From sinkholes to sod-turning: Gyproc’s new quarry
The official sod turning at Gyproc’s new open cast quarry extension was hailed in the accompanying press release as a celebration.
Marking the company’s 90th anniversary, senior executives stood alongside a government minister, local authority officials and contractors to herald an investment that would secure Ireland’s domestic supply of gypsum for decades to come. It was a carefully choreographed moment - no media was invited - and designed to symbolise progress, confidence and a long-term commitment to the construction and mining sectors.
Shadowing this new chapter, however, is the catastrophic incident of September 2018, when part of the old underground Drumgoosat gypsum mine collapsed after the transportation and storage of water in an unused part of the mine caused pillars to collapse.
It triggered a series of worrying fissures and enormous sinkholes, destroying Magheracloone Mitchells GAA ground and the local community centre, forcing some families from their homes, and closed the R179 between Carrickmacross and Kingscourt for weeks while engineers determined whether further collapse remained possible.
The event also became a defining backdrop against which every subsequent planning application would be judged.
Sinkhole
Saint-Gobain, Gyproc’s parent company, has consistently pointed out that no conviction was ever recorded arising from the 2018 events, and the new open-cast quarry is unrelated to the underground workings that failed. Yet when planning was sought, local residents still questioned whether the legacy of the disaster had been fully addressed.
Agreed remediation works were completed by 2022, and throughout 2019 and 2020 the company undertook extensive drone surveys, installed extensometer monitoring systems beneath local roads and repeatedly reported newly identified features on company-owned land. Each announcement emphasised that areas had been secured, and how the earlier issues no longer presented a danger to nearby homes or public infrastructure.
Monitoring continued throughout subsequent years. New surface depressions were reported in 2021, 2022 and 2023 before an 11-metre crown hole was detected during routine aerial surveying in February 2024. That discovery occurred while the company’s application for a new open-cast quarry was progressing through the planning system. Planning files later confirmed that An Bord Pleanála was aware of the subsidence before ultimately deciding to uphold planning for the development.
September 2018:
Underground mine workings at Drumgoosat partially collapsed, creating major sinkholes that destroyed Magheracloone Mitchells GAA Club and the local community centre, displaced families and closed the R179 for several weeks. The company later attributed the collapse to the failure of mining pillars after water had been stored in disused workings.
2019-2020:
Extensive monitoring, drone surveys, remediation works and ground stability investigations were undertaken. Several new crown holes and surface cracks were identified, while extensometer monitoring was installed beneath local roads and an EPA industrial emissions licence review commenced.
2021-2022:
Planning permission was granted for replacement GAA facilities and applications were submitted for a new open-cast quarry, sports complex and community infrastructure. A further 10.8-metre crown hole was detected during monitoring.
2023:
Routine surveys identified additional surface depressions.
February 2024:
An 11-metre crown hole was detected in February 2024, shortly after Monaghan County Council granted planning permission for the new quarry.
April 2025:
An Bord Pleanála dismissed appeals and upheld planning permission despite the recent subsidence record.
January 2026:
Saint-Gobain announced the withdrawal of a High Court Judicial Review, bringing the planning and legal process to a close according to the company.
July 2026:
The sod was turned on Gyproc's new open cast quarry extension.
Quarry plan
The planning process itself lasted more than three years, and became one of the most closely scrutinised industrial developments in the region. Objectors argued that the development conflicted with provisions of the Monaghan County Development Plan intended to protect environmentally sensitive areas from extractive industries.
Residents also repeatedly raised concerns regarding potential impacts around dust, air quality, groundwater, vibration and noise, while questioning whether planning conditions alone could provide sufficient reassurance given the area’s previous experience with subsidence.
Gyproc rejected those criticisms, pointing instead to what it describes as extensive consultation with residents, elected representatives and statutory authorities throughout. The company says every aspect had been assessed against statutory standards and that ongoing regulatory oversight remains.
It also argues that this latest multimillion euro investment demonstrates confidence in the local community, while furthermore safeguarding skilled employment and securing an essential raw material for Irish housing, healthcare, education and infrastructure projects.
Plans include a new open-cast quarry, construction of a tunnel beneath the R179, refurbishment of the existing processing plant, as well as improvements to site access, not to mention substantial landscaping works before mining operations begin.
Essential investment
Company representatives describe the new quarry works as essential to securing Ireland’s future supply of domestically produced gypsum, while supporting employment and ensuring continuity of manufacturing operations at Ballynaclose.
Alongside the mining proposals, the company has, since the Drumgoosat mine collapse, fully addressed the loss suffered by the neighbouring community in replacing damaged facilities. New playing pitches for Magheracloone Mitchells GFC were developed on alternative lands, while later planning approvals included expanded sports facilities incorporating additional pitches, athletics facilities, a sports hall, meeting rooms and supporting infrastructure.
Throughout the planning process, Gyproc repeatedly stated that replacement sporting and community facilities would proceed regardless of the planning outcome for future mining operations.
New Chapter
The legal chapter closed in January 2026 when Saint-Gobain announced that the High Court had accepted the withdrawal and strike-out of a Judicial Review relating to the Knocknacran quarry development plan. According to the company, that decision confirmed the validity of An Coimisiún Pleanála’s decision to uphold the initial planning permission granted by Monaghan County Council.
Speaking at the recent sod turning, Kieran Holohan, Managing Director of Gyproc in Ireland, said: “The quarry is not the whole story, it is where the story begins. For 90 years, this local natural resource has helped power Irish industry, skilled employment, innovation and construction. Today’s investment ensures that contribution can continue for the next generation, supporting the people, communities and sectors that rely on high-quality Irish sourced and Irish-made building solutions.”
Welcome
Mr Holohan and Mining and Manufacturing Director John Duffy were honoured to be joined by Minister of State, Niamh Smyth, as well as Robert Burns CEO of Monaghan County Council, as well as council Cathaoirleach Aidan Campbell.
Minister of State with special responsibility for Trade Promotion, Artificial Intelligence and Digital Transformation, Deputy Smyth said: “This project demonstrates confidence in both the local community and the future of Irish industry. Gyproc’s investment will help secure jobs, strengthen supply chains and support the delivery of the homes, schools, healthcare facilities and infrastructure that Ireland needs.
“Gyproc has been an important part of the area’s industrial heritage for many decades, and it is encouraging to see the company continuing to invest for the long term as it celebrates its 90th anniversary.”