Sewage in the Supreme Court

The Supreme Court has handed down judgment in a long running dispute between the Manchester Ship Canal Company Ltd (MSCC) and United Utilities.

The factual problem was - MSCC owns the banks and beds of the Manchester Ship Canal. United Utilities has rights to discharge water into the canal via outfalls. When the capacity of United Utilities' system is exceeded, foul water is discharged into the canal. It was recognised that this could be avoided if United Utilities invested in improved infrastructure and treatment.

MSCC wanted to bring a claim against United Utilities on the grounds of trespass and nuisance as a result of this discharge. United Utilities sought a declaration that there was no such right of action on the basis that, in the absence of negligence or deliberate wrongdoing, it was incompatible with the sewerage regulation under the Water Industry Act 1991 (1991 Act).

The High Court made the requested declaration, and this was upheld by the Court of Appeal. The lower court decisions meant that, in the absence of negligence or deliberate wrongdoing, it was not possible to bring a claim in trespass or nuisance against a sewerage company for expelling polluting discharge into watercourses, however frequent and damaging this was to the watercourse. The Environmental Law Foundation was allowed to make submissions on the wider implications.


United Utilities appealed to the Supreme Court who unanimously allowed the appeal.

At the heart of their findings was that as part of its property rights, the owner of a watercourse is entitled to preserve water quality on its property, and this is protected by the common law. Discharge of pollution into a privately owned watercourse by a statutory undertaker would breach this right, is not authorised by the 1991 Act and could give rise to a claim in trespass or nuisance.

The judgment explains the historic changes to the statutory regulation of sewage disposal and drainage since the 1840s. In the 1980s privatisation moved the water supply and sewerage functions into commercial, profit driven, companies. Under the 1991 Act, Ofwat was established as the regulatory body and the 1991 Act consolidated prior statute. The 1991 Act does not expressly or impliedly oust common law causes of action and remedies to protect property rights of watercourse owners because:

  • The Act includes provision for arbitration if water quality is damaged without consent reflecting common law remedies as an alternative to the statute.
  • Statutory compensation is given for damage caused by authorised acts of sewerage undertakers (but not for unauthorised acts indicating common law rights are retained in relation to these).
  • It would be a substantial change to the law compared to the position before the 1991 Act which was intended to consolidate the position.

Rather than forcing undertakers to pay for infrastructure upgrades by imposing an injunction as a remedy, courts can instead award damages allowing the statutory regime to determine investment into infrastructure.  

Outfall fall out

The Supreme Court reiterated the principle that if a statute, such as the 1991 Act, deals with rights and obligations in detail, it is intended to be exhaustive. Clear and specific words are needed for a statute to take away private rights.

Publicity of the problems of water pollution mean this decision will be of interest and clarifies the right for owners of private watercourses to make a claim in nuisance or trespass for unauthorised foul water discharge. This judgment has the potential to open the flood gates to actions by riparian owners. However, the judgment does not look at the merits of the claim in this instance; it merely states that it is possible to initiate it.