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1.7 Overview of the stages of the EIA process

This section very briefly presents an overview of the stages of EIA to help place them in the context of the whole process. More detail about each stage is provided later.


The EIA process begins from the very start of a project. Once a developer has identified a need and assessed all the possible alternatives of project design and sites to select a preferred alternative, two important questions must be asked: 'What will be the effects of this development on the environment? Are those effects significant?' If the answer to the second question is 'yes', an EIA may be required. Answering this question is a process known as screening and can be an essential first step into a formal EIA.

The EIA process is, it must be stressed, iterative. This is demonstrated at this early stage of screening where the requirement for a formal EIA and its associated cost implications can lead the developer to reassess the project design with a view to reducing the significant impacts to a level where an EIA is not legally required (Nielsen et al 2005).


Where it is decided that a formal EIA is required, the next stage is to define the issues that need to be addressed, that is, those impacts that have a significant effect on the environment. This is known as scoping and is essential for focusing the available resources on the relevant issues.

Baseline study

Following on from scoping, it is essential to collect all relevant information on the current status of the environment. This study is referred to as a baseline study as it provides a baseline against which change due to a development can be measured.

Impact prediction

Once the baseline study information is available, the important task of impact prediction can begin. Impact prediction involves forecasting the likely changes in the environment that will occur as a result of the development.

Impact assessment

The next phase involves the assessment of the identified impacts - impact assessment. This requires interpretation of the importance or significance of the impacts to provide a conclusion, which can ultimately be used by decision-makers in determining the fate of the project application.


Frequently, the assessment of impacts will reveal damaging effects upon the environment. These may be alleviated by mitigation measures. Mitigation involves taking measures to reduce or remove environmental impacts and it can be seen that the iterative nature of the EIA process is well demonstrated here. For example, successful design of mitigation measures could possibly result in the removal of all significant impacts; hence a new screening exercise would reveal that there might have been no need to carry out a formal EIA had the mitigation measures been included from the start.

Producing the environmental impact statement

The outcome of an EIA is usually a formal document, known as an environmental impact statement (EIS), which sets out factual information relating to the development, and all the information gathered relating to screening, scoping, baseline study, impact prediction and assessment, mitigation, and monitoring measures. It is quite common that a requirement of an EIS is that it also produces a non-technical summary. This is a summary of the information contained within the EIS, presented in a concise non-technical format, for those who do not wish to read the detailed documents. This is very important, as EISs are public documents intended to inform the public of the nature and likely consequences of a development in time to comment and/or participate in the final project design.

EIS review

Once the EIA is complete, the EIS is submitted to the competent authority. This is the body with the authority to permit or refuse development applications. The competent authorities are often in a position of having very little time to make a decision and have a detailed and lengthy EIS to read through which may contain errors, omissions, and developer bias. It is essential, therefore, that they review the document. Review can take a number of forms: it may be purely an ad hoc process whereby the document is read and commented on by decision-makers; it can be more formalised and expert opinion is sought; or it can be through the use of formal review methods designed specifically for the purpose. Basically, the review process should enable the decision-maker to decide whether the EIS is adequate (eg whether it is legally compliant), whether the information is correct, and whether it is unbiased. If it is, they are then in a position to use the EIS as information to be considered in determining whether the project should receive consent. This issue of review is discussed in more detail elsewhere in this module.

The competent authority is now in possession of the information they require about the possible effects of the development on the environment. They will use this information, in combination with all of the other details and representations they have received, to help them come to a decision.

Follow up

Follow up relates to the post-approval phase of EIA and encompasses monitoring of impacts, the continued environmental management of a project, and impact auditing. Without any form of follow up EIA would operate as a linear rather than an iterative process, and an important step towards achieving environmental protection will also have been omitted.

Follow up presents an opportunity both to control environmental effects and to learn from the process and cause-effect relationships. Ideally, data generated by monitoring and other aspects of follow up should be compared with the original predictions and mitigation measures in the EIS to determine

  1. the accuracy of the original predictions
  2. the degree of the deviation from the predictions
  3. the possible reasons for any deviation
  4. whether mitigation measures have achieved their objective of reducing or eliminating impacts

Information generated by this process can contribute to the improvement of future EIA practice, for example, by enabling more accurate predictions to be made.

The diagram in 1.7.1 provides a summary of the basic EIA procedure.

1.7.1 Key stages of EIA

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