There was a subsidence event in Co. Monaghan on 24 September 2018, which affected the Magheracloone GAA club and the associated Community Centre. SRK Consulting (SRK) were commissioned to investigate this subsidence event. SRK is a consultancy company working for St Gobain Mining (Ireland) Ltd, the operator of the Drummond and Drumgoosat Mines. SRK has previously undertaken work on the stability of underground mine workings in the area.
Following SRK's report on the investigation into this subsidence event, the Exploration and Mining Division (EMD) commissioned Wardell Armstrong, a multidisciplinary engineering, environmental and mining consultancy, to independently review and verify the findings of SRK's work.
Wardell Armstrong's report entitled 'Investigation of the Collapse of Workings at Drumgoosat; An Independent Review of the Works Completed by SRK' was published on 17 December 2018.
Update July 2019
In December 2018, a 10 metre diameter crownhole developed above abandoned mine workings at Drumgoosat, some 35 metres from a local road (LP4900). The road was not affected by the crownhole. However, as a precautionary measure, the L4900 was closed whilst a detailed investigation of the crownhole was completed by Gyproc, the former operator of Drumgoosat Mine. As part of this investigation, Gyproc commissioned SRK Consulting (UK) Ltd to:
- Establish the likely cause of the crownhole development;
- Carry out assessments to determine the stability and potential failure of any mine workings underlying the LP4900
- Make recommendations to provide early warning of, manage or mitigate future subsidence risk along the line of the LP4900.
EMD engaged independent consultants Wardell Armstrong (Wardell) to verify the findings of the SRK investigation. The Wardell report concludes that it is safe to re-open the LP4900, subject to the completion of road drainage works and provided that regular monitoring of the road is undertaken in the future to monitor for any potential underground movements. The report verified the SRK Investigation which stated that the risk of further crownholes impacting on the LP4900 road was very low.