National Geological Screening for a GDF - Central England region
Our work shows that we may find a suitable geological setting for a GDF in some of this subregion.
Rock can be seen at the surface in some of the subregion such as Cannock Chase and the Wrekin and in man-made excavations such as quarries or road cuttings. Combined with numerous deep boreholes and some geophysical investigations, this gives us an understanding of the rocks present and their distribution.
There are clay-rich rock layers, in which we may be able to site a GDF, in the west of the subregion, west of Stoke-on-Trent, Stafford and Wolverhampton and in the south-east of the subregion, east of Worcester and south of Birmingham and Lichfield. There may also be slates and similar strong rocks between Telford and Market Drayton 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 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 to depths below 100m, such as the North and South Staffordshire, Leicester, South Derbyshire and Warwickshire Coalfields, and there are also known oil and gas resources north-east of Stoke-on-Trent. In these areas the mining and drilling 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-west and north-east 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 this area, such as to the north of Stoke-on-Trent, east of Warwick and around Telford, Cannock and Tamworth, 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 also continue to monitor how this exploration programme progresses.
Parts of the subregion which are mined for rock salt, around Stafford, Burton-on-Trent and Droitwich Spa, 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