What is GasSim2.5?
The GasSim2.5 model simulates the path of landfill gas (LFG) arising from (un)managed landfill sites. It was developed by Golder Associates for the Environment Agency of England and Wales, in order to provide a consistent and systematic approach for the risk assessment of LFG. This includes the assessment of LFG generation, emissions, migration or dispersion and impact on the environment and human health. The model is designed to assist authorities responsible for waste, operators and consultants or others who are familiar with the subject.
GasSim2.5 allows the user to:
- Assess different LFG management options, that can support landfill design and operation by identifying gas that is lost uncontrollably that could otherwise have been utilised (minimising the environmental impact);
- Simulate atmospheric dispersion (assessing the potential exposure of neighbouring residents);
- Model the dispersion of odorous releases to air (assessing the impact of odour on neighbouring properties);
- Calculate the global impact of the landfill in terms of global warming (by determining the emissions of gases with a global warming potential);
- Report the emissions of gases covered by the European Pollutant Emissions Register (EPER), also known as the Pollution Inventory (PI) – in a suitable format; and
- Determine the limit of vegetation stress (assessing the impact of laterally migrating methane and carbon dioxide on vegetation in the environment of the landfill).
In short, GasSim2.5 can assist those with no in-depth knowledge of programming, in assessing LFG generation, emissions, migration/dispersion and impact/exposure of LFG.
How to use GasSim2.5?
The main screen of the decision support tool (DST) shows a cartoon that guides the user along the process of defining the landfill characteristics, the gas management options and details of the contaminant pathways (from source to various receptors). At each stage along the pathway, pop-up dialogue boxes can be accessed by clicking on active areas of the cartoon. These can be used to enter data for the calculation of the LFG generation, the emissions from the landfill and combustion products, the lateral migration and atmospheric dispersion of these emissions, and the impact on human health, the local environment and the global atmosphere. The dialogue boxes are customised to the chosen landfill design. A detailed description on the use of the tool can be found in the GasSim manual.
Why is the GasSim2.5 model included in the Orion tool?
The Orion tool can suggest the user to develop an ELFM project or to develop a business case. In that case, the Gassim2.5 model will be indicated by the dashboard at the end-points of the roadmap. When assessing the mining or rehabilitation potential of a landfill, the potential health effects of living near and working on landfills is an important aspect to take into account. Furthermore, emissions of greenhouse gases to the environment (mostly methane) should be minimized in each way possible. The GasSim2.5 model can assist the user in assessing the impact of a selected landfill on the environment, the climate and human health.