Air Emissions – Permitting and Compliance

We advise on all manner of traditional and emerging air issues impacting virtually every business enterprise in America today. Whether involved in crafting new regulations, obtaining permits, or defending operations against alleged violations, Foley’s attorneys take the long view, working closely with you to achieve your business goals with the most practical, timely, and cost-effective strategies available.

Bringing together a broad range of individuals with specific knowledge, the Foley air lawyers are adept at communicating with all stakeholders – from the C-suite to the shop floor and from governmental agencies to environmental advocates – while driving projects toward success. Foley’s national air practice serves investors, owners, and operators in a wide range of sectors faced with constantly evolving air regulations and economic challenges.

Leading companies in most major heavy and light industrial sectors look to the Foley air team for strategic thinking and skillful implementation in the complex arenas of project development and permitting, regulatory development, enforcement, defense, and compliance counseling at the federal, state, and local administrative and judicial levels. We have the air experience you need whether you are in pharmaceuticals, electric power generation (including fossil fuels and advanced energy storage), oil and gas production, pipeline transportation, engine manufacturing, organic and inorganic chemicals and plastics, pulp and paper, metal foundries, fabrication and coating, sand mining, solid and hazardous waste disposal, building products, airlines, Data Center and Digital Infrastructure and industrial reuse.

New and Existing Source Permitting

An “air permit” is more than just a legal document that authorizes the emission of contaminants into the atmosphere. For new or modified capital projects and business expansions, an air permit often dictates the construction schedule, production start-up date, plant layout, operating procedures, costs, and even plant location. Once the plant is operating, the emission limitations and the operating, monitoring, and reporting requirements of the permit become just as important for business success as the customer’s quality specs. We make it a habit to learn our clients’ business operations and offer strategic and practical advice for obtaining well-understood permits that enhance, rather than hinder, facility production. We regularly represent clients in new and existing source permit actions involving typical and not-so-typical federal, state, and local issues, including:

Conducting initial applicability determinations, which involves determining whether and which federal or state permit requirements apply, and equally important, which ones do not apply
Developing the analysis and implementing procedures and limits to avoid the applicability of New Sources Review (NSR) and Title V major source requirements. We provide specialized counsel on synthetic minor permitting for Data Center emergency generator fleets to minimize operational restrictions and project timelines. Where major source status cannot be avoided, developing Prevention of Significant Deterioration (PSD) and NSR preconstruction permit application strategies, negotiating reasonable permit conditions, and litigating unfavorable permitting decisions
Negotiating Title V and state operating permit conditions and Greenhouse Gas permit requirements
Facilitating the removal of Maximum Achievable Control Technology (MACT) requirements from active permits following the end of EPA’s “once in, always in” policy under Section 112 of the federal Clean Air Act
Responding to neighbors’ concerns and, if necessary, defending third-party actions, such as nuisance claims, or appeals of air permits brought by non-government organizations

Enforcement Defense

We can guide you through the arc of federal, state, local and citizen suit investigations and enforcement actions, beginning with agency inspections or information requests through resolution. We maintain our focus and support you through the implementation of corrective action and Supplemental Environmental Projects, staff training, monitoring, and reporting. Foley’s experience includes:

Representing power generation, pulp & paper, industrial packaging, medical providers, and chemical and pharmaceutical manufacturers against enforcement actions alleging violations of NSR and hazardous air pollutant (MACT) permitting and operating requirements
Representing multiple engine, emission component, and vehicle manufacturers against alleged violations of mobile source emission requirements under Section 205 of the Clean Air Act and related state requirements
Representing chemical and oil and gas companies in federal consent decrees involving Leak Detection and Repair (LDAR) requirements
Leading or supporting emissions event and incident investigations through root cause analysis, internal reporting, corrective action implementation and agency negotiations
Representing clients in civil environmental enforcement matters, and in coordination with our governmental investigations team, criminal environmental enforcement matters

Regulatory Development

We can represent you in state and federal Clean Air Act rulemakings, involving agency efforts to collect and analyze industry emissions, technology and costs data and to propose, negotiate, issue, reconsider and litigate rules.

Foley has been at the forefront of agency actions addressing the development, review, and implementation of National Ambient Air Quality Standards (NAAQS), Regional Haze and Best Available Retrofit Technology, NSR and PSD programs, MACT Standards for Hazardous Air Pollutants (HAPs), Greenhouse Gas reporting and permitting, Clean Air Interstate Rule (CAIR) and Cross-State Air Pollution Rule, motor vehicles and mobile source emission control systems, requirements for state and federal Part 70 Operating Permit Programs, Section 112(r) Accidental Release Prevention/Risk Management Plan and Process Safety Management (PSM) Program updates, and issues related to Tribal implementation of Clean Air Act programs.

Our experience with regulatory development includes:

Negotiating the terms of agency information requests
Drafting responses to information requests, drafting comments on proposed rules
Monitoring and shaping emerging federal and state regulations specifically targeting data center generator usage (e.g., limitations on non-emergency operations for grid support) and emissions from Energy Transition projects.
Advising on the intersection of air permitting with CA Climate Disclosure and other ESG requirements, including the development of verifiable Scope 1 emissions data.
Preparing petitions for reconsideration
Litigating and settling petitions for review for clients on proposed federal air regulations
Counseling clients through the process of obtaining variances from state and federal regional haze requirements

Compliance Counseling and Auditing

Foley applies detailed knowledge of permit requirements and your operations and objectives to help ensure compliance and identify issues for resolution, by:

Developing and conducting environmental and safety audits and appropriate corrective action and by managing potential liabilities through voluntary self-disclosures to state and federal agencies
Counseling on compliance with applicable permitting and regulatory requirements
Training management officials regarding the requirements for certifying compliance with Title V permitting requirements and evaluating existing internal recordkeeping programs as a part of the “reasonable inquiry” required for compliance certifications

Navigating the Diesel Generator Challenge

The need for uninterruptible power is the lifeblood of a data center, making backup diesel generator fleets—often numbering in the hundreds—a mission-critical component of nearly every facility. However, these fleets represent the single largest source of on-site air emissions, placing them squarely in the crosshairs of federal, state, and local air quality regulators. The legal distinction between “emergency” and “non-emergency” use is a complex and high-stakes battleground, as even minimal non-emergency operation can push a facility’s Potential to Emit (PTE) above critical thresholds, triggering onerous and time-consuming permitting requirements.

At Foley & Lardner, we specialize in developing sophisticated air permitting strategies during the project’s design phase to legally and operationally manage this risk. Our focus is on avoiding the designation of “Major Source” under the Clean Air Act’s Prevention of Significant Deterioration (PSD) or Nonattainment New Source Review (NNSR) programs, which can add years and millions of dollars to a project’s timeline and budget. We achieve this by structuring the project to qualify for “Synthetic Minor” permits, establishing legally enforceable limits on operating hours, fuel consumption, and emission rates. This approach requires precise modeling of air emissions, particularly for criteria pollutants like Nitrogen Oxides, to demonstrate compliance with National Ambient Air Quality Standards (NAAQS), especially in non-attainment areas.

Furthermore, the regulatory landscape is continuously shifting. We closely monitor evolving EPA interpretations—including those related to the permissible use of emergency generators for grid support or demand response programs—to ensure your operational flexibility remains legally protected. Whether through negotiating reasonable limits with state agencies (like TCEQ, DEQ, or MPCA), challenging unfavorable permit conditions, or defending against citizen suits, our attorneys provide the strategic counsel necessary to secure the permits that keep your project on schedule and your mission-critical operations compliant, avoiding the significant fines and project delays associated with non-compliance.

Key Air Quality Permitting Services For Data Centers

Our targeted air quality services for data centers include:

Potential to Emit (PTE) Analysis: Calculating maximum theoretical emissions and establishing legally binding operational restrictions to maintain Synthetic Minor status and avoid Major Source permitting.
New Source Review (NSR) Strategy: Advising on compliance with PSD and NNSR regulations, including Best Available Control Technology (BACT) and Lowest Achievable Emission Rate (LAER) analyses if Major Source status cannot be avoided.
Air Dispersion Modeling (AERMOD): Conducting advanced air quality impact assessments to demonstrate that emissions from backup fleets will not violate NAAQS standards, especially for Nitrogen Oxides in non-attainment zones.
Permit Negotiation and Defense: Representing clients before federal and state environmental agencies to secure permits with practical, well-defined operational limits and defending permits against appeals or litigation.
Compliance with RICE NESHAP and NSPS: Ensuring generator engines meet applicable National Emission Standards for Hazardous Air Pollutants (NESHAP) and New Source Performance Standards (NSPS).
Grid Support Regulatory Interpretation: Advising on the latest EPA guidance regarding the limited use of emergency generators for non-emergency grid stability purposes to prevent loss of “emergency” status.