9.—(1) This paragraph applies where—
(a)any person is carrying on, or proposing to carry on, any activity on or in the ground, and
(b)that activity might lead to a discharge mentioned in paragraph 3(1)(a), (b) or (c).
(2) The regulator may serve a notice on the person prohibiting the carrying on of the activity.
(3) The regulator may withdraw a prohibition notice at any time by further notice served on the person.