the SetUp menu.
                          Chemical...
                          Rtmosphieric   r
                          Source        fc
2    Click Let model decide (select this if you're unsure).
                      ComputotlOMol Proforonco*
Soloct spreading algorithm
model docldo.
® Lot modal dacldo
O U*e Gaussian disi
O U*c Heavy 6as dl
Define dose:
Dose - Jc(T)dT
• OK J



(select this If «nsura)
torsion only
iperslon only

( Help
n-|l.O ]
I Concol ]


1


1

     Click OK.
                              A-l-14

-------
Eighth...

I    Select Options... from the Display menu.
                          Tent Summary
                          Footprint
                          Concentration...
                          Dose
                          Source Strength
                          Calculate^.
                          Calculate Now
2    The scenario describes the level of concern as 10 ppm. Click the
     button for User specified concentration and  enter 10.   For the
     units, click the button for ppm.


3    Click Plot on grid and auto-scale to fit window.


4    Click the Output Units button for English units.
                            Display Options
  Select Leuel of Concern or Output Concentration:   [   Help ~]
        O IOLH Concentration
         i User specified cane, of |lfl(
® ppm
O milligrams/cubic meter
 Select Footprint Output Option:                   f
       ® Plot on grid and auto-scale to lit window.
       O Use user specified scale.
 Select Output Units:
       © English units
       O Metric units
      1   Help   ]
                                             Cancel
     dick OK.
                               A-l-15

-------
Ninth...
I    Select Footprint from the Display menu.
                         Tile windows
                         Stack Window*
                         Options.
                         Tent Summary
                         Fuutpiint
                        . Concentration...
                         Dose
                         Source Strength
                         Calculate...
                         Calculate Now
      Once you select Footprint, a bar graph should briefly appear on
      the screen.  The bar graph will indicate how much time the
      model needs to finish calculating the footprint.  It will also
      indicate which module is being used for the calculations. For
      this scenario, the Gaussian module was used.
                        Footprint Window
             750
                                   1,000   1,900   2,000
      Notice that ALOHA opted to use the Gaussian calculation even
      though the molecular weight  of benzene is  greater than air.
      This is one of the instances when the concentration of benzene
      in the air is not enough to make the air/benzene density much
      greater than that of pure air.  From the Text Summary screen,
                             A-l-16

-------
     we can see that the maximum concentration of benzene that
     could be in the air at 80°F is 134,995 ppm; or a maximum of
     13.5% of the air/benzene mixture directly above the puddle is
     benzene (ambient saturation concentration).
     After a few moments, the screen will display the footprint for
     the vapor cloud.  The solid line around  the footprint indicates
     the level of concern of 10 ppm.   The dashed lines reflect the
     uncertainty in the wind direction for the atmospheric stability
     class  E.   This means that  in a five-minute period,  we could
     expect the benzene cloud to rotate within the area drawn by the
     dashed lines or "uncertainty lines." The dashed lines represent
     a "certainty" level of 95%;  or, 19  out of 20  times the  footprint
     will be within these lines.

     A verbal summary of the footprint information should appear
     at the bottom of ALOHA's text summary screen.   For this
     scenario, the downwind maximum threat zone for the level of
     concern of 10 ppm is 1338 yards.
BSS^Si^SSB^^gS^^g Tent Summary __   .
SITE MTfl  IHFOVMTian:
   Leeetlen: BATON MUK, LOUISIMM
   Building Hlr Exchange* far Mew: 0.*7 {Sheltered single storied)
   Date I  TIM: Fixed at August 20, 1990 t 2230
                                    flolecular Height: Tt.ll kg/fcoel
                                    IOLH: MOO. 00 ape
Chealcal Haae: MMZENE
TLU-TUn: 0. 10 ppe
Not*; Potential or canflreed
Footprint Laval of Concern:  10
•ailing Paint: 176. IP' F
Uapor PTMAT* «t tablont
   lant Satwatlon Cancel (ration
                                  0.13 at*
                              134.409 ffrn or H.3I
Ulnd: 7 knots free E
Stability Clan: I
Relative. Hwidity: 751
Claud Cower: 7 tenths
INPUT OF OATn)
           Ha Inversion
          Air Teoperature.
          Ground UmijhmM
                                                  K>* f
                                                 : Opan cauntrv
SOUKE STWMTH IhTORmTIOH:
  Liquid look 1n» halt In vertical cylindrical ton* Mloctod
  Tank OloMtar: 4 faat                 Tank Length: 9.32 feet
  Tank Veluee: 900 gal lam
  Internal Teaperature: M* F
  Chaeleal HOB* In Tank: 1.B2 tan*        Tank l> 1001 full
  Circular Opening OloMler: 6 Inchea
  Opening I* 10 Incna* froe tnk bettaei    tell Type: Default
  Oravid Teep: equal  to oBblont          nox Puddle Olaaeter: Unknown
  Meleoae Duration: 33 elnule*  .
  Ita Ceeputed HelaaM Mete: 123 powd»/eln
  nan eyarag. Sustained Release Beta:  114 potndc/aln
     (averaged ever e alnute or aere)
  Total taeunt BoIeased: 3,073 pounds

FOOTPRINT INFOM1MTION:
  Dispersion ttodule:  Oausslen
  User saeeifled LOC: 10 ppa
  Itoc Threat Zone far LOC:  IS3
  flax Throat Zone far IDLH: 34
                              A-1-I7

-------

-------
                                                               1
                                                                                                              •j
                                                                                                              >V
                                                                                                             <
•      •

-------
n
 o

-------
Example 2
Direct Input  (Heavy Gas)
A paper mill located at a highly industrialized area in Columbia,
South Carolina stores large amounts of liquid chlorine.  On May 15,
1990 at 13:00, a reckless forklift operator breaks open a pipe. About 2,000
gallons of liquid chlorine are sprayed out in a fine mist and
immediately evaporate. The chlorine is normally stored at a
temperature of -30°F. The paper mill's single-storied office building is
located about 100 yards directly downwind of the accident. The
building has been recently landscaped with bushes and trees. Since the
weather for the past few days has been rather cool/ most people in the
building have kept their windows closed.

At the time of the spill, the sky was completely overcast, the air
temperature was 70° F and  the wind was from 360° at 10 knots. The
relative humidity was 67%. We will use ALOHA to help determine
the indoor concentrations of chlorine for the paper mill's office
building.

First..

I     Double-click on ALOHA and, after reading the ALOHA caveats,
      click OK
      Choose Location from the SiteData menu.
                       SiteData
                        Location...
                        Building Type.
                        Date Of Time.
                            A-2-1

-------
        Use the scroll bar or type the character "C" to find the city. Once
        you have found Columbia, South Carolina, either double-dick
        on the city or select the city and click Select.
      COLLEGE r«MC, MMVLftNO
      COLORADO SPRINGS, COLORADO
      COLOMBIA, MMVLMNO
      COLUMBIA, MISSOURI
      COLUMBIA, SOUTH CAROLINA
      COLUMBUS, OHIO
      CONCORD, CALIFORNIA
      CONCORD, MASSACHUSETTS
      :ONCORO, NEW HAMPSHIRE
      CON ROC, TEWS
      CONUIRV, NEW HAMPSHIRE
       OOPEASTOUIN, NEW V8MC
       ORflOPOLIS. PENNSYLVANIA
      CORNING, NEW YORK
      CORONA, CALIFORNIA
      CORPUS CHRISTI.TEKRS
      CORURLLIS, OREGON
      CBtSTON. IOUJA	
H«lp
Second...  -
 I      Choose Building Type-, from the StteData menu.
                                 A-2-2

-------
       The scenario describes the office building as being single-
       storied. Since the building has windows that open, we might
       suspect that the air exchange rate is not controlled and the
       choice of single-storied building would be most appropriate.
       Because the building is landscaped, you should
       select Sheltered surroundings.
                    Infiltration Building Parameters
            Select building type er enter aHchange parameter
                                               Help
 O Enclosed office building
 ® Single storied building
 O Double storied building
 O No. of air changes is ||     j par hour
                                                Help
Select building surroundings
  Sheltered surroundings (trees, bushes, etc.)
 O Unsheltered surroundings
                                           Cancel
       Click OK.
Third...
I      Choose Date & Time... from the SiteData menu.
                           MteUatd
                           Location...
                           Building Type...
                               A-2-3

-------
       Select Set constant time and enter the month, day, year, hour

       and minute for this scenario. You may tab to each of the fields
       to enter the date and time.
                        Date and Time Options
         You can either use the computer's internal clock for the
         model's date and time or set o constant date and time.

             O Use internal clock   (g> Set censtant time
          Input constant date and tlrne
            Month   Day     Veer
            15    I  |15    j 11990
            (1-12)   (1-31)  (1900-~.)
                            [   Cancel   ]   [    Help    J
       dick OK.
Fourth...
I      Select Chemical... from the Setup menu.
                         Setup
                          Chemical.
                          atmospheric
                          Source         >
                          Computational...
                               A-2-4

-------
       Use the scroll bar or type the character "C" to find the chemical.
       Once you have found chlorine, either double-dick on the
       chemical or select the chemical and dick Select.
       DRMPMENf
       CAMPHOR
       CRRBON BISULFIDE
       CRRBON OIOKIOE
       CRRBON MONOHIDE
       CARBON TETRABROMIOE
       CflRBON TETRHCHIORIDE
       CARBONVL FLUORIDE
       CRRBONVL SULFIDE
       CflRVONE
       CHLORINE
       CHLORINE DIOHIOE
       CHLORINE TRIFLUOftlOE
       CHLORMCPHOS
       CHLORORCETBLOEHVDE
       CHLOHORCmc RCID
       CHLOROBCETYl CHLORIDE
       CHLORQBNILINE	
              [ CMMBl
              [ Modify
                 Help
Fifth...

 I      Select User Input., from the Atmospheric submenu in the
       SetUp menu.
                    Chemical...       I
                                  a	
                    SOUK e         > |  SHM Station...
User Input.
                    Computational...
2      Determining the stability class for this scenario is relatively
       easy.
                                A-2-5

-------
 When the sky is completely overcast, the stability class is always
 D regardless of the wind speed and time of day.  Click Help if
 you need assistance in making this choice. Click the button for
 stability class D.
stability Clots I*:  Q«  O§ OC  •• Qt  QF  {  Help  ]
Inversion Might Options ire:   |    Mote   1    	
  9 No Inversion   O Inversion Present, Height Is: I        I _ .. .
                                        >        i o Meiers
Wind optlens ore:   1   Help  ]
  Wind Speed IK ho~
  VIM to from:
Mr Temperature Is: [w

Sround Roughness IK
  O even Country
  ©Urben or Forest
                             OMPN  OM*1«n/S«c.
                                    «r l«Ht (l.«. ESE)
                  if|
                                   C^c.1
 After selecting the stability class, enter the wind speed and select
 the units button for knots. Enter either N or 360 for the wind
 direction. The air temperature is 70 and the selected units
 should be degrees F.  Nothing in the scenario indicates the
 presence of an inversion, therefore, the default setting, No
 Inversion, should not be changed.
The button for Urban or Forest  should be selected for the
ground roughness as the spill is in a highly industrialized area,
mat is, an area that contains many buildings and obstacles.


dick OK when you've filled in all of the data.
                         A-2-6

-------
       The scenario describes the cloud cover as completely overcast,
       so dick the button under the complete cloud cover icon.
                          Cloud Cower end Humidity
                                     O   M OMtorvolu*  [I*
                                               (e-ini
                                     cloor
                                     ft
                                     O   M ® outer value  |M  ]%
                                     dry        (t-100)    	
                                       [  Concol  ]
       Select the enter value button and enter 67 for the humidity.
8
      dick OK.
       The information that you have entered into ALOHA should

       appear on the text summary screen.  Under the heading SITE

       DATA INFORMATION, you see the air exchange rate ALOHA

       will use in its calculations.
                              Tctit Summary
 SITE DATA InrOnTWTION:
    Location:  COLUnBIM, SOUTH CMAOUNA
    Building Air Exchanges Por Hour: 0.17 
    Date t TIM: Flxad at nay 19, 1990 I 1300 hour*
CHEniCflL INFOMinTIOH:
   ChMleal NOM:  CHLMIIC
   TLW-TUft: 0.90 PDB
   Pooiprlnt Lew* I of Bancarn; M ppa
   Boiling Point:  -29.25* F
   Uopor Prusvr*  at Aslant T«*pvatur«: or«at«p than I at*
   flabiant Saturation Coneantratlon: 1,000,000 ppn or 100. M
                                        Itolooular Ual^tt: 70.40 kg/loal
                                        IDLH: 30.00 pp*
 rnnosncRic ifFonrmTioN:(nAhunL INPUT OF DATA)
    Ulnd: 10 knot* fro* N
    Stability Class:  D
    Aalatlwa Hi^ldlty: B7*
    Cloud Cowar: 10 Unths
                                       No  Inversion Halght
                                       Air Toaporatura:  70* F
                                       Ground Aoughntcs: Urban or forest
                                  A-2-7

-------
Sixth...
I      Select Direct- from the Source submenu in the SetUp menu.
      The scenario describes the pipe breaking and spraying 2000  .
      gallons of chlorine instantly into the atmosphere. ALOHA
      assumes that an instantaneous release is one that occurs in 60
      seconds.  For this scenario, however, it would probably take a
      little more than 60 seconds for all of the product to be released
      into the atmosphere.  We can still use an instantaneous source
      since we do not have any more  information, but the model's
      estimates may be conservative as a result. Click the buttons for
      gallons and instantaneous source.
                        Uter Input Source
      Select source *trength unlti of men or MOlume:       [ Help ]
         O grant       O kilograms Opoimdi     Q teiu(2,000 ibi)
         O cubic meter*  Q liter*     O cubic feet   ® gallant
      Salact an Inctentanaou* or cantlnuau* taurca:        [  Help
         O Centlnuau* tauna        £ Inttantaneaiu taurca
Enter the amount af
pollutant ENTCRINfi 12000
fur KTMncpurBr.   •
      THE HTMOJrilERE:
                                  gallant
      Enter lourca height
      (0 If ground tevrcal:
                             ®feat
                             O mater*
                                          Cancal
      Enter 2000 for the amount of pollutant entering the
      atmosphere. Do not change the default of ground-level for
      source height.
                               A-2-8

-------
4     Click OK.

5     The chlorine was refrigerated at -30°F and stored as a liquid.
       The text summary screen indicates that the boiling point for
       chlorine is -29.25°F, so it is barely in the liquid stage.  Click
       Liquid and Chemical temperature.  Enter -30 for chemical
       temperature. Be sure to select the correct units.
                        llaluma Input Information
         ii tha chemical stored ai • got or liquid?
            O Sa«     fit liquid
         Entor tha tamperatura ot wMch the chamical it ttarad.
            O UrnWent Tamparotura    _____
® Chamlcal tamparatiira UJ-3
dagraai
                                                    Q C
                             cancai
      Kalp
6      Click OK.

7      An alert box warning you that the chemical may flash boil
       and/or result in two-phase flow will appear on the screen.  If
       you are unsure what this means, click Help. Otherwise, dick
       OK.
                               A-2-9

-------
       The source strength information that you have entered into
       ALOHA should appear on the Text Summary screen.  The Text
       Summary screen will also remind you that the chemical may
       flash boil and/or result in two-phase flow.
Seventh...
 i    Select Computational... from the SctUp menu.
                          Chemical...
                          Atmoipheric
                          Source
       The scenario describes the chlorine as being stored at very cold
       temperatures; the chlorine will behave as a heavy gas. Click Let
       Model Decide. ALOHA will be able to determine that the
       appropriate dispersion calculations will be for a heavy gas.
                       Computational Prafaranca«
           Salact spreading algorithm. If un*vn, tot
           modal tfacMa.
                ® Lai modal daclda (salad this If unrara)
                O U«a Gmsitan diiparvion only
                O Ui« Heavy Sat 4l«aar*la« anlg
                                                 Mala
                                    [  CiBtrt)
                              A-2-10

-------
      Do not change the default for Define dose. Don't use this
      option unless you have some technical expertise or guidance to
      do so.


      Qidc OK
Eighth...

\    Select Concentration from the Display menu.
                       Display
                       Tile Windows
                       Stack Windows
                       Options...
                       Tent Summary
                       Footprint
                       Concentration.
                       Dose
                       Source Strength
                       Calculate...
                       Calculate Now  X-
                            A-2-11

-------
  The scenario describes the paper mill's office building as being
  about 100 yards directly downwind of the spill. Enter the
  downwind distance of 100 yards and the crosswind distance of 0
  yards. Be sure to select the correct units.
                 Concentration end Dose Location I
    Specify the locetlon at which gen want te evelueto the
    concentration and o)e*e ever limn.
      _ Relative Coordinates
      v (DownwInd.CroiMvtod)
      _. FlKad Coordlnatat
      u tCesl-iDe*t.Nortli-Sauth)
    Input X, the downwind dlstence
    from the source end V, the
    perpeftdkuler dlctence free* tM
Input K, the downwind dlslence:  |IM
Input Y, the crosswlnd dlttence :  [fl]
          •K
                   Ceiwel
                                           O Miles
                                           O Meters
                                           O Kilometers
Help
Click OK.
  Once you have clicked OK, a bar graph should appear on the
  screen.  The bar graph will indicate how much time the model
  needs to finish calculating the graphs.  It will also indicate
  whether Gaussian or heavy gas calculations are being used. For
  this scenario, the heavy gas calculations were used and, if you
  are using a Mac Plus (or other Mac without a math
  coprocessor), it may take a few minutes for ALOHA to do the
  calculations.
                          A-2-12

-------
 After ALOHA has completed its calculations, the Concentration
 window will appear. The dotted line indicates the estimated
 concentrations inside the office building.  Hie solid line is the
 estimated concentration  outside of the office building (on a
 color monitor these will  appear blue and red/ respectively).
90,000

40,000

30,000

20,000'

U,000-

    o
                          • Inuta*
You can see from the concentration window that the chlorine
cloud passes by the office building within the first few minutes.
After that, the outdoor concentration drops back to zero. The
indoor concentration is very difficult to determine from this
graph; however, the Text Summary screen will display the
maximum  values.
                       A-2-13

-------
        Here is ALOHA's footprint for this scenario.
                                  T»Ht Summary
 SITE DATM INFOMwriON:
    Location:  COLUMBIA, SOUTH CPMLINH
    •wilding nlr EMhangas fur Hour: O.t7 {Shattered single storied)
    Date t T!M: Fixed «t Hay 15. 1990 I 1300 haw*
       nalacular Ual^it:
       IDLH: 30.00 pe*
CHEHICM. IHFOWMTIOn:
   Cheeical  Haea:  CHLOP.IIC
   TLU-TIM:  0.90 ppa
   Footprint Laval of Concern: 30 pp»
   •oiling Point:  -29.29* F
   Uapor Pressure  at Aaoient TMcerature:  greater  than  I ate
   tablent Saturation Concentration: 1,000,000 ppe or 100.04
                                                              70.90 kg/kM>l
 BTMOSPHEHIC INTOWVITIOH: 
        Ho Inversion Height
       nlr Toaparature: 70* F
       Ground IVxtghneii  Urban or
             Haiaht: 0
                                     and/or result In tee
 FOOTPRINT
    Nodal  nvri: Hoawu Oaf
    (tear spaelftad LOC: aquaI* IDLH (30 ppa)
    Max Throat ZanV for LOC: 9.8 allac
    Iteta:  Tha Haavu 6a» footprint \m an Initial »a-aa
      For  short ra I eases It Mg be on ovorestloatlon.
      •e sura to «hoek eoneantration Interaction at *
                          floa.
               elflc
                                                              •tit
 TIME DEPBCENT  IMFOntWTION:
   Concentration Estloates at the paint:
   Daamlnd:       100
   Off Cantorline: 0
   HOK Coneantratian:
      Outdoor: 42,100 ppa
      Indoor:  Tee ppa
   Itote:  Indoor graph Is shaan olth a dotted  Una.
2L
                                     A-2-14

-------
Example 3
A  Pipe  Source
At a rural road construction site near Portland, Oregon, a  heavy
equipment operator accidentally cuts open a methane pipe on
November 17,1990 at 1430. The pipe runs 1,000 feet to the emergency
shutoff valve but the valve has been left open. The inside diameter of
the smooth pipe is 8 inches. The methane in the pipe is at ambient
temperature and the pressure is 100 PSI.

The on-scene weather is completely overcast skies, with an air
temperature of 44°F and 78% relative humidity.  The wind is from the
SE at 15 knots.

Although methane is relatively non-toxic, the lower explosive limit
(LEL) is about 5% or 50000 ppm. We will use ALOHA to help
determine the downwind distance for the explosive atmospheric
concentration.

First...

I    Double-click on ALOHA and, after reading the ALOHA caveats,
    dick OK
    Choose Location from the SiteData menu.
                            A-3-1

-------
        Use the scroll bar or type the character "P" to find the city.  Once
        you have found Portland, Oregon, either double-click on the
        city or select the city and click Select.
       POCRHUO, IMW
       •OMONR, CttJFORNIH
       POMPftNQICRCK, FlORiDR
       •ONTIRC, MICMIfiRN
       PORT RRTHUR, TEMRS
       »ORT HURON. MICNISRN
       POHTLRND, MRINE
       PORTLAND, ORCfiWK
       PORTSMOUTH, NEW HRMFSHIRE
       PORTSMOUTH. VIMINIR
       PRESC01T. RRIZONR
       PRINCETON. NEW JERSEY
       ROUO. VfRN
       1UINCV, CRLIFtRNIR
       IJUINCt, ILLINOIS
       RflCINE. WISCONSIN
       RRNUfRV, NEW JERSEV
       HRLEI6H. NORTH CBBflUNH
Second...
I      Choose Date & Time... from the SiteData menu
                            SiteData
                             Location...
                             Building Type.
                             Date G Time...
       Select Set constant time and enter the month, day, year, hour
       and minute for this scenario.  You may tab to each of the fields
       to enter the date. Don't forget to enter the hour as a military
       time.
                                 A-3-2

-------
                        Bate and Time Options
         You can either use the computer's Internal clock for the
         model's date and time or set a constant date and time.

             O U*e Internal clock    ® Set constant time
          Input constant date and time
            Month    Peg     Vear
            11   I  |I7   |  11990
            (1-J2)    (1-31) (1900-..)
(0-59)
                           [  Cancel   )   [    Help    ]
3    dick OK.
Third...
I     Select Chemical... from the SetUp menu.
                          Atmospheric
                          Source
                          Computational.
      Use the scroll bar or type the character "M" to find the chemical.

      Once you have found methane, either double-click on the

      chemical or select the chemical and click Select.
                              A-3-3

-------
                        Chemical Information
  fHETHRNE
  HETHHNESULFONVL FLUORIDE
  HETHVL ftCETRTE
  HETHVLACETVLENE-PROPflO IENE
  HETHVL RCRVLflTE
  HCTHVLflL
  HETHVL HLCOHOL
  HETHVL flLLVL CHLORIDE
  HETHVLflMINE
  HETHVLAMVl HCETftTE
  HETHVL HMVL KETONE
  HETHVLflNILINE
  HETHVL BROMIDE
  3-METHYL-t-BUTCNE
  METHVL BUTYL ETHER
  HETHVL BUTYL KETONE
  HETHVL CHLORIDE
  HETHVL CHLOROFORMRTE	
  Cancal  J
[ Modify, )
Fourth...
       Select User Input., from the Atmospheric submenu in the
       SetUp menu.
                   Chemical...
                             n	
                   SounIP         >[  SBM Station...
                   Computational.
      Click the button for stability class D because the sky is
      completely overcast. Remember, stability class D is always
      selected if the sky is completely overcast regardless of the wind
      speed and the time of day. Since the scenario does not mention
      anything about an inversion, the default setting, No Inversion,
      should not be changed.
                              A-3-4

-------
                       HTMOSPHERIC OPTIONS
Stability Class Is:  Q«  OB  QC
Inuersion Height Options are:    [
                                            OF   [  Help  ]
  ® No Inuarslon   O Inuersion Present, Height Is:
Wind Options are:
                                                         ®Feet
                                                         O Meters
                      Help
      J
  UJInd Speed Is: [|is      | ® Knots  O MPH  O Meters/Sac.
  Ullnd Is from:  |$E      | Enter degrees true or tent (I.e. ESE)
RlrTemperature Is: [44  ~|Degrees  ® F  Q C
                                                Help
Ground Roughness is:   [ __ Help   ]
  ® Open Country                                 r—
                     OB  O Input rougltness(Za):   3.
                                                 '
  O Urban or Forest
                                                         ®cm
         L
                OK
3
C
Cancel
J
     After selecting the stability class, enter the wind speed and select
     knots. Enter SE for the wind direction. Don't forget that the
     wind direction is entered as the direction from which the wind
     is blowing.  Enter 44 for the air temperature.  Be sure to select
     the correct units (Degrees F).

     Click Open Country because the spill occurs at a rural road
     construction site. Since the scenario does not describe the
     location of the accident in great detail, it may be a good idea to
     run the model a second time with Urban or Forest selected as
     well.

     Click OK when you've filled in all of the data.
                             A-3-5

-------
6      Click the button for the complete cover and enter 78 for

       humidity.
    Salect Cloud Cower
    complete
    cover
pertly
cloudy
                         [  Help  J
O   OR  O enter value  |10
             10*10)
deer
    select Humidity:
                                     1*4
                                              f  Help  1
                                     O   OR  ® enter value
                                     dry          (0-100)
                                        [   Cencel  )
       Click OK.


       The information that you have entered into ALOHA should

       appear on the Text Summary screen. For this scenario, we are

       not considering the infiltration rate into buildings; you should

       ignore the building exchange rate as it will not be used.
  SITE OHTH  IHFOWWTiON:
    Location: PORTUWD,  OREGON
    •wilding ftlr Exchanges Per How: 1.M (Sheltered slngU storied)
    Dot* I TlM: Fixed at Nm»eeh»r  17,  f«W t 1430 hours
  ocnicM.
    Choefcal MOM: ICTHNNE                  Hoiceular Italght: 16.04 kg/tool
    TLU-TUft: -vwwail-                     IDLH: -unava)!-
    Footprint L*v*t of Coneorn: N*o4* to bo Ml bofar* footprint Mloctlon
    •oiling Point: -2SS.M* F
    Uapor rfa*Mra «t Hoblont To^oraturo: groator than 1 ate
    tablant Saturation Concentration: 1,000.000 ppa «r 100.01
 ATMOSPHERIC ll«70HnnTION:(nM««L  INPUT OF OMTM)
    Ulnd:  13 hnoto fro* SE
    Stability Clan: 0
    Meletlu* HuBldlty: 7M
    Cloud Cower:  K>
                   No Inversion Height
                   Mir Temperature: 44* F
                                   Op Ml CM*lt
                                  A-3-6

-------
Fifth...                   '  •

I      Select Pipe... from the Source submenu in the SetUp menu.
                     Chemical
                     Atmospheric
       Enter 8 for the pipe diameter and select for units, inches.  Enter
       1000 for the pipe length, selecting feet for units.
                             Pipe Input
Input pipe diameter
  Diameter is  8
                                            [  Help  ]
                              | ® Inches  Qcm
           Input pipe length
                                 [  Help  ]
  Pipe length Is [tooo   [ ® ft  O yds  O meters
           The unbroken end of the pipe is       [  Help  ]
               connected to Infinite tank source
              O closed off
           Select pipe roughness
             ® smooth Pipe
             O Rough Pipe
                                 [  Help  ]
                                         Cancel
      In the scenario, the pipe is connected to a safety valve but the
      valve has been left open.  This means that the pipe will
      continually release methane.  We do not know how much
      methane will be supplied to the pipe, but we do know that the
      pipe is supplied by a very large source, that is, this source is
      much larger than the amount of methane in 1,000 feet of pipe.
      Since the source is very large, we  can say the pipe is attached to
                              A-3-7

-------
       an infinite source.  The best choice for this scenario is to dick
       the button for connected to infinite tank source.
       If the safety valve for the pipe had been dosed, we would have
       then selected the button for closed off.

       The scenario described the inside of the pipe as being smooth,
       so you should dick Smooth Pipe.

       dick OK.
       Enter 100 for the pipe pressure and select for the units, PSI.
                     Pipe Pressure and Hole Size
      Input pipe pressure
        Pressure Is hoof
                                             I  "«'»  1
                                    psi  Q ««n  O P«
     Input pipe temperature
        ® Unknown (assume ambient)
        O Temperature Is [44
                                             [
            Hole size equals pipe diameter.
                                                Help  1
                                       (  Cancel  ]
       In this scenario, the temperature of the pipe is given as
       ambient, so click Unknown (assume ambient).
8
Click OK.
      The information that you have entered into ALOHA should
      appear on the Text Summary screen. Remember, for this
      scenario we are not considering the infiltration rate into
                              A-3-8


-------
        buildings; you should ignore the building exchange rate as it
        will not be used.
                               TeHt Summary
  SOURCE STRENGTH INFOWWIOM:
     Pip* DioMtw: • Inch**                 Pip* Length: 1000 f**t
     Pip* T*»p*r«itur-*:  44* F                 Pip* Pr**»: 100 lb*/M In
     Pip* Rougrnuc: wooth                  Hol« !*••*: SO.3 *q  in
     Uhbrokan and »f th* pip* Ic corvwcUd to on Inflnlt* MUTC* .
     M*lMB* Duration:  flLOHH  Halted th* dtntlon to 1 hour
     flax Co*put*d K*I*OM Hat*:  1,410 potnds/Bln
     NOK Rv*rag* Swtainwt M*!MM Rat*: 1,410 pounds/tin
       (aw*rao*d ow*r  a •inut* or Mr*)
     Total taomt ItalMMd: M,S60
S/xt/i...
 I       Select Computational... from the SetUp menu.
                              Chemical^.
                              Rtmotpheric    r
                              Source          p
                              Computational...
        Select Let model decide (select this if you're unsure).
                          Computational Pr*Ter*nc«t
             Select spreading algorithm. If un*ur>, 1st
             model decld*.
Help
                   ® Let model decide (select this If unsure)
                   O Use Goussion dlipervlon only
                   O Use Keeuy Ges dispersion only
                             Mar
                                                     IHelp
                                             Cancel   )
       Click OK.
                                   A-3-9

-------
 Seventh...
 I     Select Options-, from the Display menu.
                           Tent Summary
                           Footprint
                           Concentration „.
                           Oos*
                           Source Strength
                           Calculate...
                           Calculate Now
       The scenario describes the level of concern as 50000 ppm. Click
       User specified concentration and enter 50000. For the units,

       dick ppm.
    select level of Concern or Output Concentration:   [   Help   ]
          O lolH nal «p«tl«ble
          ® User specified cone, of [ 50000]
®ppm
O milligrams/cubic motor
    Select Footprint Output Option:                  f
         © Plot on grid end auto-scale to fit window.
         O I'M user specified scale.
    Select Output Unit*:
         ® English units
         O Metric units
      t   »»'P  1
                                           [ Cancel )
3      Select Plot on grid and auto-scale to fit window and English

       unite.


4      dick OK.
                                A-3-10

-------
Eighth...

I      Select Footprint from the Display menu.
                         Display
                          Tile Windows
                          Stack Windows
                          Options...
                          TeHt Summary
                          Footpnnt
                          Concentration...
                          Dose
                          Source Strength
                          Calculate...
                          Calculate Now
   Ei
The footprint that ALOHA gives us is too short to plot
(approximately 60 yards). This near the source, concentration
patchiness could be significant (see the Use Caution section of
Chapter 2, Introduction to Air Modeling).  When using this
information, we can see that the explosive threat is likely to be
on the order of one hundred yards.  We would also suspect that
the direction of cloud travel is fairly consistent since the wind
speed is 15 knots.  However, for this short a threat distance and
considering near-field patchiness, it is prudent to consider a
circular clanger zone in the one hundred-yard range (again, see
Chapter 2).

                  Footprint UHndoui
        Dispersion Nodule:  Gaussian
        User specified LOC: 50000 ppe
        flax Threat Zone for LOC:  57 yards
        Note: Footprint eas not drawn because
          effects of near-field patchiness Make pluee
          presentation unreliable for short distances.
                               A-3-11

-------

-------
 Example 4
 ...Using  ALOHA,  MARPLOT,
 and a  PICT map
 At 11:15 am on February 14,1992, the Seattle, Washington Police find
 several 12-quart plastic containers labeled "anhydrous hydrazine" in
 the middle of a vacant, concrete parking lot The lot is at the
 intersection of 5th Avenue South and South Donovan Street.  The
 police officers report that some of the product has been spilled, and
 that there is a strong odor directly downwind of the containers.   The
 fire department is then notified of a potential chemical spill.

 When the fire department arrives, they find one police officer
 complaining of eye and nose irritation.  Using a pair of binoculars, the
 Assistant Chief assesses the spill site.  The chief sees that a 40 square
 foot puddle has formed around the containers.  Three of the
 containers appear to be open and lying on their sides.

 The firefighters report the following on-scene weather observations:
 the air temperature is 45° F, the sky is almost completely covered with
 clouds, the winds are from the west at 15 mph and  the relative
 humidity is 70%.

 A representative from a state environmental agency suggests running
 the air model with a level of concern of 0.03 ppm.  Assuming that the
contents of three containers have spilled, what  is the extent of the
 footprint for this concentration? What area on a map does this
footprint cover?
                            A-4-1

-------
Fim...
      Before obtaining estimates of source strength and dispersion
      from ALOHA, you'll begin by preparing and loading a map of
      Seattle in MARPLOT.  You should find a folder titled "Seattle"
      in your MARPLOT folder. This contains a PICT file, rather
      than a MARPLOT map derived from TIGER data.  Be sure that
      this file is in a folder by itself. Then double-dick on the
      MARPLOT icon to launch the application.
      Choose New from the Pile menu.
                         Open.
                         Close
MO
XS
XUi
                         Sai'0 ft* PICT...
                         Poge Setup...
                         Print...     XP
                         Import...
                         Export,,.
                         Preferences-.
                         Quit
XO
      Choose Seattle and click Open,
            Open a PICT to use as the Base Map.
                   |Q Seattle^ \
        iHtheno
            0 Seattle
                             A-4-2
       [  Eject  ]
       [ Desktop ]
                                          [ Cancel 1

-------
 You'll need to indicate the position of two points on the map to
 MARPLOT, so that the program knows where on the earth the
 mapped area lies, and how large an area the map encompasses.
 You'll do this by choosing two points on the map scale bar, and
 telling MARPLOT the location of these two points.
 First, click on the zoom in tool ^—', from the row of four tools
 above the top right comer of the map.
               Set Latitude And Longitude
Click to zoom in.
Point 1:  lat: o.oooooo* N
long; 0.000000* ill    [
Point 2:  lot: o.oooooo* N
long; o.oooooo* uj    [
                        A-4-3

-------
       Click once within the map legend to zoom in.  Then click on

       L2lJ. You'll use this tool to position Point 1.  Your screen
       should now look like the one below.
                      Set Latitude Rntf Longitude
       Click to position Point 1.
      Point 1: lot: o.OOOOOO* N
                         long: 0.000000* U>
      Point 2: lot: 0.000000* N
                         long: o.oooooo* III
       Go to the scale bar of the map, and dick on the bar at the '0 feet'
       mark. You'll see the following dialog box. For Point 1, you'll
       enter the geographic coordinates of Seattle Click on the Use
       deg/min/sec button. Then enter Seattle's coordinates: 47° 21' N
       and 122° 12'W.  Click OK.

                     Set the lot/Long for Point 1
          Latitude: Oeg:(47 j Mln:[I^ Stc;|p.DO [  |  North  V]
                       _             ^
Longitude: Peg;] 122) Mln:{TI] Sec;|n.po |   {  Ulett  ^|

O Ploui degrees as decimal
® Use deg/min/sec
                                 { Help-. ) | Cancel
NOTE       To find the coordinates of Seattle or any other
             city in ALOHA's city library, go to ALOHA.
             choose Location from the SItePata menu, click
             on the city's name within the scrolling city list.
             then click on the Modify button to see
                              A-4-4

-------
              ALOHA'a values for the coordinate* of the
              city.
7     Now set the position of Point 2. Click on the map scale bar at
       the "2000 feet" mark.
                      Set latitude flnd Longitude
      Click to position Point 2.
                     \    \    \
                    Legend
                    SCALE I'• 1900*  ^^

                      FEET
              ARKS, ETC       — STREETS
          -J- HOSPITAL        — HUHVAVS

             SCHOOL          — FMSVAVS
             CHEMICAL FACLITIES — CffV LMriS
     I Point I; lot; 47.350000' N      long; 122.200000* III  [Beset
      Point 2; let; Q.OOQDOO* N       long; 0.000000* 0)    j
8
Click the Distance from Point 1 button.
             mould you like to specify the second point by
             giving its distance from point I or by gluing its
             latitude/longitude coordinates?
                         Distance from Point I
                    Latitude/Longitude Coordiantes
       Enter "2000" in the distance field, and choose 'feet' from the
       pop-up units menu.  Click OK
                               A-4-5

-------
                     Specify Pittance
         Point 2 it
            2000
                                   feet
              from Point I.
1 0
I I
 Your screen should look like the one below.  Note the vD and
 Ve) marking the locations of Points 1 and 2 on the map scale
 bar. If you need to reposition either point, dick on the
 corresponding Reset button,, or dick on the map again with
 either the l-=J (if you wish to reposition Point 1) or L-sU (if you
 wish to reposition Point 2) tool.
                 Set latitude flnd Longitude
Click to repetition Point I.
               \    \   \T
              Legend
              SCALE1-* taOO1
                ^^^M
                 FEET       	
    liiT PARKS, ETC       —— STREETS
    -(- HOSPITAL        — HDHVAVS
    ^ SCHOOC         -^ FREEVAVS
    S CHEMICAL FACLITHS —. CfTY LMfTS
                                                  Quick Scroll
                                                    [Cancel j
Point I: lot: 47.350000* N
Point 2: let: 47.349945* N
                                   long: 122.200000* III  jHeiet
                                   long: 122.191898* 111  I Retet
 Once you're satisfied, click OK. The Seattle map should appear
 in the MARPLOT window.
                          A-4-6

-------
   12   Now that you've loaded the Seattle map, you're ready to run
         ALOHA. Choose Go to ALOHA from the ALOHA submenu in
         MARPLOT'S Sharing menu. This will launch ALOHA and
         bring it forward.
              Shdimy
               Rbout Shared Menus...
                   Shared Menus...
               te» Info
               Unlink
              CRMEO
XI
                                   Help.
                                   Set Source Point
                                   Set Cone 9 Dose Point
                                   Delete HLOHR Objects
                                   Go To RLOHR
-  Second...
   I     After reading the ALOHA caveats, click OK
   2     Choose Location from the SiteData menu.
                           Building Type

Date l
> Time...
                              A-4-7

-------
        Use the scroll bar or quickly type the characters "SE" to find
        Seattle, Washington in the scrolling list. Once you have located
        Seattle, double-dick on it or dick once, then click Select
                            U»llm infwiMtlm I
        MNlfl FC. NCI* MEKICO
        MM* MONICA, CAUFMNII
        EANTH PAULA, CALIFORNIA
        EANTH ROSR, CALIFORNIA
        SAIK.T $TI MAAIC, HICHIiWD
        liUHNNRH, SCORCH
        ICHONMIE, NC0 f MK
        SCRFORD, DCLRIDHRE
              IIIHStllNf.IilN
        SHRUNK, OKLMMOMfl
        (HERMAN. TEKflS
        ttOUI FILLS, SOUTH MKITI
        iMimraoiN, NEW vine
        INOROMISH, WASHIN6TDN
        lOMERSUIORIH, NEW HHMPSNIAE
        EBMERUILLE, MASSACHUSCm
        (OUTH iENB. INDIANA
        tPRRKS. NEIIA8A	
Th/rd...

Well ignore Building Type during this scenario.

I      Choose Date & Time... from the SiteDaU menu.
                             Location...
                             Building Type
                                 A-4-8

-------
       Select Set constant time and enter the month, day, year, hour

       and minute for this scenario.
                        Date and Time Option*
         You can either use the computer's Internol clock for the
         model's date and time or set a constant date and time.
             O Use internal clock
' Set constant time
          Input constant date and time
            Month    Pay     Year
            Ib     |  ||4   I  \\992
            (1-12)    (1-31)  (I900-..J
          Minute
           (0-59)
                           [   Cancel  ~)    f
           Nelp
3      Click OK.
Fourth...
I     Select Chemical-, from the SetUp menu.
                         Setup
                          Chemical...
                          Htmospheric
                          Source
                          Computational.
                              A-4-9

-------
      Use the scroll bar or quickly type the characters "HY" to find
      "hydrazine, anhydrous." Double-click on this name or click
      once on it, then dick Select.
                          ChomlcBl Information,
      IVOROCNIORIC RCIO, HNHVDROUS
      IVOROCVRNIC RCIO, RNMVMWK
      1VDROFLUORIC RCID, RNHVDROUS
      IVDROiEN
      HYDROGEN RROMIDE
      MVOR06EN CNLORIDE
      KVOR06EN CVRNIDE
      MVOR06EN riWRIK
      MVOR06CN rCROKIQE
      MVOR06EN SELENIDE
      HVOROGEN SUIFIDC
      KVOROHVETHVLRCRVLRTC
      RON PENTRCRRBONYL
      SORMVLRCETRTE
      SORHVL R1COHOL
      SDBUTRNE
      JOBOTRNOi	
      Check the Text Summary window to review information about
      the properties and toxicology of hydrazine.  ALOHA alerts you
      that this chemical is a potential or confirmed human
      carcinogen.  Boiling point of hydrazine is well above air
      temperature, so it's a liquid.
                             Text Summary
SITE OATH IHFOftnflTIOI:
   Location:  SEATTLE, UftSHINGTON
   Building:  Shattered single »tori«j
   Dot* ft T)M: Flx«d at Fobrua-y 14,  IM2 t  HIS hour*
CHEniCM.
   ChMleal  MOM: HVDfWZtfC, (WHVDROUS
   TLV-TUn:  0.10 op*
   Note: Potential or eonfiraad
   Boiling Point: 236.30* F
         g  »oint: 34.77* F
Ho I ocular Malght: 32.04.kg/kMl
IDLH: BO.00 ppo
                               A-4-10

-------
fifth...
       Select User Input., from the Atmospheric submenu in the
       SetUp menu.
                   Chemical...
                            3H
                   Source        »|  SRM Station
      The wind speed is about 15 mph and it's almost completely
      cloudy. By clicking on the stability class Help button (in the
      upper right corner of this screen), you can see that the best
      choice for stability class is D. Click on the button for stability
      class D.
                         fltmotpherlc Op I Ion i
Stability Class Is : Q« OB OC ®0 Of OF f Help ]
Inversion Height Options on
® No Inversion O 'nut

s: [ Help ]
irslon Present, Height IK I 1 *? JT"t*
*••» "*"••*
Wind actions are: 1 lelp 1

Wind Speed Is: is
Ullnd Is from : tu

Mir Temperature Is: J4S

Ground Roughness Is: (
O Open country
® Urban or forest
O Knots ®MPH OMoters/Soc. ( Help ]
Enter degrees true or lent (e.g. £SEI
Oeqreos »F OC I Help ]

Help ]
O Input roughness (Zo); llOtt 1
i i (§) era
i OK i ( Cancel J
      There's no inversion, so the default setting, No inversion,
      should not be changed.
      Enter "15" as your value for wind speed, then click on the mph
      units button. Enter either "W" or "270" to indicate that the
      wind is from the west
                             A-4-11

-------
 5     Type in 45 as the air temperature, and dick F.
       This spill is in an urban, industrialized area, with many

       buildings and obstacles, dick on the Urban or forest button.
7     Once you've made these selections, dick OK.
                        Cloud Covtr mtf Humidity
          o    o
          mat
O     O
O  OR  9 «it«r mlii*  [70

«ri        tt-IM)
8     The sky is almost completely doudy. Type "9" in the cloud

      cover data field.
9     Relative humidity is 70%. Type "70" in the humidity data field.
10   Click OK.
                              A-4-12

-------
 I I    Check the Text Summary screen to be sure that you've entered
       these data correctly.
                             Tent Summary
  ATMOSPHERIC lhFORnflTIOM:ph froa •                   No liwwslon
    Stability dm: D                    fllr T««p«r-«tur«: 45
    talatliM HMldity: 7M                 Qround ROU^WWM
    Cloud Cow: 9 tvttlw
or f
Sixth...

The containers of hydrazine have leaked to form a pool of liquid on
the concrete parking lot. ALOHA's Puddle source option is therefore
the most appropriate one for this scenario.

I      Choose Puddle from the Source submenu in the SetUp menu.
2      Type "40" in the puddle area data field, and click the square feet
       units button.
                              A-4-13

-------
                      Puddle Input
  Puddle erea I«;J40     | square  feet O yerds O meters

  Select one and enter appropriate data
   ® Uolume of puddle
   O Bwerage depth of puddle
   O Mast of puddle
   Volume It: [9
® gallons    Q liter*
O cubic feet O cubic meters
                     [   Cancel   ]     f
                  Help
       J
Three 12-quart containers have leaked hydrazine. There are
four quarts in a gallon, so 9 gallons of hydrazine have spilled
into the puddle.  Click on the button for Volume of puddle,
then type "9" in the puddle volume data field. Click gallons,
then click OK.
The puddle has formed on a concrete parking lot, so click
Concrete.
           Soil Type, fllr end Ground Temperature
  Select ground type              [   Help   J
     O Default   ©Concrete  Q Sandy   Q Moist
  input ground temperature
            Help   ]
     <8> Use air temperature (select this If unknown)
     O Ground temperature is [45I  ® F   O C
  Input initiel puddle temperature   {_  Help   J
     © Use ground temperature (select this If unknown)
     O Use elr temperature        ^__^^
     O initial puddle temperature Is [45    I   ®F  QC
                              C
              el
J
                        A-4-14

-------
   No estimate of ground or puddle temperature is available, so

   leave both equal to air temperature, the default value. Click

   OK.
   Check the Text Summary screen to be sure that you've entered

   the source strength data correctly, and to review ALOHA's

   estimates of maximum and averaged release rates and other

   information about the release. ALOHA expects the release to

   last more than one hour, and predicts that 2.8 pounds of

   hydrazine will have evaporated during the first hour of the

   spill.
                        TeHl Summary
SOURCE STRENGTH IHFOIVfflTION:
  Pvrtdl* Broa: 40 *quan tot             Puddla UO!UM: 9 gallon*
  Sail Typ«: Concrat*                   Orcmd T**p«rotur«: 45* F
  initial Puddl* T«ap«ratur<: Ground t«*t>«rnUr«
  ft*l«oc« OtMtiof): ALOHA li»it«d th* A*-ation to t haw
  new C«^,ut«d Ralaan Mat*: 0.047 pounds/Bin
  (tax Bmrog« Suctairwd R*l«ara KdU: Q.0460 (KW>d«/»ln
     
-------
Seventh...
       Choose Source Strength... from the Display menu to view

       ALOHA's graph of source strength, or release rate, for the first
       hour of the spill. ALOHA does not expect evaporation rate to
       change during this hour. Trie model expects the puddle to be
       cooled as it evaporates, but wanned by its environment at the
       same time, so that its temperature (and hence its evaporation
       rate) remain unchanged.
                         Display
                         Tile Windows.
                         Stack lUindoiut
                         Options.
                         Tent Summary
                         Footprint
                         Concentration.
                         Dose
                         Souice Stiennth
                         Calculate...
                         [ulculale NBUI  X-
                     iourci Strength (R»l«tt«« »•!•> I
          0.09
        - o.oa

        •8 o.oa

        *o.ov
                                •InutM
                             A-4-16

-------
Eighth...

I      Choose Computational from the SetUp menu.
                            Chemical...
                            Atmospheric
                            Source
                            Computational.
       Check to be sure that Let model decide is selected (This is the
       default setting).  Click on this button if it is not selected, then
       dick OK
                        I Computational f references
            Select spreading algorithm. If unsure, let
            model decide.
                  ® let model decide (select this If unsure)
                  O Use Gaussian dispersion only
                  O Use Heavy 6es dispersion only
            Define dose:
                   Dose
4
                                   n •
                                          Cencel
                                A-4-17

-------
Ninth...
I      Select Options... from the Display menu.
                           Tile Windows
                           Stack Windows
                           Tent Summary
                           Footprint
                           Concentration...
                           Dose
                           Source Strength
                           Calculate...
                           Calculate Now  X*
       The state official suggested a level of concern of 0.03 ppm. Click

       User-specified cone, and enter "0.03." Click ppm.


       Check to ensure that Plot on grid and autoscale to fit window is

       selected.


       Click English units, then click OK.
      Select Level of Concern or Output Concentration:
           OIOLH Concentration
         Help
           ® llier specified cone, of [.03
<&»•<•
O mlNlgronuXcunlc moti
      Soloct Footprint output Option:
           QPIot on flritf end outo-»olo to fit window.
           O U«e uior (poclfiod tcnlo.
         Nolp
      Soioct Output unlit:
           Q English unite
           QMotrtcunltt
                               A-ft-18

-------
Tenth...
I     Choose Footprint from the Display menu.
                        Display
                        Tile Windows
                        Stack Windows
                        Options.
                        TeHl Summary
                        Footprint
                        Concentration...
                        Dose
                        Source Strength
                        Calculate...
                        Calculate Noui »
      ALOHA will display a diagram of the footprint for this
      hydrazine release. Check the Text Summary window to see the
      maximum downwind distance that the footprint may extend
      (the Maximum Threat Zone).  ALOHA expects the footprint to
      extend downwind for about 211 yards. Although the molecular
      weight of hydrazine is about 32 kg/kmol, and b heavier than
      that of air (which is about 29 kg/kmol), ALOHA chose the
      Gaussian dispersion model instead of the Heavy Gas model.
      That's because the model expects the hydrazine to evaporate so
      slowly that it does not form the dense blanket of gas typical of a
      heavy gas release.
                           A-4-19

-------
                          Tent Summary
             FOOTPRINT INFOWWTIOH:
               Dispersion nodul«: Gaussian
               U*«r «p«if)«d LOC: .03 ppv
               Now Ttv«at 2an* for LOC:  211
                fit lT!;
Eleventh...
      You're ready to use MARPLOT to plot this ALOHA footprint on
      the map of Seattle.  Select Go to Map from the MARPLOT
      submenu under ALOHA's  Sharing menu to bring MARPLOT
      forward.  The Seattle map should still be displayed in
      MARPLOT'S window.
      Click on the zoom in tool,
, in the tool palette to the left of
      the map, then click once in the middle of the map to zoom in
      so that you can read street names. Search near the middle of
      the map for the intersection of 5th Avenue South and South
      Donovan Street.
                             A-4-20

-------
      Once you've identified this intersection, choose
                                from the
      tool palette. Click once on the intersection.  MARPLOT will
      place a visible crosshair mark, or "click point" at this location.

Note       If you don't Bee a crosshair click point mark at
            the point where you clicked, choose
            "Preferences" from the File menu, make the
            click point Visible, then click OK.
                          Preferences
       -Scale Format
          O 1 in • N yd
          ® Window Distance
         -Uiew Let/Long Coordinates
            ® as a decimal
            O In deg/mln/sec
        CIIck Point
          Uisible
        O invisible
Units:   ards
Background Color  CD White
                           [Help... ]  [Cancel]
      Choose Set Source Point from the ALOHA submenu in

      MARPLOT'S Sharing menu. An ALOHA footprint should

      automatically appear on the MARPLOT map (this may take a
      few seconds).
            About Shared Menus..
            Sane Shored Menus...
            fret Info
            Unlink
      XI
                                Set Cone 0- Dose Point
                                Delete ALOHR Objects
                                Go To ALOHA
                            A-4-21

-------
 Choose the zoom in tool to zoom in more closely, if you like.
 The footprint should look like the one below.
Cl Ich H: 47.3M970*H  122. IM304*U 11230 x M3 gd | Tcp
 You can see from this footprint plot that ground-level
 concentrations of hydrazine may be high enough to be of
 concern for the area along S. Donovan Street between 5th and
 7th Avenues S. The confidence lines drawn on either side of
 the footprint delineate the area within which the cloud of
 hydrazine is 95% likely to remain, if the wind shifts it about
 during the release. You can see that hydrazine concentrations
 aren't predicted to reach your level of concern more than half a
 block north or south from Donovan Street.
Remember, though, that ALOHA was designed to give you
"ballpark" estimates of source strength and dispersion. It
cannot give you completely accurate predictions for a real
release, because no model can account for every uncertainty.
For example, if the wind shifted direction or changed speed, the
footprint might be longer or shorter, or oriented in a different
direction. Likewise, you had to guess the exact amount of
hydrazine in the puddle.  In real response situations, ALOHA
gives you a "best guess" rather man an exact answer.
                       A-4-22

-------
 Example 5
 ...Using BitPlot with  ALOHA
 in  Windows
The Seattle, Washington Fire Department responds to a freight train
derailment on August 25,1992 at 10:15 am.  The police dispatcher
reports that the derailment has occurred about 3 miles south of the
downtown area next to the intersection of 16th Ave. South and East
Marginal Way. When the firefighters arrive on-scene, they find
several tank cars off the tracks and on their sides. There is no fire, but
one tank car is damaged, and a large volume of fine mist and vapor
can be seen spraying out of a crack in the tank bottom. The entry team
members cannot get very dose to the tank, but they estimate that this
crack is about 36 inches long and 1 /2-inch wide.

The train's crew is unharmed and immediately hands the train's
consist to a police officer. From the consist, the entry team finds that
this tank car was carrying 19,789 gallons of liquid methyl chloride and
that the tank car capacity is 24,750 gallons.  They estimate the tank
diameter to be about 10 feet.

The firefighters report the following on-scene weather observations:
there are some high cirrus clouds visible and they estimate that the
coverage is about 20%. The winds are from the northeast at about 10
mph.  The humidity is about 50% and the air temperature is 75° F.

The fire chief notes that residential neighborhoods to the southwest of
the derailment are  in the path of the dispersing chemical cloud.  Most
of the homes are single-storied structures surrounded by shrubs and
trees.  The closest residence is about 600 yards downwind from the
derailment, at the intersection of Southern Street and 12th Ave. S.
                            A-5-1

-------
A toxicologist recommends 100 ppm as an appropriate level of
concern. What is the downwind distance to this concentration?  What
is the estimated maximum indoor concentration for the house closest
to the derailed rail car? What is the expected maximum outdoor
concentration at that point?


First...

I     Double-dick on ALOHA and, after reading the ALOHA caveats,
      dick OK
      Choose Location from the SiteData menu.
                         SiteData
                          Location.
                          fiuilding Type...
                          Hate £ Time.
      Use the scroll bar or quickly type the characters "SE" to find
      Seattle, Washington in the scrolling list.  Once you have located
      Seattle, double-click on it or click once and click Select.
                         Location Information
        SAN JOSE. CALIFORNIA
        SAN LUIS OBISPO. CALIFORNIA
        SAN PEDRO, CALIFORNIA
        SANDWICH. MASSACHUSETTS
        SANTA ANA, CALIFORNIA
        SANTA BARBARA. CALIFORNIA
        SANTA CLARA. CALIFORNIA
        SANTA FE. NEW MEXICO
        SANTA MONICA. CALIFORNIA
        SANTA PAULA. CALIFORNIA
        SANTA ROSA. CALIFORNIA
        SAULT STE MARIE. MICHIGAN
        SAVANNAH. GEORGIA
        SCHOHARIE. NEW YORK
        SEAFORD. DELAWARE
        >eAHLE, WASHINGTON
                              A-5-2

-------
Second...
 I      Choose Building Type-, from the SiteDaU menu.
       The residences are mostly single storied buildings, so click on
       the Single storied building button. Because the buildings are
       surrounded by trees and other buildings, you should select
       Sheltered surroundings. Click OK
                     Infiltration Building Parameters
            Select building type or enter exchange parameter
                                               __
              O Enclosed office building
              ® Single storied building
              O Double storied building
              O No. of air changes is |      | per ho
                      ur
            Select building surroundings
                  iHelp   I
              <§>{Sheltered surroundings [trees, bushes, etc.)!
              O Unsheltered surroundings
                    OK
J
Cancel   |
Third...
I      Choose Date & Time... from the SiteData menu.
                           Location...
                           Building Type...
                               A-5-3

-------
  2     Select Set constant time and enter the month, day, year, hour
        and minute for this scenario. Click OK.
                          Date and Time Options
         YM an either me the computer** internal deck for the

         Input e constant date end tine!
                               Yew
                    l»I  -EHl
                              Hotff
                            I"    I
                              0-Zfl
 Minute
l«
'     °*    •    '    <*"*    '
                                                Help    1
 Fourth...
~ I      Select Chemical-, from the SetUp menu.
                          SetUp
                           Chemical.
                          Atmospheric
                          Source
                           Computational...
       Use the scroll bar or quickly type the characters 'ME' to find
       methyl chloride. Double-dick on "METHYL CHLORIDE" or
       dick once on this name, then click Select.

-------
                         Chemical Information
       METHYL CHLOROFORMATE
       METHYL ACRYLATE
       METHYLAL
       METHYL ALCOHOL
       METHYL ALLYL CHLORIDE
       METHYLAMINE
       METHYLAMYL ACETATE
       METHYL AMYL KETONE
       METHYLANIUNE
       METHYL BROMIDE
       ^METHYL-1-BUTENE
       METHYL BUTYL ETHER
       METHYL BUTYL KETONE
       J
Modify  |.
     Check the Text Summary window to review information about

     the properties and toxicology of methyl chloride. ALOHA alerts

     you that this chemical is a potential or confirmed human

     carcinogen. Its boiling point is well below ambient air

     temperature; this indicates that the chemical was stored in the

     tank car as a pressurized liquid.
SHE »ATA IfFORHATlON:
  Location: SEATTLE.  MSNIMBTMI
  •uilding: Sheltered single storied
  Pate and Tine: Fixed at logest 2S. 1M2  itiS bows

CHEMICAL INFORMATION:
  Chenlcal Kane: ICTHVL CHLORIDE
  Molecular Height: Si.»9 kg/kMl
  TLU-TWA: :•.•• pp«          IDLH: IMM.M pea
  Note: Potential or confirmed NUMM carcinogen.
  Footprint Level of Concern: 1M ppn
  loiling ••lot: -11.ir F
  •apor Pressure at AMtient Tenperature: greater than 1 at*
  •noient Saturation Concentration: 1,•».••• ppn or 1M.A
                              A-5-5

-------
Fifth...

I      Select User Input., from the; Atmospheric submenu in the
       SetUp menu.
      The firefighters estimated the wind speed to be 10. mph, with
      about 20% of the sky obscured by clouds. By clicking on the
      stability class Help button (at the upper right comer of the
      screen), you can see that for this combination of strong solar-
      radiation and 10 mph winds, the best choice for stability class is
      B. Click on the button for stability class B.
                          Atmospheric Options
       stability cisss is: OA «*B Oc OD OE OF
       ImmralMi Height Options m:
 9 N0 Inversion O bveraion Present Height is : |
Wind Option* are : I   Help  I
 Wind Speed Is : |lQ     [Q Knots ® MPH O Meters/sec
 Wind Is from  : JNE     | Enter degrees true or text (e.g. ESE)
Air Temperature is : |?5    | Degrees ® F O C  I  Help '_J
Ground Roughness Is : I
                                                   I® Feet
                                                   JO Meter.
                                                      Help
             _
        or Forest!
                       OR O Input Roughness (Z.) : fTiuT"lS 1
                                             '       'W cm
                L
               OK
      There's no inversion, so ensure that the default setting, No
      inversion, is selected.
      Enter "10" as your value for wind speed, then click on the mph
      units button. Enter either 'NE' or '45' to indicate that the wind
      is from the northeast
                               A-5-6

-------
5      Type "75" as the air temperature, and click F.
6      This spill is in an urban, industrialized area, with many
       buildings and other obstacles. Click on the Urban or forest
       button.
7      Once you've made these selections, dick OK.
8      The sky is described as about 20%, or 2/10 cloudy. Type "2" in
       the cloud cover data field.
9      Relative humidity is 50%, so ensure that this button is selected
       (it's the default value).
                        Cloud Cove' arid Humidity
       Select Cloud Cover:                   -


          O    O    O    O    O OR ® entervalue:
       complete      parity        dew        (0-10)
       cover        cloudy
       Select Humidity:
O    O    ®    O
wet       medium
                                 O OR O enter value :  [50   |X
                                 dry       (0-100)    ' -
             OK
                                    I    C«ncel
10    Click OK.
                               A-5-7

-------
        Check the Text Summary screen to be sure that you've entered

        these data correctly. Under the heading, "Site Data

        Information,'' you can see the air exchange rate that ALOHA

        has calculated for the residences near the spill site.
      DATA 1HFBRHATION:
    UcatlM: SEOTTU. WUMIMTtN
    •vildinj Mr Exchanges r»r Mur: i.77 (SMlttretf siftglt storied)
    Date v* Tint: Tint* at Mgwt 25. IDfZ  1tl5 bows

  CHEMICAL IirMmTIMf:
    Cfce»lcal NM»: METHYL CW.MIK
    Molecular Wight: St.fcl kf/kHol
    TLV-TMH: M.M ffm          ItLN: IIHt.M ppa
    Note: Potential *r cvnflraed IMAM carelacf**.
    FMtprint L»wl •* cmc*rii: 1M pfm
    lolling Mint: -11.»r F
    Vapor Pressure at takient Tciperatiir*: freattr tkaa 1 at*
    Antient SatvratiM CMceatratiM: l.iN.Hl ••• «• 1M.«
  •TWSPRERIC
    Wind: ft «ph frra 1C
    stability Class: •
    Mclatiw* Miiaidity: 5
(MIMML INW if MM)
                •eight
                   75* F
     SrwiM Roughness: Mrba* or forest
S/xth...
       Select Tank,., from the Source submenu in the SctUp menu.
                     £henticai...
                     Atmospheric
2      Click Horizontal Cylinder.


3      The tank car is 10 ft in diameter and has a capacity of 24,750

       gallons.  Enter "10" for diameter, don't enter a value for length,

       then enter "24,750" for volume.   Click feet for diameter and

       gallons for volume. ALOHA will calculate and display the

       correct length automatically.  Click OK.
                                A-5-8

-------
  CaUct tank type
   0        )

                         Enter hn •flam vvtaM:
                            1«       |
                                    :  oiMt
                            Z47SI
J  •gXton*  O 01. feat
                                       I  Hrip   |
The methyl chloride is stored as a liquid.  The tank temperature
wasn't reported, so air temperature is the best guess.  Click the
buttons for Tank contains liquid and Chemical stored at
ambient temperature. Click CSC.
                Chemical State and Temperature
  Enter state of the chemical:
    9 Tank contains liquid
    O Tank contain* gas only
    O Unknown
            Help
  Enter the temperature within the link:
    ® Chemical stored at ambient temperature
    O Chemical stored at  [?S|      ~\ degrees

         'F  OC
After the heading The liquid volume is:, type in the responders'
estimate of the amount of methyl chloride in the tank car.
Click on the gallons button. Click OK.
                         A-5-9

-------
                        Liquid Mass or Volume
Enter me maes In the tank OR vefwne of the iiq«ld
The imeelnme tank le:  i75-1
J   •toMfZ.MOIh*)
    OUograiM
                               OR.
Enter Ifuld level OR velum*
volume to
                                         |ia.7ia|
Ocuhlcfed
Ollter.
O cubic meters
                               !»•••    I  XfuRbyvehjme
   Click Rectangular opening and enter "36" for the opening
   length and "1/2" for the opening width. Click inches.  "Hole"
   is the default leak type; ensure that this button is selected. Click
   OK.
                         Area and Type o! Leak
          S*l*c* «M m*»fm DM! b**t rapramite »• mhmfu •!
          *• •penlng thfongh which the pollutant !• edfji|
                                  9 RectMigulM ••ening
                                      e^ Inchce
          Opening
    J  OtMl
                                      O meter*
         Is leek through • hele er ehert
            • Hete               OShertelpeAralw
                             A-5-10

-------
     The hole is at the bottom of the tank car. This is the default
     setting, so just click OK.
                            ill Hit* Tint Gin
                              The •••DM ut »e ktafc to
                              [B	|  Om. •«. Don.  Om.
                                         .OR.
                                      X •( ftc my M Ike toy ml
                                             I   He»  I
     Check the Text Summary screen to be sure that you've entered

     the source strength data correctly, and to review ALOHA's

     estimates of maximum and averaged release rates and other

     information about the release.  ALOHA expects the release to

     last about 36 minutes. Because the methyl chloride was stored

     as a pressurized liquid, ALOHA expects it  to escape from the

     tank as a two-phase flow of aerosol (a fine mist of liquid

     droplets) and vapor.
                           Text Summary
SOURCE  STRENGTH INFORMATION;
  Liquid leak fro* hoi* in horizontal cylindrical tank selected
  Tank  Diameter: 19 feet      Tank Length: 42.1 feet
  Tank  Uolune: 24751 gallons
  Internal Temperature: 75* T
  Chenlcal Nass In Tank: 75.1 tens
  Tank  is OOX Full
  Opening Length: 36 inches    Opening Width: 1/2 inches
  Opening is 0 feet fron tank bettoa
  Release Duration: 36  Minutes
  Max Computed Release  Rate: 27.700 pounds/Bin
  Kax Outrage Sustained Release Rate: 13,600 pounds/Kin
    (averaged over a ninute or More)
  Total Amunt Released: 151,600 pounds
  Note: The release MS a two phase flow.
                             A-5-11

-------
Seventh...
      Choose Source Strength... from the Display menu to review
      ALOHA's graph of source strength/ or release rate, over the
      duration of the spill.
                    Display
                     Hie Window*
                     Stack Windows
                     Options...
                     Tegt Summary
                     footprint
                     Concentration...
                     Qose
                     Source Strength
                     Calculate...
                     Calculate
    Ctrl+M
      You can see from the source strength graph that ALOHA
      expects the release rate to be highest at the beginning of the
      release, when the pressure in the tank is greatest, and then to
      decline as chemical escapes and pressure drops. The maximum
      computed release rate shown on the Text Summary screen,
      27,700 pounds/min, would have occurred just as the tank began
      to leak.
                         Sourer Rrlrwir FUtr
      20,000

      15,000

      10,000

      5,000

          0
                       10
20
30
40
                             A-5-12

-------
Eighth...
I      Choose Computational from the SetUp menu.
                           Chemical...
                           Atmospheric
                           Source
                           Computational..
       Check to be sure that Let model decide is selected (Unless you
       specify otherwise, ALOHA will default to this setting). Click on
       this button if it is not Click OK.
                         Computational Prclefenee;
          Select spreading algorithm, tf unsure, let
          modet decide.
               ® Let model decide (select this If unsure)
               O Use Gaussian dUperalon mly
               O Use Heavy Gas dispersion only
          Define dose:

                 Dose
                                    n* 1.0
                                            Cancel  \
                               A-5-13

-------
Ninth...
1) Select Options-, from the Display menu.
                    Display
                    lile Windows
                    Stack Windows
Test Summary
footprint
Concentration..
Qose
Soufce Strength
Calculate...
Calculate MOW
Ctrl+M
      The lexicologist has recommended that you use the TLV-STEL
      value for methyl chloride, 100 ppm, as your level of concern
      (The TLV-STEL is a 15-minute workplace exposure limit).
      Since ALOHA's chemical library doesn't include a value for
      TLV-STEL, dick User-specified cone and enter "100."  Be sure to
      dick ppm.

      Check to ensure that Plot on grid and autoscale to fit window is
      selected.  Click on this button if it is not
                             A-5-14

-------
       Click the English units button. Then dick OK
                              Display Options
      Select Level of Concern or Output Concentration:     |    Help   I
            O H>LH not ovilloble
            • User specified cane, of fiqg      I    PPm
                                  1 - ' O milligrams/cubic meter
Select Footprint Output Option:
      €> Rot on grid and «uto-sc«le to ffi window.
      O Uoe uoer specified scsle.
                                                  |   Help   I
      Select Output Unto:
            9 English wills
            O Metric unite
                                                 Cancel |
Tenth...
I      Choose Footprint from the Display menu.
                       Display
                        lilc Windows
                        Stack Windows
                        Options...
                        Text Summary
                        Footprint
                        (Concentration...
                        fiose
                        Souice Strength
                        Calculate...
                        Calculate HOW
                                    Ctrl+M
                                 A-5-15

-------
                        Foulprinl Window
          •vilos
           0.75
                 Hay overosti i.at»
          0.75
                                ail**
     ALOHA will display a diagram of the footprint for this methyl
     chloride release. Check the Text Summary window to see the
     maximum downwind distance that the footprint may extend
     (called the Maximum Threat Zone). You'll also see that
     ALOHA chose to use the Heavy Gas model to make its
     calculations, and that the model reminds you that a Heavy Gas
     footprint represents an initial screening. ALOHA must
     simplify its Heavy Gas calculations so that a footprint can be
     completed and displayed in a short time. For pressurized
     releases such as this one, such a footprint can be an
     overestimate. In a moment, you'll check concentration at a
     location downwind of the source for a more  accurate estimate
     (concentration calculations are not simplified).
FOOTPRINT INFORMATION:
  Model nun: Heavy sas
  llstr specified LOC: 1N pp«
  Max Threat Zone Mr LOC: 1.7 olles
  Max Threat Zone for IBLM: 178 yards
  Not*: The Heavy Kas footprint is an initial screening.
   For short releases it My fee an overestimation.
   •e sure to check concentration information at specific locations.
                            A-5-16


-------
EJevent/i...
      You're ready to use BitPlot to plot this ALOHA footprint on a
      map of Seattle. Select Go to Map from the BitPlot submenu
      under ALOHA's Sharing menu to launch BitPlot or to bring it
      forward if it is already running.
                   Sharing
                    BitPlot
       Go to map
      Go to the Maps directory in the ALOHA folder and dick on the
      Seattle map. Click OK.
     FleN<
                          Wheie is the map?
                           Pjioctwi**:
                           c\aIoha\M|M
                              K\
                              t aloha
    Lkt Fiet of lypw
                                                    Caned  [
    [Aloha Map file. (-.BMP)[±J
Dri%e*:
      Next, you'll need to enter your map scale. You will see the
      Seattle map displayed on your screen inside a scrolling window.
      Move the crosshair cursor to the 0 feet point on the scale bar
      inside the map legend, and click your mouse button at that
      point. Then move the crosshair to the 2000 feet point on the
      scale bar and click the mouse button again.
                             A-5-17

-------
 Enter "2000," the distance between the two points. Click on the
 popup units menu and choose feet for distance units. Click OK
 when you're finished.
                    Scale by Mouse
  Distance Equals:
      OK
Cancel
Help   |
Next, you'll need to indicate the location of the spill. Scroll the
map down until you can see the intersection of East Marginal
Way and 16th Avenue South.  The train tracks cross 16th
Avenue on the south side of this intersection; this is the
location of the leaking tank car.  Click once on this point. You
should see a red cross marking this point.  If you didn't dick in
just the right spot the first time, just click again. When you're
satisfied, dick OK
                        A-5-18

-------
Cancel
                      Position the Source
           M«ih m »ource tartan on the •••
 Once you have positioned the source, BitPlot will display the
 ALOHA footprint on the map. On this footprint plot, the
 innermost oval represents the Maximum Threat Zone, the area
 where ground-level concentrations of methyl chloride are most
 likely to exceed 100 ppm, your level of concern.  On either side
 of this oval, you can see confidence lines. These delineate the
 area within which ALOHA is 95% sure the chemical cloud will
 remain, if the wind shifts it about during the release.
                        A-5-19

-------
 Next, to find out the concentrations expected inside and outside
 the nearest residence, you'll need to indicate the building
 location so that ALOHA can calculate and display a
 Concentration vs. Time graph. The closest homes are located
 near  the intersection of Southern Street and 12th Avenue
 South, across the river and southwest of the spill location.
 Double-dick on this intersection. ALOHA will come forward
 automatically, and will display a Concentration graph for your
 location.
 2,000

 1,500

 1,000

   500

    0
                    20
                                   40
                                                 CO
                          minuta*
You can also view estimates of maximum indoor and outdoor
concentrations in ALOHA's Text Summary window.  ALOHA
predicted that people at the residence nearest the spill may be
exposed to a maximum outdoor concentration of about 1400
ppm, within 20 minutes of the start of the release, and a
maximum indoor concentration of about 150 ppm at the end of
the first hour.
                       A-5-20

-------
                           Text Summary
  TINE DEPENDENT  INFORMATION:
    Concentration Estimates  at  the  point:
    Downwind:       593 yards
    Off Centerline: 99 yards
    Hax Concentration:
       Outdoor: 1,151 ppn
       Indoor:  15% ppn
    Note: Indoor  graph is shown with  a  dotted line.
8     When you've finished viewing the graph and Text Summary,
      choose Go to map from the hierarchical BitPlot menu item
      under ALOHA's Sharing menu to return to BitPlot

      Don't be concerned if the numbers that you see on your screen
      don't exactly match the ones shown here. ALOHA's estimates
      are affected by exactly where on the map you dick. ALOHA was
      designed to give you "ballpark" estimates of source strength
      and dispersion.  It cannot give you completely accurate
      predictions for a real release, because no model can account for
      every uncertainty. For example, if the wind shifted direction or
      changed speed,  concentrations at the location you selected could
      be higher or lower than ALOHA's estimates.  Likewise, you had
      to guess the temperature of the methyl chloride in the tank,
      and the firefighters had to guess the dimensions of the hole in
      the tank. If you or the firefighters were wrong, ALOHA's
      estimate of release rate was inaccurate. In real response
      situations, ALOHA gives you a "best guess," rather than an
      exact answer.
                            A-5-21

-------

-------
Example 6
Using ALOHA and a
MARPLOT  map
On June 4,1992, a train traveling on the Southern Railway near Manassas,
Virginia, collided with a stalled truck at U. S. Highway 29 (also numbered
211). During the hour from 15:00 to 16:00,4,000 pounds of chlorine gas
were released from a derailed tank car. The land between the tank car
and the intersection of Gallerher Road with U. S. Highway 29 is flat with
no obstructions. Two workmen repairing potholes at this intersection
were overcome by fumes and treated at a local hospital for chlorine gas
inhalation. At the time of the release, winds were out of the ENE at about
12 knots, one-third of the sky was covered by clouds, the humidity was
about 80% and the air temperature was 72° F.

Given this information, what is the concentration of chlorine that the
workmen may have been exposed to?

You'll evaluate this scenario first by using ALOHA to obtain a source
strength estimate and a footprint, then by plotting the footprint on a
MARPLOT map in order to obtain a concentration estimate for the
location where the workmen were injured.

F/rrt...

I     Double-click on the ALOHA icon to launch the application.

2     After reading the ALOHA caveats, dick OK.
                            A-6-1

-------
 YouTl need to add Manassas, Virginia to ALOHA's city library.
 Choose Location from the SiteData menu.
                     SiteDdta
                      Lotdtion...
                      Building Type...
                      Date 9 Time...
 dick Add.
ABERDEEN, MARVUWD
HBILENC.1DMS
UlttN, SOUIM CRROLINR
HLRMEDft. CRLirORNIM
RIBRNV, NEW VORK
RLBRNV, ORCEON
RLEKRNORIfl IRV, NEW VORK
RLEHRNDRIR, LOUISIRNfl
RIEKRNDRIR, IflRGINIR
RUEN, TEKRf
RMBIER, PENNSVLUHNIH
RMES, I HIM
RMESBURV. MRSSRCHUSCm
RNRCONOR, MONTRNR
RNRMEIM, CRLlFORNtH
RNCHORN8C, RLRSKR
HNN RRBOR, MICHISRN
HNNRPOllt. MRRVLRNB
                          A-6-2
J

-------
  Type "Manassas" in the location name field. Click In U.S. Enter
  "200," the approximate elevation of Manassas, and dick feet.
  Enter the city's latitude and longitude, 38° 50' N and 77° 30' W.
  Click N and W. Choose "Virginia" from the scrolling list of state
  names. Click OK.
                        I Location laput 1
 Enter full location nomo:
  Location is  JMUNASIRS
  It location In a tIJ. stoto or territory?
   ®lnU.S.    ONothiU.!.
Solact *toto or territory
 Entor approKlmoto olauotlon
 Clovotlonlt 1200   | 0 ft O
Entor approNlmate location
                                    lUflKE ISLAND
                                    WASHINGTON
                                    WEST VIRGINIA
                                    WISCONSIN
                                    UIVOMING
 Click Select.
                      Location information
HHNCH£$TIH, IOUIH
•4HNCHES1ER, NEW HHMPSNIRE
MANSFIELD. MASSACHUSETTS
MANSFIELD, OHIO
MRRIETTA, 6EOREIR
MRRQUETTE, MICHIGAN
MARTINEZ, CALIFOANiA
MRRVSUILLE, CALIFORNIA
MEMPHIS, TENNESSEE
HENLO PHRK, CALIFORNIA
HENOMONEE FHUS, WISCONSIN
MENTOR, OHIO
MESH, RRI20NI
HESQUITE.TEMRS
HlflMI, FLORIDA
>
-------
Second...
       Well ignore Building Type during this scenario, since we're

       interested in estimating outdoor concentration. Choose Date &

       Time... from the SiteData menu.
                         SiteData
                          Location
                          Building Type
      Select Set constant time and. enter the month, day, year, hour and
      minute for this scenario.
                        Data and Time Option*
         You can either use the computer's Internal clock for the
         model's date and time or set a constant date and time.

             O u*0 Internal clock    ® Set constant time
         input constant dale and time
            Month    Day    Year

            (1-12)   (1-31)  (1900-™)
Minute
 (0-591
                              Cancel
 Help
      Click OK.
                               A-64

-------
TMrrf...
I      Select Chemical... from the SetUp menu.
                           SelUp
                           Chemical...
Htmospheric
Source
r
r
Computational...
       Use the scroll bar or quickly type the characters "CH" to find
       "chlorine." Double-click on this name or click once on it, then
       dick Select
                           Chamlcal Information
      CRMPHCNE
      CflHBON BISULFIDE
      CHRBON DIOHIDE
      CARBONMONOHIDE
      CHRBON TCTRABROMIDE
      CHRBON TnRflCHLORIDE
      CflRBONVL FLUORIDE
      CRRBONVL SULFIDE
      CHLORINE DIOHIDE
      CHLORINE T*IFLUORIDE
      CHLORMEPHOS
      CHLOROMCETRLOEHVOE
      CHLORORCETIC RCID
      CHLOROHCETVL CHLORIDE
      CHLOROHNILINE
      :HLOROBENZENC
       Check the Text Summary window to review information about
       the properties and toxicology of chlorine.
                             Teitt Summanj
    Location: IVHRSSHS, UIMINIH
    •ulldlng: SholUrod cinglo star I ad
    Date t T!M: Find at JUno 4,  IWJ t 1900 hoir*
 CHEHICM.
   Cho»Jeal NOM: CttJMINE
   TUMltt: 0.30 ppa
   •oiling Point: -20.23* F
   Froazing Point: -\49.9S* F

™
                                       Holoeular Uolaht: TO.flO kg/kwl
                                       IOLH: 30.00 poo
                                 A-6-5

-------
Fourth...
I      Select User Input., from the Atmospheric submenu in the SetUp
       menu.
      The wind speed is 12 knots and one-third of the sky is covered by
      clouds. By clicking on the stability class Help button (in the upper
      right comer of this screen), you can see that the best choice for
      stability class is C. Click C for stability. No inversionls present,
      so there's no need to change the default No inversion selection.
      Type in the wind speed and click knots. Type in the wind
      direction and air temperature and click F for temperature units.
      The area between the derailed tank car and the injured workmen
      is flat and free of obstacles, so choose Open Country for ground
      roughness. Click OK.
     	I ntmo«phtrtc Option*
     StabilityClo*sI*:  Q«  OS  ®C OB  OE
Invonlon Nolght option* oro:   (   Holp ~~1
  €> No iMioraiou   O Inmnlon Prosont, Holgnt I*:
•find Option* oro:
                                                       ®Foot
                                                       O Motor*
                     L
                         J
        WindSpootf to: ||2    j• Knot*  OMPM OMotor*/loc.
        HIM I* from: |ono    | Entor tfogroo* truo or tont (o.g. EKI

                          IpOfTOM f)F  QC   C
(round •ougnnm* to:  [   Kolp  "1
  • tponCooiitni    m  0((lpMtrwi8(|n.M(z.h
  O Vrpon or Forocl
                                                      ON.
                                    [   ConcoT


-------
The sky is about one-third cloudy, so type in "3" for cloud cover,

and then enter "80%" as the relative humidity value. Click OK.
                    Cloud Comr and Humklltti
 cover
                      partly
                      cloudy
                                O  OH fi)Mtl*rvaliM  |3
                                            (0-10)
                                ClMf
 Satect Humidity:
    O    O      O     O
                                         I  »•»  1
                                     O  OR  fj> anlar valua 100
                                     dry         (0-100)
                                     cancal  1
Check the Text Summary screen to be sure that you've entered

these data correctly.
                       j TeHt Summary
SITE MTU INFOMWTION:
   Location:  nRHBSSHS, UIMHNIA
   •uildlng Air Exchangas Par Hour: 1.O4
   Oat* I T)M: Flx«d at JUTM 4,  IW2 C 1500 towr»
                                         >lnola »tori«d>
                                   nolaeulor Uaiaht: 70.90 ka/Mal
                                   IDLH: 30.00 ppa
   Chuical NOM: CM-ORI«
   TLU-TUR: 0.50 pp>
   Footprint Level of Concam: X ppji
   •ailing Point: -29.29* F
   Uapor rruswa at taeiant T«paratira: graator than I at*
   ABbiant Saturation Coneantratlan: 1.000,000 ppa or 100.Of

BTnOSWCBIC INFOBnflTION:(t«KJflL  IWUT OF DflTH)
   Mind: 12 knot* froaj ano                 No Invnian Hoight
   Stability Clan: C                     Hlr Taapargliri: 72* F
   Malatlva Hualdltv:  Ml                  Orawtd Roughno«>: Opan eoimtrv
   Claud Cavar: 3 tanUv
                            A-6-7

-------
fifth...
       This is a release from a tank car, but you don't have all the
       information that you would need to model the release with
       ALOHA's Tank source option.  You can model this release as a
       Direct Source, however. Choose Direct., from the Source
       submenu of the SetUp menu.
                   Chemical
                   Rtmosipheric
                                       Puddle
                                       Tank...
                                       Pipe...
      The chlorine was released over the course of an hour. Click
      pounds. Click Continuous source, then type "4000" as the
      release amount. Click on the pounds/hour button. Leave the
      source height as "0," and click OK.
                       User Input Saurc* Strength
      Select source strength wilts ef mass ar uakmw:      [ Help
        O grams      O kilograms ® pounds     O »onil2,0oa HM)
        O cable maters O lltars    O cubic Taat   O gallons
      Salad an Instantaneous or continuous source:
        ® Continuous sauna       Q Instantaneous source
      Enter the amount of	
      pollutant ENTERING 14000
      TOE H1MOSPHERE:   '	
Opounds/sac
      Enter source height
      CO If ground source):  '*
   Qfaet
   O motors
      ALOHA will display the warning below. The model recognizes
      that because the boiling point of chlorine is well below air
      temperature, the chemical may have been stored as a pressurized
      liquid. If so, it may flash-boil when released through a tank hole.
      During flash-boiling, much of the stored liquid turns instantly to
                               A-6-8

-------
    vapor as it leaks, so that a mixture of liquid droplets and vapor (a
    two-phase flow) is released to the atmosphere.  ALOHA's Tank
    release calculations account for these processes, but the Direct
    Source option does not. Since we don't have the necessary
    information to run the Tank option, well use the Direct Source

    calculations as the best approximation that we can make/

    recognizing that the model will treat this release as a steady flow
    of gas from the tank instead of a two-phase release. Click OK.
                        Not* I
                  This chemical may flash boll
                  anil/or result in two phase
                  flour.
                                     Help
    Check the Text Summary window to be sure that you entered
    these data correctly.
                         Tent Summary
SOURCE STRENGTH INFOWWTIDN:
  Direct Source:  4000 pounos/hr           Source Height: 0
  Release Duration: M.OHA Halted the duration to I hour
  Release Rote: M.7 pounds/Bin
  Total Awount Released: 4,000 pound*
  Note: This choeieal oau flash boil and/or result in too phase fle».
                             A-6-9

-------
Sixth...
I      Choose Computational from the SetUp menu.
                           Chemical...
                           fltmosphertc    p
                           Source         p
                           (.omputationdl.
      Check to be sure that Let model dedde is selected (unless you

      specify otherwise, ALOHA will default to this setting). Click OK.
                        Computational f reference!
           Select spreading algorithm. If wutire, tat
           model dtcld*.

                 ® Lot model decide (setoct MU If u
                 O "ie GausclM dispersion only
                 O U*e Neevy £•• dlipenlen only
           Ooflne dote:

                  Dote <
dT
                                        Cencel
                              A-6-10

-------
Seventh...
 I      Select Options... from the Display menu.
                            Display
                            Tile Windows
                            Stack Window*
                            TBHt Summery
                            Footprint
                            Concentration...
                            Dose
                            Source Strength
                            Calculate-..
                            Ialculate Now  X>
2     Check to be sure that IDLH Concentration is selected.


3     Check to ensure that Plot on grid and autoscale to fit window is

       selected.
       dick English units. Then dick OK.
                              Oltplay Optloni
       Select Level of Concern or Output Concentration:   [   Help   ]
            ® IDLH Concentration
            O tt»w tptelfled cone, of
®ppm
O mllllgremt/cublc melt
       select Footprint Output Option:                 r—jjjj_-
            ® Not on grM and euta-icale to fit ivlntfoiv. 	
            O <>*• usor spoclflotf tcole.
       Select Mtpvt Mils:
            ® EoglKh mlti
            O Metric unlti
         Help
                                            f Concol  1
                                 A-6-11

-------
Eighth...


I      Choose Footprint from the Display menu.
                         Display
                          Tile Windows
                          Stack Windows
                          Options...
                         Text Summary
                          Footprint
                          Concentration.
                          Oose
                          Source Strength
                          Calculate...
                          Calculate Now X>
      ALOHA will display a diagram of the footprint for this chlorine

      release. Check the Text Summary window to see the maximum

      downwind distance that the footprint may extend (the Maximum

      Threat Zone). ALOHA expects the footprint to extend downwind

      for about 362 yards.
                           TeHt Summary
 FOOTPRINT INFORmTIOH:
   Model Run: Heavy Gas
   User Specified LOC: equals IOLH C30 pp*>
   tax Threat Zone for LOC: 362 yards
   Note: The Heavy Oas footprint  is an Initial screening.
     For short releases  It MU be an overestimation.
     Be sure to cheek concentration Information at specific locations.


                              A-6-12


-------
Ninth.
      You're now ready to plot this footprint on a map of the area in
      MARPLOT, and to obtain a concentration estimate for the
      workmen's location. Select Go to Map from the MARPLOT
      submenu under ALOHA's Sharing menu to bring MARPLOT
      forward.
      Choose Open from MARPLOT's File menu.
                         Sai'e fl* PICT...
                         Page Setup...
                         Print...     XP
                         Import...
                         Export,..
                         Preferences...
                         Quit
KQ
                            A-6-13

-------
 Click on the map folder titled "Prince William County." dick
 Choose Map "Prince WiLlia.-."

Choose folder containing the r
JO MARPLOT maps " |
nap:
c=> Rthena
O Liberty County K>
(• [ i Punrc lliilli.im [mintu •

IH
O
Choose Map "Prince Ulillla^"

[ EJecl ]

[ Desktop ]

rsp^ri
[ Help... ]

[ Cancel ]

You're about to change the map settings to make streets and
railways visible. You'll need to zoom the map in before you do so.
(Otherwise, so many features will be visible on the map that you
won't be able to distinguish among them.) First, we'll choose
units for the map scale. Choose Preferences from the File menu.
                     Neui...
                     Open...
                     Save
                     Close
XN
xo
xs
XUJ
                     Save Rs PICT...
                     Page Setup...
                     Print...     XP
                    Import...
                    Export...
                        A-6-14


-------
 Choose yards from the popup menu as your units of map scale.
 Also check to be sure that Visible dick point is selected. (This
 means mat MARPLOT will place a small crosshair mark wherever
 you last dick on the map.) If you wish, you may also change the
 map's background color and/or the formats for displaying the
 map scale and the geographical coordinates of locations on the
 map. Click OK.
rScele Format	
   O1:N
   O * ft - N yd
   ® Window Distance
                          -Uiem Lit/Long Coordinates
                             ® os o decimal
                             O In deg/mln/sec
   Click Point
   ® Visible
   O Invisible
               Units:   yard*
               Beck ground Color [  rnuinlte
                       [ Help...
Choose Set Scale... from the View menu.
Uieui Entire Map
Center On Click Point
Zoom In
Zoom Out
Redraw
Saue Currant Uiew...
Edit mews...
60 to Uieui...
60 to Lat/Long._
Mart Point
XE
XT
X*
X-
xo
xu
XR
X6
r
Show Inset Uieut
Hide Tool Palette
                       A-6-15

-------
       inter "500" in the middle data field, so that the map scale
       becomes 1 inch to 500 yards, dick OK.
                              Set Scale
                                t :  18000
                             I in- [SOP
              Current Window Width -|4lil
                    [ Help... ]   [ Cancel ]   [  OK
8      Choose Feature Settings... from the Features menu.
                Features
                 Feature Settings.
                 Find Street...                      XV
                 Identify Feature Near Click Point...  XK
                 Show Rll Features
                 Show Street Names
                 Highlight Street
                 Unhlghllght Street
      Click on Primary Roads, then click Display Settings.™
                          feature Settings
        Feature Name
      Display
                 Line Type
      County Boundaries
      Secondary Roads
      County Roads
      Ml Other Roads
      Railroads
      Miscellaneous Features
      Non-visible Boundaries
        Line Width:   1 Pt
H  Colon|
                     Black
                  Una Pattern:(_
       Display Settings..
(  Help...  ]   [  Cancel  ]
                               A-6-16

-------
10   Click on Show at all scales, then dick QIC
                           Feature Display
      Feature: Primary Roads
     •Display Criteria	
       ® Show at all scales
       O Hide at all scales
       O Snow at scales greater than:  t In - |{278
               Ulldth of window at this scale: 2164
                                  [ Help... ]  [ Cancel ]
11    Repeat this procedure for the following features: Primary Roads,
      Secondary Roads, County Roads, All Other Roads, and Railroads.
      (As a shortcut, you can toggle a feature's setting by holding down
      the option key, then clicking on the feature's name in the Feature
      Settings screen.) Your Feature Settings screen should look like the
      one below. When you've finished, dick OK.
                          Feature settings
       Feature Name
Display
Line Type
      County Boundaries
      Primary Roads
      Secondary Roadt
      County Roads
      Rll Other Roads
      Miscellaneous Features
       on-visible Boundaries
       Line Width: ItPt
                  Line Pattern:
      [Display Settings...]   {  Help...  )  [ Cancel )
      MARPLOT will automatically redraw the map, with streets and
      railroad lines visible.
                              A-6-17

-------
 12    Choose Show Street Names from the Features menu.
                 Features
                 Feature Settings...
                 Find Street...                    »V
                 Identify Feature Near Click Point... XK
                 Show HII Features
                 Shoui Street Names
                 Highlight Street
                 UnhlghHglit Street
13    Now you'll search on the map for the area where the accident

      occurred. Choose Find Street from the Features menu.
                Features
                Feature Settings...
                Find Street.
                 Identify Feature Near Click Point... XK
                Show Rll Features
               v'Shouj Street Names
                Highlight Street
                Unhighlight Street
14    To search for Gallerher Road, type "GALL" in the Search list for

      name starting with: field. Click Search
                             Find Street
            CT
    BDflriS ST
    flGUSTA ROflO
    RLAN CT
    ftLBEIMRLE OR
    RLDIE ROAD
    ALLEOHANY ROAD
    flLPIHE ST
    HIUEV PR
   Search list far name starting with:
    iRLIj
Narrow search te
part of a street:
(intersection...  )

[Address Hange~.)
                                                     Help.
                               A-&-18

-------
15    dick "GALLERHER ROAD," then click Show on Map.
                           Find Street
    FOREST LRHE
    FORESTUOOD LflME
    FORRESTER LRNE
    FORUn UflV
    FRIE CT
    BRINES RORD
    GHLES CT
    Search list for name sterling with:
    BULL
   Narrow search te
   pert or e street:
   [ Intersection.,  j
   [ ftddresi Renge... J
                                               Shou» on Map
]l
                                                  Seerch
16    Your map should look like the one below. If you have a color
      monitor, Gallerher Road will appear in red, and all other streets
      and roads will be drawn in black. U.S. Highway 29 (211) crosses
      the map as a straight line from the lower left to the upper right of
      the map. The Southern Railway, which is not labeled, crosses the
      map as a winding line from the upper left comer to  the middle
      right side of the map.
                             A-6-19

-------
17   Find the point where the Southern Railway line crosses U. S.
      Highway 29 (211).
      Choose L-2-1 from the tool palette, then dick once at that point to
      set a source location for ALOHA. MARPLOT will place a visible
      crosshair mark, or "dick point" at this location.
18    Choose Set Source Point from the ALOHA submenu under
      MARPLOT'S Sharing menu.
             About Shared Menut...
             Saue Shared Meitui~.
                                 Set Cent & Dese Point
                             A-6-20

-------
19    An ALOHA footprint should automatically be drawn at that point
      (this may take a few seconds).
      If you wish, click on '—^ in the tool palette, then dick on the
      footprint to zoom in for a closer view.
      Now you'll choose the location for which you'd like an ALOHA
      Concentration graph.  Find the intersection of Gailerher Road and
      U. S. Highway 29 (211).  (The leading edge of the footprint should
      nearly touch this intersection.)
Be sure that you've selected the arrow tool,
palette, men click on this point.
                                                 , from the too!
                             A-6-21

-------
21    Choose Set Cone & Dose Point from the ALOHA submenu under
      MARPLOT'S Sharing menu.
           Sharing
            RboutShared Menus.
            Saue Shared Menus~.
            Set Info
            Unlink
ill
                                Delete ALOHfl Objects
      ALOHA will come forward and will display a Concentration
      graph for the location you choose. Review the graph and the Text
      Summary window. ALOHA estimated that the workmen were
      exposed to an outdoor concentration of about 25 ppm, somewhat
      less than the IDLH for chlorine, for about an hour after the start of
      the release.
                     Concentration Window
      20-
      W-
                       20
                               InutM
                                       40
                                                      60
                            A-6-22

-------
                          Tent Summary
     Ting DEPENDENT INFOWWTION:
        Concentration EstlMtM at th« point:
        Downwind:       365 yards
        Off C*nt«rlirM: 21 yards
        Flax Concentration:
          Outdoor:  25.3 pp*.
          I ftdoor" *   16* 1 DOB
        Not*: Indoor graph.is shown with a dotted (in*.
 The purpose of running this scenario in ALOHA and MARPLOT was to
 get an estimate of the concentration of chlorine to which the workmen
 were exposed. Don't be concerned if the numbers that you see on your
 screen differ slightly from those shown here. ALOHA's estimates are
 affected by exactly where on the map you click. ALOHA was designed to
 give you "ballpark" estimates of source strength and* dispersion. It
 cannot give you completely accurate predictions for a real release,
 because no model can account for every uncertainty. For example,
 ALOHA predicted that the workmen were exposed to a steady
 concentration of about 25 ppm of chlorine. That concentration would
 have been high enough to cause adverse health effects in the workers.
 However, if the wind shifted during the course of the release, the
 concentration at the workmen's location could have been higher or lower
 than ALOHA's estimate. If the chlorine was stored as a pressurized
 liquid, its initial release rate was probably greater than ALOHA
 predicted. Downwind concentrations then would have been higher, too.
 If you were responding to a real event, you might wish to obtain values
 for the tank car's dimensions, the amount of chlorine it contained, the size
and location of the hole, and other information that you'd need to run
ALOHA's more realistic Tank option.
                             A-6-23

-------

-------
Appendix B
Troub leshooting
This section addresses some of the issues that may raise the most
questions in ALOHA. These include things that are not truly problems
but may be troublesome when you're trying to interpret what ALOHA
is saying or asking of you. In most cases, when you encounter a problem
while running ALOHA, the model will alert you of the problem and
suggest a solution. These cases are not discussed here. Less often, you
may encounter problems and be unsure of how to solve them. Following
are some of these cases.
                                                  B-l

-------
 Appendix B
 I want to modify a chemical   The property in question is inter-
 (eitherinskleALOHAorusing   ^^taj.,.^ ALOHA fcom
 ChemManager), and I can't   .   '   a  .  _ '    .  .,..
 changeaproperty-Htappears   mformanonm,tscr*rrucal library.
                                 You must add a new chemical
                                 (with a different name, such as
                                 chlorine-2) and enter a new value
                                 for the.property.
 I have drawn a footprint, but
 when I double-click inside to
 get  the concentration and
 dose curves, I get a message
 saying that the concentration
 at that point is insignificant.
Your footprint was drawn using
the heavy gas calculations.  Re-
member that, for the footprint cal-
culation, the heavy gas calculations
use the maximum average release
rate as though it were continuous
for the entire  60 minutes or sec-
onds (whichever is appropriate).
In a case where the release rate is
high to start with, then decreases
significantly (e.g.,a pressurized re-
lease), the heavy gas model will
overpredict the footprint ALOHA
calculations of concentration and
dose made for a particular loca-
tion, however, account for changes
in the release rate over time, and
are not overpredicting. Gaussian
footprint calculations also account
for changing release rateover time.
B-2

-------
                                                    Appendix B
I am  trying to model the
release of gas from  a gas
pipeline, but ALOHA will not
run because it says the pipe is
too short. It tells me that the
length  must be at least 200
times the diameter of the pipe.
                               In some instances the pipe may be
                               too short relative to its diameter. If
                               this is the case, and the diameter of
                               the pipe is greater than 20 on, you
                               may use the Tank option instead,
                               selecting  the configuration of a
                               horizontal tank. If the length of
                               your pipe is less than one meter
                               and it is connected to a tank source,
                               you may also use the Tank option
                               and select short pipe/valve as the
                               type of leak. Both of these alterna-
                               tives should produce conservative
                               estimates of downwind dispersion.
message, or the  file opens,
then gets lost.
I'm  using  a Macintosh, and   Your save file may not be compat-
ALOHAwiMnotopenmysave   ible with the vmfm of ALOHA
file.   I  either get an  error
                               that y°u are usinS-  The current
                               ALOHA cannot readany save files
                               made with previous versions of
                               ALOHA. In addition, check to see
                               whether you have installed both
                               the math coprocessor and the non-
                               math coprocessor  versions of
                               ALOHA on your hard drive.  If
                               you have, ALOHA  may save a
                               math coprocessor version-file as a
                               non-math coprocessor-version file.
                               Remove the version that you do
                               not need (e.g., if you're using a
                               machine without a math coproces-
                               sor, remove the math coprocessor
                               version of ALOHA).
                                                        B-3

-------
  Appendix B
  I have a SAM hooked up, and
  I have set the SAM options
  using the Atmospheric menu,
  but the Source menu option is
  grayed out—I  can't set imy
  source.
The SAM has not been collecting
data for five minutes or it has not
received valid data In order for
the SAM to send information to
help determine the most appro-
priate stability class, it must have
at least five minutes' worth of data.
Your text Summary screen should
tell you that you do not have five
minutes' worth of data yet or that
the transmissions have not been
valid. In addition, look at the Show
processed data option under the
SAM Options menu. If it reports
sigma theta as -1.0, the station has
been running for less than five
minutes.
 ALOHA tells me thatmy value    ALOHA will accept values for
 is not within allowable limits.    numeric inputs within specified
                                 ranges.  These  restrictions help
                                 ensure that you do not inadvert-
                                 ently use unrealistic values for an
                                 input If you enter a value outside
                                 of the  allowable range, ALOHA
                                 will warn you and tell you what
                                 the limits are. You must reset the
                                 value before  ALOHA will con-
                                 tinue.  Most of these ranges are
                                 summarized in  the table in this
                                 appendix. Check ALOHA's on-line
                                 help topic for more information
                                 about any ALOHA input
B-4

-------
                                                   Appendix B
The Tact Summary screen
shows a Maximum Computed
Release Rate that is signifi-
cantly higher than the Maxi-
mum  Sustained Averaged
Release Rate. How should I
interpret these numbers?
 ALOHA averages the release rate
 over five steps. The maximum
 computed release rate corresponds
 to the very highest release rate pos-
 sible with the given scenario. The
 maximum sustained averaged re-
 lease rate is averaged over at least
 a minute. If these values are sig-
 nificantly different, the maximum
 release rate was sustained for less
 than a minute.  This is most com-
 mon in {he case of pressurized re-
 leases.
When I change atmospheric
conditions, ALOHA tells me
that it is unable to verify the
consistency between my new
atmospheric data  and  the
source data. Then I have to
reset the source.
Puddle, Tank, and Pipe source
strength calculations are directly
affected by atmospheric condi-
tions. Changing atmospheric con-
ditions will change these source
calculations so source strength
must be recomputed.  The Text
Summary screen will remind you
which source option was lastused.
If you return to the same source
option, information about the sce-
nario will still be there EXCEPT
information about the amount re-
leased (puddle size, height of hole
in tank, etc.).
                                                       B-5

-------
 Appendix B
 I want to make a few changes,
 but every time I make one
 change I  have to wait for
 ALOHA to  recalculate and
 redraw everything before I can
 make the next change.
You should select Calculate from
the Displaymenuand tell ALOHA
that you only want to  update
ALOHA's windows when you se-
lect them manually. To do this,
choose Manual update of all vis-
ible windows. The Calculate op-
tion is set by default to update the
windows automatically every time
something is changed.
 When saving an ALOHA file,
 not all of my data is saved.
ALOHA will save all information
which does not pertain to meteo-
rological conditions and the
amount spilled.  The model was
developed as a tool for first re-
sponders; saving a wind speed
and release  scenario that would
most likely  never be exactly re-
peated may be misleading. Hence,
all information EXCEPT meteoro-
logical conditions and information
about the amount spilled can be
saved. If you want to archive the
results of an ALOHA scenario run
for later viewing, save a Spy file.
B-6

-------
                                                   Appendix B
When I save an ALOHA file in
the Spy format, I can't open it
from ALOHA.
                               Spy files can only be opened by
                               AlohaSpy.  These files cannot be
                               opened or used by ALOHA.
I am trying to run a scenario,
and  a progress bar  saying
"Heavy Gas Calculations in
Progress" has been up forever!
How long will this take to run?
                               Heavy gas calculations may be
                               slow to complete, especially if
                               you're using a computer without a
                               match coprocessor. Use  the
                               progress bar to get a rough esti-
                               mate of how long ALOHA will
                               take to finish calculating. If you've
                               waited three minutes and the bar
                               is about half-way across the dia-
                               log, you have about three minutes
                               to go. If you don't have that long to
                               wait, you may cancel the calcula-
                               tions and then run the Gaussian
                               module. You should rerun the sce-
                               nario with the heavy gas module
                               as time allows.
                                                       B-7

-------
  Appendix B
  The Text  Summary screen   The floppy disk or hard drive to
  warns me that it is unable to   which you are archiving SAM data
  save the archived SAM data   has no more room left. Insert an-
  because the disk is full.          other ^  (of hook up anofcer
                                 hard drive) and continue archiving
                                 your data.
  I'm using a Macintosh. While
  unpacking ALOHA, I get the
  message, "Can't  write  to
  destination file."
You have run out of space on your
hard drive or have tried to unpack
the rile to the original floppy disk.

If you tried to unpack to your hard
drive and received this message,
remove unneeded files from your
hard drive, including the partially
filled ALOHA™ folder, until you
have at least two  megabytes of
hard disk space available, and be-
gin the unpacking process again.

If you received the message  be-
cause you tried to unpack to the
floppy that the file came on, dick
OK, then  begin the unpacking
process again, this time clicking
the Drive button till your hard
drive appears.
B-8

-------
                                                  Appendix B
 I'm running  BitPlot with
 ALOHA in Windows. I have a
 map file that I created by
 scanning  in a paper  map.
 However, I can't open it in
 BitPlot What's wrong?
 A variety of graphic file formats
 are available for users of DOS and
 Windows. The scanned map that
 you created is likely to be in .pot
 'onnat Youmust convert it to .bmp
 format before BitPlot can read it in;
 that's the only format that BitPlot
 recognizes.  We describe how to
 make the conversion in the BitPlot
 Appendix.
 I'm running  BitPlot with
 ALOHA in Windows. I have
 the current ALOHA footprint
 displayed on a map in BitPlot,
 and I'm trying to print it. If s
 so slow! Am I doing something
 wrong?
Bitmapped  graphics may print
very slowly because the graphic
must be resized while it's being
printed. If your time is limited and
you need a  printout of the foot-
print, print out the footprint dis-
played on a grid from  within
ALOHA.
I'm  running BitPlot  with
ALOHA in Windows while I'm
responding to a spill. I'm also
using a SAM station to collect
weather  data. I've had a
footprint displayed in BitPlot
for the last half hour. I know
the wind has shifted direction
but  the  footprint  hasn't
changed at all. What*s wrong?
Whenever you bring BitPlot for-
ward in Windows, you'll halt data
transmission from the SAM to
ALOHA. The same thing can hap-
pen when you use MARPLOT and
ALOHA together on a Macintosh.
Bring ALOHA forward to update
the weather data and footprint
                                                      B-9

-------
  Appendix B
  I thought  I  knew what an
  ALOHA footprint looks like
  But on my current footprint
  plot, I see a big, shaded circle
  around my source point. What
  is it?
There are two possible explana-
tions, depending on your scenario.
Is your source a puddle of spilled
liquid (either standing by itself or
pooling under a leaking tank)? If
so, and if the puddle is large in
diameter relative to the size of the
footprint, you may be seeing it on
the footprint plot.

You may also have a heavy gas
footprint. If a heavy gas is escap-
ing into the atmosphere at a fast
enough rate, it will  form a large
"blanket" of gas over the source
point before it moves downwind.
If the  blanket is big  enough,
ALOHA will show it on your foot-
print plot.
 We have two computers in    Individualcomputerscancomeup
 our office that sometimes give    ^th different answers when they
 difrerentanswersforthesame    ^ ^ same calculations. ta
 ALOHA scenario.                  .  ,   ..„
                                 particular, different computers will
                                 round off numbers differently as
                                 they make their calculations. This
                                 can have a visible effect on
                                 ALOHA's source and dispersion
                                 estimates. You may have one ma-
                                 chine with a math coprocessor and
                                 one without, or a Macintosh and
                                 an IBM-compatible, or your com-
                                 puters may differ in other ways.
B-10

-------
                                                 Appendix B
I'm using a Macintosh. I just
copied ALOHA onto .my hard
drive. I started the program,
and chose Location from die
SiteData menu. But instead
of seeing the list of cities, I got
an error, "Error returned
from FillCityUstO".   Then
when I chose Chemical from
the SetUp menu, I got another
error, "Error returned from
FillChemLJstO". Did I break
ALOHA?
You may have very little room re-
maining on your hard drive.
ALOHAneedsabout 100 kilobytes
of space to create index files for its
city and chemical libraries.  The
program displays the errors that
you saw if it can't find enough
room. From your Desktop, dick
on the icon for your hard drive,
then choose Get Info from the File
menu to see how much room you
have left. You can solve this prob-
lem by removing some files from
your drive to make more room for
ALOHA's index files.
I'm running  ALOHA under
Microsoft Windows.  Every
now and then, I get an error
message, "System Error -
Cannot write to device AUX."
Then I'm given a choice of
choosing "CanceP' or "Retry."
Am I doing something wrong?
What should I do here?
This error message is Windows'
way of alerting you that some-
thing is wrong. It can appear when
you're trying to select an item from
the menu, print an ALOHA docu-
ment, or at other times. It's hard to
figure out what the problem may
bewhenthismessageappears. The
best thing to do is to choose "Can-
cel," then quit ALOHA, and
restart the program.
                                                     B-ll

-------
 Appendix B
 Allowable Input
Must be-

Properties
SiteData
Air exchange rale
Beaton
l^Mlii4j
LoBgttde
Mood)
l»r
Hour
Minute
Meteorological
Air temperature
Cloud cover
Ground roughness
inversion height
Relative humility
Wmdspeed
Source Input
jjaUiUHj M^MIM llfeA
/Boom tnti nig me
atmosphere (Direct)
Ground temperature
Pipe diameter
Pipe hole size
Pipe length
Pipe pressure
Pipe temperature
Puddle ana
toddle depth
Puddkmaas
Puddle volume
Source betjht
Tank diameter
Tank length
Tank mass
Tank opening

Tankpresture
T^lnpenon
Disptay
DoseseatBt
User spec. CMC.
User spec, scale
^greater than
(or equal to)

0.01 per bow
-500 ft (-153 m)
M
%r
V
I
1
0
0
-100»P(-73*O
0/10
0.0004 to (0.001 oc)
10 ft (3m)
OX
2 to (1mA, 2.3 mph)


0 (any unto)
-58»P(-50»C)
0.4 in (1 cm)
0
200 times pipe diameter
twice ambient
boding pool
4 sq. to (25 sq.au)
0. tin (0.25 an)
0.22 to (O.I kg)
0.03 |H (.10
0
0.7ft (20 an)
1.7 ft (50 an)
0
0.04 in (0.1 an)

1.1 aim
-459*P(-273"O

1
0
Ifl
^Jessthan
(or equal to)

60 per hour
28,000 ft (8^35 m)
m*
9tT
180*
12 . .
31
23
59
150«P(65'C)
10/10
78 in (200 en)
5000ft (1.524 ra)
100%
100ku(5Irryj, llSmpb)


1,000,000,000 (any noils)
I88*P(70'C)
32.8h(IOm)
diameter of the pipe
6.2 mi (10 km)
680 aun (10,000 psi)
2,795*F(1535"C)
12,100 sq.jds (10,000 sq.m)
110 jds (100m)
110 ions (100 metric tods)
2,640 flOOgal (10000 cun)
5000ft(lj25n)
3^801 (1^)00 m)
3J80ft(l#»m)
2,000.000 Ibs (907,200 kg)
drcular. ccosS'Sedtooil
area or 10% of surface area
	 *"*rTIMa*f ff "PflDf**
68 atn (1,000 psi)
19537^ (5503*C)

5
1,000,000 ppm
1:U67^00
B-12

-------
                    Appendix C

                    AlohaSpy
                    AlohaSpy is a companion application to ALOHA.  Use it to
                    view or print archived Spy files that you have previously
                    saved from within ALOHA. You may wish to create a Spy file
                    whenever you have run an ALOHA scenario and would like
                    to save your results for later viewing. An archived Spy file
                    contains the information from all the  windows visible in
                    ALOHA at the time the file was saved.
Spy files can be opened
   onV win AlohaSpy.
Whenever you'd like to create a Spy file, first check that all of
the windows that you'd like to archive are visible in ALOHA.
Then select Save As... from ALOHA's File menu. Click SPY
on the Save As Options dialog, type in a file name, andclick
OK.

Double-click on the AlohaSpy icon when you wish to use the
application to view or print Spy files. Each menu item avail-
able in AlohaSpy is described below.
                                                                    C-l

-------
 Appendix C: AlohaSpy
  AJohaSpy's File menu
  Open Window Archive...
  opens a Spy archive file  that
  has been created in ALOHA. If
  you are currently viewing a
  Spy archive file, selecting a
  new archive file to open  will
  close the current file.

  Close Window Archive
  closes an open Spy archive file.

  Close
  closes the  front window of the current archive display.

  Print...
  prints the  contents of the front window.
Open Window ftrchiue...
Close Window Rrchlue
Clou
Page Setup...
Print...
Printflll...
Quit
«0
Hill
JtP

«Q
 Edit menu
 Copy
 copies the contents of the front window to
 paste  into another application.
Undo
tut
Copy
Paste
Clear
                                                   xc
The Undo, Cut, Paste,
and Clear menu items are
not avaiabte in AlohaSpy.
C-2

-------
                                 Appendix C: AlohaSpy
 tlimdouis
  Tile
  Stack
  Tent Summary
 •Footprint Window
  Concentration Window
  Dose Window
  Source Strength (Release Bate)
Windows menu
Tile
allows you to view all of
the open archive win-
dows simultaneously on
the screen, with the win-
dows arranged side by
side and fit to the screen.
Stack
layers all of the open archive windows on top of each other,
so that only the title bars from the back windows, along with
the entire front window, are visible.

Menu items displayed below the Stack menu item represent
the individual window names.  To open a closed window or
bring a window forward, choose  the desired window name
from this list. A check mark is placed next to the name of the
current front window.
                                                 C-3

-------

-------
             BitRot
                     Appendix D

                     BitPlot
In this appendix...

Plotting a footprint...D-1
Opening a map	D-2
Entering scale	D-3
Locating source	D-4
Displaying footprint .D-5
Modifying footprint ..D-6
Cone. vs. Time	D-6
No BitPlot	D-7
Convening .pcx files D-8
 Introduction
 BitPlot, a companion application provided with ALOHA Win-
 dows, is installed in your ALOHA Directory when you install
 ALOHA (and it needs to be kept in the same directory as
 ALOHA). It allows you to use a simple electronic map of your
 city or community with ALOHA. When you open such a map
 in BitPlot, mark the location of a spill on the map, and run a
 footprint calculation  in ALOHA, BitPlot will display  the
 ALOHA footprint on your map.

 BitPlot can use any map saved as a Windows device-indepen-
 dent bitmap (.bmp) file. Such files have names ending with a
 .bmp extension.  BitPlot cannot directly use files produced
 with  vector-based graphics programs such as AutoCAD.
 However, it is possible to convert many vector-based graph-
 ics files to  .bmp format by first converting them to .pcx
 format. BitPlot cannot use MARPLOT maps; use MARPLOT
 if you wish to plot an ALOHA footprint on a MARPLOT map.
 Refer to the MARPLOT manual for information about how to
 do this.

 Plotting an ALOHA footprint in BitPlot
Once you have created a background map for footprint plot-
 ting, and have saved it as a .bmp file, you can load it into
BitPlot and  plot a footprint on it. You must be running both
ALOHA and BitPlot simultaneously in order to do this.
                                                                     D-l

-------
 Appendix D: BitPlot
 In ALOHA, choose a chemical, enter atmospheric conditions,
 complete a source option, and ask for a footprint. If BitPlot is
 present in your ALOHA directory, ALOHA will display a hierar-
 chical BitPlot menu item under its Sharing menu.  Select Go to
 map from the BitPlot menu item to launch BitPlot or to bring it
 forward if it is already running.
                            Sharing
                             BitPlot
Go to map
 Opening a^new map
 When you first open BitPlot, the program will display a dialog box
 titled "Where is the map?"  (You can access this dialog later by
 choosing Open Map... from BitPlot's File menu.) Choose the map
 file that you'd like to open.  Click OK to open the map.
                           Where is the map?
                               cA
         U«t Fix of Iyp«:
         |Aloh«M«>Fi««r.BMPl|
D-2

-------
                                   Appendix D: BitPlot
Entering the map scale
Next, you'll need to enter your map scale. You will see your
map displayed on your screen inside a scrolling window.
You'll need to know the distance between any two points
visible on your map. These can be physical places, such as the
grocery store on Main Street and the Post Office on Elm, or
tick marks on a map legend. We recommend that whenever
you create a map for use with ALOHA and BitPlot, you place
a scale bar in the upper left corner to facilitate setting the map
scale. Scroll the map  until both points are visible on your
screen. Move the cross-hair cursor to the first  point, click
your mouse button once, then move the cross-hair to the
second point and click the mouse button again.
                                                 D-3

-------
 Appendix D: BitPlot
 You'll see the following dialog box:
                          Scale by Mouse
          Distance Equals:    I
              OK    | |  Cancel   |  |  Redo  | |   Help   |
 Enter the distance between the two points in the input field
 next to 'Distance Equals:'. Click on the pull-down units menu
 and choose appropriate distance units. If you madea mistake
 when you chose  your two points,  click Redo.  You'll be
 returned to your map for another opportunity to choose two
 points and set a distance. Click OK when you're finished.
 Locating the spill source
 After you click OK, you'll see your map again on your screen.
 Scroll the map until you can see the spill location on your
 screen.  You can navigate rapidly around on your map by
 clicking on the approximate spill location on the small map in
 the Quick Scroll window in the lower left corner of the screen.
 The full-sized map will center on the point that  you clicked.
 Once you have located the spill point on the full-sized map,
 click once directly on it. You will see a blinking red cross-hair
 mark at that point.  If you make a mistake, just click again on
 the correct location; the cross-hair mark will be  relocated  to
 the new click point. Once you are satisfied, click OK to set
 your source point.
D-4

-------
                                                        Appendix D: BitPlot
                                          Pnsifinn ihc Simrcc
                     r  IOKI   i
                     (Me* Sort
                                Ms* • sura tocMwi on
    Remember that
   ALOHA dpes not
    axotm for hits,
   vateys. and other
 terrain types when}
    makes footprint
   calculations. The
 footprint that you wil
    see in BitPlot wil
simply be plotted over
         the map.
Displaying the footprint
If a footprint is already displayed in ALOHA, it will auto-
matically be drawn on your map in BitPlot.  (If you haven't
completed footprint calculations in ALOHA, choose Go to
ALOHA from BitPlot's Sharing menu to return to ALOHA or
to start ALOHA if it's not yet running.  Complete footprint
calculations in  ALOHA, then choose 'Go to map' from the
hierarchical BitPlotmenu item under ALOH A's Sharingmenu
to return to BitPlot; your footprint will automatically be
drawn on the BitPlot map  when you do so.)

-------
 Appendix D: BitPlot
  Copying, printing, and modifying the footprint
  You may choose to change the line thickness and color of the
  footprint and the confidence lines drawn by BitPlot. Choose
  from among the hierarchical Line Color and Line Thickness
  menu items in the Options menu to make these changes.
  Checkmarks in the menu
  will identify the colors and
  thicknesses that you  have
  chosen. Also, the settings
  that you choose  will be
Option?
 saved and will be in effect
 for your next BitPlot ses-
 sion.
 Exposition Source
 Footprint Line Color
 Footprint Line Thickness
 Confidence Line Color
 Confidence Line Thickness
 Choose Copy from the Ed it menu if you wish to copy the map
 and footprint displayed in Bit Plot's window into the Win-
 dows Clipboard.

 Choose Print from the File menu to print the footprint dis-
 played on the  background  map.  Note that printing of
 bitmapped graphics from BitPlot can be very slow, because
 the graphics must be resized before  being printed.

 Getting a Concentration vs. Time graph
 If you'd like to see ALOHA's Concentration vs. Time graph
 for a location on your map in BitPlot, just double-click on that
 point on the map.  ALOHA will come forward automatically,
 and will  display a Concentration graph for your location.
 When you've finished viewing the graph, choose Go to map
 from the BitPlot submenu  under ALOHA's Sharing menu to
 return to BitPlot.
                               When you indicate a
                               location to ALOHA by
                               clicking on your map in
                               BitPlot, ALOHA wi
                               remember the location in
                               terms of its fixed east*
                               wost, north-south
D-6
                                                              J

-------
                                                             Appendix D: BitPlot
                          If you later wish to reposition the source location, choose
                          Reposition Source from the Options menu. You can close the
                          map by choosing Close Map... from the File menu. You also
                          can open a new map at any time, by choosing Open Map...
                          from the File menu.  Opening a new map will automatically
                          close any map that you had already opened.
               Figure E-1.
An ALOHA footprint displayed on
   a background map in BftPbt
                          If you won't be using BitPlot..
                          If you do not wish to use BitPlot, you may remove it from your
                          computer by deleting the program 8itPlot.exe and its associ-
                          ated help file BitPlot.hlp from your ALOHA directory.
                                                                           D-7

-------
 Appendix D: BitPlot
 Converting .poc files to use with BitPlot
 Graphic files saved in .pcx format are a common type of
 bitmapped graphic file available to users of DOS and Win-
 dows.  This is a typical format for maps or other images
 created using a scanner.

 You can easily convert .pcx files to .bmp files with your
 Paintbrush program/ which should have come packaged with
 your copy of Windows. If you have a map in .pcx format that
 you would like to use with BitPlot, follow these steps to make
 a .pcx to .bmp conversion:

 I     Open your .pcx file in Paintbrush. Choose Open from
       the Paintbrush File menu to do this. Click once to
       highlight the name of your map file, then click on the
       OK button.

 2     Next, choose Save As from the Paintbrush File menu.
       Choose Monochrome bitmap (.BMP) from  the
       pulldown list of file types. The file name extension for
       your file will automatically change to .bmp, the appro-
       priate extension for files to be used with BitPlot. (You
       may also save BitPlot maps as 16-color bitmaps - but
       you will rarely want to  do so.  Color graphic files
       require about four times as much space in memory as
       monochrome maps.)

 3     Finally, click OK to save your converted map file.  It's
       now ready to be loaded into BitPlot whenever you
       need it.
D-8


-------
Glossary
ALOHA
ALOHA Helps

ALOHA
Resources

Aerosol

AlohaSpy
The air dispersion model, Areai Locations of
Hazardous Atmospheres, also known as the
CAMEO Air Model. (ALOHA is a trademark of
the U.S. Government.)

•The file containing all of the text that ALOHA
uses during on-line Help inquiries.

The file that con tains most of the resource code
for ALOHA.

Liquid or solid particles suspended in a gas.

AlohaSpy  is a companion application to
ALOHA. Use it to view or print ALOHA model
runs.
Ambient
 pressure

Ambient
saturation
concentration
Ambient
temperature
The atmospheric pressure at a given location.
The concentration of the vapor in equilibrium
with the atmosphere. The value shown on the
ALOHA screen represents the maximum con-
centration at which the vapor could be sus-
tained in a closed room at the given (ambient)
temperature and pressure. Substances that are
gases at ambient temperature and pressure have
an ambient saturation concentration of 100%,
or 1,000,000 ppm.

The temperature of the air at a given location.
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Glossary
Anhydrous
Without water. Some chemicals are commonly
shipped or stored as a solution, using water as
the solute.
Archive data
Atmospheric
stability
An option that allows an ASCII tab-delineated
file Ito be created  from data transmitted to
ALOHA by a meteorological station (SAM).

A measure of the tendency of a "parcel" of air to
move upward or downward. In the air model
the stability is scaled from A-F, where  A im-
                                « -    *
plies very unstable conditions and F is for very
stable conditions.
Automatic
update
Average

Boiling point
An option that lets you automatically update
all visible windows that are opened in ALOHA
each time that location, building type, source
strength, or display options are changed (see
Calculate).

The sum of n values divided by n.

The maximum  temperature at which  a
substance's liquid phase can exist in equilib-
rium with its vapor phase. Above the boiling
point a liquid vaporizes completely. (The boil-
ing point is also the temperature at which the
vapor pressure of a liquid is equal to the ap-
plied atmospheric pressure.)  The boiling point
depends on the  chemical's  composition and
pressure.  As pressure increases, the boiling
point of a substance also increases. The "nor-
mal" boiling point is the temperature at which
a liquid under one atmosphere of pressure boils.
8-2


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                                                       Glossary
 Calculate
 CAMEO Air
 Model
 For example, the normal boiling point of pure
 water is 100°C Because pressure variations can
 be significant within a tank or pipe, the tem-
 perature at which a liquid boils under these
 conditions can differ significantly from its nor-
 mal boiling point.

 Located on the Display menu, this option lets
 you choose whether the windows in ALOHA
 will be updated manually or automatically.

 The air dispersion model that is used in con-
 junction  with Computer-Aided Management
 of Emergency Operations (CAMEO™ 4.0). The
 CAMEO Air Model is also known as ALOHA.
ChemLJb
Chem Manager
ALOHA's library of chemical properties.  This
library contains available physical and toxico-
logical properties for each chemical in ALOHA.

An application that  can be used to perma-
nently add, modify, or delete chemicals in the
ChemLib.
CityLJb
Cloud cover
Computational
ALOHA's location  library. This  library con-
tains latitude and longitude, elevation, and time
zone information.

The fraction of the sky overhead that is ob-
scured by clouds.

Located  on the SetUp menu, this option lets
you select the type of dispersion calculation to
use in ALOHA (Gaussian or heavy gas). You
can also  change the dose exponent in the dose
vs. time  equation with this option.
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Glossary
Concentration
The amount of a chemical in the air. It is usually
expressed in ppm (by volume) or milligrams
per cubic meter.
 Conservative
 estimate
An estimate is "conservative" if it is an overes-
timate.
 Continuous
 source
A release of pollutant into the air that lasts for
a period of  time.  The maximum time that
ALOHA considers is sixty minutes.
Crosswind
The direction perpendicular, or at right angles,
to the wind.
 Cryogenic
A term relating to substances at low tempera-
tures. For purposes of the air model, this term
refers to the use, storage and possible spilling
of gases liquefied by refrigeration.
 DEGADIS
DEnse GAs DISpersion model. These are the
computations that ALOHA uses to calculate* the
dispersion of a heavy gas.
DIPPR
Design Institute for Physical PRoperty data.
Many of the chemicals in ALOHA's chemical
library use physical and chemical data from
DIPPR.
Daylight
savings time
One hour is added to the local time during the
spring for most U.S. locations; ALOHA checks
the da te that you enter and automatically makes
this correction. If you select a location where
the daylight savings time correction is unknown
(e.g., outside the U.S.), ALOHA will ask you for
this information.
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                                                        Glossary
Density

Direct Source
Dispersion
Dose
Dusts
Eddies
The mass of a substance per unit volume.

A source option that allows you to enter the
amount of vapor entering the atmosphere. This
can be entered as an instantaneous or continu-
ous release.

The distribution of molecules or finely divided
particles into a gaseous or liquid medium (e.g.,
the distribution of a toxic chemical cloud in the
atmosphere).

The accumulated amount of chemical to which
a person is exposed.

Fine, solid  particles at rest or suspended in a
gas (usually air).  These may have damaging
effects on the environment, may be dangerous
by inhalation or contact, and frequently consti-
tu te an explosion hazard when dispersed in air.

Parcels of air of various sizes that leave their
normal position within an otherwise orderly,
smooth flow. For example, air that encounters
an obstacle must go over or around it.  This
change in the direction of air flow often causes
"swirls" of air, or eddies, to tumble off the back
of the obstacle. Impediments to airflow can
range from simple friction (grass) to larger ob-
stacles (buildings), leading to eddies generated
at many different sizes.
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Glossary
 Entrainment
Flash
Footprint
Freezing point
Fumes
 The mixing of environmental air into a preex-
 isting organized air current so that the environ-
 mental air becomes part of the current. For
 example, as a toxic cloud moves and mixes air
 into it, the pure gas cloud quickly becomes a
 gas/air mixture.

 The sudden vaporization of a liquid. This most
 often occurs when a chemical is a  gas at stan-
 dard temperature and pressure, but is stored as
 a liquid by pressurization. If the storage con-
 tainer  is breached, the  sudden reduction in
 pressure can superheat the material (leave the
 material in a liquid state above its boiling point),
 at which point it will flash boil.

 One of ALOHA's graphical outputs. The "foot-
 print"  gives a picture that shows an overhead
 view of the ground-level dispersion of a vapor
 cloud out to the level of concern that you set.

 The temperature at which the solid and liquid
 phases of a substance exist in equilibrium. The
 freezing point depends on the chemical compo-
 sition and the applied pressure. The "normal"
 freezing point is defined at a pressure of one
 atmosphere. For example, the normal freezing
 point of water is 0°C.

The characteristic smoky appearance and chok-
 ing cloud resulting from the release of fuming
materials, such as highly reactive liquids, gases,
or molten metal (e.g., concentrated  hydrochlo-
ric acid, sulfur monochloride). Fuming corro-
sive materials produce dense, choking, smoke-
8-6

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                                                       Glossary
                      like emanations on contact with the moisture in
                      air. Some liquefied gases that react with water
                      when they evaporate may also be said to fume
                      (e.g., anhydrous hydrogen fluoride, anhydrous
                      hydrogen chloride). Fumes from hot or molten
                      metals may not have a dense, smoke-like ap-
                      pearance but are hazardous, usually by inha-
                      lation.
GMT
Greenwich Mean Time or Coordinated Univer-
sal Time. The reference time along the prime
meridian or 0° longitude at Greenwich, En-
gland.
Gas(es)
A very even dispersion of molecules of a mate-
rial above its boiling point at the ambient tem-
perature with the ability to occupy a space with
uniformity. Typical gases include oxygen, air
(a mixture of nitrogen, oxygen, and trace
amounts of other gases),  chlorine, and carbon
dioxide.
Gaussian
Ground
 roughness
A bell-shaped, or "normal," probability curve.
ALOHA can use a Gaussian distribution to de-
scribe the movement and spreading of a gas
that is neutrally buoyant

A description of the size of the obstacles on the
ground that the toxic cloud is moving over. In
ALOHA, you can select either Urban or Forest
or Open Country, or enter a roughness length.
                                                          8-7

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Glossary
Ground
temperature
Ground type
Heavy gas
IDLH
The temperature of the ground surface. The air
model uses the temperature of the ground to
estimate the amount of heat that is transferred
from the ground to an evaporating puddle.

The physical  composition  of the ground  be-
neath a puddle. The ground type is especially
important for a spill of refrigerated liquids,
where the heat required for evaporation is of*
ten supplied by the ground rather than by the
atmosphere.
                                 «.

A gas that has a density greater than that of the
surrounding air. There a re several reasons why
a gas may be a heavy gas, or may behave like a
heavy gas:  1)  because its molecular weight is
greater than that of air (29 kg/kmol), 2) because
it is stored cryogenically (refrigerated), or 3)
because aerosols form in sufficient amounts
during a release to make the mixture behave
like a  heavy gas.

Immediately Dangerous to Life or Health. This
value represents a maximum concentration from
which a person could escape within 30 minutes
without any escape-impairing symptoms (like
severe eye or respiratory irritation) or any irre-
versible health effects. (NIOSH/OSHA Pocket
Guide to Chemical Hazards, 1987).
8-8

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                                                       Glossary
 Infinite tank
 source
 Instantaneous
 source
 An approximation used to describe a situation
 in which the volume of a discharging, pressur-
 ized tank is much greater than the volume of a
 long pipe connecting it to its discharge point.
 The pressure and temperature of the material
 in the pipe can then  be taken to be  constant
 throughout the duration of the release.

 A release  that occurs very rapidly.  ALOHA
 assumes that an instantaneous release lasts one
 minute.
Inversion
Latent heat of
vaporization

Level of
concern

Manual update
Mass
An atmospheric condition in which a shallow,
unstable layer of air near the ground lies be-
neath a markedly stable layer of air above. The
height  of the abrupt change of atmospheric
stability is known as the "inversion height."

An inversion can cause the surface concentra-
tion of a pollutant to remain considerably higher
than might be expected:

The amount of heat released when a unit mass
of a substance vaporizes.

The concentration at which you wish ALOHA
to draw a footprint.

When this option is selected, the visible win-
dows will be updated only when you  select
Calculate Now from the Display menu.

Amount of chemical by weight.
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Glossary
 Maximum
 sustained
 average
 release rate
Maximum
computed
release rate
Military time
Mist
 The highest average release rate sustained for
 at least a minute. This value will be seen on the
 source strength graph. Note that a pressurized
 release may have a very high rate for the first
 few seconds and a considerably lower release
 rate once the pressure inside the releasing ves-
 sel has been reduced. In this case, the maxi-
 mum sustained average release  rate may be
 considerably lower than the maximum  com-
 puted release rate.

 The maximum release  rate that  could occur
 from the given scenario. This rate can be sig-
 nificantly higher than the maximum sustained
 average release rate seen on the source strength
 graph of ALOHA, particularly in the case of a
 pressurized release. (See maximum sustained
 average release rate).

 Time based on a 24-hour clock (e.g., 1330 is the
 military expression of 1:30 p.m.). The spill time
 for the air model is taken from either the inter-
 nal clock in the Macintosh or the spill time that
 you enter. The time that you enter must be in a
 military time format.

 A dispersion of fine droplets in  a gas cloud
 (mostly air) resulting from air entrainment,
spray atomization, or condensing  of a material
as its vapor cools. Mists are also referred to as
aerosols.
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                                                       Glossary
 Mixing
 For the purposes of ALOHA, mixing is the
 process by which the air gets mixed.  This
 includes both mechanical (wind and ground
 roughness-induced) and thermal  (heat-in-
 duced) mixing.
Mole
A quantity of a substance that contains 6.02 x
10" molecules.   The molecular weight  of a
chemical is the mass of one mole of that chemi-
cal.
Molecular
weight
The sum of the atomic weights of all the atoms
in the molecule (the weight of one molecule of
the chemical).
Neutrally
buoyant gas
A gas that behaves like air or has the same
density as air.
Open country
An area of few, or widely spaced, obstacles,
such as a parking lot or open field.
Parts per
billion (ppb)
Commonly used to express the concentration
of a gas or vapor in air: parts of vapor or gas per
billion parts of contaminated air. ALOHA uses
ppm (1 ppm = 1 ppb x .001).
Parts per
million (ppm)
Commonly used to express the concentration
of a gas or vapor in air: parts of vapor or gas per
million parts of contaminated air. In ALOHA,
ppm is by volume, not by weight.
Particulates
Fine, solid particles. ALOHA does NOT model
particulate dispersion.
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Glossary
 Patchiness
 Pipe
Pipe pressure
Plume
Plume rise
Isolated puffs of higher concentrations of a pol-
lutant often caused by eddies or by the varying
orientation of a dispersing chemical  cloud.
Think of patchiness as campfire smoke, which
varies with wind direction, speed, and inten-
sity of turbulence.

A type of carrier for hazardous materials.
ALOHA  considers only gas leaks (no liquid
leaks) from pipes. Pipe lengths must be at least
200 times the diameter of the pipe.

The pressure of the gas inside a pipe before the
leak occurred.

A cloud  of dispersing chemical, referred to
throughout this manual as "footprint."

The term used for gases in a plume being trans-
ported upward  (e.g., out  of a smokestack).
ALOHA does not incorporate plume rise calcu-
lations.
Processed data
A menu item that will display the meteorologi-
cal station's data. These data have been pro-
cessed.
Puddle

Puff


Raw data
Liquid pooled on the ground.

In short-duration footprints, the cloud of dis-
persing chemical appears as a series of puffs.

An option that displays unprocessed ASCII data
that has been transmitted by the meteorological
station.
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                                                        Glossary
 Relative
 humidity
 Release
 duration

 Rough pipe
 The percentage of the measured vapor pres-
 sure to the saturation vapor pressure at the
 observed temperature. ALOHA lets you select
 dry, medium, or wet, or enter a percent value.

 The period of time over which the release oc-
 curs. ALOHA limits this period to one hour.

 An interior pipe surface that is pitted or cor-
 roded.
 Roughness
 length
 Running
 average
SAM
STP
Saturation
concentration
 A measure of the size of the "roughness ele-
 ments," such as grass, trees, or buildings, that
 act as obstacles to the movement of air. The
 average size of roughness elements determines
 ground  roughness. See Z .

 An average taken in overlapping segments (e.g.,
 the average  of  the first  five values, then the
 average of the  second through sixth  values,
 then the average of the third through seventh
 values, etc.)- See Average.

 Station for Atmospheric  Measurements. The
 meteorological measurement station that can
 be directly linked to the  air model through a
 computer serial port.

 Standard Temperature and Pressure.  Chemi-
 cal  properties (e.g., boiling point) are often
 expressed  at standard temperature, 0°C and
 standard pressure, one atmosphere.

The maximum concentration that a vapor in air
can maintain without raining out.
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Glossary
 Serial port
 A data interface on the back of the computer
 that can be hooked up to other peripheral de-
 vices, such as a SAM, scanner, printer, or digi-
 tizing tablet., ALOHA uses a serial port to re-
 ceive ASCII  data from SAM.
 Sigma theta
Smoke
The standard deviation of the wind direction.
The SAM Station transmits a sigma theta based
on a five-minute running average. The stability
class is. then determined by the sigma theta and
the wind speed.
                                «»    «

A mixture of gases, suspended solid particles,
and vapors resulting from the combustion pro-
cess. Color varies from thick black for hydro-
carbon fires to light gray for cellulose (wood)
smoke burning in an air-rich environment. Class
A (wood/paper) fires release a rich yellow to
brown smoke in air-lean environments such as
basements  or concealed spaces.  Hazardous
components may include varying percentages
of HC1, NO/s, sulfur compounds, acrolein, and
free radicals.
Smooth pipe

Solution
A smooth interior pipe surface.

A mixture of compounds in which the mol-
ecules of the chemical are intermixed. Many
commonly encountered solutions are mixtures
of soluble chemicals and water. For example,
alcohol in water or table salt in water
8-14

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                                                       Glossary
Source height
Source
strength
Stability class

Stable
The distance above the ground level from which
a chemical has been released. This allows you
to model releases from elevated pipes or other
above-ground sources, but you must know the
amount entering the atmosphere and choose
the Direct source option.

The amount of a pollutant entering the atmo-
sphere, either all at once (instantaneously) or
over a period of time (continuously).

(see Atmospheric Stability).

A term used in atmospheric dispersion to indi-
cate that the atmosphere has little tendency to
mix.
Stack Windows
Located on the Display menu, this option lay-
ers all the windows containing ALOHA data on
the computer screen.  The active window will
be the front window and only the titles of the
other windows will remain visible.
Standard
deviation
Street canyon
A measure of how much individual values de-
viate from the average value.

An area with high-rise buildings that channel
the wind parallel to the streets.
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Glossary
 TLV-TWA
Threshold Limit Value-Time Weighted Aver-
age. The time weighted average concentration
for a normal 8-hour workday and a 40-hour
workweek, to which nearly all workers may be
repeatedly exposed, day after day, without ad-
verse effects (Threshold Limit Values and Bio-
logical Exposure Indices for 1990-91, American
Conference of Governmental Industrial Hygien-
ists).
Threat distance
The downwind distance along the centerline of
a chemical cloud, out to the level of concern
that  you set. ALOHA's footprint length, re-
ported in the Text Summary window, is a threat
distance.
Threat zone
The area downwind of the source of an escap-
ing pollutant, within which concentrations of
pollutant are high enough to threaten people.
ALOHA's  footprint is a diagram of a threat
zone.
Text summary
screen
Tile Windows
The window always open while you are in
ALOHA. This window summarizes your input
and the  model's calculations as you move
through ALOHA.

Located on the Display  menu, this option
places all of the windows containing ALOHA
data next to each other on the computer screen.
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                                                       Glossary
Time-
dependent
dispersion
Time-
dependent
source
Two-phase flow
Unstable
Urban
Vapor
Vapor pressure

Volatility


Wind direction
A time-dependent value is  something that
changes over time. ALOHA's dispersion mod-
ules take into account release rates that change
over time.  The dispersion modules do NOT
account for changing atmospheric conditions.

A release rate that changes over time.
A gas-aerosol mixture that  may be released
when a pressurized liquid is stored in a tank.

A term used in atmospheric dispersion to indi-
cate that the atmosphere has a great tendency
to mix.

For the purposes of ALOHA, an area where
there are a lot of obstacles interrupting the flow
of air. This would include suburban areas as
well as areas that are forested.

The gas produced by the evaporation of a liq-
uid or sublimation of a solid. For example, the
gas produced when liquid water evaporates is
water vapor.

The pressure of a vapor in equilibrium with its
liquid or solid form at a given temperature.

The tendency of a liquid  or solid  to form a
vapor.

A measurement of which way the wind is com-
ing from, expressed in either angular or one- to
three-letter directional terms.
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Glossary
 Wind rose
A diagram that summarizes the last ten values
received from the SAM for wind direction and
speed.

A term used to define ground roughness. Ap-
proximately 1/30 of the height of the underly-
ing obstacles.
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 References
Brutsaert, Wilfried.  1982. Evaporation into the Atmosphere:
Theory, History, and Applications. Boston: D. Reidel Publish-
ing Company. 299pp.

Daubert, I.E. and R.P. Danner. 1989. Physical and Thermody-
namic Properties of Pure Chemicals: Data Compilation.  Bristol,
Pennsylvania: Hemisphere Publishing Corporation.  Three
Volumes.

Havens, Jerry, University of Arkansas, Fayetteville, NOAA
DEGADIS evaluation report,  memorandum to Jerry Gait,
NOAA, 1990.

Havens, Jerry and Tom Spicer.  1990. LNG Vapor Dispersion
Prediction with the DEGADIS Dense Gas Dispersion Model.
Topical Report (April 1988-July 1990). Chicago: Gas Research
Institute.

National Oceanic and Atmospheric Administration.  1992.
CAMEO™ 4.0  for  the Apple Macintosh Computer.
Washington, D.C.: National Safety Council. 235pp.

National Institute of Occupational Safety and Health (NIOSH).
1990.  Pocket Guide to Chemical Hazards.  Washington, D.C.:
U.S. Government Printing Office.
                                                9-1

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 References
  Spicer, Tom and Jerry Havens. 1989. User's Guide for the DEGADIS
  2.1 Dense Gas Dispersion Model. Cincinnati: U.S. Environmental
  Protection Agency.  EPA-4SO/4-89-019.

  Turner, D. Bruce. 1974. Workbook of Atmospheric Dispersion Esti-
  mates. Springfield, Virginia: National Technical Information Ser-
  vice.

  Turner, D. Bruce and Lucille W.  Bender.  1986. Description of
  UNAMAP (Version 6). Springfield, Virginia: National Technical
  Information Service. 13pp.
                                                     ft r   ,
  Wilson, DJ. 1987. Stay indoors or evacuate to avoid exposure to
  toxic gas? Emergency Preparedness Digest I4(l):19-24.
9-2

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 Index
 adding chemicals (see
    ChemManagerand ChemLib)
 adding locations, 4-5 to 4-6
 advection, 2-2
 aerosol, 5-31
 air exchanges, 4-7,4-8
 air dispersion modeling, 2-2 to
    2-13, 5-47
 air infiltration rates (see air ex-
    changes)
 air temperature (see temperature)
 ALOHA
    allowable input, B-12
    design of, 2-1,2-2
    features, 2-2,2-3,2-4
    Gaussian model, 2-2 to 2-3,2-7
    heavy gas model, 2-2 to 2-7
    installing
       Mac, 1-5 to 1-8
       troubleshooting, B-8
       Windows, 1-9 to Ml
    running
       Mac, 1-8
       Windows, 1-12
    use caution, 2-8 to 2-13
       doesn't consider, 2-13
ALOHA DECADE, 2-4 to 2-5
ALOHA Helps, 1-11 to 1-12,9-10
ALOHA Resources, 1-7
AlohaSpy, 1-8,3-2 to 3-3,5-10, C-l
    toC-3
    Archive, C-2
    Edit menu, C-2
    File menu, C-2
    SAM, 1-2,5-27,5-28
    Stack, C-3
    Tile,C-3
    troubleshooting, B-7
Archive data, 5-26
aluminum phosphide, 2-13
Atmospheric (menu), 5-11 to 5-29
atmospheric stability class, 5-12 to
    5-15,5-47, A-l-5,A-2-5 to
    A-2-6,A-5-6
                                                           10-1

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 Index
 bell-shaped curve, see Gaussian
     distribution
 BttPtot, B-9, D-l to I>8,7-1 to 7-3
     footprint, D-l, D-5, D-6
     map scale, D-3
     MARPLOT DOS, 7-3
     new map (opening a), D-2
     .poc to .bmp file conversion, D-8
     SAM, 5-23
        Archive Data, 5-26 to 5-27
        Macintosh, B-9
        Processed Data, 5-28 to 5-29
        Raw Data, 5-27 to 5-28
        SAM Options, 5-26 to 5-29
        Windows, B-9
        Wind Rose, 5-29
    spill source (locating), CM
 Building Type, 1-2,4-7 to 4-9, A-20
Calculate, 1-4,6-17 to 6-18
Calculate Now, 1-4,6-18
chemical
    mixtures, 2-13
    reactions, 2-8,2-13
    required property fields, 5-3 to 5-5
    solutions, 2-13
chemical library, (see ChemLJb)
ChemLib, 1-7,5-2 to 5-11 (see also
    ChemManager)
    adding a chemical, 5-5 to 5-7
    modifying a chemical, 5-7 to 5-8
    deleting a chemical, 5-9
    saving changes, 5-10 to 5-11
 QiemManager,l-8,5-5 to 5-11
 CityLib, 1-8 (see also Location)
 dosed-off pipe (Tank source), 5-43,
    A-3-8
 cloud cover, 5-12,5-21 to 5-22,5-26
 Computational, 2-7,5-46 to 548
    Let model decide, 1-3,547
    Use Gaussian dispersion only,
    1-3,547
    Use Heavy Gas dispersion only,
    1-3,2-7,547,549
    Concentration, 14,6*1,6-9 to
       6-14,7-6
       and dose location, A-2-12
       indoor, 6-1,6-9
       outdoor, 6-1,6-9
       over time, 548
    Concentration vs. Time, 6-9 to
       6-10
concentration patchiness near the
    source (see near-field patchi-
    ness)
confidence lines, 2-9,6-7to 6-8
continuous release, 5-30 to 5-33
    dose and concentration vs. time
    graphs, 6-14
    source strength graph, 6-15
Copy, 6-15
crosswind distance, 2-3,6-11
cryogenic gases, 2-7
10-2

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                                                                 Index
 DECADE, 2-4 to 2-8
 DIPPR, 5-3,5-4,5-11
 Date & Time
    Mac, 1-2,4-9,5-35, A-l-3, A-2-7,
        A-3-3,A-4-9,A-64
    Windows, A-54
 degrees true, 5-19
 deleting a chemical (see ChemUb)
 deleting a location, 4-7
 diffusion, 2-2
 Direct source option, 5-31,4*32
    to 5-33,5-18,6-15 to 6-16
 dispersion choices in ALOHA, 2-7
    to2-S
 dispersion modeling (see air
    dispersion modeling)
 Display menu, 1-1,1-3 to 1-14,
    5-49,6-1 to 6-18
    MARPLOT, A-3-10 to A-3-12
    Options, 1-3,6-3 to 6-5
dose, 1-3,1-4,5-J6,5-48,6-1,6-12 to
    6-14
    concentration, 6-9 to 6-12,6-14
       indoor, 6-1,6-9to 6-10
       outdoor, 6-1,6-9 to 6-10
       over time, 5-48 to 5-49
Dose vs. Time, 6-8,6-11,6-14
double-storied building, 4-7 to 4-9
 £
eddies, 2-12
Edit menu, 1-2,3-1,3-4
    AlohaSpy, 3-2 to 3-3, C-l to C-3
elevated source, 5-32 to 5-33
enclosed office building, 4-7 to 4-9
evaporation rate, 5-34 to 5-36
File menu, 1-1,1-2,3-1 to 3-3
    AlohaSpy, 3-2 to 3-3,5-10, C-l to
       C-3
    MARPLOT, A-3-10
Finder, 1-8
fires, 2-13,5-32
flash boil (see two^phase flow)
footprint, 1-3,1-4,2-4 to 2-5,2-6,
    2-9,2-11,6-1,6-3,6-4 to 6-5,6-6
    to 6-8,6-9,6-12 to 6-13, A-l-16
     BitPlot, 1-2, A-5-1 to A-5-21, B-9,
       D-l,D-5toD«
     concentration, 6-7 to 6-14
     DEGADIS,2-4to2-5
     Gaussian, 2-3,5-7,547 to 5-48
     heavy gas, 2-4,2-6,2-7,2-8,5-47
       to 548,6-8,8-10
     location (designating a), 6-10 to
       6-12
     MARPLOT, A-4-1 to A-4-22,
       A-6-1 to A-6-23
     plot on grid, 6-5 to 6-7
     SAM, 6-7
     troubleshooting, B-2
                                                               10-3

-------
 Index
       uncertainty lines, 2-9,6-7 to 6-8
       user-specified scale, 64,6-5
       wind shifts, 2-11
 fugitive emissions, 2-2
 gases (heavy) (see heavy gas
    calculations)
 gas in a tank, 5-38 to5-39
 Gaussian, 2-2 to 24,2-7 to 2-8,2-12
      calculations, 2-8,5-11,5-21,547,
      chemical properties required,
        54to5-5
      footprint, 1-3,2-3,2-4, 2-12,5-47
        to 549
 Go to Map, A-4-20
 gravity, 2-6,2-12 (see also slump-
    ing)
 ground
    level release, 5-12, 5-32 to 5-33
    roughness, 5-8 to 5-21,5-25, A-l-5,
        A-2-6, A-3-5, A4-12, A-5-7,
        A-6-6
    temperature, 5-34 to 5-35,5-42
    type, 5-34,5-35
H
hardware considerations,
    Macintosh, 1-8
    Windows, Ml
    heat transfer, 5-12 to 5-13,5-34 (see
    also ground temperature)
 heavy gas, 1-3,24 to 2-8,2-13,5-11,
    5-21, Wl, 5-47 to 548,6-8,6-17,
    A-2-9toA-2-14
    chemical properties required,
        54to5-5
    footprint 2-5,2-13
    time steps,2-5
 Help (on-line), Ml to 1-13
 hole (in tank), 540 to 541
 humidity, 5-22,5-25,5-34, A-l-6,
    A-2-7, A-3-5 to A-3-6, A4-12,
    A-5-8,A-6-7
IDLH (see also level of concern),
    24,5-20,6-3 to 64
immediately dangerous to life and
    health (see IDLH)
indoor air dose calculations, 6-1,
    6-9
infiltration rates (see air changes)
infinite tank source, 543
Input (allowable), B-12
installing ALOHA
       Macintosh, 1-5 to 1-8
       Windows, 1-9 to 1-11
instantaneous release, 5-31,6-16
    Source Strength, 6-15
internal clock, 5-27
    Mac 4-9,4-10,5-26, A-l-3, A-2-7,
104

-------
                                                              Index
    Windows, A-54
 inversion, 5-14,5-15,5-16,5-24
 LOG (see level of concern)
 large obstacles (and footprint), 2-11
 leak size (see hole)
 Let model decide (see
    Computational)
 level of concern, 2-4,6-3 to 6-4 (see
    aJsoIDLH)
    user-specified, 64
 Loading (see installing)
 Locating spill source (BitPlot), D-4
 Location, 1-2,4-1 to 4-7,6-9 (see
    also City Lib)
    adding, 4-3 to 4-6, A-6-3
    deleting, 4-7
    modifying, 4-6
    troubleshooting, B-ll
        scale
           BitPlot, F>3
 mass of chemical in tank£-38 to
    5-39
 math coprocessor chip, 547,1-5,
    1-7,1-8,1-11
    Macintosh, 1-8
    Windows, Ml
 maximum computed release rate,
    5-30,5-5
 maximum average release rate,
    5-30, B-5
 mechanical stirring, (see mixing)
 memory (see also Finder and
    MultiFinder)
    Macintosh, 1-8
    Windows, 1-11
 met station (see SAM)
 mixing, 2-9,5-13,5-14,5-15
 mixtures (chemical), 2-13
 modifying the Location Index, 4-6
 MultiFinder, 1-8,7-4
M
MARPLOT, 7-3 to 7-6
MARPLOT-DOS, 7-3
Macintosh clock time, 4-9,4-10,
   5-26, A-l-3, A-2-7, A-3-3, A-4-9,
   A-64
Maps, 7-3 to 7-6, D-l to D-3
   BitPlot, D-l to D-3
   MARPLOT, 7-3 to 7-6, A-4-1 to
       A-4-22,A-6-ltoA-6-23
N
near-field patchiness, 2-8,2-12 to
   2-13
neutrally buoyant, 2-3
non-pressurized liquid (see tank)
non-pressurized release, 5-42
                                                            105

-------
 Index
 obstacles (see ground roughness)
 Open country, 5-18 to 5-21,8-11,
    A-l-5, A-3-5, A-6-6 (see also
    ground roughness)
 Options (Display menu), 1-3,6-1,
    6-3 to 6-5
    footprint, 6-4 to 6-5
 outdoor dose calculation (see dose)
 output units, 1-3,6-5
ppb, 8-11
ppm, 6-4,8-11
participates, 2-8,2-9,2-13
    patchiness (see near-field patdu-
    ness)
phosphine, 2-13
PICT (and MARPLOT), A4-1 to
    A-4-22
Pipe source option, A-3-1 to A-3-
    13,B-5
    diameter, 5-43 to 544
    gas, 5-43 to 544
    hole, 545 to 546
    length, 543 to 544
    liquid, 544
    rough, 5-44
    smooth, 544
plume spread (see footprint)
pressurized releases, 2-6,544,5-48,
    B-2
    non-pressurized release, 543
 PirintAlU-2
 Puddle, 5-31,5-33 to 5-36, S42 to
    543, B-5
    MARPLOT, A4-1 to A4-22
    diameter, 543
    temperature, 5-34,5-35,542,
        A4-14
radioactive chemicals, 2-2* • .   •
relative humidity (see humidity)
roughness (see ground roughness)
rough pipe (see pipe)
SAM, 1-2,5-23 to 5-29,6-7, B-4
    archive data, 5-26 to 5-27, B-8
    footprint, 6-7
    Macintosh, B-9
    processed data, 5-28
    raw data, 5-27 to 5-28
    SAM Option*, 5-26
    troubleshooting, B4, B-8
    Windows (BitPlot), B-9
    wind rose, 5-29
Save
    troubleshooting, B-6
Save As (see AlohaSpy)
scale (see map scale or Options)
sea smoke, 5-15
10-6

-------
                                                               Index
 set constant time (see Date &
    Tune)
 SetUp menu, 1-1,1-2 to 1-3,5-1 to
    549, A-l-3 to A-l-12, A-2-4 to
    A-2-10, A-3-3 to A-3-9, A4-9 to
    A4-15
    Windows, A-54 to A-5-1, A-6-5 to
        A-6-IO
 Sharing menu, 7-1 to 7-6
    BitPlot,7-l
    help, 7-5
    MARPLOT DOS, 7-3
    Macintosh, 7-1,7-3 to 7-6
        scale, A48 to A49
    maps, A-4-1  to A-4-22, A-6-1 to
        A-6-23
        scale, A4-21
    Set Source Point, A4-21
    sheltered surroundings, 4-8 to 4-9,
    A-2-3,A-3-6,A-5-3
 short pipe/valve (see tank)
 sigma theta, 5-28 to 5-29
 single-storied building, 4-7,4^8, A-
    2-3,A-3-6,a-5-3
 SiteData menu,  1-1,1-2,4-1 to 4-10,
    A-l-1 to A-l-3, A-2-1 to A-2-4,
    A-3-1 to A-3-3 A4-7 to A-W,
    A-5-2 to A-5-4, A-6-2 to A-64
 slumping (chemical cloud), 2-6,
    2-12
 smoke, 2-12,2-13
 smokestack, 2-2,5-32
smooth pipe (see pipe)
    solar radiation, 4-2,5-21,5-34 (see
    also cloud cover)
solutions (chemical), 2-13
Source
    height, 5-32 to 5-33
    locating (BitPk)t),D4
    SetUp menu, 5-30
    strength, 1-4,5-33,544,6-1,6-15
       to 6-17
Source Strength (Display menu),
    544,6-15 to 6-17
spherical tank, 5-37
spreading, (see diffusion)
Spy (see AlohaSpy)
stable atmospheres, 2-8,2-9 to 2-10
    and wind rose, 5-29
stability class (see atmospheric
    stability class)
Stack Windows, 14,6-2 to 6-3
    AlohaSpy, C-3
Station for Atmospheric
       Measurements (see SAM)
stirring (see mixing)
street canyon, 2-11,8-15
sun angle (see solar radiation)
r
TIGER, 7-3
TLV,3-16
Tank, 5-31,5-36 to 5-43,547, A-l-1
    toA-l-17,B-5
    chemical state in, 5-37 to 540
    gas in a tank, 5-38 to 5-39
                                                              10-7

-------
 Index
    leak location, 540 to 541
    liquid in a tank, 5-38
    non-pressurized liquid, 542
    rough pipe, 5-44
    size, 5-37
    smooth pipe/valve, 544
    temperature, 542
    unknown in a tank, 5-39
 temperature
    air, 5-18,5-34 to 5-36
    ground, 5-34 to 5-35
    pipe, 545
    puddle, 5-18,5<34,5-35,542,
        A-4-14
 -  tank, 5-18,5-37
 terrain steering effects, 2-8,2-10 to
    2-11
 Text Summary, 1-4,54,5-31,542,
    543,6-1,6-6, A-l-7, A-l-12, A-
    1-17, A-2-7, A-2-10, A-2-14, A-
    3-6, A-3-9, A-4-10, A-l-15, A-4-
    20, A-5-5, A-5-8, A-5-11, A-5-16,
    A-5-21, A-6-5, A-6-7, A-*-9, A-
    6-12, A-6-12, A-6-23, &-5, W
 threat zone (see footprint)
Threshold Limit Value (see TLV)
Tile Windows, 1-4,6-2
    AJohaSpy,C-3
tune (see Date & Tune)
    dependent release, 2*6,6-14,
       6-15106-15
    dose and concentration graphs,
       6-13 to 6-15
    Source options, 6-15 to 6-16
 topography, 2-1,2-8,2-11,2-13 (see
    also streeet canyon effect)
 troubleshooting, B-l to B-12
 two-phase flow, 2-7,5-31, A-2-9
 u
 uncertainty lines (see confidence
    lines)
 unpacking ALOHA files
    Macintosh, 1-5 to 1-8
    Windows, 1-9 to Ml
 unsheltered surroundings, 4-8 to
    4-9
 unstable atmospheres (see atmos-
    pheric stability class)
 Update Windows, 6-17 to 6-18
 Urban or Forest, 5-19 to 5-22, A-2-
    6,A-4-ll,A-5-6
 use caution, 2-8 to 2-13
 Use Gaussian dispersion only (see
    Computational)
 Use Heavy Gas dispersion only
    (see Computational)
 User input (Atmospheric menu),
    5-U5-23,S-26
VHP radio frequenc (for SAM),
    5-24
vapor pressure, 5-5,5-35
104

-------
                                                                Index
vertically oriented cylinder (tank),    £
    5-37
                                    Z. 5-19 to 5-21 (see also ground
volume                             ^           v
                                       roughness)
    puddle, Ml to 534               Zoom-in tool (MARPLOT), A-4-3
                                       I  A >,£
                                       toA-4-6
 w
wind
    around obstacles, 2-10 to 2-11
    direction, 2-10 to 2-11,5-16 to 5-18,
       6-7 to 6-8
    rose, 5-29
    shifts (see wind direction)
    speed, 2-8,2-9,5-15,5-16 to 5-18,
       6-8,6-11,6-12
    stability, 2-8,2-9 to 2-10,5-12 to
       5-15,547
    street canyons, 2-11,8-15
windows (Tile and Stack), 1-4,6-2
    to 6-3
    AlohaSpy,C-2,C-3
    updating, 6-17 to 6-18 (see also
       Calculate)
Windows1*1
    internal clock, A-54
    troubleshooting, B-ll
Workbook on Atmospheric Dispersion
    Estimates, 2-1
                                                               10-9

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