<p>SMAQMD prepared a comprehensive update to California Environmental Quality Act (CEQA) Guide to Air Quality Assessment. The project included a comprehensive revision to all nine chapters of the guide, which instruct lead agencies how to analyze the potential air quality impacts associated with the construction and operation of proposed projects and land use plans in County of Sacramento. Examination of methodologies and approaches used by other air districts, literature searches, thorough testing of the constraints and nuances of URBEMIS, and close collaboration with SMAQMD staff was required.</p>