National Geological Screening for a GDF - Wealden District region
Our work shows that we may find a suitable geological setting for a GDF in most of this region, but the thickness and properties of the potential host rocks present may not be suitable.
Given that the south and east of this subregion are the inshore, which extends to 20km from the coast, rock can only be seen at the surface in the sea cliffs and man-made excavations such as quarries or road cuttings. Combined with numerous deep boreholes and geophysical investigations, this gives us an understanding of the rocks present and their distribution.
There are clay-rich rock layers under the whole of the subregion in which we may be able to site a GDF. There are also slates and similar strong rocks to the south of Folkestone under the English Channel, in which we may be able to site a facility. 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 support the siting 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 has been mined for coal resources to depths below 100m, around Hersden, Aylesham, Elvington and Deal. 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.
The onshore parts of the subregion are Coal Authority Licence Areas allowing companies to explore for coal. It is not known whether coal in these licence areas will be exploited. RWM will continue to monitor how this exploration programme progresses.
For further information, read the report below.
We have also produced a summary of the geological attributes of the Wealden District Region.