The carrying out of operations for the erection, extension, installation, rearrangement, replacement, repair or other alteration of any—
(a)plant or machinery,
(b)buildings,
(c)private ways or private railways or sidings, or
(d)sewers, mains, pipes, cables or other similar apparatus,
on land used as a mine.
Development is not permitted by Class A—
(a)in relation to land at an underground mine—
(i)on land which is not an approved site; or
(ii)on land to which the description in paragraph D.1(b) applies, unless a plan of that land was deposited with the mineral planning authority before 5th June 1989;
(b)if the principal purpose of the development would be any purpose other than—
(i)purposes in connection with the winning and working of minerals at that mine or of minerals brought to the surface at that mine; or
(ii)the treatment, storage or removal from the mine of such minerals or waste materials derived from them;
(c)if the external appearance of the mine would be materially affected;
(d)if the height of any building, plant or machinery which is not in an excavation would exceed—
(i)15 metres above ground level; or
(ii)the height of the building, plant or machinery, if any, which is being rearranged, replaced or repaired or otherwise altered,
whichever is the greater;
(e)if the height of any building, plant or machinery in an excavation would exceed—
(i)15 metres above the excavated ground level; or
(ii)15 metres above the lowest point of the unexcavated ground immediately adjacent to the excavation; or
(iii)the height of the building, plant or machinery, if any, which is being rearranged, replaced or repaired or otherwise altered,
whichever is the greatest;
(f)if any building erected (other than a replacement building) would have a floor space exceeding 1,000 square metres; or
(g)if the cubic content of any replaced, extended or altered building would exceed by more than 25% the cubic content of the building replaced, extended or altered or the floor space would exceed by more than 1,000 square metres the floor space of that building.
Development is permitted by Class A subject to the condition that before the end of the period of 24 months from the date when the mining operations have permanently ceased, or any longer period which the mineral planning authority agree in writing—
(a)all buildings, plant and machinery permitted by Class A shall be removed from the land unless the mineral planning authority have otherwise agreed in writing; and
(b)the land shall be restored, so far as is practicable, to its condition before the development took place, or restored to such condition as may have been agreed in writing between the mineral planning authority and the developer.