This report describes the metadata generated during the creation of a 3D geological model for the
Environment Agency (EA) in the Knowsley area in NW England. Knowsley Industrial Park,
NW England and its buried sewerage network presents a potential source of pollution to the
underlying Triassic Sherwood Sandstone Group aquifer. Weakly permeable superficial deposits
beneath the site may provide a barrier to potential pollution of groundwater in the aquifer. The
aim of the study was to develop and apply a 3D model of the superficial deposits beneath the
park to a qualitative assessment of the vulnerability of the underlying aquifer to potential
pollution. The study also aimed to devise a method for the integration of the 3D geological
model of the shallow sub-surface with the buried utility network.
The 3D model revealed 7 superficial units. Glacial till, comprising clay and silt, was the only
weakly permeable deposit identified. Other deposits were interpreted as permeable. The
underground utility network was integrated in 3D with the geological model. Those utilities
overlying less than 2.5 m of till were interpreted to represent the most vulnerable parts of the
underlying aquifer. The greatest relative vulnerability to the aquifer occurred in the south and
south-west of the project area.
The study identified a novel method for the integration of a 3D geological model and a buried
sewerage network. The identification of these utilities prioritised the areas of highest relative
vulnerability of the Sherwood Sandstone aquifer to potential pollution from utility leakage. This
approach enabled the development of a hazard identification and prioritisation scheme for future
improvements to the buried sewerage network serving Knowsley Industrial Park