21. In relation to a work which is a specified work because of its proximity to or effect on a sewer, the plans to be submitted to the specified undertaker under paragraph 20 must be detailed plans describing—
(a)the exact position of the specified work;
(b)the level at which it is proposed to be constructed or renewed;
(c)the manner of its construction or renewal;
(d)the position of all sewers within 15 metres of the specified work or upon which the specified work will impose a load; and
(e)by way of detailed drawings, every alteration proposed to be made to any such sewer.