Under the California Environmental Quality Act of 1970, when must an environmental impact report be prepared?

An environmental impact report (EIR) must be prepared when a project is determined to have a substantial environmental impact under the California Environmental Quality Act (CEQA) of 1970. This requirement ensures that potential environmental effects are thoroughly analyzed and considered before any project approval.

CEQA aims to promote informed decision-making by requiring public agencies to assess the environmental consequences of their actions. When a subdivision or any other project is likely to significantly affect the environment—such as through land use changes, habitat destruction, or increased traffic, among other factors—it necessitates the preparation of an EIR.

This process includes not only identifying and assessing the environmental impacts but also considering alternatives and mitigation measures to minimize adverse effects. The scope of requiring an EIR is determined by the potential significant impact of the project, distinguishing it from projects with minor impacts that may not require a detailed report.

Other choices do not accurately reflect the statutory requirements of CEQA. The law is not limited to commercial projects or private land sales exclusively, nor does it apply to all subdivisions indiscriminately regardless of their impact. The focus is specifically on significant environmental impacts, making it critical to determine the project's potential effects to ensure comprehensive analysis and public transparency.