An important judgment was issued by the UK Supreme Court in early July that could pave the way for civil actions against water companies for causing sewage pollution. In the wake of mounting public concern over increased sewage overflows into rivers and waterways, this judgment clarifies the circumstances where owners of watercourses or other water bodies may have rights to bring claims for nuisance. 

Owners of the Manchester Ship Canal sought clarification on their right to bring claims for pollution from sewer overflows

The case related to a long-running action by the owners of the Manchester Ship Canal against United Utilities Water Ltd (“UU”) which owns and operates wastewater treatment infrastructure in the area through which the canal runs. Manchester Ship Canal Company Ltd (“MSCC”) threatened to bring a claim in nuisance and trespass against UU for discharges of sewage into the canal from outfalls maintained by UU. Overflows occurred from the outfalls – as they do in many other areas of the UK – when the capacity of the sewer network was exceeded. UU sought a declaration that no such action in nuisance or trespass arose. The issue before the UKSC was not whether an actionable claim in fact existed, but rather the question was, could MSCC bring such a claim at all? Both the High Court and Court of Appeal agreed that no such claim could arise, and MSCC appealed to the Supreme Court. 

The key question for the UKSC was whether the statutory scheme under the Water Industry Act 1991 (the “WIA 1991”) barred any civil claim because any potential remedy was contained within that Act. 

In a heavily regulated sector what does statute provide for?

For anyone interested in the history of wastewater regulation and associated case law within England, the UKSC provided a deep-dive analysis stretching back to the reign of King Henry VIII but focusing on the period from the 1840s when public health legislation began to emerge with some force. This was not a history lesson for the sake of it, however, the Court identified a clear thread throughout and up to the WIA 1991 which demonstrated that water undertakers were not and never had been expressly authorised to cause nuisance or trespass through discharging foul water. Importantly, the UKSC also noted that the WIA 1991 was not new legislation but a ‘consolidating’ Act incorporating previous legislation but also to facilitate privatisation of the water industry. The principles that were laced through earlier legislation, and in the absence of any express provision to the contrary, were therefore preserved. 

How does this change the effects of the 2003 Marcic case?

For the last couple of decades, the Marcic case has loomed large over civil actions against water utilities. That case related to damage caused to Mr Marcic’s property from flooding caused by overflowing sewers owned and operated by Thames Water. The UKSC held in 2003 that, despite the fact that the sewers had insufficient capacity, no claim for damages or other remedy arose. This was because, amongst other considerations, the WIA 1991 contained an express and enforceable duty to provide an adequate sewer network. 

As a result of Marcic, there has perhaps been a perception that nuisance actions against water utilities were restricted, and certainly this was one point that UU raised in its defence. The UKSC has now made it clear that the application of Marcic is more limited and did not apply in the circumstances of this case. An important distinction in Marcic was that the flooding arose because of matters outside of Thames Water’s control, namely increased pressures on the existing sewer network designed to convey wastewater. The perhaps subtle but important difference in the present case was that the sewer overflows discharging into the Manchester Ship Canal were an intrinsic part of the system. Whilst increased pressure on sewer capacity was leading to more frequent overflows, the outfalls were simply doing what they were designed for. In such circumstances, and consistent with case law stretching back to the 1950s, the UKSC confirmed that the operator of the sewer system is responsible for any resultant nuisance. 

A right to claim in nuisance against water companies for pollution from sewer overflows is confirmed

The Court concluded that as a starting point, the owner of a watercourse or a riparian owner has a right of property in the watercourse which includes a right to preserve the quality of the water. Discharge of polluting effluent from sewers or sewage treatment works into a privately owned watercourse was an actionable nuisance. Whilst the WIA authorised the discharge of treated effluent, there was no statutory authority for the discharge of untreated sewage. 

Importantly, the UKSC was not asked – and did not answer - the question as to whether MSCC in fact had a valid claim in nuisance or trespass. This will need to be the subject of further proceedings. The purpose of these proceedings, and the wider importance of them, relates to the principle that the UKSC has confirmed. 

TLT Comment

Excessive overflows from storm outfalls and the resultant increases in untreated sewage entering rivers, lakes and other watercourses have been a high-profile issue over the last couple of years. The judgment strongly suggests that claims in nuisance and trespass may now become an increasing feature in the lower courts. An important caveat however is that ownership is a pre-requisite; this judgment does not open up claims for anyone that has an interest in preserving water quality, such as NGOs or other interested action groups. That said, qualifying ‘ownership’ of water bodies is a broad church and the UKSC has confirmed that this would include riparian owners who own the banks of a watercourse. This undoubtedly raises the potential of claims from many different affected parties. 

This decision was specific to the Water Industry Act which applies only to England and Wales. No doubt interested parties in Scotland and Northern Ireland - of which Northern Ireland in particular has its fair share of water quality issues - will be dusting off their copies of the relevant statutes and considering the implications. Never perhaps has the phrase “opening the floodgates” been more apposite. 

This publication is intended for general guidance and represents our understanding of the relevant law and practice as at July 2024. Specific advice should be sought for specific cases. For more information see our terms & conditions.

Date published

04 July 2024


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