(5)No new building or wall shall be erected nor any existing building re-erected or added to on any land within the projected sewage disposal site but the owner of the land on which it was sought to erect, re-erect or add to the building or wall may call upon the Board at any time either -(a)to pay him compensation, or(b)to acquire so much of his land as falls within the projected sewage disposal site.and the Board shall thereupon -in case (a), pay reasonable compensation to the owner, andin case (b), forthwith take steps to acquire the land.
