What does ‘reasonably practicable’ mean in the context of investigating a complaint about a potential statutory nuisance? 

. . . where a complaint of a statutory nuisance is made to [a local authority] by a person living within its [area][district], to take such steps as are reasonably practicable to investigate the complaint. (Section 79 of the Environmental Protection Act 1990 / Section 64 of the Clean Neighbourhood and Environment (Northern Ireland) Act 2011)

Reasonably practicable is a phrase that appears in various legislation and is not solely related to functions associated with environmental health. It is often used to reduce the burden of a duty that might otherwise appear to be open-ended. It is a phrase that is used to qualify duties placed on public authorities, employers and others. 

A leading case that is regularly cited in debates on this issue is the House of Lords’ decision in Marshall v Gotham Co [1954] AC 360. The question there was whether the mine owners had done everything that was reasonably practicable to make sure the roof of a passage in their mine was safe. They were sued both for negligence and breach of statutory duty. They were found not liable under either head – the meaning given to the word ‘practicable’ was that it was possible for something to be done with known means or resources or capable of being carried out in practice. The court also held that adding the word ‘reasonably’ did not further qualify the duty.

In Jenkins v Allied Ironfounders Ltd [1970] 1 WLR 304, the court held that it was not reasonably practicable for the floor of the foundry to be swept continually throughout the day to remove any loose metal from the castings. It also highlighted the earlier decision of Edwards v National Coal Board [1949] 704 at 712:

• ‘Reasonably practicable’ is a narrower term than ‘physically possible’ and seems to me to imply that a computation must be made by the owner, in which the quantum of risk is placed on one scale and the sacrifice involved in the measures necessary for averting the risk (whether in money, time or trouble) is placed in the other; and that if it be shown that there is a gross disproportion between them — the risk being insignificant in relation to the sacrifice — the defendants discharge the onus on them.

In West Bromwich Building Society Ltd v Townsend [1982] ICR 257, a Principal EHO had served an improvement notice under the Health and Safety at Work etc. Act 1974 on the Building Society. This required them to fit ‘bandit screens’ at a particular branch to protect the cashiers and was regarded by the council as a test case covering similar premises throughout their area. While the tribunal upheld the notice, it was quashed on a further appeal to the High Court. The question to be decided was whether it was a reasonably practicable measure at the actual location, taking into account the risks, costs and physical ability. It was not appropriate to assess this based on general desirability and could not be a test case. The court also held that such a notice could not ask for more works than required by the building regulations.

More recently, in R (on the application of Friends of the Earth) v Secretary of State for Business, Enterprise and Regulatory Reform [2010] HLR 18, a challenge about an alleged failure to deliver on targets in the Fuel Poverty Strategy was dismissed, as the availability of current resources was a relevant factor which qualified the statutory duties of the government. 

The Northern Ireland Court of Appeal reviewed this recent case: ‘In the matter of an application by Noeleen McAleenon for Judicial Review’ [2025] NICA 44. The case included a challenge as to whether the council had taken reasonably practicable steps to investigate complaints of an odour nuisance from a waste disposal site. A duty under section 64 of the Clean Neighbourhood and Environment (Northern Ireland) Act 2011 mirrors the statutory nuisance duty for the rest of the UK under section 79 of the Environmental Protection Act 1990. Both the High Court and the Court of Appeal agreed that a council witness had been wrong to characterise the Northern Ireland Environment Agency (NIEA) as having primary responsibility for the site. However, the steps they had taken (as set out at paragraph [11] of the judgment) included 46 visits over several months, as well as close liaison with the NIEA. On this basis, both courts were clear that the council had discharged its qualified duty to investigate and had come to a reasonable conclusion that there was no such statutory nuisance.

What is reasonably practicable, and whether the steps taken will stand up to a challenge, depends on the nature of the complaint and what is practicable in the specific circumstances. The seriousness of the matter complained of, and the scale of the impacts, will be relevant to deciding the level of resources to be applied, as will the resources actually available. Taking the pandemic as an example, clearly, what was practicable then was even more limited than perhaps it would be at a different period of time. 

As an example: I have long doubted the general lawfulness of simply sending out noise diary sheets and closing a complaint if no sheets are returned within a short time. And as Lambeth LBC found out in 2018, refusing to investigate domestic noise complaints unless three separate households complained about the same source within a month was held to be unlawful by the Local Government and Social Care Ombudsman (Report 17 018 747). Lambeth was required to amend its policy to ensure compliance. 

Each case must be taken on its own merits and carefully considered. One size does not fit all.

For practical guidance refer to RIAMS procedures - Guidance Note: Factors When Assessing Statutory Nuisance (MP64), and Abatement Notices (MP5), available on RIAMS Libraries.