Monitoring and post-auditing in environmental impact assessment: a review

Environmental impact assessment (EIA) is a procedure for predicting environmental impacts of projects prior to their development, while post-auditing seeks to assess the accuracy of such predictions. A literature review examines the need for post-auditing, highlighting several benefits to EIA performance that could arise if the results were effectively used. this reveals that, in practice, post-auditing activities are not widespread, and suggests reasons why this is so. An overview of post-audit findings from a survey of published studies is then presented, and it is concluded that there is much scope for raising the profile of post-auditing in EIA world-wide. Preliminary results from a recent UK post-auditing study based on eight projects are described. Information on impact predictions was gathered and compared with actual impacts. A total of 366 impact predictions were made of which 78% were qualitative in nature; 57% of the predictions were auditable and of these nearly three-quarters were accurate. Reasons for inauditability were ascertained including, for all cases, a lack of data or unsuitable information.