Landfill Gas Emissions Model (LandGEM)
Estimates emission rates from municipal solid waste landfills
The Landfill Gas Emissions Model (LandGEM) is used to estimate emission rates for total landfill gas, methane, carbon dioxide, nonmethane organic compounds, and individual air pollutants from municipal solid waste (MSW) landfills.
Landfill owners and operators can use LandGEM to determine if a landfill is subject to the control requirements of the federal New Source Performance Standards for new municipal solid waste landfills (40 CFR 60 Subpart XXX), the federal Emission Guidelines for existing municipal solid waste landfills (40 CFR Subpart CC), or the National Emission Standards for Hazardous Air Pollutants (NESHAP) for MSW landfills (40 CFR Subpart AAAA).
This tool can use site-specific data to estimate emissions or it can use default parameters if no site-specific data are available.
Software, Compatibility, and Manuals
The LandGEM is a macro-enabled Microsoft Excel file (.xlsm) that utilizes visual basic for applications (VBA) processes to function. It has been tested on systems running Microsoft Office 2007 and more recent versions. Earlier versions of Excel have not been evaluated and may no longer be compatible. For more information on required software settings, refer to the Version 3.02 User's Guide or contact us using the link under Technical Support.
The current version, LandGEM, Version 3.03, was released in 2020. This version fixed a minor error in the weighting and calculation of carbon dioxide masses in landfill gas. Methane and other pollutants volumes/masses were not affected.
Software
| Date | Tool Files for Download |
|---|---|
| 12/2023 | BETA Release: LandGEM, Version 3.1 (xlsm)* |
| 06/2020 | LandGEM, Version 3.03 (xlsm) |
* Version 3.1 is a BETA release that is currently in draft form. It is only available for testing and should not be used for regulatory purposes.
Manuals
| Date | Tool Files for Download |
|---|---|
| 05/2005 | LandGEM, Version 3.02 User's Guide (pdf) |
Background
Air emissions from landfills come from landfill gas generated by the decomposition of waste in the landfill. Landfill gas is assumed by this model to be roughly half methane and half carbon dioxide with additional, relatively low, concentrations of other air pollutants.
Emission rates at a landfill may be affected by the following:
- Waste design capacity of the landfill,
- Amount of waste-in-place in the landfill or the annual waste acceptance rate for the landfill,
- Methane generation rate,
- Potential methane generation capacity,
- Concentration of total nonmethane organic compounds and speciated nonmethane organic compounds found in the landfill gas,
- Number of years the landfill has been in operation, and
- Whether the landfill has been used for disposal of hazardous waste (co-disposal).
The EPA has determined that emissions from municipal solid waste landfills cause, or contribute significantly to, air pollution that may reasonably be anticipated to endanger public health or welfare. Some nonmethane organic compounds are known or suspected carcinogens, or cause other noncancer health effects. Public welfare concerns include the odor nuisance from the landfill gas and the potential for methane migration, both on-site and off-site, which may lead to explosions or fires. The methane emitted from landfills is also a concern because it is a greenhouse gas and contributes to global climate change.
Related Resources
- New Source Performance Standards for New Municipal Solid Waste Landfills
- Municipal Solid Waste Landfills: National Emissions Standards for Hazardous Air Pollutants (NESHAP)
- Resources, Waste and Climate Change
Technical Support
For comments or questions, email [email protected].