A pure phase of heating oil was observed in a monitoring well at this project site in the Netherlands. Neither the origin nor the extent of the contamination was known. Further investigation at this challenging location was required. A steep embankment, a busy bicycle path and various utility services including a pressurized gas pipeline were limiting accessible drilling locations. Our compact and light Geoprobe drilling rig was a perfect fit for this job.
EnISSA conducted 5 OIP-UV soundings on a line of 60 m to enable rapid collection of insightful data. We detected high fluorescence signals from the groundwater level to approximately 7.5 metres below ground level on two central locations.
HPT measurements provide insight into the heating oil’s migration route
We also conducted simultaneous HPT measurements during these probes to measure the pump pressure needed to inject a constant water flow into the ground. A lower pump pressure indicates a more permeable soil. The results of this survey demonstrate a clear correlation between the presence of heating oil in the soil layers with a low injection pressure. An indication that the contamination is spreading in a more permeable soil layer.
The good preparation and close cooperation with our client enabled us to complete the entire project, including sealing the holes with bentonite grout in one working day.