Georgia EPD DNR PSD

A Prevention of Significant Deterioration (PSD) permit application requires the applicant to demonstrate that air emissions from the proposed project will not cause or contribute to an exceedance of the National Ambient Air Quality Standards (NAAQS) or consume more than the available PSD Increments. NAAQS and PSD Increment modeling requires an up-to-date emissions inventory database of air emissions sources. The Georgia Department of Natural Resources (DNR), Environmental Protection Division (EPD), Air Protection Branch (APB) has authorized the development of a central database of statewide emission sources and associated emissions data. The data in the inventory will be developed and maintained for the express purpose of supporting those in the regulated community in need of emissions modeling data for the preparation of PSD air permit applications. This database will help to ensure consistency among permit applications and reduces the review time needed to issue a PSD permit. Any and all database users should engage in a thorough reading of the Quality Assurance Project Plan (QAPP) prior to using the database. This will equip the user with a firm understanding of the procedures and methodologies used to collect, analyze, and quality-assure the information from the agency files and then translate this information into a format suitable for modeling purposes. A summary of the QAPP is provided below.

The facility potential to emit (PTE) for each Synthetic Minor (SM) site was determined as follows:

(1) The Air Permit Search Engine (http://search.georgiaair.org/) was utilized to download all available permits and agency permit narratives. When this search was successful, the facility PTE was transcribed from the relevant agency narratives as described in SM Step 6A of the QAPP. This is the preferred method and was utilized for approximately 85% of SM sites.

(2) In some cases, particularly with older facilities that have had little or no agency contact for a considerable period of time, agency permit narratives do not contain a facility PTE. In this case, the PTE calculations performed by a consultant, PTE calculations performed by the facility, or PTE summaries (no supporting calculations) provided on application forms were used as described in SM Step 6B of the QAPP. This method was utilized for approximately 10% of SM sites.

(3) With all other avenues of obtaining PTE information exhausted, the facility PTE was created from scratch in accordance with Procedures to Calculate a Facility's "Potential to Emit" as described in SM Step 6C of the QAPP. This method was utilized for approximately 5% of SM sites.

The emission unit PTE for each Title V (TV) stack was determined as follows:

(1) PTE calculations performed by a consultant, PTE calculations performed by the facility, or potential emission summaries (no supporting calculations) provided on application forms were used as described in TV Step 6A of the QAPP. This is the preferred method and was utilized for approximately 90% of TV emission units.

(2) With all other avenues of obtaining PTE information exhausted, the emission unit PTE was created from scratch in accordance with the Procedures to Calculate a Facility's "Potential to Emit" as described in TV Step 6B of the QAPP. This method was utilized for approximately 10% of TV emission units.

With the PTE compiled, a determination was made as to whether, based on the PTE of each pollutant under consideration, the SM facility or Title V emission unit (as applicable) was "Exempt" from NAAQS or PSD Increment modeling demonstrations. A facility was considered "Exempt" based on two criteria:

(1) PTE below the values noted in Table 1 for SM or Table 2 for TV (a "Below Threshold" source),

OR

(2) The only significant emissions from the source were volatile organic compounds (VOC) or hazardous air pollutants (HAP) (a "VOC/HAP" source).

The VOC/HAP source determination was primarily based on the lack of any NOX, CO, SO2, PM10, or PM2.5 PTE estimates in the permit narrative as well as a qualitative assessment of the activities in which the site engages in (e.g., surface coating, organic chemical storage, etc.). Sources with primarily VOC/HAP emissions that also had NOX, CO, SO2, PM10, and PM2.5 emissions below the Table 1 criteria could fit under either exemption criteria. For the sake of this analysis, these sources were classified as "Below Threshold" sources.

Table 1. SM Site Exemption Criteria

Pollutant	Facility PTE
CO	50 tpy
PM10	20 tpy
PM2.5	20 tpy
SO2	20 tpy
NOX	5 tpy*
NOX	20 tpy**

* For facilities located in Cherokee, Clayton, Cobb, Coweta, DeKalb, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding, or Rockdale counties.
** For all other facilities.

Table 2. TV Emission Unit Threshold Criteria

Pollutant	Emission Unit PTE
CO	25 tpy
PM10	10 tpy
PM2.5	10 tpy
SO2	10 tpy
NOX	2.5 tpy*
NOX	10 tpy**

* For facilities located in Cherokee, Clayton, Cobb, Coweta, DeKalb, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding, or Rockdale counties.
** For all other facilities.