On 2 July 2024, the Supreme Court gave its judgment on The Manchester Ship Canal Company v United Utilities Water Ltd (No. 2).  The Court ruled that a nuisance claim could be brought in a situation where effluent was discharged into a canal, unless the action had been authorised by Parliament or the common law right of action had been excluded. The case will be of interest to owners of watercourses who are seeking to understand their rights as regards pollution by sewage undertakers. 

United Utilities Water Ltd was the sewerage undertaker for the north west of England. This case rested on the question of whether United Utilities could discharge foul water into the canal without the consent of the canal company, and if it must pay a licence fee to do so. The question was whether The Water Industry Act 1991 prevents owners of watercourses or bodies of water from bringing nuisance or trespass claims for the pollution of their waters by foul water from the infrastructure of statutory sewerage undertakers, in the absence of negligence or deliberate misconduct.

The judgment examined case law in this area, particularly the case of Marcic v Thames Water Utilities Limited. Marcic focused on whether or not the failure of a sewage authority to construct new sewers constituted an actionable nuisance, when it led to severe flooding. It found that the court is not in a position to decide if a party should have constructed a new sewer that would have prevented this from happening, but that it could decide on a situation where there is a discharge of sewage from a sewerage system which is operating as it was designed to operate- if that is the case, the operator of the sewage system is responsible for the resultant nuisance. 

When the case was considered by the Court of Appeal, it was held that the facts in this case were indistinguishable from Marcic: although the discharge of inadequately treated effluence was unlawful, it occurred without United Utilities doing anything to cause it and so there was nothing that United Utilities could do to help stop this, apart from carrying out improvements to their sewerage system. The Court of Appeal therefore found that there was no cause of action with either trespass or nuisance. 

The Supreme Court disagreed with this. It took the view that the claim in Marcic had been dismissed because it considered the defendant’s breach of obligation to construct a new sewer, which the court could not give judgment on. 

The Supreme Court held that Marcic had no bearing here, as United Utilities were responsible for polluting waters through its sewers, sewage treatment works and associated works which occurred from these systems being exceeded in their capacity. The Supreme Court ruled that this was something that United Utilities caused or adopted, seen by how their system is designed in a way that deliberately involves the discharge of effluent into the canal.  So, unless this action had been authorised by Parliament or the common law rights of action had been excluded, the Canal Company had a cause of action under nuisance. 

The Supreme Court ruled that the Canal Company was able to claim in nuisance against United Utilities. It also said that although there may be cases where it is not appropriate to grant an injunction as a remedy for claims of nuisance or trespass in relation to cases where sewerage undertakers have polluted watercourses, damages will be awarded instead.