1-2 Purpose and aims of EIA

Simply defined, EIA is a systematic process to identify, predict and evaluate the environmental effects of proposed actions and projects. This process is applied prior to major decisions and commitments being made. A broad definition of environment is adopted. Whenever appropriate social, cultural and health effects are considered as an integral part of EIA. Particular attention is given in EIA practice to preventing, mitigating and offsetting the significant adverse effects of proposed undertakings.

The purpose of EIA is to:

  • provide information for decision-making on the environmental consequences of proposed actions; and
  • promote environmentally sound and sustainable development through the identification of appropriate enhancement and mitigation measures.

Sustainable development is a key concept that has gained increasing international acceptance during the last two decades. A milestone in this process was the ‘Brundtland’ report, which defined sustainable development as ‘development that meets the needs of today’s generation without compromising those of future generations’. Five years later, the UN Conference on Environment and Development (UNCED), the Earth Summit, established a number of international agreements, declarations and commitments (see table below). Agenda 21, the global action plan for sustainable development, emphasises the importance of integrated environment and development decision-making and promotes the use of EIA and other policy instruments for this purpose.

Four cornerstones of the Earth Summit
Cornerstone Summary

The Rio Declaration on Environment and Development A set of principles which provide guidance on achieving sustainable development.
Framework Convention on Climate Change An international treaty to stabilise greenhouse gas concentrations in the atmosphere.
Convention on Biological Diversity An international convention with three objectives: the conservation of biodiversity, the sustainable use of its components, and the equitable sharing of benefits from genetic resources.
Agenda 21 A global programme of action for achieving sustainable development to which countries are ‘politically committed’ rather than legally obligated.

Perspectives on sustainable development

Sustainable development is an evolving concept, which is continually being redefined and reinterpreted. The starting point for most people is the ‘Brundtland definition’ (described above), which also can be formally stated as twin principles of intra- and inter-generational equity. In practice, these principles mean improving the welfare of the world’s poor and maintaining the development opportunities for the generations that follow.

The challenge of sustainable development may be summarised by comparing three overriding indicators:

  • First, human activity is estimated to currently consume or pre-empt 40 per cent of net primary productivity on land.
  • Second, 60 per cent of the world’s population live close to or under the poverty line.
  • Third, the world’s population is projected to double by mid-century.

Without major policy and technology changes, UNEP and other institutions have concluded that such trends threaten the stability of the world community and the global environment.

Why EIA is important

Reducing the burden of environmental impacts is necessary if development is to become sustainable. These impacts are more complex, larger in scale and further reaching in their potential consequences than thirty years ago when EIA was first introduced. As a result, EIA has become of ever increasing importance as a tool for development decision-making.

This role is formally recognized in Principle 17 of the Rio Declaration on Environment and Development:

‘Environmental impact assessment, as a national instrument, shall be undertaken for proposed activities that are likely to have a significant adverse impact on the environment and are subject to a decision of a competent national authority’.

In practice, EIA is applied primarily to prevent or minimise the adverse effects of major development proposals, such as power stations, dams and reservoirs, industrial complexes, etc. It is also used as a planning tool to promote sustainable development by integrating environmental considerations into a wide range of proposed actions. Most notably, strategic environmental assessment (SEA) of policies and plans focuses on the highest levels of decision making, when better account can be taken of the environment in considering development alternatives and options. More limited forms of EIA can be used to ensure that smaller scale projects, conform to appropriate environmental standards or site and design criteria. Such projects include dredging activities, road realignment and upgrading, and housing subdivisions.

What are the aims and objectives of EIA?

The aims and objectives of EIA can be divided into two categories. The immediate aim of EIA is to inform the process of decision-making by identifying the potentially significant environmental effects and risks of development proposals. The ultimate (long term) aim of EIA is to promote sustainable development by ensuring that development proposals do not undermine critical resource and ecological functions or the well being, lifestyle and livelihood of the communities and peoples who depend on them.

Immediate objectives of EIA are to:

  • improve the environmental design of the proposal;
  • ensure that resources are used appropriately and efficiently;
  • identify appropriate measures for mitigating the potential impacts of the proposal; and
  • facilitate informed decision making, including setting the environmental terms and conditions for implementing the proposal.

Long term objectives of EIA are to:

  • protect human health and safety;
  • avoid irreversible changes and serious damage to the environment;
  • safeguard valued resources, natural areas and ecosystem components; and 
  • enhance the social aspects of the proposal.

Limitations of EIA

EIA is also a way of ensuring that environmental factors are considered in decision-making process along with the traditional economic and technical factors. Importantly EIA requires the scientific (technical) and value issues to be dealt with in a single assessment process. This helps in the proper consideration of all advantages and disadvantages of a proposal. Environmental considerations may, therefore, be set aside in favour of what are felt to be more important considerations. Alternatively, predicted adverse effects on the environment might lead to strict conditions being imposed to avoid these effects or remedy any adverse effects, or perhaps lead to the complete abandonment of a proposal.

However, it is most important to recognise that EIA cannot be regarded as a means of introducing an environmental “veto” power into administrative decision-making processes. Decisions that are unsatisfactory from an environmental point of view can still be made, but with full knowledge of the environmental consequences. The final decision about a proposal depends upon the likely severity of the adverse effects, balanced against other expected benefits.

In other words, EIA is an administrative process that identifies the potential environmental effects of undertaking a proposal, and presents these environmental effects alongside the other advantages and disadvantages of the proposal to the decision-makers. In the vast majority of EIA procedures this means that the outcome of the EIA process provides advice to the decision-makers – it does not provide a final decision. So, by itself, the EIA procedures cannot be expected to stop a proposal – although this is an outcome that some members of the general community and environment groups may expect.

In summary then:

  • only a very small fraction of proposals are halted, permanently or temporarily, as a direct result of EIA at the end of the review process;
  • preemption or early withdrawal of unsound proposals has been reported though it has proved difficult to document;
  • EIA has been useful in developing support for and confirmation of positive environmentally sound proposals;
  • the greening or environmental improvement of proposed activities is frequently seen; and
  • particular indirect effects of EIA are both instrumental (such as where policy or institutional adjustments are made as a result of EIA experience) and educational where participation in the EIA process leads to positive changes in environmental attitudes and behavior.

With regard to the last point there is considerable advantage to the general community where those people involved with the proposal, as well as decision-makers, are required to think about the environmental effects (and thence avoid negative effects), and the public can be made aware of the details of the proposal.

The limited power of EIA may seem to greatly reduce its value. However, as you have seen there are many benefits that come from using EIA.

Practical Examples and Case Studies

On the EIA wiki that accompanies this course module there are a large number of case studies exploring EIA in practice. It is recommended that where possible you review these case studies and where possible add to them.

Another very interesting resource is the online video documentary produced by Prof. Sharon Beder dealing with the EIA for the Sydney Harbour Tunnel in Australia.

July 26, 2006 Uncategorized — brendan @ 11:43 am


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    Comment by Cely Salazar Binoya, Ph.D0. — February 1, 2008 @ 7:51 am

  3. The EIA material is very helpful. Thanks a lot

    Comment by Cely Salazar Binoya, Ph.D. — February 1, 2008 @ 7:54 am

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  6. This doc will help me a lot in doing EIA here in the Philippines. I will share this with my students

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  7. Very clear and cohesive, thank you!

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  11. The information on this site was very useful to me.

    Comment by Alandia — June 28, 2009 @ 4:59 pm

  12. this is first after working 6 years in EIa i knew all about tha eia through this thanks

    Comment by G. Ponnusamy — July 21, 2009 @ 1:59 pm

  13. good notes with world wide understandable english

    Comment by Magdalena Raymond — June 4, 2010 @ 12:24 am

  14. can you please elaborate the key environmental parameters that are assessed when determining a suitable site for a clinic?

    Comment by sephule — October 7, 2010 @ 4:38 am

  15. these are very good notes they give a very clear understanding of the purpose as well as the aims of environmental impact assessment

    Comment by Y NOPOTSO — October 22, 2010 @ 11:46 pm

  16. at first i couldnt believe but after reviewing some notes i realize that this could be help full from the bigginers to the higher level student, researcher, practitioner, lecturer, proffesors and interested stakeholders!

    Comment by Mathayo BARIKIEL — March 5, 2011 @ 7:42 pm

  17. Thank you so very much on this, most superb, presentation.

    I am using this to supplement my studies in EIA. It is really helpful.


    Comment by Predrag — April 22, 2011 @ 5:57 pm

  18. EIA should always be an integral part of every scientific study as we try to cope up with recurrent global climatic changes.
    I’ve found the study extra beneficial

    Comment by hobic — May 8, 2011 @ 5:57 pm

  19. found it interesting. EIA should be an integral topic of every scientific study

    Comment by hobic — May 8, 2011 @ 5:59 pm

  20. EIA can be used by in rural areas if yes how? since im care iwould like to know about the application if EIAs to the development. can community assess the proposed development on their own? thanks for this opportunity i will always getting involve.

    Comment by jali mh — September 13, 2011 @ 5:57 am

  21. This material is very helpfull. I was about to go write my exam on Environmental Management course and had a quick glance at your website and it really helped me alot. Thanks

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  22. This material is very brief and concise, I really love it . Keep it up

    Comment by Michael Acquah — December 1, 2011 @ 5:45 am

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    Comment by chaitanya madhunapantula — February 21, 2012 @ 3:30 am

  25. improving decision on environment there should be an inforcement on EIA

    Comment by meshack osiah — May 3, 2012 @ 12:50 am

  26. Thanks for your information on EIA , i would like to request sample reports on all EIA procedures specifically starting with Project registration report/document, Project Brief report, Scooping Report, EIA final report and Non-Executive summary report on either Road project or mining project.It will be very helpful to me once you send.

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    Comment by Meshack Osiah — November 10, 2012 @ 6:12 pm

  27. I have been looking for information on EIA practice and was glad to have eventually come across such a great site. Thank you so much,

    Comment by definition essay topics — January 7, 2013 @ 2:33 pm

  28. Thanks for sharing. Will use it to beef up my lectures to my students. Karma dictates that when you give out kindness to the world, kindness will also come back to you…Love from Malaysia

    Comment by Zawawi Samba Mohamed — April 4, 2013 @ 2:24 pm

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