CEQA Tools

August 16, 2016
August 25, 2016
August 25, 2016
September 22, 2016

CEQA Guide to Air Quality Assessment

Determine if a project will have significant air quality impacts by consulting the CEQA Guide to Air Quality Assessment (CEQA Guide). The CEQA Guide works in conjunction with the State CEQA Guidelines Appendix G.

Please review the AQMD's Notice of Change in Greenhouse Gas Emissions Analysis Recommendations (PDF) as a result of a recent decision by the California Supreme Court.

The CEQA Guide provides methods to review air quality impacts (including greenhouse gases, Chapter 6) from development projects, screening approaches, methods for calculating emissions, and mitigation measures.

Additional information on mitigation measures is available on the AQMD’s mitigation page.

Guidance on assessing the potential increase in cancer risk from diesel exhaust by siting sensitive receptors adjacent to major roadways is available on the AQMD’s Roadway Protocol page.

For questions on specific projects, contact:

Staff Jurisdiction

Teri Duarte

City of Sacramento, Health Impacts

Rachel Dubose

City of Citrus Heights, North and Central Areas of the County of Sacramento

J.J. Hurley

City of Sacramento, City of Folsom

Karen Huss

City of Galt, Flood Control Projects

Charlene McGhee

City of Elk Grove, South Area of the County of Sacramento

Molly Wright

City of Rancho Cordova, Transportation Projects
Staff contact information can be found on the AQMD’s staff directory (PDF).

Thresholds of Significance

The AQMD Board adopted its original significance thresholds on March 28, 2002 (PDF). Subsequently, recommended greenhouse gas emissions (GHG) thresholds (PDF) were adopted on October 23, 2014, and revised particulate matter thresholds (PDF) were adopted on May 28, 2015.

The significance thresholds are compiled in the CEQA Guide’s thresholds table (PDF).

AQMD staff are currently working on updates to the CEQA Guide to incorporate the newly adopted thresholds.

Models and Meteorological Data

Models are commonly used to calculate project air emissions.

The California Emissions Estimator Model (CalEEMod) calculates both criteria pollutant and greenhouse gas emissions from land development projects. The model and user’s guide can be downloaded at

SMAQMD Tips for Using CalEEMod (PDF) (02/03/2015) is available to assist new model users in addition to the CalEEMod provided documents.

The AQMD has set April 1, 2013 as the date when agencies conducting air emissions analyses for land development projects for CEQA purposes must use CalEEMod.

In addition to CalEEMod, the Road Construction Emissions Model (Version 8.1.0, June 2016) is available to assess the emissions of linear construction projects.

For air dispersion modeling, the AQMD provides local meteorological data files (ASC) for the BEEST/ISCT3 model:

The following meteorological data files are available for the AERMOD air dispersion model:

  • Executive Airport 2010-2014 PFL and SFC files
    Exec10-14 N1MD (ZIP)
  • International Airport 2010-2014 PFL and SFC files
    Int10-14 N1MD (ZIP)

Contact Karen Huss ( or (916) 874-4881) regarding CalEEMod or Roadway Construction Emissions Model questions.