National Geological Screening for a GDF - Hampshire Basin region
Our work shows that we may find a suitable geological setting for a GDF in most of this subregion.
Half of the subregion is the inshore area which extends to 20km from the coast, but rock can be seen at the surface in the sea cliffs between Weymouth and Studland and in man-made excavations such as quarries and road cuttings. Combined with numerous deep boreholes and geophysical investigations, particularly around the Poole Harbour area, this gives us an understanding of the rocks present and their distribution.
There are clay-rich rock layers under the whole 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 in the depth range of interest for a GDF.
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, around Poole Harbour and Moreton to the east of Dorchester, has known oil resources. In these areas the 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.
Most of the onshore parts of this subregion and part of the inshore part between Poole Harbour and the Isle of Wight 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.
For further information, read the report below.
We have also produced a summary of the geological attributes of the Hampshire Basin and adjoining areas Region.