Penrhyn Quarry: Slate mine expansion 'to add 15 years'
A Gwynedd slate quarry has been given the go-ahead for a 20-acre (eight hectare) expansion that will extend its working life by up to 15 years.
Penrhyn quarry in Bethesda said the permission was "critical" to the long-term future of the site.
The quarry is a major employer in the area, with around 290 staff producing roofing slate and construction and industrial aggregates.
Welsh Slate said it hoped the extension would open "in the very near future".
Managing director Chris Allwood said: "It is great news that we have secured planning permission, which has been achieved after almost four years' preparation."
He said the communities of Bethesda and Mynydd Llandygai had "provided invaluable feedback" in consultation meetings over the firm's plans.
He added: "I would also like to pay tribute to our loyal workforce who have been through a lot in recent months, and for the support of our local councillors and elected members in the Welsh government."
Mr Allwood said the firm was working with Gwynedd council and others to finalise the planning conditions of the extension.
Welsh Slates said 85% of its staff were directly involved in the recovery, processing and transportation of its finished products.
In April this year around 90 workers at the site had their hours reduced or were redeployed after a rockfall saw half a million tonnes of stone tumble off a rock face.
Penrhyn is one of the oldest slate quarries in the world. It has been producing roofing slate since the 13th Century.