28. Until the date on which the first regulations made under Article 7B(5) of the 1999 Order (as substituted by Article 280 of the 2006 Order) come into operation, Article 7 of the 1999 Order (as so substituted) shall apply as if the discharges referred to in it did not include any discharge from a sewer or works vested in a sewerage undertaker into a waste water treatment works operated by a person other than the sewerage undertaker under, or pursuant to, an agreement with the sewerage undertaker, in circumstances where –
(a)the operator was bound to receive the discharge there either unconditionally or subject to conditions which were observed; or
(b)the operator was bound to receive the discharge there subject to conditions which were contravened in circumstances where—
(i)the contravention was attributable to a discharge which a person other than the undertaker made into the sewer or works so vested;
(ii)the undertaker either was not bound to receive the discharge into the sewer or works so vested or was bound to receive it there subject to conditions which were not observed; and
(iii)the undertaker could not reasonably have been expected to prevent the discharge into the sewer or works so vested;
and in this paragraph references to works vested in a sewerage undertaker shall be taken to include references to a tanker operated by, or on behalf of, such an undertaker.