CJEU: mitigation should not be considered at habitats screening stage

The decision by the Court of Justice of the EU (CJEU) in the Irish case of People Over Wind and Sweetman v Coillte Teoranta ('the POW case') is a departure from previous case law particularly in the UK, with the potential to create significant issues for developers and competent authorities. In many areas, the need for appropriate assessment is regularly screened out on the basis of well-established mitigation measures.

Going forward, a greater number of projects will need to be subject to appropriate assessment if mitigation cannot be relied on when screening. While this change will place a greater burden on applicants, statutory nature conservation bodies (SNCBs) and the relevant decision-makers, it is unlikely to change the overall position reached for most developments as mitigation measures can continue to be relied upon at appropriate assessment.

In some cases, there are likely to be practical difficulties in ascertaining what part(s) of a plan or project is a mitigation or avoidance measure, rather than a core design feature of the project. In some cases this will be clear: for example, the provision of vegetative screening to mitigate the effects of a development on the landscape. However, there will be measures that form part of a project's design that have been selected for a number of reasons, including because there are environmental benefits associated with it. An example might include the layout of turbines in an offshore wind farm array area.

What did the CJEU decide?

The POW case concerned a proposed electricity cable serving a windfarm. The environmental issue related to the potential impacts on freshwater mussels in a special area of conservation arising from the release of sediment into waterbodies along the proposed route.

The planning permission for the windfarm included a condition requiring compliance with an approved construction management plan which was to include provisions to control surface water run-off to prevent silt and other pollutants entering the water.

Under the relevant Irish legislation, a decision was made that the proposal did not require appropriate assessment for the purposes of the Habitats Directive. In reaching that conclusion, the relevant authority relied on the "protective measures that have been built into the works design of the project".

The planning permission was challenged by a group of environmental campaigners. The case made its way to the Irish High Court, which asked the CJEU "whether, or in what circumstances, mitigation measured can be considered when carrying out screening for appropriate assessment under article 6(3) of the Habitats Directive?"

The CJEU answered that the Habitats Directive "must be interpreted as meaning that, in order to determine whether it is necessary to carry out, subsequently, an appropriate assessment of the implications, for a site concerned, of a plan or project, it is not appropriate, at the screening stage, to take account of the measures intended to avoid or reduce the harmful effects of the plan or project on that site".

It was the court's view that the existence of mitigation measures in the first place "presupposes that it is likely that the site is affected significantly and that, consequently, such an assessment should be carried out". Taking account of these measures at the screening stage would "be liable to compromise the practical effect of the Habitats Directive in general, and the assessment stage in particular, as the latter stage would be deprived of its purpose and there would be a risk of circumvention of that stage, which constitutes, however, an essential safeguard provided for by the directive".

How does this differ from UK position?

The CJEU's judgment seems to be inconsistent with established practice in the UK, and with well-established case law such as the 2008 R (Hart DC) v SSCLG case. In the Hart case, Mr Justice Sullivan found that mitigation measures should be taken into account in screening proposals under the Habitats Regulations and Directive, notwithstanding an indication to the contrary in the European Commission's methodological guidance. The judge said that it was a "matter of common sense" for mitigation measures to be incorporated at the "earliest possible stage" of the planning process.

The relevant planning guidance in England will need to be reviewed and updated as a consequence of the decision. This will apply to Circular 06/2005, the Natural England standard 2017 and the Planning Inspectorate (PINS) advice notes applicable to DCO applications. Statutory bodies, including PINS and Natural England, will also need to adopt a position following the case.

What should projects already in the system do now?

Action to be taken by developers and scheme promoters will depend on a number of factors, including:

• whether they considered mitigation and avoidance measures as part of the screening;
• the outcome of any screening process, if it took into account mitigation and avoidance measures; and
• what stage of the application process the promoter is currently at.

Promoters at the pre-application stage which are intending to submit a negative screening report on the basis that mitigation and avoidance measures will ensure that there will be no likely significant effects on any European site should reconsider this strategy and rescreen the project, disregarding any mitigation and avoidance measures proposed.

Promoters which have carried out screening and have concluded that the plan or project is likely to have significant effects on a European site or its features cannot be discounted should review their 'report to inform' the appropriate assessment (RIAA) in light of the decision. If additional effects were screened out and not considered in detail based on their mitigation and avoidance measures, the promoter will need to update the RIAA before submitting it with their application for planning permission or development consent.

It is worth noting that the position reached in the POW case applies to the Habitats Directive regime only. The consideration of mitigation measures at the screening stage in the context of an environmental impact assessment (EIA) is expressly accepted within the wording of the 2014 EIA Directive.

Tom Edwards is a planning law expert at Pinsent Masons, the law firm behind Out-Law.com.