EIR stands for Environmental Impact Report. An EIR is a document required by CEQA when an agency determines that a proposed project may have a significant effect on the environment. An EIR describes the proposed project, the existing environmental conditions, the impacts from construction and operation of the proposed project as well as mitigation measures to reduce or eliminate impacts. Information in the DEIR enables decision-makers, interested parties and the public to evaluate the proposed project and its environmental effects.