Under Regulation 61 of the Conservation of Habitats and Species Regulations 2010 (as amended) there is a legal requirement to consider the impacts of any plan or project on European sites. This legislation requires that an ‘appropriate assessment’ is carried out for any plans or projects that are likely to have a significant effect on a European site.
In practice the assessment is undertaken in three stages, each of which effectively culminates in a test. The stages are sequential, and it is only necessary to progress to the following stage if a test is failed. The stages are:
Stage 1 – Likely Significant Effect Test
This is essentially a risk assessment, typically utilising existing data, records and specialist knowledge. The purpose of the test is to decide whether ‘full’ Appropriate Assessment is required. The essential question is ”Is the project, either alone or in combination with other relevant projects and plans, likely to result in a significant adverse effect upon European sites?”. If it can be demonstrated that significant effects are unlikely, no further assessment is required.
Stage 2 – Appropriate Assessment
If it cannot be satisfactorily demonstrated that significant effects are unlikely, a full “Appropriate Assessment” will be required. In many ways this is analogous to an Ecological Impact Assessment, but is focussed entirely upon the designated interest features of the European sites in question. The essential question here is “Will the project, either alone or in combination with other relevant projects and plans, actually result in a significant adverse effect upon European sites, without mitigation?”. If it is concluded that significant adverse effects will occur, measures will be required to either avoid the impact in the first place, or to mitigate the ecological effect to such an extent that it is no longer significant.
Stage 3 – Imperative Reasons of Overriding Public Interest (IROPI) Test
If a project will have a significant adverse effect upon a European site, and this effect cannot be either avoided or mitigated, the project cannot proceed unless it passes the IROPI test. In order to pass the test it must be objectively concluded that no alternative solutions exist. The project must be referred to Secretary of State on the grounds that there are Imperative Reasons of Overriding Public Interest as to why the plan should nonetheless proceed.