61.—(1) The carrying out of operations by the British Coal Corporation for the purpose of prospecting for coal workable by opencast methods and the use of land for that purpose while such operations are being carried out.
(2) Development is permitted by this class subject to the following conditions:—
(a)at least 42 days before the development is begun, notice in writing has been served on the planning authority, indicating the nature, extent and probable duration of the development;
(b)as soon as possible after the end of the period of the carrying out of the prospecting operations—
(i)any buildings, plant, machinery or waste materials shall be removed; and
(ii)any boreholes shall be sealed and any other excavations filled in and levelled, any topsoil removed being replaced as the uppermost layer.