Calderdale Council own and manage Heptonstall Quarry and are very happy to allow access for climbing providing that only belay stakes are used as anchors above the crag (not fence posts).
It's also worth highlighting that as with any piece of in situ equipment, all belay stakes should be checked before use to ensure they are solid. If you are concerned about the condition of any of the stakes pease contact access@thebmc.co.uk with full details.