Understanding Air Permitting

Why It Matters Before, During, and After a Project

Air Quality Laws in the United States

On July 4, 1776, when the Declaration of Independence was adopted in Philadelphia, there was no concept of “air quality” as we understand it today, and air pollution was not measured or recorded. Thomas Jefferson’s personal weather journal for that day showed that the temperature ranged from 68°F to 76°F. In the 19th century, as the United States industrialized, new factories, power plants & manufactured gas plants burned coal that emitted black smoke. In response, individual citizens filed public nuisance lawsuits against facility owners and lobbied local governments to regulate smoke. The first municipal laws banning smoke emissions were in 1881. The first comprehensive air quality State law was adopted in 1952. Federal air pollution regulation began with the Air Pollution Control Act of 1955.

The Clean Air Act Amendment of 1970 is the foundation for air quality regulations in the United States and included key provisions for

• ‘National Ambient Air Quality Standards’ (NAAQS) for criteria pollutants - ground level ozone, particulate matter, carbon monoxide, sulfur dioxide, nitrogen dioxide, and lead - to protect public health.
• ‘State Implementation Plans’ (SIPs) that must be developed by each State to describe how NAAQS will be achieved.
• ‘New Source Performance Standards’ (NSPS) to be established by the Environmental Protection Agency (EPA) to set emission limits for new and modified stationary sources.

Air Permits and Emission Limits

After the Clean Air Act Amendment of 1970, individual States began to develop SIPs and air quality regulations that included requirements for stationary sources of emissions to obtain air permits and to reduce emissions. In 1990, the Clean Air Act was amended again and included:

• ‘Hazardous Air Pollutants’ (HAPs). A list of 189 HAPs was established, with mandatory emission limits for major industrial sources.
• ‘Operating Permits Program’ (Title V of the Act) created a national operating permit program, consolidating all air pollution requirements for major industrial facilities into a single, enforceable document. This permit is required for a facility that emits either 100 tons per year of any criteria pollutant, 10 tons per year of any HAP, or 25 tons per year of combined HAPs.

For facilities that emit pollutants below these thresholds, individual States issue minor source air permits, which are required to construct or modify an industrial facility. Each state has its own requirements for permit applications.

Air Permit Planning

The strongest permitting strategies start early—with source identification, emissions estimates, exemption reviews, control technology considerations, applicable requirement reviews, and, when needed, modeling or public notice planning. Each decision can affect the permit pathway and the overall project timeline.

An air permit is more than a construction milestone. Once issued, it becomes an operating framework that may include emission limits, monitoring, control equipment requirements, recordkeeping, reporting, maintenance expectations, and inspection readiness. Successful compliance depends on turning permit language into practical systems that operations, environmental, and management teams can follow consistently.

Partnering with Experienced Air Permitting Experts

As regulatory programs continue to evolve, companies need permitting partners who can see beyond the application checklist. They need advisors who understand emissions, compliance obligations, agency expectations, and the realities of project delivery.

Project Consulting Services, Inc.’s environmental engineers bring decades of experience preparing applications and obtaining air permits for new and modified industrial facilities.

That experience has shown us that strong permitting outcomes come from early planning, disciplined execution, and timely communication with regulatory agencies. When air permitting is integrated into the broader project strategy, it becomes more than a compliance step—it becomes a tool for reducing risk, protecting schedules, and supporting long-term operational resilience.