An Environmental Impact Assessment (EIA) is an analytical process that systematically examines the possible environmental consequences of a project´s implementation. EIA provides a way of assessing key issues effectively and transparently, and highlights opportunities to achieve wider environmental objectives. An EIA is carried out for new projects that are likely to have significant adverse impacts on the environment.
An Environmental Management Plan (EMP) is one of the outputs of an EIA process. An EMP establishes how impact mitigation measures are to be implemented and monitored.
An EIA provides competent environmental authorities insight on the environmental risks of a project to determine if it should be rejected, approved, or approved conditioned to the implementation of mitigation measures. It is also used by the EU to determine the acceptability of a project on environmental grounds, and elements to improve its design from an environmental sustainability perspective.
The EMP is used to ensure the impact mitigation measures get implemented and provides the elements to monitor key environmental variables.
The need for an EIA is determined by the environment and climate risk screening process.
The EIA and EMP are prepared during formulation and the EMP is implemented and monitored with the project.
The need for an EIA is determined by a screening process (Annex 3 of the Guidelines). An EIA consists of the following typical components: (A) screening; (B) scoping; (C) identification of potential impacts; (D) impact assessment; (E) analysis of alternatives; (F) EIA report; (G) preparation of an Environmental Management Plan (EMP). Public participation should be integrated throughout the process.
Data/information. Preparation of and EIA requires extensive details of the project, considering its construction, operation and decommissioning phases. It also requires data for a variety of dimensions: biological, physical, sociological, cultural of the receiving environment. Various impact identification and assessment methodologies are available, which vary depending on the type of project (e.g. Leopold-type matrices, cause-effect diagrams, map overlays, mathematical modelling, habitat fragmentation analysis). Quantitative assessments are the norm in EIA, but qualitative approaches may be required when data availability or quality if lacking.
Time. The time required to prepare an EIA can vary a lot, depending on the complexity of the project. EIAs require more time than other types of assessment (e.g. SEA), given the level of detail required, and the need to prepare an environmental baseline (which can require the generation of primary data). The time require can be calculated in months, although more than a year may be necessary for highly complex projects for which incomplete baseline information is available.
Skills. An EIA requires an interdisciplinary team able to assess the potential impacts of all project components on the different environmental and social components, particularly where scoping indicates the existence of complex issues.
Facilities and materials. N/A
Financial costs and sources. Cost of an EIA has been estimated to be generally less than 1% of the total project cost.
Tips and tricks. The scoping phase is critical to define, at an early stage, the key issues the EIA will focus on. Public participation is fundamental to identify key risks and concerns.
The EU EIA Directive requires that an EIA also assessed the project's vulnerability to climate change. In this sense, the elements of a Climate Risk Assessment (CRA) can be incorporated into the EIA.