National Geological Screening for a GDF - Central England region
The screening report hosted on this site is a technical exercise across England, Wales and Northern Ireland. No specific location in England, Wales or Northern Ireland has been identified as a potential GDF site. Any future decision on geological disposal would be subject to community agreement and planning and environmental consents.
Our work shows that we may find a suitable geological setting for a GDF in much of this subregion.
Rock cannot generally be seen at the surface in this subregion, except in man-made excavations such as quarries or road cuttings. However, deep boreholes and geophysical investigations, particularly in the mining areas between Northwich and Crewe and around Oswestry, give us an understanding of the rocks present and their distribution.
There are clay-rich rock layers and rock salt layers under much of the central and eastern parts of the subregion in which we may be able to site a GDF. We would need to do more work to find out whether these rocks have suitable properties and thicknesses.
Even where individual clay-rich rock layers are found not to be thick enough to host a GDF they may contribute to the safety of a GDF in deeper rocks as they could act as a barrier to groundwater flow from depth. This is important because movement of groundwater is one of the ways in which radioactive material could be carried back to the surface.
Some of the subregion around Oswestry has been mined for coal resources to depths below 100m. In these areas the mining is likely to have affected the way in which water moves through the rock. Also possible exploration in the future in these areas means that it is more likely that future generations may disturb a facility.
Parts of the north of the subregion have Petroleum Exploration & Development Licences to allow companies to explore for oil and gas. This exploration is currently at an early stage and it is not known whether oil or gas in these licence areas will be exploited. RWM will continue to monitor how this exploration programme progresses.
Parts of the Cheshire Basin which have been mined for rock salt would also need to be taken into account in the siting of a GDF, although the nature of mining in evaporites does not affect the movement of groundwater in the surrounding rocks in the same way as other mining.
For further information, read the report below.
We have also produced a summary of the geological attributes of the Central England Region.