Owners of waterways fed up with the discharge of sewage into them may now be able to take action against the water companies (statutory sewage undertakers) even if there has been no negligence or deliberate misconduct, following the Supreme Court’s judgment handed down on 2 July 2024.

This is the long-running litigation associated with the discharges of foul water contaminated with untreated sewage into the Manchester Ship Canal that reached a conclusion with the Supreme Court unanimously allowing the appeal.

In The Manchester Ship Canal Company v United Utilities Water Ltd the Supreme Court was asked to decide “whether the owner of the beds and banks of the canal, the Manchester Ship Canal Company Ltd (“the Canal Company”), can bring a claim in nuisance or trespass when the canal is polluted by discharges of foul water from outfalls maintained by the statutory sewerage undertaker, United Utilities Water Ltd (“United Utilities”)”.

It was made clear that “there is no suggestion that these polluting discharges are caused by negligence or deliberate wrongdoing on the part of United Utilities. However, they could be avoided if United Utilities invested in improved infrastructure and treatment processes.” By way of background, the Canal Company threatened to bring a claim against United Utilities for trespass and nuisance. In response, United Utilities applied for a declaration that there was no right of action on the basis that the claim would be inconsistent with and therefore barred by the statutory scheme for regulating sewerage established by the Water Industry Act 1991 (“the 1991 Act”). The High Court and then the Court of Appeal had previously found that the sewage undertaker would need to be guilty of negligence or deliberate wrongdoing in order for such a claim to be brought.

The Supreme Court unanimously allowed the Canal Company’s appeal, holding that “the 1991 Act does not prevent the Canal Company from bringing a claim in nuisance or trespass when the canal is polluted by discharges of foul water from United Utilities’ outfalls, even if there has been no negligence or deliberate misconduct”.

United Utilities suggested that it had “inherited a pre-existing implied statutory power to discharge water and treated effluent into private watercourses without the owners’ consent” and that the provisions of the 1991 Act excludes common law rights of action in nuisance and trespass. A question of statutory interpretation, the Supreme Court ruled that a common law remedy against nuisance survives the provisions of the 1991 act, which contains 'no express ouster of all common law causes of action and remedies to protect the enjoyment of the property' and that sewerage undertakers “do not have statutory authority to discharge untreated sewage into watercourses”.