Anna McClean
The requirement that the impacts of certain development be assessed before planning permission can be granted is an established part of the planning process in the UK, and there are two key pieces of legislation which deal with this.
The Town and Country Planning (Environmental Impact Assessment) Regulations 2017 require the environmental impacts of certain major development projects to be assessed. Some types of development, often referred to as Schedule 1 development, will always require an EIA. Other specific types of development, such as some agricultural development and infrastructure development, referred to as Schedule 2 development, may require an EIA but only if the proposed development is likely to have significant effects on the environment.
The Conservation of Habitats and Species Regulations 2010 apply to development which may impact on a site designated as a Special Area of Conservation or a Special Protection Area under European law (‘European sites’), and require that where a development is likely to have a significant effect on a European site an assessment of its impacts on the site must be carried out before planning permission can be granted.
So whether or not an impact assessment needs to be carried out under both the Habitats Regulations and Schedule 2 of the EIA Regulations depends upon the likely significant impacts of the proposed development. Prior to the 2018 landmark case, People Over Wind v Coillte Teorante Case C323/17, it was settled law that when looking at what the likely significant impacts of a proposed development under either set of regulations, any mitigation measures which the developer had included in their proposal in order to avoid or reduce the harmful effects of the development could be taken into account, at least so far as those measures were sufficiently specific, available and effective. Such an approach was generally regarded as advantageous as it encouraged developers to consider mitigation measures at an early stage.
However, the Court of Justice of the EU’s decision in the People Over Wind, appears to have changed this. The case was a Habitat Regulations assessment case concerning the potential impacts of a wind turbine connection cable on freshwater pearls in a European site, and the Court ruled that in deciding whether a proposed development is likely to have a significant effect on the site concerned and therefore whether a Habitats Assessment is required, it is not appropriate to take account of mitigation measures.
This decision has gained academic attention for seeming to contradict previous decisions, but it has also been suggested that it may not be as out of kilter with previous decisions as it initially seems. As explained above, prior to People Over Wind, mitigation measures were required to have a degree of precision and effectiveness before they could be taken into account in deciding whether an impact assessment was required, and the type of mitigation measures which were taken into account often formed an integral part of the development. Although the Court of Justice of the EU made no reference to any distinction between types of mitigation measures, in People Over Wind the details of the proposed mitigation measures were to be agreed with the LPA after the planning permission had been granted and contained within a Construction Management Plan. The decision could therefore be interpreted as following previous decisions regarding the type of mitigation measures that could be taken into account.
The subsequent High Court case of Langton v Secretary of State for Environment, Food and Rural Affairs and Natural England could be seen to support this. This case concerned a judicial review of various decisions by Natural England to grant badger culling licences. The culling areas included or were near to a number of SPAs. Natural England’s decisions (which predated the People Over Wind decision) were challenged on the basis that in deciding that granting the licences was not likely to have significant effects on the SPAs and no Habitats Assessment was therefore required, Natural England had taken into account mitigation measures. The High Court, rejected this argument, taking the view that the mitigation measures concerned were not of the type in the People Over Wind, but were integral features of the development proposal. It held that not only was Natural England entitled to take them into account, but that it would have been ‘contrary to common sense’ not to. The applicant appealed this decision on a number of grounds, one of which was that the High Court had been wrong to find that the mitigation measures in question were of a type that could be taken into account in deciding whether a Habitats Assessment was required. The Court of Appeal, however, declined to address this point on the basis that it was purely academic given that Natural England had by then changed its practice.
Neither was the position clarified in the case of R (oao Wingfield) v Canterbury City Council, decided in July 2019. In this case, an application for outline planning permission had been made in 2015 for a development in respect of which a Habitats Assessment was potentially required. The application for outline planning permission contained details of mitigation measures which would be used to address some potential adverse effects of the development and in 2017 outline planning permission was granted without a Habitats Assessment having been carried out. In September 2018, following the ruling in People Over Wind, the LPA required that a Habitats Assessment be carried out at the reserved matters stage. The Habitat Assessment was duly undertaken and concluded that the proposed development would not have an effect on the integrity of the designated sites, and planning permission of the reserved matters was granted in February 2019. A local resident brought a judicial review claim challenging the 2019 decision to grant approval for the reserved matters on the grounds that the original grant of outline planning permission was unlawful because mitigation measures had been taken into account at the outline stage when deciding that a Habitats Assessment was not required. Although the claim was dismissed on a number of grounds, in particular that the error did not nullify the decision to grant outline planning permission and that the LPA had taken steps to remedy its error by requiring a Habitat Assessment to be undertaken at the reserved matters stage, the court was clearly of the view that the decision to grant outline planning permission would have been challengeable by the claimant had they brought a claim within the time frame for challenging that decision. However, it is noteworthy that in Wingfield, like in People Over Wind, the detail of the mitigation measures was finalized after the decision that no Habitats Assessment was required had been made and therefore did not form an integral part of the development proposal although, as was the case in People Over Wind, the court made no reference to any distinction between different types of mitigation measures. This failure of the court in People Over Wind to consider the issue of integral mitigation measures and if and when they can be taken into account has led to the decision being criticized for being a little too black and white and there consequently remains a significant amount of uncertainty regarding this point.
The decisions in People Over Wind and Wingfield have come under additional criticism for not only having removed the incentive for developers to consider and incorporate mitigation measures at an early stage, but also having thrown into question the legality of strategic mitigation systems that have previously been put in place to protect European sites. However, the other side of the argument, and the position that the court appears to have taken in People Over Wind, is that the question of whether an impact assessment is required should be based on a very low, de minimis, threshold and just be used to filter out those cases where there is clearly no risk of adverse effects. According to this argument, the assessment itself then provides the opportunity for there to be a detailed and expert evaluation of the development and any adverse effects it will have on the integrity of the European site, and at this stage any measures to mitigate the effects can be taken into account.
In any event, it is likely that there will be further cases regarding the question of integral mitigation measure and when they can be taken into account, as well as the question of whether the People Over Wind decision applies to EIA Regulation cases as well as the Habitat Regulations. Until these questions have been fully considered by the courts, any decisions regarding whether a Habitats Assessment or EIA is required ought to be approached with caution and in the knowledge that, for the moment, there is a greater risk of them being challenged.