1. An accurate plan, which should be prepared on a scale not less detailed than 1:2500, showing—
(a)the boundaries of the mine or premises on which the mine or tip, or proposed mine or tip, is or is to be situated;
(b)the site of the mine or tip, or proposed mine or tip;
(c)any contiguous land or structures which might be affected by the mine or the tip or proposed mine or tip; and
(d)all mine workings (whether abandoned or not), buried quarry workings, known cave systems, active or former landslips, springs, artesian wells, watercourses and other natural or manmade features including tunnel pipes or culverts which might affect the safety of the mine or tip, or proposed mine or tip, or which might be relevant for the purpose of determining whether mining or tipping operations can be carried out safely,
which plan must be contoured to Ordnance Datum Newlyn(1) at a vertical interval not greater than 5 metres and orientated to and correlated with the Ordnance Survey National Grid and marked with squares corresponding to the 100 metre squares shown on Ordnance Survey sheets on the scale of 1:2500.
Ordnance Datum Newlyn is the national height system for mainland Great Britain and forms the reference frame for heights above mean sea level (ordnancesurvey.co.uk).