Cumulative Impact Assessments

Cumulative Impact Assessments April 26, 2021

In February 2021, the High Court issued a Judgment surrounding the understanding and implementation of the Infrastructure Planning (Environmental Impact Assessment) Regulations 2009, specifically in relation to the consideration of cumulative effects.

What are the implications of this Judgment for EIA practitioners?

Overview of Pearce v Secretary of State

Consent was initially given to Vanguard wind farm which had assessed cumulative landscape and visual impacts of the development alongside Boreas wind farm, which was at pre-application stage but known to be shortly forthcoming. The cumulative assessment indicated the likelihood of adverse environmental effects, and while the Secretary of State noted that the information relating to Boreas wind farm was “limited”, permission was granted and recommendation was made to assess cumulative effects more fully in the Boreas wind farm EIA.

Subsequently, consent was applied for Boreas wind farm, for which more detailed information was available on which to undertake the cumulative assessment. Following this, a claim was made that the Secretary of State had breached the Infrastructure Planning (Environmental Impact Assessment) Regulations 2009 by determining the Vanguard application when in fact, at that time, there was not sufficient information on which to come to a reasoned conclusion in terms of the overall cumulative impact of both projects.

In specific reference to the EIA Regulations and applications made to a local planning authority, Schedule 4 Paragraph 5 requires that the likely significant effects specific to the factors outlined in Regulation 4(2) should be considered in respect of a range of effects including, but not limited to, cumulative effects. Regulation 18(4) subparagraph (b) indicates that the information submitted within an ES should be “reasonably required for reaching a reasoned conclusion on the significant effects”.

Requirements specific to an application for development consent via the Secretary of State are provided for within the EIA Regulations including, but not limited to, Regulations 21, 30 and 31. The requirements of the EIA Regulations are reflected within the Infrastructure Planning Regulations including, but not limited to, Schedule 4 Part 1 Paragraph 20, Regulation 2 and Regulation 3(2). In the Judgement, Mr Justice Holgate referred to the additional clarity that the EIA Regulations provide to the Infrastructure Planning Regulations, giving greater detail than that presented in the Infrastructure Planning Regulations.

The implications

Considering the regulatory similarities and overlap between Infrastructure Planning Regulations and the EIA Regulations, this Judgement has possible implications for those projects subject to the EIA Regulations.

The Judgement highlights the need to thoroughly scope a cumulative assessment in the first instance. Schedule 3 Paragraph 3 sub-paragraph (g) of the EIA Regulations requires that the “cumulation of the impact with the impact of other existing and/or approved development” is to be assessed. Helpfully, by this definition only “existing” or “approved” projects need to be scoped into an assessment. Developments that are yet to have gained approval can be scoped out of the assessment. In practice, it is often the case that proposed developments within the vicinity of the development are scoped into a cumulative assessment to enable a wholly worst-case assessment to be presented, as is seemingly the situation in the Vanguard case. In so doing, it is inevitable that the level of information available on which to undertake the assessment has the potential to be limited.

Due process should align with the requirements set out in the EIA Regulations. This Judgement provides a reminder to practitioners to ensure all relevant information is obtained to inform an assessment or otherwise bear the risk that the submitted information is insufficient for the relevant planning authority to reach a reasoned conclusion. To minimise this risk as far as possible, practitioners should look to robustly scope the cumulative assessment at an early stage to ensure that the assessment is appropriate and proportionate.

This article is for general awareness only and does not constitute professional or legal advice. Whilst every attempt has been made to ensure the accuracy of the information contained within it as at the date it is published, no party shall be entitled to rely on it and Avison Young accepts no liability for any party’s losses which may be caused by their reliance on it.

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