Which projects require environmental impact assessments in the European Union?

In the European Union, environmental impact assessments are required for two specific categories of projects:1

• Annex-I Projects: These projects are generally subject to mandatory assessment due to their significant potential impact. Examples include oil refineries, toxic waste landfills, and thermal power stations with a heat output of 300 megawatts or more.1
• Annex-II Projects: These projects, which include activities in the chemical, food, textile, leather, wood, and paper industries, require an assessment only when individual member states determine that the project's specific characteristics necessitate one.1

These assessments are essential for evaluating the direct and indirect effects of a project on humans, fauna, flora, soil, water, air, climate, and landscape, as well as the interactions between these elements. By mandating these evaluations, the EU ensures that environmental consequences are transparently considered in decision making and environmental policy before a project proceeds.1