Linhay Quarry
E. & J.W. Glendinning Ltd.
Linhay Quarry is a large limestone quarry and important local resource on the outskirts of Ashburton, Devon. To extend its operational life, the quarry needed to expand eastwards to exploit the considerable depth of Devonian limestone underlying the adjacent fields. Concerns were raised about the impact this expansion could have on the adjacent aquifer and water levels within several cave systems nearby, some of which have been designated as SSSIs and within which the groundwater shrimp Niphargus glennieioccurs. Niphargus glenniei is endemic to Devon and Cornwall and is a “species of conservation concern” (formerly listed on several BAPs) due to its limited distribution, endemicity and ancient lineage, being over 19.5 million years old (McInerney et al. 2014), making it by far one of the oldest elements of the British fauna.
To inform the planning process for the extension, surveys were undertaken of the groundwater communities present within the limestone fissure aquifer, in particular the groundwater shrimp Niphargus glenniei, but also found to include a further two groundwater Crustacea Niphargus aquilex and Microniphargus leruthi.
Once approved, part of the planning conditions for the extension involved a commitment by Glendinning to fund future groundwater invertebrate monitoring surveys throughout the initial five-years of the quarry’s expansion (2022 – 2027), as well as surveys along the eastern range of Niphargus glenniei (adjacent to Somerset and Dorset) to inform further research on the ecology and distribution of the species. Sampling initially involved a network of boreholes within the quarry and its environs, set up to monitor groundwater levels and quality. However, Geosock filters caused problems with the inflow of fauna, such that the monitoring programme was later limited to springs arising from the limestone aquifer and exposed fissures within the quarry workings. This is the first study of its kind in the UK to use the ecological monitoring of groundwater communities to assess the impact of quarrying on the habitat.