29.—(1) Paragraph (2) applies where there is a risk (“the prescribed risk”) that water supplied by a relevant supplier would, for the reason mentioned in paragraph (3), after leaving the relevant supplier’s pipes—
(a)contain a concentration of copper in excess of 2 mg/litre; or
(b)contain a concentration of lead in excess of 10 μg/litre.
(2) Every water undertaker or supplementary licensee which introduces water into the supply system used by the relevant supplier must, subject to paragraph (4), treat the water in such a way as will, in its opinion, eliminate the prescribed risk or reduce it to a minimum.
(3) The reason referred to in paragraph (1) is the presence in the water of a concentration of copper or lead which is attributable to the fact that copper or lead is the major component of such a pipe as is mentioned in section 68(3)(a)(1) of the Act, or its associated fittings.
(4) Paragraph (1) will not require a water undertaker or supplementary licensee to treat water—
(a)if the treatment is unlikely to achieve a significant reduction in the concentration of copper or lead; or
(b)if treatment is not reasonably practicable.
Section 68(3) was amended by paragraph 18(5) of Schedule 8 to the Water Act 2003.