Environmental Impact Assessment (EIA) is the process by which the anticipated effects on the environment of a proposed development or project are measured. If the likely effects are unacceptable, design measures or other relevant mitigation measures can be taken to reduce or avoid those effects.
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. An EIA must provide certain information to comply.
There are seven key areas that are required:
1. Description of the project
- Description of actual project and site description
- Break the project down into its key components, i.e. construction, operations, decommissioning
- For each component list all of the sources of environmental disturbance
- For each component all the inputs and outputs must be listed, e.g., air pollution, noise, hydrology
2. Alternatives that have been considered
- Examine alternatives that have been considered
- Example: in a biomass power station, will the fuel be sourced locally or nationally?
3. Description of the environment
- List of all aspects of the environment that may be affected by the development
- Example: populations, fauna, flora, air, soil, water, humans, landscape, cultural heritage
- This section is best carried out with the help of local experts, e.g. the RSPB in the UK
4. Description of the significant effects on the environment
- The word significant is crucial here as the definition can vary
- ‘Significant’ must be defined
- The most frequent method used here is use of the Leopold matrix
- The matrix is a tool used in the systematic examination of potential interactions
- Example: in a wind farm development a significant impact may be collisions with birds
5. Mitigation
- This is where EIA is most useful
- Once section 4 is complete, it is obvious where impacts are greatest
- Using this information ways to avoid negative impacts should be developed
- Best working with the developer with this section as they know the project best
- Using the wind farm example again construction could be out of bird nesting seasons
6. Non-technical summary (EIS)
- The EIA is in the public domain and be used in the decision making process
- It is important that the information is available to the public
- This section is a summary that does not include jargon or complicated diagrams
- It should be understood by the informed lay-person
7. Lack of know-how/technical difficulties
- This section is to advise any areas of weakness in knowledge
- It can be used to focus areas of future research
- Some developers see the EIA as a starting block for poor environmental management
