60. Where practicable, the undertaker and Northern Powergrid will make reasonable efforts to liaise and co-operate in respect of information that is relevant to the safe and efficient construction operation and maintenance of the authorised development. Such liaison shall be carried out where any works are—
(a)within 15m of any above ground apparatus and / or;
(b)are to a depth of between 0 – 4m below ground level of apparatus.