Preliminary Assessment of the Possible Groundwater Exposure Routes from Oil and Gas Wells to Drinking Water Extraction Locations in the Netherlands
Summary
As the source of drinking water supply in the Netherlands, the groundwater is prone to
exposure from oil and gas extraction activities. The exposure is possible due to well leakage in
case of a well failure that can occur in conventional and unconventional oil and gas wells. There
is a lack of publicly available studies in the European context that address the possible human
exposures to emissions from oil and gas extractions through groundwater. Besides, in terms of
research methodology, there is a lack of studies addressing the connection between groundwater
extraction for drinking water and oil and gas wells via groundwater flow. This study fills this
knowledge gap by providing a preliminary assessment of the possible exposure of drinking water
extraction locations in the Netherlands to oil and gas related chemicals via groundwater. With
regard to the methodology, this study starts to close the knowledge gap by taking into account
the direction and travel time of the groundwater flow from oil and gas wells.
The direction and travel time of the groundwater flow are simulated using the Darcy Flow
and Particle Track tool of ArcGIS. The time for possible contamination to reach the drinking water
extraction locations is estimated by using the groundwater travel time in relation to the oil and gas
well age. Exposure possibilities are further assessed based on the degradation of oil and gas
related chemicals.
Eighteen drinking water extraction locations (9.6%) are assessed to have possible future
exposures to oil and gas wells in case failure has taken place in these locations. Fifteen out of
the 18 drinking water extraction locations have higher exposure possibilities with respect to the
degradation of oil and gas chemicals.
Considering the low failure probability and the low exposure possibility via groundwater,
the overall possibility of exposure is low. Additionally, the possible exposures in the event of a
failure are all predicted to occur in the future. These results show that there is no immediate
concern.