Residents living beside Craig yr Hesg quarry near Pontypridd, south Wales, say repeated rock blasting shakes their houses, knocks pictures off walls and frightens their children, and they are calling for the practice to be paused. The Glyncoch community's concerns have intensified after a blast at another quarry six miles away triggered flooding that forced people from their homes. Quarry operator Heidelberg Materials UK says it remains confident in the safety of its operations and will continue meeting all regulatory obligations.
Craig yr Hesg has operated since 1885, but its footprint has expanded considerably in recent years, pushing the working area steadily nearer to Glyncoch. According to a local campaign page reported by Nation.Cymru, the extended quarry now comes within 109 metres of the closest property, well short of the 200-metre buffer that planning guidance identifies as suitable.
What happened at the other quarry, and why does it matter here?
A Health and Safety Executive inquiry into an incident at the Taff's Well quarry near Cardiff, which damaged 15 properties, concluded that a planned blast released a substantial volume of water from old iron mine workings, flooding nearby homes. This story is directly linked to two events already covered in our earlier reporting: residents in Gwaelod-y-Garth were evacuated on 30 July 2026 after the blast-related flooding left some homes with up to five feet of water inside, and Wales' first minister subsequently visited the affected area and pledged a swift investigation after 13 households were evacuated.
The HSE has characterised the Taff's Well episode as an isolated incident, though its investigation is ongoing. Since Craig yr Hesg was granted permission to extend operations through to 2047, residents say frustration in the village has grown.
How has the blasting affected daily life in Glyncoch?
Claire Allen, 40, who was born in the village and runs a summer camp for children at the local rugby club, said vibrations and dust from the blasts have worsened in recent years.
"We shouldn't have to be anxious waiting in our own homes just for someone to blast our mountain up," she said.
"Some people have said photo frames have come off their walls, others have fallen over. It's horrible."
"The children are scared when it happens and the dust is really thick. You could polish in the morning and then the dust comes back. It affects people's chests as well especially ones with things like COPD and asthma."
Allen said learning of the destruction caused by the Taff's Well blast left her shaken.
"Only once it needs to happen and now it has happened and we don't need it to happen to another area," she added.
What does the quarry operator say?
The HSE describes the Taff's Well event as isolated, but Heidelberg Materials UK has sought to reassure Glyncoch residents that Craig yr Hesg sits on markedly different geology. Area director Marius Klein said each quarry's underlying rock structure is distinct.
"We want to reassure local communities that each quarry's geological profile is unique. Craig-yr-Hesg quarry has a very different geological profile from the quarry in Taff's Well."
"Importantly, there are no comparable bodies of water either on the surface or below ground close to our site that would pose a flooding risk to our operations or to the community."
"In addition, as part of the planning process for the approved quarry extension, the location of mines and associated infrastructure was carefully assessed."
The company has previously defended its blasting practices. Following a blast on 5 August 2024, Heidelberg Materials said the detonation had been "carefully designed by specialists to minimise ground vibration" and that recorded vibration levels stayed within permitted limits, according to reporting at the time.
What has the campaign against expansion said?
Opponents of the quarry's growth want ministers to step in and halt blasting until the Taff's Well investigation is finished. Chris Whiles, one of the community's lead campaigners, said the flooding elsewhere had left him rattled after years of fearing something comparable could strike Glyncoch.
"We're asking for an immediate suspension of all blasting until a full investigation is done," he said.
"There were properties with rushing water up to about five foot. That's happened five, six miles from us due to a blast in a quarry."
"Next time, I don't want it to be Craig yr Hesg. I don't want that, I don't want my kids to go through that."
Concerns raised by campaigners are not new. A Senedd debate on Craig yr Hesg in June 2024 heard that residents had reported weekly blasting, homes shaking, cracks appearing in walls and dust drifting over the community, according to a record of the Senedd proceedings. Protests also followed the Welsh Government's decision in August 2024 to approve the quarry's continued operation, with the company noting the minister's approval came after an independent inspector had assessed the proposals, as reported by WalesOnline at the time.
What are elected officials doing about it?
Pontypridd MP Alex Davies-Jones has written to the Welsh government pressing for safety assurances on behalf of constituents. She asked whether geological, hydrological and flood-risk assessments at Craig yr Hesg were current, and whether the Taff's Well incident should trigger an urgent review of safety measures at quarries situated near residential areas.
The Welsh government confirmed it had received the letter but said responsibility for regulating active mines and quarries rests with the UK government, meaning it was unable to comment further. The UK government has been approached for comment.
Is Craig yr Hesg an isolated case of communities living near unstable ground?
Concerns about homes affected by historic mining or quarrying activity have also surfaced elsewhere in recent months. In Coalsnaughton, more than 250 residents have been displaced amid an ongoing investigation into ground movement linked to former mining, with further homes evacuated in July 2026 as monitoring continued with government support. Some of those residents have since said they fear their properties could ultimately be demolished.
What happens next?
According to Heidelberg Materials' own community update page, a further blast at Craig yr Hesg is scheduled for Monday, 15 September, between 12:00 and 14:00, though the company notes that timings can shift due to weather or operational safety requirements. The firm says blasting generally takes place between 10:00 and 16:00 on weekdays, and it is encouraging residents to join a WhatsApp alert group so they can be notified in advance of scheduled blasts.
Key Facts
- Craig yr Hesg quarry has operated since 1885 and has permission to continue until 2047.
- The quarry's working area now sits within 109 metres of the nearest property, below the 200-metre buffer suggested by planning guidance.
- The Taff's Well quarry blast damaged 15 properties and forced the evacuation of 13 homes on 30 July 2026.
- Pontypridd MP Alex Davies-Jones has asked the Welsh government for updated risk assessments and a safety review.
- A further blast at Craig yr Hesg is scheduled for 15 September between 12:00 and 14:00, subject to change.
