This map layer shows the distribution of superficial deposits, as mapped at 1:250 000 scale, which are considered to have the potential to store and transmit significant amounts of groundwater. The areas defined are based upon a sub-set of superficial deposits as mapped by GSNI at 1:250 000 scale where the following mapped deposits are considered to have potentially significant permeability and storage properties: glacial sands and gravels, blown sand, raised beach deposits and alluvium. A regional, detailed assessment of the individual deposits in terms of their aquifer potential (aerial extent, thickness, saturated depth etc.) has not yet been undertaken. Hence formal classification of each deposit as an aquifer area is not possible at present. In some cases limited aerial extent or minimal thickness may result in the mapped geological deposit not being considered as an aquifer. Due to natural geological variability and data availability, this map cannot and is not intended to represent actual conditions on a site-specific scale. For site specific investigations more detailed geological and hydrogeological information is available from GSNI. Advice on groundwater management and protection matters is available from the GSNI hydrogeologist or by contacting the Groundwater Team at NIEA. Further information on the hydrogeology of Northern Ireland is available in Hydrogeology of Northern Ireland, Robins N S (1997) and Hydrogeological Map of Northern Ireland, BGS 1994 both of these are available from the BGS bookshop or from the GSNI office (note: the aquifer classification used on the 1994 hydrogeological published map differs from the classification shown on the GeoIndex layer). NOTE: When considering the distribution of aquifers within a certain area, reference should also be made to the bedrock aquifer layer, available on this website.
