Under what condition is an environmental impact statement usually required?

An environmental impact statement (EIS) is typically required for major development projects because these types of projects have the potential for significant effects on the environment. The purpose of the EIS is to assess the potential environmental consequences of proposed actions and to explore alternatives and mitigation measures to address any adverse impacts.

Major development projects often involve large-scale land use changes, significant alterations to the natural environment, or potential effects on public health and welfare. Therefore, they demand a thorough review process to ensure that decision-makers and the public are adequately informed about environmental risks and benefits associated with the proposed project.

In contrast, the other conditions—such as minor projects, all construction projects, or projects under zoning compliance—generally do not meet the thresholds that necessitate a comprehensive EIS. These projects may still undergo some form of environmental review, but it typically would not reach the level of detail or scope involved in preparing an EIS, which is reserved for more impactful projects.