41. The undertaker must not interfere with, build over or near to any apparatus within the Order land or execute the placing, installation, bedding, packing, removal, connection or disconnection of any apparatus, or execute any filling around the apparatus (where the apparatus is laid in a trench) within the standard protection strips, which are the strips of land falling the following distances to either side of the medial line of any relevant pipe or apparatus: 2.25 metres where the diameter of the pipe is less than 150 millimetres; 3 metres where the diameter of the pipe is between 150 and 450 millimetres; 4.5 metres where the diameter of the pipe is between 450 and 750 millimetres; and 6 metres where the diameter of the pipe exceeds 750 millimetres, unless otherwise agreed in writing with Anglian Water, such agreement not to be unreasonably withheld or delayed, and such provision being brought to the attention of any agent or contractor responsible for carrying out the authorised development on behalf of the undertaker.