Ambisense was commissioned to monitor and assess the construction of a trial embankment on a former landfill.
The 3 month period of real-time, online continuous ground-gas monitoring was undertaken along a transect from where the trial embankment was located to the site boundary.
It was undertaken to ascertain the potential risk to off-site residential receptors adjacent to the site boundary during future landfill development and to determine if a cut-off trench was required.
Working with the client, Ambisense designed a suitable monitoring programme which targeted selected boreholes along a transect.
Key ground-gas parameters were supplied to the client online in real-time so that a continual assessment of gas migration could be undertaken.
In addition to Ambisense assessed geotechnical settlement data using our in-house Ambilytics platform.
The use of Ambilytics facilitated a deeper understanding of the data and allowed the consultant to quickly ascertain the key influences upon gas behaviour as the trial embankment was constructed.
The deep relationship between geotechnical data & ground-gas migration was fully explored. The detailed analysis quickly and robustly ascertained that the key influencer upon gas migration was the construction of the trial embankment & not traditional landfill gas generation.
Critically, the analyses determined that the extent of gas migration was minimal and localized to the immediate vicinity of the embankment.
As such the risk to off-site receptors from gas migration due to development was negligible & the Local Authority accepted that a cut-off trench was not required.
Rapid assessments of disparate data.
The client saved >£400k
Need for cut off-wall negated & development allowed to proceed