3D groundwater vulnerability

Attributed 3D geological model

The BGS is working with the Environment Agency (EA) to develop an approach to assess the vulnerability of groundwater to contamination from deep subsurface activities. The 3D groundwater vulnerability (3DGWV) project aims to improve our understanding of the hydrogeological environment at depth, and how human activities such as hydrocarbon extraction may release contaminants and/or create new pathways for contaminant transport.

Groundwater is potentially vulnerable to pollution from a wide and growing range of activities. Until now, the vulnerability of groundwater has tended to be considered in relation to contamination moving down from the surface or near surface, e.g. related to activities such as farming or waste disposal. With the deeper onshore subsurface being increasingly exploited for hydrocarbon resources, there is a need to assess the vulnerability of groundwater to activities taking place beneath it, from which areas contaminants may move upwards into groundwater.

Aims of the 3DGWV study

At present in England our existing methods and mapping for groundwater vulnerability relate to contaminants spilled on the surface of the ground or released into the shallow subsurface. In contrast we lack a consistent, accepted approach to assess the vulnerability of our aquifers to potential contamination from activities in the deep subsurface. At present, any such assessments must be done on a case by case basis. Consequently, the BGS and the EA are working together to better understand the complex factors that affect groundwater vulnerability at depth. This work will help us to better understand and explain the risks from onshore oil and gas activities, but will also be useful for any other activities deep in the subsurface, for example geothermal energy, mining and disposal of radioactive waste. The work is focusing on four main areas:

  • improved conceptualisation of the potential sources of subsurface contamination, and the release scenarios and pathways for subsurface movement of contaminants in the context of groundwater vulnerability
  • improved conceptualisation and characterisation of relatively deep groundwater systems that may be vulnerable to subsurface contamination
  • development of an approach to undertake initial screening of deep subsurface groundwater vulnerability — one that is similar to current approaches to vulnerability assessments at, or near to, the land surface
  • tools to visualise the complex 3D subsurface systems, to provide a better understanding of the relationships between sources of contamination and deep groundwater systems

Contact

Please contact Rob Ward for more information or contact the Environment Agency National Customer Contact Centre (NCCC).