16.—(1) The deadline by which an environmental objective referred to in regulation 13(2)(b) or (c), (5)(c) or (6) must be achieved may be extended for the purposes of the phased achievement of the environmental objectives for a body of water, provided that no further deterioration occurs in the affected body of water when the conditions set out in paragraphs (2) to (5) are or will be met.
(2) All of the necessary improvements in the status of a body of water cannot reasonably be achieved within the timescales set out in the provisions of regulation 13 mentioned in paragraph (1) for one or more of the following reasons—
(a)the scale of improvements required can only be achieved in phases exceeding the timescale, for reasons of technical feasibility;
(b)completing the improvements within the timescale would be disproportionately expensive;
(c)natural conditions do not allow timely improvement in the status of the body of water.
(3) Subject to paragraph (4), a deadline must not be extended beyond 22nd December 2027, except in cases where the natural conditions are such that the environmental objectives cannot be achieved by that date.
(4) Paragraph (3) does not apply to the deadline specified in regulation 13(2) for an objective of aiming to achieve good surface water chemical status—
(a)in relation to substances 2, 5, 15, 20, 22, 23 and 28 in the table of priority substances, which may be extended until 22nd December 2033;
(b)in relation to substances 34 to 45 in the table of priority substances, which may be extended until 22nd December 2039.
(5) The relevant river basin management plan must set out—
(a)the extension of the deadline, and explain the reasons for it;
(b)a summary of the measures to be applied to achieve the environmental objectives set pursuant to regulation 12 which are envisaged as necessary to bring the body of water progressively to the required status by the extended deadline; and
(c)the reasons for any significant delay in making these measures operational, and the expected timetable for their implementation.
(6) Following an extension in accordance with paragraph (1), the next update of the relevant river basin management plan, in accordance with regulation 26, must include a review of the implementation of the measures referred to in paragraph (4) and a summary of any additional measures necessary for the purposes set out in that paragraph.