The California Environmental Quality Act (CEQA) requires state and local agencies to identify any significant environmental impacts that occur as a result of their actions. CEQA also requires that these agencies avoid or mitigate any impacts to the extent feasible. One of the District’s directives is to review and comment on the air quality analyses included in the CEQA documents prepared for projects in our jurisdiction. The District seeks to provide guidance to lead agencies and project applicants so that their air quality analyses are complete, comprehensive, and will stand up to legal scrutiny.
CEQA Handbook
To assist lead agencies and project applicants as they prepare air quality analyses, the District produced the Handbook for Assessing and Mitigating Air Quality Impacts. This document provides guidance on how to accurately assess and mitigate project-related impacts to air quality. This document was adopted in 2007 and as such there are better models available today. The District supports project proponents to estimate their emissions using the latest tools available (see below). This document also contains “thresholds of significance” for air quality impacts. The District supports using the existing thresholds with the below clarification for GreenHouse Gases (GHGs).
CEQA Tools
A number of tools are available to assist lead agencies and project applicants when preparing air quality analyses for CEQA documents:
- CalEEMod is a software program that allows a user to calculate the amount of pollutant emissions generated by a land use project. The online tool is available here: www.caleemod.com. The District recommends using the new online version, but if this project had already been modeled in the previous version (2020), you may use the older version that can be downloaded here.
- The Sacramento Metropolitan Air Quality Management District’s (SMAQMD) CEQA Guidance & Tools webpage includes related guidance documents, emissions estimators, and calculation tools to assist in air quality impact analysis for plans and projects.
- In 2005, the State Air Resources Board published the “Air Quality and Land Use Handbook: A Community Health Perspective”. This document provides information concerning land use compatibility issues associated with placing sensitive receptors near certain kinds of sources that produce toxic air contaminants.
- The California Air Pollution Control Officers Association (CAPCOA) has produced technical guidance entitled Health Risk Assessments for Proposed Land Use Projects which can be used when conducting health risk assessments to quantitatively evaluate impacts from toxic air contaminants.
Climate Change
The issue of climate change has become increasingly connected to the CEQA process in recent years. As a result of the passage of legislation aimed at combating climate change, recent case law, and the involvement of the State Attorney General, the District recommends that impacts to climate change be evaluated for every CEQA project. The District has not established a threshold of significance for GHGs. As it is unlikely that any one project would substantially contribute to global climate change, the District considers GHG impacts to be cumulative in nature and lead agencies should evaluate whether a project’s incremental direct and indirect GHG emissions are cumulatively considerable. If the lead agency jurisdiction has adopted a Climate Action Plan or General Plan goals and policies with regard to GHGs, the environmental review should base its analysis on the provisions of those documents. If the lead agency jurisdiction has not adopted a Climate Action Plan or General Plan goals and policies, then the District recommends that lead agencies consider a project’s total emissions in relation to the AB 32 and AB 32 Scoping Plan goals (and additional state goals as they are adopted) or the thresholds established by other jurisdictions.
Updated February 2022: Handbook for Analyzing Greenhouse Gas Emission Reductions, Assessing Climate Vulnerabilities, and Advancing Health and Equity
This statewide handbook provides methods to quantify GHG emission reductions from a specified list of measures, primarily focused on project-level actions. The Handbook also includes a method to assess potential benefits of different climate vulnerability reduction measures, as well as measures that can be implemented to improve health and equity.
