A multidisciplinary project was carried out in New Brunswick (eastern Canada), where hydrocarbon exploration was stopped in 2015 due to a moratorium on hydraulic fracturing, to investigate the vulnerability of shallow aquifers to industrial activities from both potential surface contamination and upward fluid migration. The study area included an active unconventional gas field (which also encompassed a potash mine in operation until late 2015) and a prospect hydrocarbon field. This project, a collaboration between two levels of government, universities and an oil and gas operator, created an unprecedented opportunity by allowing several monitoring wells to be drilled directly on gas well pads.Multiple datasets from geological, geophysical, geomechanical, hydrogeological and geochemical studies were collected and the interpretation of aquifer vulnerability resulted from the integration of their findings. The data coverage from reservoir depths to the surface provided no evidence for the presence of a natural connection between the deep units targeted by the industry and the shallow aquifers, or of contamination from the surface. The intermediate zone between the shallow aquifers and reservoirs appears to provide an effective barrier preventing upward migration of fluids. In particular, the locally ambiguous origin of methane in groundwater and the presence of salts in a few shallow monitoring wells were resolved through a sound understanding of the interacting elements of the geological – geophysical – geomechanical and the hydrogeological – geochemical components of the holistic system. Although this article focuses primarily on the hydrogeological component, highlights of the other components are presented here to give an overview of this multidisciplinary project's results and their contribution and to provide readers with a practical framework that can be used in other regions or other industrial contexts involving deep subsurface activities.