15(1)Authorising a regulator, where a person is carrying on an activity of a specified description—E+W+S
(a)to serve notice on the person requiring them to cease carrying on the activity or, at their own cost, to take such action in connection with the activity as may be specified in the notice, or
(b)to arrange itself for action to be taken in connection with the activity.
(2)Authorising a regulator to—
(a)to serve notice on persons of a specified description requiring them, at their own cost, to take such action as may be specified in the notice, or
(b)to arrange itself for action to be taken,
in respect of a structure or obstruction of a specified description.