CEQA Handbook and Associated Tools: The California Environmental Quality Act (CEQA) was created to ensure that environmental impacts from new development are addressed and adequately mitigated. The District's CEQA Handbook provides information on the District's significance thresholds for determining potential air quality impacts from proposed residential and commercial development and provides recommendations on the level of mitigation necessary to reduce those impacts. Appendix A to the CEQA Handbook outlines the building permit requirements for facilities potentially subject to air district permitting. The CEQA Handbook was last updated on April 2012. The CEQA Handbook and tools listed below are intended to assist with CEQA reviews.
South County Air Quality Forecast Zone Map
CalEEMod Model: The California Emission Estimator Model (CalEEMod) is the emissions estimation model the District recommends using for landuse project. The model is free and available for download from the link below. The most recent verison of the model should be used.
Final GHG Threshold Supporting Documentation
ARB's Air Quality and Land Use Handbook: As part of the Air Resources Board's (ARB) Community Health Program, they have developed an Air Quality and Land Use Handbook (Handbook) which is intended to serve as a general reference guide for evaluating and reducing air pollution impacts associated with new projects that go through the land use decision-making process. More 
ADAM Air Quality Data Statistics allows user to select and view air quality data for various pollutants throughout the State, including trend summaries, days above the standard, daily stats, 24-hour stats, etc.