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Air Emissions Factors and Quantification

TANKS Emissions Estimation Software, Version 4.09D

***IMPORTANT NOTE - The TANKS model was developed using a software that is now outdated. Because of this, the model is not reliably functional on computers using certain operating systems such as Windows Vista or Windows 7. We are anticipating that additional problems will arise as PCs switch to the other operating systems. Therefore, we can no longer provide assistance to users of TANKs 4.09d. The model will remain on the website to be used at your discretion and at your own risk. We will continue to recommend the use of the equations/algorithms specified in AP-42 Chapter 7 for estimating VOC emissions from storage tanks. The equations specified in AP-42 Chapter 7 ( can be employed with many current spreadsheet/software programs.

Released October 5, 2006

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What Is TANKS?

TANKS is a Windows-based computer software program that estimates volatile organic compound (VOC) and hazardous air pollutant (HAP) emissions from fixed- and floating-roof storage tanks. TANKS is based on the emission estimation procedures from Chapter 7 of EPA's Compilation Of Air Pollutant Emission Factors (AP-42). The user's manual, available in Adobe Acrobat format and WordPerfect, explains the many features and options of TANKS. The program includes on-line help for every screen.


TANKS is designed for use by local, state, and federal agencies, environmental consultants, and others who need to calculate air pollutant emissions from organic liquid storage tanks.

Program Capabilities

TANKS uses chemical, meteorological, roof fitting, and rim seal data to generate emissions estimates for several types of storage tanks,including:
vertical and horizontal fixed roof tanks
internal and external floating roof tanks
domed external floating roof tanks
underground tanks

See the TANKS FAQ for additional information about TANKS.

The TANKS program employs a chemical database of over 100 organic liquids, and a meteorological database of over 240 cities in the United States. The program allows the addition of more chemicals and cities, if desired. TANKS is capable of calculating individual component emissions from known mixtures and estimating emissions from crude oils and selected refined petroleum products using liquid concentration HAP profiles supplied with the program.

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System Requirements

TANKS 4.09 will run on Windows XP desktops. The program requires 8 MB of random access memory (RAM). The installed program requires 8 MB of available hard disk space. TANKS is designed for operation from a PC's hard drive. Many users are able to share tank databases via LAN connections to increase the utility of the program.

You must have administrative rights to all folders on your desktop. The installation process installs files to the Windows system directory.

TANKS is not supported on desktops using Windows Vista or Windows 7. Suggestions and fixes for running TANKS on a Vista or Windows 7 platform will be posted whenever possible. Please see the "Errors and fixes" table below.

Installations requiring TANK program files to be resident on a LAN are not advisable and are beyond our support capabilities.

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How To Get A Copy Of TANKS

Version 4.09D of the TANKS software is available here.

You are advised to bookmark this web site and check it from time to time for information about updates to the TANKS program.

TANKS 4.09D - October 3, 2005 (TANKS 4.09D supersedes all previous versions of the TANKS software program.)

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What's new in 4.09D?

  • The program is now compatible with all versions of MS Access.
  • The program installation has been streamlined and the program files are smaller.
  • TANKS displays and prints reports with an Internet browser. The report formats have not changed.
  • Chemical Data:
    • The chemical data was updated with missing CAS numbers.
    • New compounds were added to the database.
    • Antoine's coefficients were corrected for several compounds.
    • A new partial speciation profile for gasoline oxygenated with ethanol was added.
  • Incorrect meteorological data was corrected.

Installation instructions - PLEASE READ(2 K) (TXT)
TANKS 4.09D Installation File Windows Installer file(6 MB) (MSI)
User's Manual for TANKS 4.0 The manual has not been updated (PDF) (87 pp, 646K)
Alternate TANKS 4.09D Installation File(13 MB) (If the Windows Installer file does not correctly install, use this file. Please read the installation instructions(2 K) . (EXE 12M))

TANKS 4.09D errors and available fixes


Determining monthly emissions.

One of the errors in TANKS is that it uses annual average liquid bulk temperature when computing monthly emissions rather than calculating a monthly liquid bulk temperature.  Since TANKS uses annual average liquid bulk temperature in the monthly calculations, a change in the temperature for one month will affect every month, in that changing one month changes the annual average. As such, the TANKS program will NOT adequately account for the monthly variations. Therefore, TANKS should NOT be used for determining maximum monthly true vapor pressure and users should not rely on the TANKS model for accurately determining monthly emissions in general. Users should rely on the equations specified in AP-42 Chapter 7.1 to perform those calculations.

Use Section 7.1 of AP42, Organic Liquid Storage Tanks to correctly calculate monthly emissions.
There are revised deck fitting loss factors in the 2006 update to Section 7.1 of AP42, Volatile Organic Liquid Storage Tanks. How can I include those in my TANKS program? Updating the fitting table in TANKS (PDF 101K)
For more detailed information about the deck fittings, see Section 7.1 of AP42, Organic Liquid Storage Tanks
When I create a MS Excel or MS Access report from TANKS, I don't know what all the fields mean. Field descriptions for MS Excel and MS Access reports from TANKS (PDF 2 pp, 50K)
For more detailed information about the fields, see Section 7.1 of AP42, Organic Liquid Storage Tanks
MS Vista users: TANKS does not run. Possible solution for Vista users(41 K)  (ZIP 40K)
Internet Explorer version 7 users: The report function won't work and program locks up.  Possible solution for IE 7 users(1 K)  (TXT 2K)
Some of the partial speciation profiles that come with version 4.09D do not work.  Instructions for updating chemical database (PDF 3 pp, 8K)
Chemicals added and Antoine's coefficients corrected in 4.09D.  Additions to TANKS 4.09D(3 K)  (TXT 4K)
Error 1935 during installation.  Use the alternate installation provided above. Follow the installation instructions.
Could not find installable ISAM error message, or 'The wizard is unable to access information in the file.'  In Windows Control Panel open 'Regional and Language Options' and add your language.
TANK reports blocked as pop-up or Active X not allowed.  Best available solution(330 B)  (TXT 1K)


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