For the purpose of maintaining and improving the quality of controlled waters the Secretary of State may, by serving a notice on the appropriate agency specifying—
establish the water quality objectives for any waters which are, or are included in, waters of a description prescribed for the purposes of that section.
The water quality objectives for any waters to which a notice under this section relates shall be the satisfaction by those waters, on and at all times after each date specified in the notice, of the requirements which at the time of the notice were the requirements for the classification in relation to which that date is so specified.
Where the Secretary of State has established water quality objectives under this section for any waters he may review objectives for those waters if—
and the Secretary of State shall not exercise his power to establish objectives for any waters by varying the existing objectives for those waters except in consequence of such a review.
Where the Secretary of State proposes to exercise his power under this section to establish or vary the objectives for any waters he shall—
and, if he decides, after considering any such representations or objections, to exercise his power to establish or vary those objectives, he may do so either in accordance with the proposal contained in the notice or in accordance with that proposal as modified in such manner as he considers appropriate.
A notice under subsection (4) above shall be given—
If, on a review under this section or in consequence of any representations or objections made following such a review for the purposes of subsection (4) above, the Secretary of State decides that the water quality objectives for any waters should remain unchanged, he shall serve notice of that decision on the appropriate agency.