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Habitat Regulations Assessments: No more screening out with mitigation measures?

habitat regulations assessments screening case law

Penny Simpson (Partner, Freeths) provides a summary of the recent case of ‘People Over Wind and Sweetman’ (C-323/17) and discusses the potential implications of the case for Habitat Regulations Assessments…

A recent decision by the Court of Justice of the European Union (“CJEU”) People Over Wind and Sweetman v Coillte Teoranta (C-323/17) means that measures intended to avoid or reduce the harmful effects of a proposed project on a European site may no longer be taken into account by competent authorities at the Habitat Regulations Assessment (“HRA”) “screening stage” when judging whether a proposed plan or project is likely to have a significant effect on the integrity of a European designated site.

Background to the case

The dispute before the CJEU concerned the assessment of the potential effects that the laying of the cable by Coillte Teoranta (“Coillte”), a company owned by the Irish State, to connect a wind farm to the electricity grid could have on two Special Areas of Conservation, one of which is that of the River Barrow and River Nore (Ireland). That river constitutes a habitat for the Irish subspecies of the freshwater pearl mussel (Margaritifera durrovensis; ‘the Nore pearl mussel’), which is included in Annex II to the Habitats Directive. According to the domestic court, it was apparent from recent monitoring surveys that this species is threatened with extinction, on account of the high level of sedimentation of the bed of the River Nore (to which the species is particularly vulnerable).

Under Irish law, certain “exempted development” projects (which would include the laying of underground mains, pipes, cables or other apparatus by an authorised undertaker to provide an electricity service) would not require planning consent under the Planning and Development Acts unless an appropriate assessment under Article 6(3) of the Habitats Directive is required.

Coillte, as a public authority, instructed consultants to prepare a HRA screening report to determine whether it was necessary to carry out an appropriate assessment. The screening report conceded that in the absence of protective measures there was the potential for release of suspended solids into waterbodies along the cable route including directional drilling. Coillte subsequently concluded that no appropriate assessment was required (and as such, no planning consent would be required) in light of recommendations drawn up based on the screening report, which took into account “protective measures”:

“As set out in detail in the … appropriate assessment screening report, on the basis of the findings that the report and in light of the best scientific knowledge, the grid connection works will not have a significant effect on the relevant European sites in light of the conservation objectives of the European sites, alone or in combination with the Cullenagh wind farm and other plans or projects, and an appropriate assessment is not required. This conclusion was reached on the basis of the distance between the proposed Cullenagh grid connection and the European sites, and the protective measures that have been built into work design of the project.”

“Protective measures” were regarded by the CJEU as “measures that are intended to avoid or reduce the harmful effects of the envisaged project on the site concerned“. It seems, though it is not entirely clear, that the protective measures consisted of a construction methodology to control surface run-off into watercourses.

The case was subsequently referred to the CJEU by the High Court (Ireland) for a preliminary ruling on “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“.

The legal regime

Competent authorities (often Local Planning Authorities) are required to undertake a HRA where proposed plans or projects relate to conservation sites which have been selected and designated on scientific criteria under European law to protect certain species and habitats under the following network of areas:

Special Protection Areas (“SPAs”) which are sites classified in accordance with Article 4 of the EC Birds Directive for certain rare and vulnerable birds, and for regularly occurring migratory species;[1]
Special Areas of Conservation (“SACs”) which are designated under the EC Habitats Directive to protect high quality conservation sites that will make a significant contribution to conserving 189 habitat types and 788 species identified in Annexes I and II of the Directive.[2] The listed habitat types and species are those considered to be most in need of conservation at a European level (excluding birds).[3]
The HRA comprises several distinct stages.[4] The first stage of the HRA process includes formally screening a proposed plan or project to decide whether it is likely to have a significant effect on a European designated site. If, at the screening stage, any significant effects of a plan or project on a SPA or SAC (alone or in combination with other plans or projects) can be excluded, then the plan or project can be “screened out” and no further assessment is required.

However, where any significant effect of a plan or project on a SPA or SAC (alone or in combination with other plans or projects) cannot be excluded, then the competent authority will be required to assess the effects in more detail through an appropriate assessment, to ascertain whether an adverse effect on the integrity of any SPA or SAC can be ruled out.

Where such an adverse effect on the site cannot be ruled out (alone or in combination with other plans or projects), and no alternative solutions can be identified, then the project can only then proceed if there are imperative reasons of over-riding public interest and if the necessary compensatory measures can be secured.

Outcome of the recent CJEU decision

The CJEU reached the following conclusion in relation to “measures which avoid or reduce the harmful effects of a plan or project”:

“In the light of all the foregoing considerations, the answer to the question referred is that Article 6(3) of 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” (paragraph 40).

Importantly, the CJEU pointed out that “taking account of such [avoidance / reduction] 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” (paragraph 37).

The case will now return to the Irish High Court for final disposal.

Implications of the case

It is clear from the case that the CJEU sees a distinction between “the plan or project” itself and “measures intended to avoid or reduce the harmful effects of a plan or project on a European site”.

The key challenge arising from this case is knowing where exactly that distinction lies in future scenarios. Where, in any one case, is a particular “facet” of a “project” (to use an innocuous / neutral term) properly to be regarded as an integral part of the project (so that it is relevant to making an assessment of likely significant effect) and where is it “intended to avoid or reduce the harmful effects of a plan or project on a European site” (so that, according to the CJEU judgment, it is not relevant to making an assessment of likely significant effect)? Understanding this distinction is now necessary to be able to apply this case to scenarios in the future.

In the case before the CJEU, the “measures intended to avoid or reduce the harmful effects of a plan or project on a European site” were the measures to prevent sediment from the cable works entering watercourses which may then lead to the River Nore SAC and harm the mussels. It follows then that the cable works were regarded as “the project”.

When identifying this distinction in future cases it is helpful to consider the exact words used by the CJEU ie “measures intended to avoid or reduce the harmful effects of a plan or project on a European site”. So a starting point might be: What is the true primary purpose of / intention behind a particular facet of a project? Is it to protect European sites from the project? Or is it to advance the central purpose of the project? A related question might be “would the particular facet of the project have been provided in any event, even if there were no European site to be concerned with?”

It does seem that this CJEU decision is a departure from the (until now) important domestic judgment of Sullivan J in the case of “Dilly Lane” (R on the application of Hart DC) v Secretary of State for Communities and Local Government [2008] EWHC 1204 (Admin)).

In the Dilly Lane case, Sullivan J ruled that mitigation measures that were “incorporated into the project” or which “formed part of the project” could properly be taken into account at the screening “likely significant effect” test stage of HRA (as long as they were effective). In that case the measure in question was the provision of a Suitable Alternative Natural Greenspace (SANG) so as to divert housing-development residents away from the nearby SPA. The SANG in that case was therefore in truth an avoidance (not a reduction) measure.

It seems that the difference between Sullivan in Hart and the CJEU in People Over Wind and Sweetman (2018) is in the interpretation and application of the word “project”:

  • Sullivan J accepted that certain facets of a project, which are intended to avoid or reduce negative impacts on a European site, can still be regarded as “incorporated into the project” if they are promoted that way by the developer;

whereas …

  • The CJEU appears to consider that measures intended to avoid or reduce impacts on a European site cannot at the same time be regarded as part of the “project”.

Therefore, following this CJEU decision, it would appear that, since a proposed off-site SANG is a facet of a project specifically designed / intended to avoid recreational pressure of a housing development on a European site, it could not be relevant to the HRA “likely significant effect” test.

However the matter gets more complex / difficult with facets of a development which might be said to have more than one purpose. Take, for example, an on-site SANG ie dog-walking areas within / around a proposed housing development. Is the green space within an on-site SANG designed specifically to protect European sites, or is it designed to make the housing development more attractive to new homeowners? Would the greenspace be provided within the development in any event? If it would, then one can see that it may well be argued that such an on-site SANG is not a measure “intended to avoid or reduce the harmful effects of a plan or project on a European site”, even if it will have that avoidance or reduction effect as a “by-product”, and so should still be regarded as integral part of the project.

Another tricky example would be a stack associated with a factory through which fumes are discharged to the atmosphere. Its primary function / the intention behind it may well be to discharge the fumes high into the atmosphere for general environmental protection reasons, as well as for SPA / SAC protection reasons. Is this an integral part of the project or is it “intended to avoid or reduce the harmful effects of a plan or project on a European site”? And is it relevant that the stack is included so as to prevent general environmental health problems as well as European site damage? The answer to this second question may be “no” since the People Over Wind and Sweetman case considered anti-water pollution protective measures which would clearly serve to protect all watercourses, not just the River Nore SAC, and yet the CJEU still considered those measures to be “intended to avoid or reduce the harmful effects of a plan or project on a European site”.

As can be seen, the CJEU’s judgment is likely to cause some difficulties in interpretation.

This judgment marks a clear distinction between the Habitats Directive regime and the EIA regime, which is interesting since the CJEU has previously been keen to draw parallels between the two regimes. Under the recently implemented 2014 EIA Directive, it is made absolutely clear (in the wording of the Directive) (in contrast to People Over Wind and Sweetman (2018)) that (i) avoidance and prevention measures (but not reduction or offsetting measures) can be taken into account at the EIA screening stage; whereas (ii) reduction and offsetting measures may only be taken into account following the screening stage, at the Environmental Statement stage.

For the avoidance of doubt, the CJEU has confirmed previously in Briels that protective measures forming part of that project aimed at avoiding or reducing any direct adverse effects for the site can be relied upon at the appropriate assessment stage of the HRA process, in order to conclude that a project does not adversely affect the integrity of the European site. By contrast protective measures provided for in a project which are aimed at compensating for the negative effects of the project on a Natura 2000 site cannot be relied upon at the appropriate assessment stage of the HRA process.


[1] Directive 2009/147/EC on the conservation of wild birds.
[2] Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora.
[3] Of the Annex I habitat types, 78 are believed to occur in the UK. Of the Annex II species, 43 are native to, and normally resident in, the UK (
[4] Articles 6(3) and (4) of Directive 92/43/EEC as implemented by Regulations 63 and 64 of the Conservation of Habitats and Species Regulations 2017/1012.

Header Image: River Barrow. Credit: Sarah777 / Wikimedia Commons.

About the Author: Penny Simpson (Partner, Freeths) is a solid and experienced all-round environmental lawyer with particular expertise in “natural environment” law. She has built a strong, national reputation in advising a wide range of private and public sector clients. She advises on the regulation of protected habitats, protected species, water resources, air quality and environmental impact assessment.  Penny is recognised as an “Elite Leading Lawyer” in Environment by The Legal 500.