4. Paragraph 3 does not apply in the case of the removal of a public sewer but where such a sewer is removed in pursuance of such a notice or order as is mentioned in that paragraph, any person who is—
(a)the owner or occupier of premises the drains of which communicated with that sewer; or
(b)the owner of a private sewer which communicated with that sewer,
is entitled to recover from Network Rail compensation in respect of expenditure reasonably incurred by that person, in consequence of the removal, for the purpose of making the drain or sewer communicate with any other public sewer or with a private sewerage disposal plant.