The hydrogeological effect of quarrying karstified limestone: operational requirements for monitoring and mitigation

摘要

Limestone extraction can impact upon both the saturated and unsaturated zones, depending upon the nature and extent of the quarry and the limestone's hydrological parameters. However, this impact can be mitigated if a programme of monitoring is instigated to determine when an impact occurs, and if viable cost effective options for mitigation have been considered in advance of dewatering. Two such monitoring and mitigation schemes are reviewed in this paper. The first, a scheme associated with a new quarry for Castle Cement at Ribblesdale, includes substantial monitoring with proposals for mitigation should an impact be identified. The second scheme relates to Torr Quarry in the Mendip Hills, which has been operating sub-water table since 1986. Extensive monitoring has been undertaken since this time with augmentation of three streams around the quarry. The system of augmentation is currently being modified as part of quarry deepening.