Nick Freer, business partner at David Lock Associates, highlights issues to be aware of when assessing environmental effects during multi-stage development projects.
Both regulation and case law has made plain the need to consider the environmental effects of projects not simply at the outset of the project but at subsequent stages involving decision making.
One common circumstance is where EIA development obtains outline planning permission and is then followed up over several years by subsequent approval of more detailed aspects of the development.
Decision makers can ask for further environmental assessment to be carried out and the information submitted with the detailed stage planning application. This happens if the decision maker believes that assessments in the original application have become outdated, or that the new application raises issues that were either not considered, or have a higher impact than those assessed in the original submission.
Applicants may decide to produce further information to help secure detailed consent for elements of the proposal which vary from the original. While radical departures from outline approvals would not be appropriate, some planning permissions include conditions which allow for minor variation as long as it does not create new environmental impacts that are greater than those assessed in the original application.
The prospect of a decision maker requiring an updated environmental statement increases along with the passage of time between the original and subsequent application. This can be an issue as staff change and knowledge and understanding is lost. If the original environmental statement is written with care and precision, knowledge drift is slower. However, even with full documentation, the situation is never perfect as mitigation is often formalised outside the original environmental statement.
If baseline data is outdated, it does not necessarily mean that further environmental information needs to be submitted. A well-constructed original statement with a clearly articulated mitigation strategy should take account of potential for change and avoid the need for wholesale new information or assessment. It is good practice for the original mitigation strategy to specifically highlight those matters which will need resurvey at a future date, thereby avoiding the need to start from scratch.
The passage of time may result in new related or other developments being approved on nearby sites, potentially resulting in the decision maker requesting that previous cumulative assessments are updated. Outline planning permission will have been obtained on the basis of the best information that could be provided at that time with a comprehensive package of mitigation based on that assessment. Other developments permitted since outline planning permission was granted should rarely be taken into account at detailed planning stage.
Decision makers can also ask for updated environmental information to support applications where new standards or benchmarks for monitoring the impacts of development have been established. However, this rarely happens in practice when considering detailed stage planning applications.
Often the assessment of the environmental effects carried out for an outline planning application will have considered the worst case scenario. It is therefore possible that minor variations to the information may emerge at detailed application stage but that they would not lead to more significant impacts than those already considered.
The need for a comprehensively updated EIA can be reduced by putting in place appropriate and specific mitigation measures in the original consent which define the timing and specific nature of new surveys which might be needed in the future.
The extent to which a detailed planning application exceeds the information given at outline consent stage can be specifically identified at the initial scoping stage. Any updated baseline reports should focus specifically on these topics and not just updated as a matter of course. Updated information should be easily comparable with the original assessment.
Suggested structure to adopt in the new application:
- Nature and parameters of the new application.
- Possible additional significant effects of the new application.
- Update of relevant baseline insofar as this is not already provided for in mitigation of initial assessments.
- Review of any updated standards to be employed in impact assessments.
- Focussed assessment of additional or new impacts – this should not be a generalised update of previous impact assessment.
