Permission granted for open cast mining on site where sinkholes destroyed GAA club
Seán McCárthaigh
Plans have been approved to allow open-cast excavation of a mine in Co Monaghan which collapsed beneath a GAA grounds seven years ago, despite strong opposition from local residents who fear it could lead to further subsidence in the area.
An Bord Pleanála has granted planning permission to Saint-Gobain Mining (Ireland) Limited for renewed mining activity at the former gypsum mine at Drumgoosat, Co Monaghan.
The underground mine, which closed in 1989, destroyed facilities at Magheracloone Mitchells GAA club and a local community centre after its partial collapse and the emergence of several large sinkholes in September 2018.
Several families living in the area had to relocate their homes while the Carrickmacross-Kingscourt road was closed for a number of weeks until the risk of further subsidence could be determined.
However, An Bord Pleanála has rejected appeals by a local community group against the decision of Monaghan County Council in January 2024 to sanction open cast mining above the disused facility at Drumgoossat.
Planning files show that the company, which is part of the Gyproc division of Saint-Gobain’s operations in the Republic, revealed that the most recent subsidence event was on February 16, 2024 when an 11-metre wide crown hole was discovered on land above the disused underground mine.
Assessments carried out by Saint-Gobain concluded that the significant subsidence in 2018 was due to a combination of several unique conditions including 12-metre high gypsum pillars at the underground location – compared to 6-metre high pillars elsewhere in the mine – which were submerged by water.
The reports calculated that the risk of a further significant subsidence event was “very low” as water is no longer stored in the underground mine.
Saint-Gobain also secured approval for the ongoing restoration of its existing open-cast mine at Knocknacran a short distance away as well as the refurbishment of its existing processing plant at the same site.
The board noted that the development, which will separately require an industrial emissions licence, will facilitate the extraction of the only known, viable and indigenous source of gypsum in Ireland.
The mineral is an essential ingredient in the manufacture of various construction industry products including plasterboard, building plaster and cement.
Saint-Gobain uses gypsum from its mines to manufacture plasterboard and plaster at its plant at Ballynaclose, Co Meath.
The company, which is a subsidiary of the French building materials multinational, also got the green light for the construction of a cut-and-cover tunnel under the Carrickmacross-Kingscourt road for the transport of gypsum to the plant at Knocknacran which will require the demolition of several properties.
As part of the planning application, Saint-Gobain also received planning permission for the further development of a community sports complex including two additional playing pitches, a running track, floodlighting, sports hall, meeting rooms, handball alley, dressing rooms and part covered grandstand.
An Bord Pleanála said the development of the mines would also be in accordance with the provisions of the National Planning Framework which acknowledges that extractive industries are important for the supply of aggregates, minerals and construction materials to a variety of sectors for both domestic and export markets.
The board observed that it also conformed with the Monaghan County Development Plan 2019-2025 which promotes the extraction of mineral reserves when it is carried out in a sustainable manner that does not adversely impact on the environment or other land uses.
Subject to compliance with a number of planning conditions, it concluded that the proposed open cast mining and the continued use and refurbishment of the processing plant would not give rise to a significant risk of pollution or subsidence.
The board said it would also not have an unacceptable impact on water quality, traffic and visual and residential amenities.
It remarked that the sports complex would provide a valuable community and recreational facility.
An Bord Pleanála observed that any environmental impacts identified in planning documents submitted by Saint-Gobain were not significant and would not justify refusing permission for the proposed development or requiring substantial amendments.
It limited the grant of permission for mining activity to 30 years.
The board also imposed a condition that any hydrogeological and stability assessments carried out by the company during the lifetime of the open cast mine about the stability of the underground mining voids should be submitted for the written agreement of Monaghan County Council.
However, one of the appellants – a local community group, D K Essential – said the full effect on the landscape of mining operations, which have been in existence in the area since the 1940s, was unknown.
The group’s secretary, Geraldine Ward, claimed the plans and details provided by Saint-Gobain were inadequate to analyse the potential consequences of the proposed development.
Ms Ward said intensive mining activity had transformed the area from “a beautiful natural, rural environment to what can only be described at this point in time as an industrial wasteland.”
She added: “It is difficult to have any confidence in this process where vast underground mining activity has taken place with scant contemporaneous records of what actual works were carried out.”
The group claimed the proposed development was in material contravention of the county development plan which states that extractive development which might have a detrimental impact on the environment should be restricted.
Locals also complained that there is no experience in Ireland of excavating and mining over existing underground mines.
Ms Ward said it had been extremely disconcerting for people living in the area to face “a constant barrage of unrelenting increased development and ravaging of the landscape.”
The group claimed the risks to human lives posed by the development were “very real” but said they had been “grossly underestimated” by Saint-Gobain.
It accused the company of “buying off” and “buying out” people directly affected by past problems with the mine – a claim disputed by Saint-Gobain.
“We are greatly fearful as a community of similar catastrophic events occurring such as the collapse of roads similar to what occurred to the football pitch and community centre in recent years,” said Ms Ward.
In response to concerns raised by the appellants, Saint-Gobain said refusing permission for the only indigenous gypsum mine in Ireland would have a detrimental impact on the Irish construction industry and would have a knock-on effect on the quality and cost of housing.
The company also stressed that open cast mining was not a factor in the subsidence event in 2018.
It pointed out that no conviction was recorded against it and no penalties were applied for breaches of its licence by exceeding water discharge limits linked to the subsidence when the case came before the District Court in November 2020.
