4.—(1) On or as soon as reasonably practicable after the relevant date, the Secretary of State must make a scheme (a “supplementary scheme”) for the adoption of private sewers and private lateral drains by every sewerage undertaker whose area is wholly or mainly in England.
(2) On or as soon as reasonably practicable after the relevant date, the Welsh Ministers must make a scheme (a “supplementary scheme”) for the adoption of private sewers and private lateral drains by every sewerage undertaker whose area is wholly or mainly in Wales.
(3) The making of a supplementary scheme is the circumstance giving rise to the relevant duty pursuant to that scheme.
(4) Paragraphs (5) to (7) specify criteria relevant to the performance of that duty.
(5) Each sewerage undertaker must perform the relevant duty pursuant to a supplementary scheme in relation to any private sewer—
(a)which is situated within the area of that undertaker;
(b)which, immediately before the relevant date, communicates with a public sewer; and
(c)in relation to which the relevant duty is not owed pursuant to a main scheme.
(6) Each sewerage undertaker must perform the relevant duty pursuant to a supplementary scheme in relation to any private lateral drain—
(a)which, immediately before the relevant date, communicates with a public sewer which is vested in that undertaker; and
(b)in relation to which the relevant duty is not owed pursuant to a main scheme.
(7) The relevant duty pursuant to a supplementary scheme is not owed in relation to any private sewer or private lateral drain—
(a)which is exempt; or
(b)which is, immediately before the relevant date, the subject of a declaration.
(8) Each supplementary scheme must provide that any declaration which is made pursuant to that scheme in relation to a private sewer or private lateral drain—
(a)must specify the supplementary adoption date as the date of vesting of that sewer or lateral drain (except any part of that sewer or lateral drain which is a pumping station), and
(b)must specify a date no later than 1st October 2016 as the date of vesting of any pumping station which forms part of that sewer or lateral drain,
except where it is not possible, in respect of a particular sewer or lateral drain, to make a declaration specifying such a date because a proposal to make a declaration in respect of that sewer or lateral drain is subject to an outstanding appeal under section 105B of the Act.
(9) Any number of declarations may be made pursuant to a supplementary scheme.