Environmental impact assessment (EIA) is the assessment of the environmental consequences of a plan, policy, program, or actual projects prior to the decision to move forward with the proposed action. In this context, the term "environmental impact assessment" is usually used when applied to actual projects by individuals or companies and the term "strategic environmental assessment" (SEA) applies to policies, plans and programmes most often proposed by organs of state. It is a tool of environmental management forming a part of project approval and decision-making. Environmental assessments may be governed by rules of administrative procedure regarding public participation and documentation of decision making, and may be subject to judicial review.

The purpose of the assessment is to ensure that decision-makers consider the environmental impacts when deciding whether or not to proceed with a project. The International Association for Impact Assessment (IAIA) defines an environmental impact assessment as "the process of identifying, predicting, evaluating and mitigating the biophysical, social, and other relevant effects of development proposals prior to major decisions being taken and commitments made". EIAs are unique in that they do not require adherence to a predetermined environmental outcome, but rather they require decision-makers to account for environmental values in their decisions and to justify those decisions in light of detailed environmental studies and public comments on the potential environmental impacts.

History

Environmental impact assessments commenced in the 1960s, as part of increasing environmental awareness. An EIA is prepared to estimate the effects of a proposed development or construction project. EIA provides technical evaluations that are intended to contribute to more objective decision making. In the United States, EIA obtained formal status in 1969, with the enactment of the National Environmental Policy Act (NEPA). EIAs have been used increasingly around the world. The number of environmental assessments filed every year "has vastly overtaken the number of more rigorous Environmental Impact Statements (EIS)." An environmental assessment is a "mini-Environmental Impact Statement (EIS) designed to provide sufficient information to allow the agency to decide whether the preparation of a full-blown Environmental Impact Statement (EIS) is necessary."

Methods

General and industry specific assessment methods are available including:

  • Industrial products – Product environmental life cycle analysis (LCA) is used for identifying and measuring the impact of industrial products on the environment. These EIAs consider activities related to extraction of raw materials, ancillary materials, equipment; production, use, disposal and ancillary equipment.
  • Genetically modified plants – Specific methods available to perform EIAs of genetically modified organisms include GMP-RAM and INOVA.
  • Fuzzy logic – EIA methods need measurement data to estimate values of impact indicators. However, many of the environment impacts cannot be quantified, e.g. landscape quality, lifestyle quality and social acceptance. Instead, information from similar EIAs, expert judgment and community sentiment are employed. Approximate reasoning methods known as fuzzy logic can be used. A fuzzy arithmetic approach has also been proposed and implemented using a software tool (TDEIA).

Follow-up

At the end of the project, an audit evaluates the accuracy of the EIA by comparing actual to predicted impacts. The objective is to make future EIAs more valid and effective. Two primary considerations are:

  • Scientific – to examine the accuracy of predictions and explain errors
  • Management – to assess the success of mitigation in reducing impacts

Audits can be performed either as a rigorous assessment of the null hypothesis or with a simpler approach comparing what actually occurred against the predictions in the EIA document.

After an EIA, the precautionary and polluter pays principles may be applied to decide whether to reject, modify or require strict liability or insurance coverage to a project, based on predicted harms.

The Hydropower Sustainability Assessment Protocol is a sector-specific method for checking the quality of Environmental and Social assessments and management plans.

Around the world

Australia

The history of EIA in Australia could be linked to the enactment of the U.S. National Environment Policy Act (NEPA) in 1970, which made the preparation of environmental impact statements a requirement. In Australia, one might say that the EIA procedures were introduced at a State Level prior to that of the Commonwealth (Federal), with a majority of the states having divergent views to the Commonwealth. One of the pioneering states was New South Wales, whose State Pollution Control Commission issued EIA guidelines in 1974. At a Commonwealth (i.e. Federal) level, this was followed by passing of the Environment Protection (Impact of Proposals) Act 1974 (Cth) in 1974. The Environment Protection and Biodiversity Conservation Act 1999 (Cth) (EPBC Act) superseded the Environment Protection (Impact of Proposals) Act 1974 (Cth) and is the current central piece for EIA in Australia on a Commonwealth (i.e. Federal) level. An important point to note is that this federal legislation does not override the validity of the States or Territories environmental and development assessments and approvals; rather the EPBC Act runs as a parallel to the State/Territory Systems. Overlap between federal and state requirements is addressed via bilateral agreements or one-off accreditation of state processes, as provided for in the EPBC Act.

The Commonwealth Level

The EPBC Act provides a legal framework to protect and manage nationally and internationally important flora, fauna, ecological communities and heritage places. It defines this as matters of "national environmental significance". The following are the nine matters of such significance:

The EPBC Act comes into play when a person (a proponent) wants an action (often called "a proposal" or "a project") assessed for environmental impacts under the EPBC Act, he or she must refer the project to the Department of the Environment and Energy (Commonwealth). This referral is then released to the public and the relevant state, territory and Commonwealth ministers, for comment on whether the project is likely to have a significant impact on matters of national environmental significance. Although EAA is the primary tool for EIA in Northern Territory, there are further provisions for proposals in the Inquiries Act 1985 (NT). Firstly, under the Integrated Planning Act 1997 (IPA) for development projects other than mining. Secondly, under the Chapter 3 of the Environmental Protection Act 1994 (Qld) (EP Act) for some mining and petroleum activities. Thirdly, under the State Development and Public Works Organisation Act 1971 (Qld) (State Development Act) for 'significant projects'. Finally, under the Environment Protection and Biodiversity Conservation Act 1999 (Cth) for 'controlled actions'.

Western Australia (WA)

Part 4 of the Environmental Protection Act 1986 (WA) provides the legislative framework for the EIA process in Western Australia. The EPA Act oversees the planning and development proposals and assesses their likely impacts on the environment.

Canada

In Friends of the Oldman River Society v. Canada (Minister of Transportation), La Forest J of the Supreme Court of Canada described environmental impact assessment in terms of the proper scope of federal jurisdiction with respect to environments matters,

Supreme Court Justice La Forest cited , "The basic concepts behind environmental assessment are simply stated: (1) early identification and evaluation of all potential environmental consequences of a proposed undertaking; (2) decision making that both guarantees the adequacy of this process and reconciles, to the greatest extent possible, the proponent's development desires with environmental protection and preservation."

La Forest referred to and who described "...environmental assessments as a planning tool with both an information-gathering and a decision-making component" that provide "...an objective basis for granting or denying approval for a proposed development."

Justice La Forest addressed his concerns about the implications of Bill C-45 regarding public navigation rights on lakes and rivers that would contradict previous cases.

The Canadian Environmental Assessment Act 2012 (CEAA 2012) "and its regulations establish the legislative basis for the federal practice of environmental assessment in most regions of Canada." CEAA 2012 came into force July 6, 2012 and replaces the former Canadian Environmental Assessment Act (1995). EA is defined as a planning tool to identify, understand, assess and mitigate, where possible, the environmental effects of a project.

Opposition

Environmental Lawyer Dianne Saxe argued that the CEAA 2012 "allows the federal government to create mandatory timelines for assessments of even the largest and most important projects, regardless of public opposition."