BGE worked alongside an undisclosed manufacturing client to develop a comprehensive air permitting solution for a large-scale facility expansion. This project required navigating intricate permitting and regulatory requirements under the Texas Commission on Environmental Quality (TCEQ) and federal standards, while minimizing capital costs and maintaining operational flexibility. Our approach combined technical rigor with strategic planning to achieve compliance without unnecessary infrastructure changes.

Case-by-Case NSR Permitting

The project centered on securing a New Source Review (NSR) case-by-case permit, which required a full air quality impact analysis to demonstrate compliance with National Ambient Air Quality Standards (NAAQS). This included evaluating site-wide emissions for nitrogen dioxide (NO₂) and fine inhalable particulate matter (PM_2.5), with particular emphasis on the annual PM_2.5 standard, recently tightened by the EPA. Our team developed a permitting strategy that addressed these challenges while avoiding costly design modifications.

Emission Factor Development and Testing

Accurate emission factors are critical for reliable modeling and compliance demonstrations. We guided the client through a rigorous process to develop and validate emission factors for combustion sources, including engines and boilers. This process began with a thorough review of existing AP‑42 factors to identify gaps and limitations for site-specific conditions. We then coordinated strategic stack testing campaigns to generate empirical data for NOₓ and PM emissions, ensuring that the results reflected actual operating conditions. We then confirmed the emission factors represented worst-case scenarios without being overly conservative. By refining these factors, we significantly reduced modeled impacts and avoided unnecessary operational restrictions that could have limited flexibility.

Dispersion Modeling and Compliance Demonstration

Our team performed detailed air dispersion modeling using AERMOD to evaluate site-wide impacts for NO₂ and PM_2.5. The modeling incorporated seasonal variation in background concentrations to reflect realistic ambient conditions throughout the year, rather than relying on static values. We also conducted an exceptional event analysis, which involves identifying and documenting unusual air quality episodes, such as wildfires or dust storms, so they can be excluded from compliance determinations under EPA guidance. This step required careful data review and justification to meet regulatory standards. Additionally, we modeled multiple operating scenarios to ensure compliance during maximum operating conditions. This comprehensive approach provided a robust demonstration of compliance, even under the recently tightened PM_2.5 annual limits.

Cost-Saving Strategies

One of the project’s critical goals was to avoid unnecessary capital expenditures. Raising boiler stack heights across the facility would have been a costly solution to reduce modeled concentrations. Instead, we implemented innovative strategies that achieved compliance without major structural changes. For example, replacing rain caps with designs that maintain vertical exhaust velocity improved dispersion and eliminated the need for taller stacks. We also optimized stack parameters and adjusted operating schedules to minimize modeled impacts during peak conditions. Combined with the refined emission factors, these measures allowed the client to meet regulatory requirements while preventing significant capital costs and maintaining operational efficiency.

Key Takeaways

• Successful NSR case-by-case permitting for a complex manufacturing facility.
• Development and validation of site-specific emission factors for combustion sources.
• Advanced dispersion modeling addressing seasonal variability and exceptional events.
• Strategic solutions to avoid costly stack height increases and other capital-intensive changes.

Conclusion

This project illustrates how BGE combines technical expertise with practical strategies to deliver cost-effective compliance solutions. By guiding clients through permitting, testing, and modeling, we help them meet regulatory requirements while preserving operational flexibility. Whether you are planning a facility expansion or navigating complex air quality standards, BGE is ready to support your next project.

For expert assistance with your projects, contact BGE today.