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Landfill Gas Emissions Model (LandGEM) Version 3.1 User Manual and Tool
Citation:
Krause, M. AND S. Thorneloe. Landfill Gas Emissions Model (LandGEM) Version 3.1 User Manual and Tool. U.S. EPA Office of Research and Development, Washington, DC, EPA/600/B-24/160, 2024.
Impact/Purpose:
The Landfill Gas Emissions Model (LandGEM) and this user manual were developed to assist landfill owners and operators as well as regulators to transparently standardize landfill gas generation calculations and predictions. The User Manual directs users on how to properly utilize the model for its two primary purposes: (1) determine applicability to Clean Air Act New Source Performance Standards and (2) estimate a facility's annual emissions as part of the annual emission inventory program. LandGEM version 3.1 reflects updates undertaken by the Office of Air Quality Planning and Standards (OAQPS) to harmonize its landfill gas estimations for annual emission inventories with those of EPA's Greenhouse Gas Reporting Program (GHGRP). Additionally, LandGEM v3.1 adds new user functionality to incorporate existing, publicly available data previously submitted by operators EPA. Users can now directly import waste tonnages and gas collection volumes from EPA's GHGRP, making the modeling process faster and consistent with other EPA programs.
Description:
The Landfill Gas Emissions Model (LandGEM) is an interactive tool with a Microsoft Excel interface that can be used to estimate generation and emission rates for total landfill gas, methane, carbon dioxide, nonmethane organic compounds (NMOCs), and other hazardous air pollutants (HAPS) from municipal solid waste (MSW) landfills. This guide provides step-by-step guidance for using this software application, as well as an appendix containing background information on the technical basis of LandGEM. LandGEM can use either default values or site-specific data to estimate emissions. The user selects one of two modes to utilize: NSPS Applicability or Emission Inventory. New Source Performance Standards (NSPS) Applicability mode utilizes the approach described in the Clean Air Act (CAA) to determine whether a landfill is subject to the control requirements of these regulations as determined by maximum estimates of NMOC release to the atmosphere. This mode assumes no air pollution control is in place. Inventory mode uses emission factors and methods defined in EPA’s Compilation of Air Pollutant Emission Factors (AP-42) and can be used to predict methane generation for the development of state emission inventories and air permits in the absence of site-specific test data. As of 2024, the calculations used in AP-42 to estimate landfill methane generation now conform with the syntax used in EPA’s Greenhouse Gas Reporting Program (GHGRP), replacing the methane generation potential (L0) with degradable organic carbon (DOC) and other equivalent parameters. Both approaches continue to use the first-order decay (FOD) kinetic equations but the parameters and values are slightly different. And both modes accept annual tons of waste for up to 80 years and predict for 140 years from the first year of waste disposal. International users or users sizing a gas collection and control system are encouraged to use the Inventory mode as NSPS applies conservative modeling values. The default parameter values in LandGEM reflect waste composition in the U.S. and may not be appropriate for modeling applications in other countries.
URLs/Downloads:
LANDFILL GAS EMISSIONS MODEL (LANDGEM) VERSION 3.1 USER MANUAL.PDF (PDF, NA pp, 2876.844 KB, about PDF)LANDGEM INFORMATIONAL WEBPAGE (PDF, 1 pp, 1 KB, about PDF)
LandGEM V3.1