Understanding the environmental impact of any project, especially concerning air quality, is crucial. This chapter dives into the essential tools and guidance documents recommended by the Sacramento Metropolitan Air Quality Management District (Sac Metro Air District) for conducting thorough air quality impact analyses. These resources help ensure compliance with the California Environmental Quality Act (CEQA) and contribute to informed decision-making.
Key Tools for Air Quality Analysis
Several models, calculators, and data files are indispensable for accurate air quality assessments.
CalEEMod: California Emissions Estimator Model
The California Emissions Estimator Model (CalEEMod) is a critical tool for quantifying emissions. Sac Metro Air District advises using CalEEMod Version 2020.4.0 for projects undergoing public review after July 1, 2021. While CalEEMod Version 2022.1.1.3 is available, it’s not yet mandatory. New guidance for using Version 2022.1.1.3 is currently under development by the Sac Metro Air District.
Road Construction Emissions Model
The Road Construction Emissions Model is now superseded by the CalEEMod Lineal Construction Module. However, Version 9.0 (May 2018) of the Road Construction Emissions Model, available for download as a .zip file, remains a valuable historical reference. This version incorporates emission factors from EMFAC2017, approved by the U.S. EPA in August 2019. Note that Version 9.0 contains a broken link to the Department of Conservation soil map website. A corrected link is available here, and an updated Version 9.0.1 .zip file incorporating the corrected link was released in August 2022.
Harborcraft, Dredge, and Barge Emission Factor Calculator
For analyzing emissions from marine equipment, the Harborcraft, Dredge and Barge Emission Factor Calculator (July 2017) is essential. A supplementary memorandum (June 2017) provides further context and instructions.
AERMOD Meteorological Data Files
The Sac Metro Air District offers two sets of AERMOD meteorological data files (2014-2018) in .zip file format. These files contain crucial PFL and SFC data for air quality modeling.
Guidance Documents for Air Quality Analysis
Beyond the tools themselves, several guidance documents are vital for accurate and compliant analyses.
Recommended Mitigation Measures
The Sac Metro Air District provides comprehensive guidance on recommended mitigation measures for both construction and operational emissions. This includes the crucial Recommended Guidance for Land Use Emission Reductions (AQMP guidance) and strategies for cool pavements to mitigate Urban Heat Island effects (December 2020).
Additional Guidance and Resources
Other crucial resources include the Friant Ranch Ruling Guidance (October 2020), the Mobile Sources Air Toxics Protocol (September 2020), recommendations for siting new projects near existing emission sources (July 2019), and the CAPCOA guidance on Air Quality Analysis in CEQA Roadway Review (August 2018). Numerous other helpful documents are available, including those addressing General Rules for Development Projects, State CEQA Guidelines, SACOG Regional Plans, and strategies for reducing Urban Heat Island effects. Finally, adopted Thresholds of Significance Resolutions and associated documentation provide critical context for evaluating project impacts.
Conclusion
Utilizing the right tools and guidance is paramount for comprehensive air quality impact analysis. The resources provided by the Sac Metro Air District empower stakeholders to conduct accurate assessments, ensuring projects meet environmental standards and contribute to a healthier environment. Refer to the linked documents for detailed information and specific instructions for each resource.
