Abstract

This case study presents the recent development of new 3D geological models for the Low Level Waste Repository in Cumbria through the review of historical and new datasets. The site is located in an area of complex Late Pleistocene glacial geology and geomorphology, which control near-surface groundwater movement, and benefits from extensive historical site characterization data. This work emphasizes the value of a quality review of existing borehole records, drilling techniques and supplementary information to build a predictive geological model. The integration of different datasets has proved crucial to our understanding of the ground conditions, which are characterized by complex Quaternary sequences, and the depositional processes responsible for their formation. The updated geological interpretation suggests that the Low Level Waste Repository is located on a former ice-dammed lake plain. This is contrary to the previous interpretation of multiple and extensive till units in the area. Although the permeabilities may be similar in both interpretations, the extents may be different. Understanding the depositional processes and extent and the hydrogeological characteristics of the deposits is key to developing a hydrogeological model that is appropriate for the assessment of the environmental safety of the site, both now and into the future.

Thematic collection: This article is part of the Ground models in engineering geology and hydrogeology collection available at: https://www.lyellcollection.org/cc/Ground-models-in-engineering-geology-and-hydrogeology