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Federal Permitting of New and Modified Air Emission Sources

Federal Permitting New and Modified Air Emission Sources EQMWhen faced with maintaining or improving the financial productivity of a manufacturing facility, a company sometimes must upgrade existing process equipment, install a new process, or build a completely new facility. These important decisions take into consideration business factors such as market trends, production forecasts, and capital requirements. The impact of environmental permitting, however, is often not considered in the decision-making process.

Without proper consideration, environmental permitting can cause serious delays in construction schedules and potentially add significant capital and annual operating cost to the new project. These factors may slow the company’s response to new business opportunities or increase the upfront project cost making the decision less financially appealing.

Overview of Air Permitting Requirements

Environmental regulations impact all areas of business. One of the more significant Federal environmental regulatory programs as it relates to business decisions is the requirement for a new or modified facility to obtain an installation/construction permit under the Clean Air Act (CAA).

With few exceptions, the construction of a completely new plant, or installation of new process equipment in an existing plant will require an air permit before construction can begin. In addition, the upgrade of existing process equipment may also qualify as a modification and therefore require new source permitting.

New Source Review (NSR) is the regulatory procedure used to evaluate the air permitting implications for the construction of new or modification of existing air emission sources. Although applicable State and Federal regulations act as a common thread to define overall requirements, the NSR requirements depend on things like source location (or proposed location), neighboring industries, and the type of manufacturing operation involved. A brief review of the current Federal air program is needed to serve as background for further discussion of NSR.

National Ambient Air Quality Standards (NAAQS)

Under the CAA, the U.S. EPA established limits on the degree of air pollution permissible in the atmosphere. These limits are called National Ambient Air Quality Standards (NAAQS), and are based on the protection of public health and welfare. NAAQS have been established for seven criteria pollutants as shown by Table 1 and are applicable in all parts of the country. They are expressed in terms of the mass per cubic meter of air or in parts per million/billion of air (ppm/ppb).


Typically, counties within each State are designated as “attainment” or “nonattainment” for each criteria pollutant based on the area’s existing air quality. An area is deemed in attainment with the NAAQS if the air quality in that region is better than (i.e., below) the appropriate standard. Conversely, a nonattainment designation occurs when an area’s air quality is worse than the NAAQS. Attainment and nonattainment designations are pollutant specific (i.e., a county can be attainment for some pollutants and nonattainment for others).

The CAA requires each State to develop and implement enforceable regulations by which areas within that State will achieve and maintain air quality in compliance with the NAAQS. These State-developed plans are referred to as State Implementation Plans (SIPs). EPA must approve a SIP before the State regulatory authority can regulate industry within the State; otherwise the EPA would become the regulatory authority by default.

Among the criteria for SIP-approvability is the inclusion of permit regulations governing construction of new emission sources and modification of existing sources. When the EPA approves a SIP, which includes NSR permitting regulations, the State receives “Delegation” to implement the NSR program.

Attainment Areas: Prevention of Significant Deterioration

Regulations governing the Prevention of Signification Deterioration (PSD) program are applicable to new major stationary sources or major modifications in areas that meet the NAAQS. The basic goal of the PSD program is to ensure that economic growth can occur while protecting the air quality of the region.

To accomplish this goal, the PSD requirements evaluate the proposed source activity with respect to how the source will impact air quality upon its installation and operation. The proposed PSD project must have:

  1. Best Available Control Technology (BACT) – a BACT evaluation is required to analyze options to reduce the magnitude of increased emissions. BACT can include installation of an inherently less polluting operation, use of lower emitting raw materials, or the use of an end-of-the-pipe pollution abatement system. BACT evaluation considers potential impacts on energy consumption, the environment, and economics.
  2. Air Quality Impacts Modeling – an evaluation of the air quality impacts of the increased emissions for compliance with PSD-defined air quality increments must be performed. The air quality analysis will evaluate the new or modified source along with all other major emitting sources within a significant impact area to determine whether the NAAQS will be protected after construction of the new or modified source. These analyses are accomplished using U.S. EPA-approved computer-based atmospheric dispersion models (g., AERMOD).
  3. Air Quality Monitoring – a collection of one year of actual ambient air monitoring data may be required before completing a PSD application if five years of recent meteorological data is not available, and/or the applicant or regulatory agency feels that having on-site meteorological data would be of significant benefit. The applicant might be required to include an evaluation of the new source impacts on soils, vegetation, and visibility within the impact area, as well as secondary impacts on demographic growth.

Nonattainment New Source Review

Regulations governing a new major stationary source or major modification in geographical areas that do not meet the NAAQS are Nonattainment New Source Review provisions (NNSR). The first step is to evaluate the proposed project against the significant source thresholds to determine if NNSR will be triggered. If NNSR is not triggered then the facility may proceed with minor source permitting independent of PSD and NNSR regulations.

The basic goal of the NNSR program is to require stringent control measures to ensure that economic growth will not worsen the air quality problems of an area and that emission offsets from existing sources will continue progress toward NAAQS attainment. To accomplish these goals, the NNSR requirements evaluate the proposed source activity with respect to how the source will affect air quality upon its installation and operation as well as seeking emission reductions from sources external to the source being permitted. The proposed NNSR project must have:

  1. Lowest Achievable Emission Rate (LAER) – employ add-on pollution abatement equipment such that the resulting emissions are representative of LAER. LAER is the most stringent emission limitation required of a similar, or technically transferrable, operation located within the US. Unlike BACT under PSD, an applicant typically has very little input into the specification of LAER by an Agency.
  2. Emissions Offsets – locate and secure available emission reductions (e., emissions offsets) from existing sources located within the same general geographical area. Contact with the reviewing Agency is normally required to determine potentially available offsets.
  3. CAA Compliance at All Owned Sources –document that all sources owned by the same entity as the new or modified source within the same State are following all applicable CAA requirements
  4. Air Quality Impacts Modeling – show through atmospheric dispersion modeling that the new or modified source taken along with the emission offsets from other sources will result in a net air quality benefit, or not consume the available increment.

Regulatory Applicability Determination

When scoping a new project or modifying an existing operation, managers and plant environmental staff must ask themselves if and how the proposal fits the current air quality and regulations of the region. In other words, is your plant in compliance now? Will your proposed change cause any additional deterioration to air quality? Will you need better operated or controlled equipment? Several questions must be answered by the facility before knowing if a proposed new source or source modification is subject to PSD or NNSR. These questions can be divided among three major components.

Attainment Status of Geographic Location

The attainment status for each criteria pollutant must be defined for the area (i.e., county) where the facility is located. These designations are given in the Federal Register and are often available online on the local regulatory agency’s website.

Determine Major Source Status

PSD and NNSR apply to new major stationary sources and major modifications to existing major stationary sources.

A major stationary source is defined under PSD as any source on a PSD-defined list of 28 source categories which emits or has the potential to emit greater than 100 ton/yr. of any regulated pollutant. If a source type is not one of the 28 named, the source must emit or have the potential to emit 250 ton/yr. of a regulated pollutant to be defined as major. A completely new operation must be defined as major under the above criteria for PSD to apply.

PSD Source Categories

Minor Source New Source Review

States will have permit requirements for minor new sources and minor modifications independent of their PSD and NNSR Regulations. These requirements will typically be less rigorous than the Federal permitting regulations, and there are State air permit exemptions for insignificant source types.

Determine the Emission Potential of the New or Modified Source

If a source is “major” the facility must determine if the proposed emissions increases are above PSD/NNSR-defined “significant” emission rates. If the increased emissions from a source modification exceeds any significant rate, it would be considered a major modification and subject to PSD/NNSR.

This step will confirm the applicability of any new source review program to the project.

De Minimis NNSR Rates

Application Development and Permit Timing

Once regulatory applicability determination of major or minor NSR requirements has been made, the proper plans can be set in motion to prepare an approvable permit application. Preparation of the requisite permit application documentation must be incorporated in all aspects of the project. Information and data specific to the new process must be gathered and used to complete all required analyses (e.g., control technology evaluation, dispersion modeling).

Preparation of a complete permit application varies with the complexity of the project, typically requiring between 3 and 6 months. This time range obviously does not consider the possibility of gathering one year of preconstruction monitoring data under PSD.

The agency permit application review process is a long-term step in the project schedule. Similar to preparing the application, Agency review depends primarily upon the complexity of the proposed source. Typical Agency review periods range from 6 months to as long as 2 years. By law, a facility cannot begin the construction or modification of a major source without having the air permit in hand. Violations of regulations pertaining to new source construction and existing source modification are rigorously enforced by the regulatory community.

EQM’s Air Permitting Experience

The ability of a company to satisfy the many regulatory requirements while at the same time keeping pace with market trends and opportunities requires diligent planning. Engineers and regulatory experts at EQM have over 100 combined years of experience helping industrial clients navigate regulatory compliance.  Contact us today and let us assist you with new project air permit applicability evaluation and permit application preparation.


Stephen J Washburn PE

Stephen J. Washburn, P.E.

Mr. Washburn has more than 25 years of experience in environmental compliance and management. As Multi-Media Compliance Group project manager he has been involved in a broad range of programs including air compliance and permitting, risk assessment, toxic release evaluation, and water pollution prevention programs. He has expertise in identifying processes and materials that emit pollutants and in quantifying criteria pollutant, hazardous air pollutant, and toxic chemical releases to the environment from many different manufacturing processes and industrial operations.

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