The results of this preliminary investigation indicate that the Fell Sandstone is the best aquifer in Northumberland, and that the groundwater potential is largely undeveloped.
The formation has an outcrop of 118 square miles (305 km2), of which 65 square miles (168 km2) are drift free. The attractive qualities of the sandstone are the friable, granular nature, the good sorting and the commonly occurring fissures and joints. The storage capacity of the formation is of the order of 1012 Imperial gallons (4·55 × 1012 litres). Analysis of precipitation data and water balance calculations suggest an average recharge of between 40 and 70 mgd, (182 × 106 l/d–319 × 106 1/d). Determinations of porosity and laboratory permeability give mean values of 13·8 percent and 6·4gpd/ft2, (314 1/d/m2) respectively; the transmissibility could be considerably greater than the mean value of 5300 gpd/ft (7900 1/d/m) calculated by pumping the existing boreholes. The results of chemical analyses show that the water quality is good.
There seems little doubt that further water supplies required for commercial development on Tweedside and in south-east Northumberland could be developed from the Fell Sandstone aquifer. Proposals for the economic development and future study of the aquifer are outlined.