The Authority may, for the purpose of performing its duty under section 27(1) or (2), serve a notice under subsection (2) on—
a water undertaker or sewerage undertaker;
a water supply licensee or sewerage licensee.
A notice under this subsection is a notice which requires the person on whom it is served—
to produce to the Authority, at a time and place specified in the notice (which must be reasonable), any documents specified or described in the notice which are in that person's custody or under that person's control, or
to provide to the Authority, at a time and place and in the form and manner specified in the notice (which must be reasonable), information specified or described in the notice.
The requirements imposed by a notice under subsection (2) are enforceable by the Authority under section 18.
Nothing in this section requires a disclosure of information that would contravene the data protection legislation (but in determining whether a disclosure would do so, take into account the duty imposed by this section).
In subsection (4) "the data protection legislation" has the same meaning as in the Data Protection Act 2018 (see section 3(9) of that Act).