Permitting and Modeling Support for the Maricopa County Air Quality Department

Under the Clean Air Act, states, local, and tribal governments work in partnership to reduce air pollution and protect public health. In Maricopa County, Arizona, the Maricopa County Air Quality Department (MCAQD) issues operating permits to both Title V (major) and non-Title V (minor) sources of air emissions to ensure that sources are complying with applicable local, state, and deferral limits on air pollution. MCAQD was facing a significant backlog of permit renewal applications requiring review and processing, which was a concern because permitting delay can lead to uncertainty for both the public and the regulated community.

To help MCAQD accelerate the processing of permit renewal applications without compromising the quality of regulatory and compliance reviews, ERG provided targeted and expert technical assistance, drawing from previous experience with thousands of permitting actions for regulatory agencies. Our MCAQD support included reviewing applications and preparing draft permit conditions and supporting documentation for 10 Title V permits and over 100 non-Title V permits. 

• Major sources. The Title V applications covered diverse sources ranging from landfills and semiconductor manufacturing facilities to electric generating stations. Despite this variety, we successfully applied a consistent, standardized review process to all 10 applications. First, we thoroughly assessed the application and its supporting materials for both technical and administrative completeness. Next, we evaluated the submitted potential-to-emit calculations, verifying their accuracy and making revisions or recalculations as necessary. When applicable, we also reviewed dispersion modeling conducted as part of the offsite consequence analysis to confirm that the facility would not cause or contribute to a National Ambient Air Quality Standards (NAAQS) violation. Then, we conducted a comprehensive regulatory analysis, where we identified all applicable state, local, and federal regulations. We documented the calculations and regulatory analysis in a Technical Support Document, which we submitted for MCAQD review. Finally, our team prepared draft permit conditions in accordance with MCAQD templates and guidance documents and the underlying regulations.
• Minor sources. For non-Title V sources, ERG optimized the process by streamlining reviews and drafting across similar facilities. For example, MCAQD receives a high volume of applications from institutions and resorts, metal fabrication facilities, and woodworking facilities. Our team quickly gained familiarity with the agency’s existing templates for these sectors, enabling us to process the renewals efficiently while ensuring consistency and compliance across similar sources.