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Mitigation Measures in Screening under Habitats Regulations

  • United Kingdom
  • Real estate sector


The decision of the Court of Justice of the European Union (“CJEU”) in People over Wind v Coiltle Teoranta¹ may be brief but is powerful in impact, raising doubt over the long-established position in UK law that as competent authorities, planning authorities should take into account mitigation measures in determining whether an Appropriate Assessment is required under the Habitats Regulations.

The High Court of Ireland referred the case to the CJEU for a preliminary ruling on the question of “whether, or in what circumstances, mitigation measures can be considered when carrying out screening for appropriate assessment under Article 6(3) of the Habitats Directive?”

At issue in the proceedings referred to the CJEU were the assessment of the effects of the works necessary to lay a cable connecting a consented wind farm to the electricity grid and in particular, the effect on a SAC which is the habitat of the Nore pearl mussel. Recent monitoring surveys made it apparent that this species is threatened with extinction, due to high levels of sedimentation of the river bed. The successful restocking of the river by juveniles is inhibited by sedimentation and reference was made to the Nore pearl mussel not having reproduced itself since 1970.

The claimant, People over Wind, were concerned that the laying of the connection cable will give rise to river pollutants, such as silt and sediment, which will have a harmful effect on the Nore pearl mussel.

Consultants undertook screening for an Appropriate Assessment (“AA”) and considered that in the absence of protective measures, there was potential for the release of suspended solids into waterbodies along the proposed cable route. Should silt or sediment enter the pearl mussel population area by way of tributaries, there would be a negative impact on the population.

However, in light of the best scientific knowledge, on the basis of the distance between the proposed grid connection and the SAC, as well as the protective measures built into the works design of the project, the consultants prepared a negative screening recommendation. This recommendation was adopted by the competent authority, Coillte Teoranta².

The CJEU do not discuss the nature of those ‘protective measures’ but define them as measures that are intended to avoid or reduce the harmful effects of the envisaged project on the European site.  It is clear that the measures were not as stringent as those attached to the development consent for the wind farm itself, which required a Construction Management Plan, to include details of the means to ensure the control of surface water run-off such that no silt or other pollutants enter watercourses.

In answering the question referred, the CJEU concluded that Article 6(3) must be interpreted as meaning that it is not appropriate to take account of measures intended to avoid or reduce the harmful effects of the plan or project on a European site at the screening stage undertaken to determine whether it is necessary to carry out an AA of the implications of the plan or project for that site.

Reference was made to the submissions of People over Wind and the Commission which noted that the fact that protective measures are taken into consideration when determining whether it is necessary to carry out an AA presupposes that it is likely that the site is affected significantly and that consequently, an AA should be carried out.

The CJEU considered this conclusion to be supported by the fact that a full and precise analysis of the measures capable of avoiding or reducing any significant effects on the site concerned must be carried out specifically at the stage of the AA and not at the screening stage.

Further support was taken from what the CJEU considered would result from taking account of such measures at the screening stage: the likelihood of compromising the practical effect of the Directive in general, and the assessment stage in particular. The assessment stage would be deprived of its purpose and there would be a risk of circumvention of a stage which is an essential safeguard provided by the Directive.

Reference was made to the integration of the precautionary principle in Article 6(3) and that to apply any less stringent authorisation criteria could not ensure meeting the objective of site protection as efficiently as the precautionary principle. In addition, Article 6(3) is the basis for the right for people to participate in a procedure for the adoption of a decision relating to a plan or project likely to have a significant effect on protected sites.   

Finally, the CJEU noted the emphasis in existing CJEU case-law that the AA must not have gaps or omissions and must contain complete, precise and definitive findings and conclusions capable of removing all reasonable scientific doubt as to the effects of the proposal on the European site concerned.

What now for the UK?

This is at odds with decisions in the UK Courts and established practice in the UK.

The established practice in the UK is that competent authorities may consider mitigation measures which are incorporated into the application for planning permission in deciding whether the project for which planning permission is sought is likely to have a significant effect on a European site. 

In ruling on the question to relation to residential development in proximity to a SPA and SSSI, the High Court ruled that there is no legal requirement that a screening assessment under the regulations must be carried out in the absence of any mitigation measures that form part of a plan or project. On the contrary, a competent authority is required to consider whether the project, as a whole, including such measures, if they are part of the project, is likely to have a significant effect on the SPA³. It was described as “ludicrous” for the competent authority to disaggregate the different elements of the package and require an AA on the basis that the residential component of the package, without the proposed mitigation measures, would be likely, in combination with other residential proposals, to have a significant effect on the SPA, only to have to reassemble the package when carrying out the AA.

The Supreme Court considered the requirements of the Habitats Directive and domestic regulations in R(on the application of Champion) v North Norfolk District Council [2015] UKSC 52. It was noted that there is no equivalent to a ‘screening process’ in the Habitats Directive or domestic Regulations, nor anything in the language of the Habitats Directive itself. The legal requirements must be found in the legislation, not in Opinions of Advocates General or Commission Guidance. The formal EIA procedures of screening, preparation of an ES and mandatory public consultation have no counterpart in the Habitats legislation.

The argument that there is an implicit requirement to screen under the Habitats Directive was rejected by the Court of Appeal who reviewed CJEU cases and found no “obligation to carry out a screening assessment, let alone any rule as to when it should be carried out. If it is not obvious whether a plan or project is likely to have a significant effect on an SPA, it may be necessary in practice to carry out a screening assessment in order to ensure that the substantive requirements of the Directive are ultimately let. It may be prudent, and likely to reduce delay, to carry one out an early stage of the decision-making process. There is, however, no obligation to do so”.&sup4;    

The implications of this CJEU case for developers and competent authorities are significant.

Should all features or elements of a proposal that could be characterised as mitigation measures be taken into account in deciding whether to carry out an AA?

Some features or elements will have clearly been introduced to avoid or reduce harmful effects on a European site or in light of a potential for a significant effect on a protected site or habitat. Others may have the effect of avoiding or reducing the harmful effects on a European site but would have been present in the proposed development in any event. There may be an argument for any such integrated features to be taken into account and not excluded from the AA ‘screening’ process. 

These two categories may be described as applied and inherent mitigation but the terms may not be helpful. Distinguishing applied and inherent mitigation has long been a persistent issue in the field of EIA and different definitions have been adopted by planning authorities and EIA professionals. The common approach of identifying inherent mitigation by the presence of a related condition does not always withhold scrutiny and should be treated with caution in light of this recent ruling.

For Habitats Regulations purposes, it will not always be a clear-cut matter to identify the extent to which a protected site or potential for a significant effect on any such site has influenced the form of a feature or element of a development. Where it is not clear where the dividing line lies between an integrated part of the development and applied mitigation, an AA may need to be undertaken, at which stage, mitigation measures can and should be taken into account.

  1. Case C-323/17
  2. An Irish State-owned company operating in the forestry sector
  3. R (on the application of Hart District Council) v Secretary of State for Communities and Local Government & Others [2008] EWHC 1204 (Admin)
  4. No Adastral Town Limited v Suffolk Coastal District Council [2015] EWCA Civ 88 at paragraph 68.