EPA Issues Air Permitting Updates for New Sources, PSD and Title V Air Permits
EPA has issued air permitting updates in order to help companies save time and reduce paperwork and compliance burdens.
EPA has issued air permitting updates in order to help companies save time and reduce paperwork and compliance burdens.
⚡ TL;DR: EPA updated air permitting guidance for new sources and modifications under PSD and Title V rules. Manufacturers planning expansions must account for stricter permitting timelines and requirements.
Air Permitting Update: Definition of Adjacent Areas
As we first reported here last fall, EPA was considering changing the interpretation of the word “adjacent” for its EPA Title V air permit and New Source Review (NSR) air permits for new construction or modifications. That interpretation change is now final.
In the regulations, the word adjacent comes into play when determining if a facility qualifies for permits. When determining sources, a building, structure, facility or installation must be under the control of the same person, belong in the same industrial grouping, and located on one or more contiguous or adjacent properties.
When it came to “adjacent”, EPA had been also considering “functional interrelatedness,” that is, grouping together facilities with similar functions, even if they were miles apart.
According to the new rule, for all industries other than oil and natural gas production and processing, adjacent is physical proximity only.
EPA makes additional comments on the word “contiguous” as well, noting the difference between adjacent and contiguous. Operations do not have to be contiguous to be adjacent. That is, operations that do not share a common boundary or border, not physically touching each other will be adjacent if the operations are nearby. If there is proximity (neighboring or side-by-side operations where the “common sense notion of a plant” can be deduced) that will be considered adjacent.
Railways, pipelines and other conveyances will not determine adjacency.
Please note that states with their own air permitting programs aren’t required to follow the new interpretation, so be aware of the regulations in your own state.
More information about EPA’s change can be found here.
Air Permitting Update: Revised Exclusions for Ambient Air
EPA has broadened the exclusions industrial facilities can take from the ambient air regulations. The Clean Air Act sets standards that affect ambient air quality, that is, that portion of the atmosphere, external to buildings, to which the general public has access.
In the air permitting process, companies are required to make air quality analyses of how their operations, (or changes to operations) will affect the ambient air quality. Within that requirement, there’s been an exclusion for areas that the public didn’t have access to. That is, you didn’t have to count the effects to the air quality of the areas of your facility that the public didn’t have access to as long as your company owned or controlled that area.
Until now, fences and other physical barriers have been the determining factor on public access. In the updated regulations, EPA is allowing for other types of measures to which deter public access. Some examples could include:
- Signage
- Security Patrols
- Remote Surveillance
- Cameras
- Drones
- Natural Barriers Such as Cliffs or Rugged Terrain (case-by-case basis)
Your company will still need to have the legal authority to prevent the public from going onto that property.
Please note that in this case as well, states with their own air permitting programs aren’t required to follow the new interpretation, so be aware of the regulations in your own state.
⚠️ What’s at stake: Noncompliance with federal environmental regulations results in significant civil and criminal penalties, operational shutdowns, and facility remediation costs that can exceed millions of dollars.
For more information, check out the EPA’s guidance page here.
Frequently Asked Questions
Q: What is the EPA’s revised definition of “adjacent” facilities for air permitting purposes?
EPA updated its definition of “adjacent” in air permitting regulations to mean physical proximity only, not functional interrelatedness. Facilities must be located on contiguous or adjacent properties and under the same control to be grouped for permitting purposes. Geographically distant facilities with similar functions are no longer automatically grouped unless they are physically proximate. The revision clarifies that operations are adjacent if they are nearby with a “common sense notion of a plant.” However, states with their own air permitting programs are not required to adopt EPA’s new interpretation. Facilities in Kansas, Oklahoma, and Texas should verify state-specific adjacency definitions. iSi Environmental helps assess facility grouping for air permit purposes.
Q: What is the difference between “contiguous” and “adjacent” under EPA air permitting rules?
“Contiguous” means sharing a common boundary or border (physically touching). “Adjacent” means nearby or neighboring without necessarily sharing a boundary—operations can be adjacent even if they don’t touch if they are in physical proximity. Both terms are relevant to determining whether multiple operations at a facility must be grouped together for air permitting. The distinction matters because facilities may be adjacent but not contiguous. iSi Environmental clarifies facility grouping based on adjacency and contiguity for air permit determinations.
Q: Can EPA air permits exclude ambient air quality impacts in certain areas of a facility?
Yes. EPA allows air permits to exclude impacts on ambient air quality in areas where the public does not have access, provided the company owns or controls those areas and has legal authority to prevent public entry. Exclusions are allowed for areas protected by signage, security patrols, surveillance cameras, remote drones, or natural barriers like cliffs. These access control measures do not require physical fences. However, only areas with effective public access restrictions can be excluded from ambient air analysis. iSi Environmental assesses facility configurations to identify areas qualifying for ambient air exclusions.
Q: Do state air permitting programs automatically follow EPA’s new interpretations of air permitting rules?
No. States with their own air permitting programs are not required to follow EPA’s revised interpretations of adjacency and ambient air exclusions. State-specific air permitting regulations may diverge from federal rules. Facilities must verify their state’s stance on adjacency definitions and ambient air analysis exclusions. Kansas, Oklahoma, and Texas may have different requirements than EPA’s federal interpretations. iSi Environmental ensures facilities comply with applicable state-specific air permitting rules, not just EPA guidance.
Not sure where your facility stands with current regulations? iSi Environmental helps manufacturing facilities and industrial operations understand their compliance obligations and close operational gaps. Get started with a compliance assessment.
💰 The cost of non-compliance: Permit grouping disputes can delay facility modifications by 6-12 months. Misinterpreting adjacency rules can result in unpermitted operations and civil penalties of $37,500–$70,000+ per day. Ambient air analysis errors trigger remediation requirements and facility closure orders. Strategic permitting analysis prevents costly delays and violations.
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