18.—(1) The undertaker may for the purposes of this Order enter on any land shown within the Order limits, or onto any land which may be affected by the authorised development up to 250 metres away from the Order limits, or onto land which may be affected by the authorised development which is more than 250 metres from the Order limits with the prior approval of the relevant planning authority (or the local planning authority for land outside the London Borough of Enfield), and—
(a)survey or investigate the land;
(b)without limiting sub-paragraph (a), make trial holes in such positions on the land as the undertaker thinks fit to investigate the nature of the surface layer and subsoil and remove soil samples;
(c)without limiting sub-paragraph (a), carry out ecological or archaeological investigations on such land; and
(d)place on, leave on and remove from the land apparatus for use in connection with the survey and investigation of land and making of trial holes.
(2) The undertaker must serve a notice on every owner and occupier of the land at least 14 days before any land may be entered or equipment placed or left on or removed from the land under paragraph (1).
(3) Any person entering land under this article on behalf of the undertaker —
(a)must, if so required when entering the land, produce written evidence of their authority to do so; and
(b)may take with them such vehicles and equipment as are necessary to carry out the survey or investigation or to make the trial holes.
(4) No trial holes may be made under this article—
(a)in land located within the highway boundary without the consent of the highway authority, such consent not to be unreasonably withheld or delayed; or
(b)in a private street without the consent of the street authority, such consent not to be unreasonably withheld or delayed.
(5) The undertaker must compensate the owners and occupiers of the land for any loss or damage arising by reason of the exercise of the authority conferred by this article, such compensation to be determined, in case of dispute, in accordance with Part 1 (determination of questions of disputed compensation) of the 1961 Act.