Soil Ground Gas including Methane and Carbon Dioxide when present in the ground can form an explosive and asphyxiant risk to a development, both in the proposed end use and during construction works.
Notable incidents are present in the past, and much more recently that demonstrate the risk from ground gases should not be overlooked.
The assessment of whether ground gasses pose a risk to site developments is undertaken within the Phase 1 Desk Top Study. Potential sources of ground gas generation include landfill sites, infilled ponds and lakes as well as natural sources.
As deemed necessary by the Phase 1 Desk Top Study, assessment of the ground gas risk is undertaken through the installation of monitoring points with subsequent return visits, timed in coincide with periods of rising and falling barometric pressure.
Should the ground gas assessment indicate that a development is at risk from ground gasses mitigation measures can be proposed within the development design to reduce risks to an acceptable level.