A permit is required for any new or modified air pollution source before construction begins or modifications are made. This includes equipment, process, or design changes that impact the level of air contaminants emitted. Air permits are issued through the Notice of Construction program. You can start a permit application on our website here: Apply for Notice of Construction Permit.

The regulations adopted by the agency to support these programs are available here: PSCAA Regulations.

The permitting process begins with an application. Follow the steps in the flow charts below to see how the process unfolds from the Agency’s perspective.

This flowchart outlines the steps involved in the application process from start to finish.

This flowchart illustrates the permitting process from the applicant’s perspective, covering each step from submitting the application and fees to receiving the draft permit and final approval.

A draft permit is made available for public comment if it meets specific criteria set by Washington Administrative Code (WAC) 173-400-171(3). This includes, but is not limited to, projects with emission levels above certain thresholds, projects with synthetic minor limits, or projects with significant public interest. If there is substantial public interest, the Agency may also hold a public hearing during the comment period. For a full list of criteria and thresholds, please refer to the Washington Administrative Code here: WAC 173-400-171

A list of new Notice of Construction applications submitted to the Agency can be found on our website here: List of New Construction Projects. New applications appear on this list for 15 days.

When the Agency opens a draft permit for public comment, the comment period lasts at least 30 days. During this time, the Agency posts notices in a local newspaper within the applicant’s county, the Daily Journal of Commerce, on the Agency’s website, and sends an email notification to those subscribed to our “Permit Actions” list.

During the comment period, the public is invited to submit comments on the draft permit. Additionally, anyone may request a hearing by submitting a written request to the Agency. The request should state the requester’s interest and a description of why a hearing is warranted.

If a hearing is scheduled, notice of the hearing will be posted on our website, shared through our social media channels, and published to a local newspaper at least 30 days before the hearing date.

A public hearing an opportunity to verbally share your comments. Hearings may be held in person or online, and the location and time will be proved in the public comment announcement. All hearings are recorded.  After the hearing, a transcript and the Agency’s written responses to comments are posted on our website. It is important to note that comments made during a hearing are treated the same as those submitted in writing.

How you choose to comment is entirely up to you. The Agency does not guide people on what to say about any issue. However, a substantive comment questions the accuracy of the information provided in the draft permit or introduces new information that may not have been previously considered.

When a draft Notice of Construction permit is open for public comment, it means we believe the project meets all necessary criteria. Substantive comments for the Puget Sound Clean Air Agency typically relate to the four criteria the Agency reviews for every application (See “What is the Agency Reviewing”). The information below can be found in the PSCAA regulations and is also cited in the Washington Administrative Code (WAC).

                PSCAA Regulations: PSCAA Regulations

                Washington Administrative Code: Chapter 173-400 WAC

There are several useful guidelines of how to post a substantive public comment.

The Bureau of Land Management Guideline: Commenting_Guide.pdf (blm.gov)

Advice from the Public Comment Project: How To — Public Comment Project

Our Agency reviews each application to ensure it meets all relevant laws and regulations under our jurisdiction. These requirements are grouped into four main categories (shown in the graphic below). Each category covers a unique part of the permitting process, which we’ve summarized below with links to guidance for further details. This information can help you better understand the permitting process and prepare any comments you might want to submit for a draft permit.

1. Controlling Emissions using Best Available Control Technology (BACT) Review:   

As the Agency reviews a project, we will examine federal and other regulatory requirements for similar processes and consider permits previously issued by us or other entities to determine Best Available Control Technology (BACT) on a case-by-case basis.

In Washington, this is defined in WAC 173-400-030: and “means an emission limitation based on the maximum degree of reduction for each air pollutant subject to regulation under chapter 70.94 RCW emitted from or which results from any new or modified stationary source, which the permitting authority, on a case-by-case basis, taking into account energy, environmental, and economic impacts and other costs, determines is achievable for such source or modification through application of production processes and available methods, systems, and techniques, including fuel cleaning, clean fuels, or treatment or innovative fuel combustion techniques for control of each such pollutant. In no event shall application of the "best available control technology" result in emissions of any pollutants which will exceed the emissions allowed by any applicable standard under 40 C.F.R. Part 60 and Part 61. Emissions from any source utilizing clean fuels, or any other means, to comply with this paragraph shall not be allowed to increase above levels that would have been required under the definition of BACT in the federal Clean Air Act as it existed prior to enactment of the Clean Air Act Amendments of 1990.”  

2. Best Available Control Technology for Toxics (tBACT):

Similar to BACT, but specifically applied to air toxics as defined by the state of Washington. A list of these chemicals can be found here WAC 173-460-150

3. State Environmental Policy ACT (SEPA): 

SEPA is required for all projects. “The State Environmental Policy Act (SEPA) process identifies and analyzes environmental impacts associated with governmental decisions. These decisions may be related to issuing permits for private projects, constructing public facilities, or adopting regulations, policies, and plans.” Learn more about SEPA here: State Environmental Policy Act (SEPA) - Washington State Department of Ecology.  This determination may not come from our Agency; it could be provided by the city, county, state or federal agencies. An additional FAQ for SEPA is available here: SEPA FAQ - Washington State Department of Ecology. Our Agency also provides a checklist to assist with the review process, which can be found here: PSCAA SEPA Environmental Checklist.

4. Project Emission Estimates:

Project emissions are an extremely important part of the review process, focusing on two key questions: What pollutants will be emitted, and in what amounts? For this analysis it’s helpful to categorize pollutants into three groups: criteria pollutants, hazardous air pollutants (HAPs) and Toxic Air Pollutants (TAPs).

There are six Criteria pollutants. Particulate Matter (PM), Nitrogen Oxides (NO_x), Carbon Monoxide (CO), Sulfur Oxides (SO_x), Lead and Ozone (O₃).  More information about these criteria pollutants can be found on the EPA website: Criteria Air Pollutants | US EPA.  

The quantity of pollutants a facility emits determines its categorization. A small facility is considered a “natural minor,” while a large facility qualifies as a Title V “air operating permit source” (AOP). Title V is a federal program, which you can learn more about here: Who Has to Obtain a Title V Permit? | US EPA.  Some industries are automatically included in this program, regardless of size. For other facilities, the thresholds for Title V classification are emissions of 100 tons/year of any air pollutant, 10 tons/year of a single hazardous air pollutant (HAP), or 25 tons/year of any combination of HAPs.  There is also a category between natural minor and Title V, known as a “synthetic minor.”  These sources agree to federally enforceable limits to stay below the thresholds mentioned.

We also review projects to determine if they fall under the Prevention of Significant Deterioration (PSD) Program.  You can find a description of the program on the EPA’s website here: Prevention of Significant Deterioration Basic Information | US EPA.

Additionally, we ensure that each project will cause or contribute to an exceedance of the National Ambient Air Quality Standards (NAAQS). More information is available from the EPA here: NAAQS Table | US EPA and from the Washington Department of Ecology here: Air quality standards - Washington State Department of Ecology.

Toxic Air Pollutants (TAPs) undergo a similar review.  First, we verify that all TAP emissions are below the Small Quantity Emission Rate (SQER) specified in WAC 173-460-150. If a TAP exceeds the SQER, we model the emissions to assess them against the Acceptable Source Impact Level (ASIL), which is determined to be safe by the state of Washington. If a pollutant exceeds the ASIL, we work with the applicant to reduce the project’s impact. This may involve agreeing to production limits, using alternative air pollution controls, or substituting materials used in the project.