EiRs

EIRs, or Environmental Impact Reports, are comprehensive documents prepared during the environmental review process for proposed projects to assess potential significant environmental effects and to identify measures that could mitigate those effects. In the United States, the best-known framework for EIRs is under the California Environmental Quality Act (CEQA), but other jurisdictions undertake similar analyses under different laws.

An EIR typically examines a project’s potential impacts on land use, air and water quality, biology, cultural resources, noise, traffic, energy, and climate change; it assesses cumulative effects and environmental justice considerations where applicable. The document also evaluates feasible mitigation measures and multiple alternatives to the proposed action, including a no-project alternative. It presents an analysis of the significance of each impact and whether mitigation can reduce it to less-than-significant levels.

Process: The EIR process includes scoping, preparation of a draft EIR circulated for public review, responding to comments, and preparation of a final EIR. The lead agency then certifies the EIR, adopts findings of significant impacts and mitigation measures, and issues a decision on the project. Public participation and opportunities for appeal or litigation are common in many jurisdictions.

Regulatory context: If significant effects cannot be mitigated to less-than-significant levels, an EIR may be required; in some cases a mitigated negative declaration or a negative declaration is used instead when no significant impacts are found. EIRs have been criticized for length and cost, but are valued for transparency and accountability in planning processes.

See also: Environmental impact assessment, CEQA, EIAs.