Sub Surface offer a number of options for assessing the risks from ground gases including a desk based appraisal of potential sources, measurement of organic carbon concentrations and assessment in accordance with CL:AIRE RB17, or the installation of standpipes and monitoring over a period of time in accordance with BS8485: 2015.

Ground gas, whether derived from landfill, mining or natural sources can pose a risk to a development when there is a viable pathway through the sub surface soils that allows gases to migrate into buildings and accumulate within confined spaces.

The first step is normally to undertake a Phase I Preliminary Risk Assessment to identify viable source, pathway and receptor linkages and to develop a robust Conceptual Site Model.

Where viable off site sources such as infilled ground or landfill sites are identified then we would normally install a number of Gas Monitoring standpipes and take readings over a period of time in order to build up a picture of the ground gas regime on the site.

Where there are no potential off site sources, or where off site sources can be demonstrated to be unproductive then we can provide a more streamlined risk assessment by assessing the site in accordance with the guidance given in CL:AIRE Research Bulletin RB17 A Pragmatic Approach to Ground Gas Risk Assessment (2012).

Where a risk to the site is identified we can advise on possible remedial strategies including ventilation, barrier membranes and pathway intervention.  We can also provide Validation services.

Whom to Contact

If you would like a quote for our Ground Gas Risk Assessment services or have any questions, please do not hesitate to contact your Regional Sub Surface Office.