4.—(1) Where the Secretary of State is of the opinion that a person–
(a)is contravening a requirement imposed on him by regulation 3; or
(b)has contravened such a requirement in circumstances which make it likely that the contravention will continue or be repeated,
the Secretary of State may serve a notice on that person in accordance with this regulation.
(2) A notice served in accordance with this regulation shall–
(a)require the person upon whom it is served to carry out such works or to take such precautions and other steps as the Secretary of State considers appropriate to remedy, or to prevent the continuation or repetition of, any contravention to which the notice relates;
(b)state the period within which any such requirement is to be complied with; and
(c)inform the person on whom it is served of the effect in relation to the notice of regulation 5 below.
(3) The period for compliance stated in the notice shall be such period as is reasonable in the circumstances and shall not in any case be less than 28 days.
(4) The Secretary of State may at any time–
(a)withdraw the notice;
(b)extend the period for compliance with any requirement of the notice; or
(c)with the consent of the person on whom the notice is served, modify the requirements of the notice.