In adopting a screening opinion, decided cases establish that a local planning authority (“LPA”) may have regard to the mitigating measures provided that they are sufficiently specific, they are available and there is no real doubt about their effectiveness.
However, the courts have pointed out that the more sophisticated the mitigating measures, and the more controversy there is about their efficacy, the more difficult it will be for the LPA to reach a decision that the environmental effects of the development are not likely to be significant.
In a similar vein, in R (on the application of Jones) v Mansfield District Council [2003] EWCA Civ1408, Dyson LJ – as he then was – stated: “It is clear that a planning authority cannot rely on conditions and undertakings as a surrogate for the EIA process. It cannot conclude that a development is unlikely to have significant effects on the environment simply because all such effects are likely to be eliminated by measures that will be carried out by the developer pursuant to conditions and/or undertakings”.
In R (on the application of Champion) v North Norfolk District Council (see PP 2015/141 and PP 2015/143), the claimant also submitted that the LPA – having initially adopted a negative screening opinion – had then sought to rely on mitigation measures at the stage of granting planning permission in order to dispense retrospectively with an environmental impact assessment that should have been initiated at the outset of the planning application process.
The Supreme Court accepted the claimant’s submission, pointing out that – at the stage the negative screening opinion was adopted – the mitigation measures as then proposed were not straightforward, and there were considerable doubts as to how they would be resolved. The court went on to state that, while there is nothing to rule out consideration of mitigation measures at the screening stage, the EIA Directive and the EIA Regulations expressly envisage that mitigation measures will – where appropriate – be included in an environmental statement. Application of the precautionary principle, which underlies the EIA Directive, implies that cases of material doubt should generally be resolved in favour of an environmental impact assessment.
In the present case, the fact that issues over mitigation were ultimately resolved to the satisfaction of the consultees did not mean that there had been no need for an environmental impact assessment. That failure to treat the proposal as an EIA development was a procedural irregularity that was not cured by the final decision.
John Martin is a planning law consultant
