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PSD PERMIT APPLICATION Oglethorpe Power Corporation > Thomas A. Smith Energy Facility

PSD Permit Application Volume II – Modeling Report

TRINITY CONSULTANTS

3495 Piedmont Road Building 10, Suite 905

Atlanta, GA 30305 (678) 441-9977

Project 181101.0217

April 2019

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TABLE OF CONTENTS

1. EXECUTIVE SUMMARY 1-1 1.1. Project Overview....................................................................................................................................................... 1-1 1.2. Permitting and Regulatory Requirements ...................................................................................................... 1-2 1.3. Modeling Summary .................................................................................................................................................. 1-3 1.4. Application Contents ............................................................................................................................................... 1-3

2. FACILITY AND PROJECTS DESCRIPTION 2-1 2.1. Facility Description .................................................................................................................................................. 2-1 2.2. Description of Proposed Projects ....................................................................................................................... 2-2

2.2.1. Advanced Gas Path Projects Description ..................................................................................................................... 2-2 2.2.2. Minimum Load Project Description ............................................................................................................................... 2-3

3. PSD MODELING REQUIREMENTS 3-1 3.1. Class II Significance Analysis ................................................................................................................................ 3-2 3.2. Ambient Background Data .................................................................................................................................... 3-3 3.3. Ambient Monitoring Requirements ................................................................................................................... 3-3 3.4. Ozone Ambient Impact Analysis.......................................................................................................................... 3-4 3.5. Class I Requirements ............................................................................................................................................... 3-4 3.6. Regional Inventory Data ........................................................................................................................................ 3-6 3.7. Additional Impacts Analysis ................................................................................................................................. 3-8

4. MODEL SELECTION AND METHODOLOGY 4-1 4.1. Selection of Model..................................................................................................................................................... 4-1 4.2. Meteorological Data and Land Use Representativeness ............................................................................ 4-2

4.2.1. Representativeness Analysis ............................................................................................................................................. 4-2 4.2.2. Urban versus Rural Dispersion Options ....................................................................................................................... 4-4

4.3. Receptor Grid Coordinate System ...................................................................................................................... 4-5 4.4. Building Downwash ................................................................................................................................................. 4-6 4.5. Modeled Emission Sources .................................................................................................................................... 4-7

4.5.1. Representation of Emission Sources .............................................................................................................................. 4-7 4.5.2. Variable Load Analysis ....................................................................................................................................................... 4-7 4.5.3. Significance Analysis ........................................................................................................................................................... 4-8 4.5.4. NO2 Modeling Approach..................................................................................................................................................... 4-9 4.5.5. Startup/Shutdown Modeling (1-hr NO2 NAAQS) ..................................................................................................... 4-9 4.5.6. Tier 1 Analysis - Consideration of Modeled Emission Rates for Precursors (MERPs) .............................. 4-10 4.5.7. Class I Visibility Analysis ................................................................................................................................................. 4-11

5. SUMMARY OF RESULTS 5-1 5.1. CCCT Load Analysis .................................................................................................................................................. 5-1 5.2. Class II and Class I Significance Analyses ......................................................................................................... 5-1 5.3. NAAQS Analysis ......................................................................................................................................................... 5-3 5.4. Soil and Vegetation Impacts.................................................................................................................................. 5-4 5.5. Toxic Impact Assessment ....................................................................................................................................... 5-5 5.6. VISCREEN Modeling Assessment – Cohutta Wilderness ............................................................................. 5-8

APPENDIX A: FIGURES A

APPENDIX B: CLASS I NOTIFICATION DOCUMENTATION AND FLM RESPONSE B

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APPENDIX C: MODELING PROTOCOL AND EPD RESPONSE C

APPENDIX D: EMISSIONS INFORMATION FOR MODELING D

APPENDIX E: ELECTRONIC MODELING FILES E

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LIST OF FIGURES

Figure 2-1. Facility Location 2-1

Figure 2-2. OPC T.A. Smith Facility Boundaries 2-2

Figure 4-1. Comparison of Land Use Categories around the Facility and the NWS Station 4-3

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LIST OF TABLES

Table 1-1. Proposed Project Emissions Increases 1-2

Table 3-1. Significant Impact Levels, NAAQS, PSD Class II Increments, and Monitoring de Minimis Levels for Criteria Air Pollutants 3-2

Table 3-2. Selected Background Concentrations 3-3

Table 3-3. Class I Significant Impact Levels and Increment Thresholds 3-6

Table 4-1. Comparison of Surface Characteristics between the Facility Site and NWS Locations 4-4

Table 4-2. Land-Use Categories Summary 4-5

Table 4-3. Worst-Case Meteorological Conditions 4-12

Table 5-1. CCCT Load Analysis 5-1

Table 5-2. Class II Significance Results for PM10 and PM2.5 5-2

Table 5-3. Class II Significance Results for NO2 5-2

Table 5-4. Class I Significance Results for PM10, PM2.5, and NO2 5-3

Table 5-5. 1-hr NO2 NAAQS Analysis Results 5-4

Table 5-6. Soil and Vegetation Impacts 5-5

Table 5-7. Facility-Wide TAP Emissions and Respective MER 5-7

Table 5-8. Summary of Toxics Modeling Analysis Results 5-8

Table 5-9. VISCREEN Modeling Results 5-9

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1. EXECUTIVE SUMMARY

Oglethorpe Power Corporation (OPC) owns and operates an electrical power plant in Murray County near Dalton, Georgia, known as the Thomas A. Smith Energy Facility (OPC T.A. Smith). OPC T.A. Smith is a major source under both the Title V operating permit program and the Prevention of Significant Deterioration (PSD) construction permitting program. This facility currently operates under Permit No. 4911-213-0034-V-08-0, effective January 4, 2016, and subsequent amendments issued March 28, 2017 and October 2, 2018. The facility was previously known as the Murray Energy Facility. OPC T.A. Smith is a natural gas-fired combined-cycle facility presently capable of producing a nominal power output of 1,240 megawatts (MW). The facility operates two power blocks each consisting of two combined cycle combustion turbines (CCCTs) and one steam turbine, referred to as a “2-on-1” configuration. Each CCCT includes a General Electric (GE) 7FA combustion turbine (CT) exhausting to a heat recovery steam generator (HRSG), which generates steam to power the block’s steam turbine. Each HRSG has a duct burner (DB) to provide supplementary firing for additional steam generation as needed. The facility also operates two natural gas-fired auxiliary boilers, each with an annual operational limit of 6,000 hours, two diesel-fired backup generators rated at 704 horsepower (hp) each, and one diesel-fired emergency firewater pump rated at 265 hp. The backup generators and emergency firewater pump are limited to 500 hours per year of operation per engine. To minimize the formation of oxides of nitrogen (NOX), each combustion turbine is equipped with dry low NOX combustors, each duct burner with low NOX burners, and each auxiliary boiler with low NOX burners and flue gas recirculation (FGR). In addition, each combustion turbine and associated duct burner stack is equipped with a selective catalytic reduction (SCR) system for control of NOX emissions. OPC is proposing two projects that involve modifications to the CCCT systems (i.e., each CT with HRSG and DB). Only one of these proposed projects, the Advanced Gas Path Project III (AGP Project III), is anticipated to result in an increase in facility emissions. The AGP Project III will result in an increase in emissions exceeding the PSD Significant Emission Rates (SERs) for filterable particulate matter (PM), particulate matter with an aerodynamic diameter of 10 microns (PM10), particulate matter with an aerodynamic diameter of 2.5 microns (PM2.5), NOX, and greenhouse gases (GHG) in terms of carbon dioxide equivalents (CO2e). Therefore, this permitting action is subject to PSD permitting for these pollutants. The application package contains the necessary state air construction and operating permit application for the proposed projects, included in two (2) separate application volumes. This Volume I of the application details the required emissions analyses, regulatory review, and control technology analyses. Volume II of the application package includes all the required air quality assessments necessary as part of this PSD permit application.

1.1. PROJECT OVERVIEW

OPC is considering making control system changes that would allow OPC T.A. Smith to increase the capacity of each block by approximately 28.6 MW in the summer and 31.0 MW in the winter (Block 1 being CCCT1 and CCCT2 and steam turbine, and Block 2 being CCCT3 and CCCT4 and steam turbine), referred to as the AGP Project III. These control changes would result in an associated increase in maximum heat inputs and maximum hourly rate of emissions when the duct burners are used at their full capability. OPC is also considering installation of new turbine components and controls to allow sustained operations at lower operating loads, referred to as the Minimum Load Project. Currently, OPC T.A. Smith’s Title V permit only allows turbine operation below 73.6 MW during periods of startup, shutdown, or special testing.1 This value was selected based

1 Permit Condition 3.3.7


on GE-provided data indicating an increase in NOX and CO emissions concentrations at lower loads potentially exceeding the facility’s emission limits for those pollutants. The Minimum Load Project, if implemented, would allow the gas turbines to operate at a lower minimum load while continuing to maintain NOX and CO emissions concentrations in compliance with the facility’s permitted emission limits. More detail regarding the proposed project is provided in Section 2.2 of this report.

1.2. PERMITTING AND REGULATORY REQUIREMENTS

OPC is submitting this construction and operating permit application, in accordance with the PSD permitting requirements, to request authorization to modify and operate the site’s combined cycle combustion turbine systems and associated HRSGs with duct burners. Since OPC T.A. Smith is a major source under the PSD permitting program, emission increases from the proposed project must be evaluated and compared to the SERs for regulated pollutants under the PSD program. OPC has evaluated emissions increases of carbon monoxide (CO), NOX, PM, PM10, PM2.5, CO2e, sulfur dioxide (SO2), sulfuric acid mist (H2SO4), and volatile organic compounds (VOC) resulting from the proposed projects for comparison to their respective PSD SERs to determine whether PSD permitting is required, as shown in Table 1-1.

Table 1-1. Proposed Project Emissions Increases

Since the projects emissions increases of filterable PM, total PM10, total PM2.5, NOX, and CO2e exceed their respective SERs, the proposed projects are required to undergo PSD review for each of those pollutants. Emission calculations are described in Section 3 of Volume I of this application, and PSD permitting requirements are detailed in Section 4 of Volume I of this application.

OPC is submitting this construction and operating permit application package in accordance with all federal and state requirements. The proposed projects will be subject to federal New Source Performance Standards (NSPS) and the Georgia Rules for Air Quality Control (GRAQC). Applicability of these programs is discussed in Section 4 of Volume I of this application. As there are no applicable National Ambient Air Quality Standards (NAAQS) for filterable PM or CO2e, this Volume II report focuses on modeling evaluations for PM10, PM2.5, and NOX (as nitrogen dioxide [NO2]).

Pollutant

Project

Emissions

Increase

(tpy)

NSR Major

Modification

Threshold

(tpy)

NSR Permitting

Required?

SO2 14.52 40 No

NOX 127.50 40 Yes

CO 47.49 100 No

PM 153.32 25 Yes

Total PM10 153.32 15 Yes

Total PM2.5 153.32 10 Yes

VOC 36.02 40 No

CO2e 2,897,635 75,000 Yes

H₂SO₄ 2.43 7 No


1.3. MODELING SUMMARY

The results of the air quality dispersion modeling analyses presented in this report are summarized as follows:

1. Ambient PM10 impacts from the projects in the form of the standard are below the Class I and Class II Significant Impact Levels (SILs) for all applicable averaging periods.

2. Ambient PM2.5 impacts from the projects in the form of the standard are below the Class I and Class II SILs for all applicable averaging periods.

3. Ambient NO2 impacts from the projects in the form of the standard are below the Class I and Class II SILs for the annual averaging period.

4. Ambient NO2 impacts from the projects in the form of the standard are above the Class II SIL for the 1-hr averaging period. Subsequent modeling demonstrated that OPC T.A. Smith’s operations do not cause or contribute to any violations of the 1-hr NO2 NAAQS.

5. Ambient NO2 impacts from the projects in the form of the standard are below the Class I SIL for the 1-hr averaging period.

6. An evaluation of plume blight, using the VISCREEN model, showed no issues with visibility based impacts for the Cohutta Wilderness Class I area.

7. Toxic Air Pollutant (TAP) modeled impacts are below applicable ambient air quality thresholds of concern. The PSD air quality analyses described in this report demonstrates that the proposed project will neither cause nor contribute to a violation of any NAAQS and/or PSD Increment for PM10, PM2.5, or NO2.

1.4. APPLICATION CONTENTS

The remainder of this modeling report is organized as follows.

Section 2 contains a description of the proposed projects; Section 3 describes the PSD modeling procedures; Section 4 discusses the technical approach employed in the modeling analyses; Section 5 describes the results of the PSD dispersion analyses; Appendix A contains an area map, site layout map, and other supporting figures; Appendix B contains the Class I notification letter and Federal Land Manager (FLM) responses (received to

date); Appendix C contains the modeling protocol and Georgia Environmental Protection Division (EPD) response; Appendix D contains the emissions information used in modeling; and Appendix E contains electronic modeling files.


2. FACILITY AND PROJECTS DESCRIPTION

2.1. FACILITY DESCRIPTION

Figure 2-1 provides a map of the area surrounding the existing proposed projects location. The approximate central Universal Transverse Mercator (UTM) coordinates of the OPC T.A. Smith facility (centered around the emissions sources) are 690.687 kilometers (km) East and 3,842.790 km North in Zone 16 (NAD 83). The area surrounding the facility is predominantly rural.

Figure 2-1. Facility Location

Figure 2-2 depicts the fence line boundary of the OPC T.A. Smith facility. The boundary area indicated in the figure is completely fenced.


Figure 2-2. OPC T.A. Smith Facility Boundaries

2.2. DESCRIPTION OF PROPOSED PROJECTS

2.2.1. Advanced Gas Path Projects Description

The AGP Project III is the third in a series of three AGP projects. Two have been completed by OPC (after each respectively receiving confirmation from EPD that a permit change was not required). The third, AGP Project III, is currently under review by OPC for possible completion. OPC’s decision to implement the first two AGP projects was independent of, and not conditioned on the later decision to pursue AGP Project III. OPC believes that AGP Project III is separate under PSD regulations2 but chose an aggregated assessment of all three projects for this permit application. In the first project (AGP Project I), GE installed the AGP components on the combustion turbines to extend the maintenance interval without creating any increase in firing temperature or hourly emissions. In the second project (AGP Project II), GE adjusted the control system to use more of the capabilities of the AGP components (which caused some increase in the maximum firing temperature and maximum heat input of the combustion turbines only) while creating corresponding decreases in the maximum heat inputs for the duct burners associated with each combustion turbine’s HRSG. As a result, there was no increase in the maximum heat input of the overall ”affected facility” (which under the NSPS for Stationary Combustion Turbines, 40 CFR 60 Subpart

2 Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NNSR): Aggregation; Reconsideration, Final action; lifting of administrative stay and announcement of effective date, 83 Fed. Reg. 57,324 (November 15, 2018).

Fence


KKKK includes the turbine and duct burner) and no increase in maximum hourly emissions from the combined stacks. These control system changes limited the output capacity of each CCCT to its pre-existing capacity. Before implementing AGP Projects I and II, OPC submitted Title V off-permit change letters to notify Georgia EPD of its plans. The first notice was submitted on September 24, 2014 and included a copy of the results of OPC’s PSD analysis for Project I. On October 3, 2014, EPD responded in a letter agreeing that “no permit change is needed” for the Project. Before implementing Project II, OPC submitted a second Title V off-permit change letter on January 26, 2015. EPD responded in a letter on February 11, 2015 agreeing that a permit change was still not necessary for AGP Project II. GE completed AGP Project I in October 2014 for CCCT3 and CCCT4 and in April 2015 for CCCT1 and CCCT2. GE completed AGP Project II in April 2015 for all four CCCTs. Since that time, OPC has conducted studies and consulted with local utilities regarding the capacity of the existing grid infrastructure to accept increased power output from OPC T.A. Smith. As a result of those evaluations, OPC is now considering implementing AGP Project III. Additional changes to the control system are needed before an increase in maximum hourly emissions or maximum capacity can be realized. Under AGP Project III, OPC is considering additional control changes that would allow OPC to utilize the maximum capability of the AGP components, via the duct burners. If implemented, this change would increase the capacity of each block by approximately 28.6 MW in the summer and 31.0 MW in the winter (Block 1 being CCCT1 and CCCT2 and steam turbine, and Block 2 being CCCT3 and CCCT4 and steam turbine). The increased capacity would lower the cost per MW to the 38 members of OPC, a not-for-profit generation cooperative. These additional control changes would result in an associated increase in maximum heat inputs and maximum hourly rate of emissions when the duct burners are used at their full capability. Implementation of AGP Project III would not increase the noise emissions from OPC T.A. Smith above historical levels, and does not require any changes in the facility’s gas supply infrastructure.

2.2.2. Minimum Load Project Description

OPC is also considering installation of new turbine components and software controls to replace selected combustion equipment and connection accessories to allow sustained operations at lower operating loads, referred to as the Minimum Load Project. The Minimum Load Project would include replacements to the combustion equipment (potentially including end covers, fuel nozzles, combustion casings, cap assembly, liners, transition pieces, flow sleeves, and X-Fire tubes) and to the connection accessories (potentially including flex hoses/pig tails, ring manifolds, cooling and sealing air piping, and gas control valves). Currently, OPC T.A. Smith’s Title V permit only allows turbine operation below 73.6 MW during periods of startup, shutdown, or special testing.3 This value was selected based on GE-provided data indicating an increase in NOX and CO emissions concentrations at lower loads potentially exceeding the facility’s emission limits for those pollutants. The Minimum Load Project, if implemented, would allow the gas turbines to operate at a lower minimum load while continuing to maintain NOX and CO emissions concentrations in compliance with the facility’s permitted emission limits. Specifically, data provided by GE for the Minimum Load Project, included in Appendix E, show that these upgrades would allow steady-state operations of the turbines at loads of approximately 49 MW, with some variations for ambient temperatures, while still achieving continuous compliance. The proposed Minimum Load Project would have no impact on the capacity of the turbines. While the proposed Minimum Load Project is a distinct project from the proposed AGP Project III, OPC is requesting approval to implement both projects as part of this permit application. In particular, OPC requests EPD remove the condition specifying an allowable minimum steady state operating load from OPC T.A. Smith’s

3 Permit Condition 3.3.7


Title V permit. Compliance with the NOX and CO emission limits will continue to be demonstrated through the use of the facility’s existing continuous emissions monitoring systems (CEMS).


3. PSD MODELING REQUIREMENTS

The following sections detail the methods and models used to demonstrate that the proposed projects will not cause or contribute to a violation of either the NAAQS or the PSD Class I or Class II Increment. The dispersion modeling analyses were conducted in accordance with the following guidance documents, as well as the approved modeling protocol4:

Guideline on Air Quality Models 40 CFR 51, Appendix W (EPA, Revised, January 17, 2017) User’s Guide for the AMS/EPA Regulatory Model – AERMOD, (EPA, April 2018) AERMOD Implementation Guide (EPA, April 2018) New Source Review Workshop Manual (EPA, Draft, October 1990) Modeling Procedures for Demonstrating Compliance with PM2.5 NAAQS (EPA, Memorandum from Mr. Stephen

Page, March 23, 2010) PSD Permit Application Guidance Document (Georgia EPD, Draft, February 2017) Guidance for PM2.5 Permit Modeling (EPA, Memorandum from Mr. Stephen Page, May 20, 2014) Guidance on the Use of EPA’s MERPs to Account for Secondary Formation of Ozone and PM2.5 in Georgia

(Georgia EPD, February 25, 2019) Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier I Demonstration

Tool for Ozone and PM2.5 under the PSD Permitting Program (EPA, Memorandum from Mr. Richard A Wayland, December 2, 2016) and associated errata document (February 2017)

Guidance on Significant Impact Levels for Ozone and Fine Particles in the Prevention of Significant Deterioration Permitting Program (EPA, Memorandum from Mr. Peter Tsirigotis, April 17, 2018)

Additional Clarification Regarding Application of Appendix W Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard (EPA, Memorandum from Mr. Tyler Fox, March 1, 2011)

Clarification on the Use of AERMOD Dispersion Modeling for Demonstrating Compliance with the NO2 National Ambient Air Quality Standard (EPA, Memorandum from Mr. R. Chris Owen and Roger Brode, September 30, 2014)

Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions (Georgia EPD, Revised, May 2017) Part C of Title I of the Clean Air Act, 42 U.S.C. §§7470-7492, is the statutory basis for the PSD program. The U.S. EPA has codified PSD definitions, applicability, and requirements in 40 CFR Part 52.21. PSD is the component of the federal New Source Review (NSR) permitting program that is applicable in areas that are not designated as in nonattainment of the NAAQS. Murray County, where the OPC T.A. Smith facility is located, is currently designated as “attainment” or “unclassifiable” for all criteria pollutants.5 Since the OPC T.A. Smith facility is an existing PSD major source, the emissions increases associated with the proposed projects must be compared to the PSD SERs for each pollutant to determine whether the projects requires PSD review. As discussed in Volume I and shown in Table 1-1, the projects emission rates trigger PSD permitting for multiple criteria pollutants with established SILs, NAAQS, and/or PSD Increment standards, specifically PM10, PM2.5, and NO2. This section addresses requirements for evaluating NAAQS, PSD Increment, Class I Area, and additional impacts.

4 Modeling protocol submitted to the Georgia EPD on October 30, 2018, with comments received from the Georgia EPD on November 26, 2018. Copies of these documents can be found in Appendix C.

5 40 CFR 81.311


3.1. CLASS II SIGNIFICANCE ANALYSIS

The Class II Significance Analysis is conducted to determine whether the emissions increases associated with the projects would cause a significant impact upon the area surrounding the facility. The Significance Analysis is limited to PM10, PM2.5, and NO2, as these are the only pollutants for which PSD modeling requirements are triggered. “Significant” impacts are defined by ambient concentration thresholds commonly referred to as the SILs, shown in Table 3-1.

Table 3-1. Significant Impact Levels, NAAQS, PSD Class II Increments, and Monitoring de Minimis Levels for Criteria Air Pollutants

Pollutant Averaging

Period Class II SIL

(µg/m3) Primary NAAQS

(µg/m3)

Class II PSD Increment

(µg/m3)

Significant Monitoring

Concentration (µg/m3)

PM10 24-hour 5 150 (1) 30 10

Annual 1 -- 17 --

PM2.5 24-hour 1.2 (2) 35 (4) 9 (3) -- (2)

Annual 0.2 (2) 12 (5) 4 (3) --

NO2 1-hour 7.5 188 (6) N/A --

Annual 1 100 (7) 25 14 (1) Not to be exceeded more than three times in 3 consecutive years (highest sixth high modeled output). (2) EPA promulgated PM2.5 SILs, Significant Monitoring Concentrations (SMCs), and PSD Increments on October 20, 2010 [75 FR

64864, PSD for Particulate Matter Less Than 2.5 Micrometers Increments, Significant Impact Levels (SILs) and Significant Monitoring Concentration (SMC); Final Rule]. The SILs and SMCs became effective on December 20, 2010 (i.e., 60 days after the rule was published in the Federal Register) but the U.S. Court of Appeals decision on January 22, 2013 vacated the SMC and remanded the SIL values back to EPA for reconsideration. EPA has recently provided guidance (August 2016) and a finalized memo (April 2018) which recommended use of a 24-hr PM2.5 SIL of 1.2 µg/m3, and an annual SIL of 0.2 µg/m3. However, the guidance indicated that the permitting authority had the discretion to continue to utilize the previously established annual SIL of 0.3 µg/m3. EPA responded to the vacature of the SMCs by indicating that existing background monitors should be sufficient to fulfill the ambient monitoring requirements for PM2.5.

(3) The above mentioned court decision did not impact the promulgated increment thresholds for PM2.5. (4) The 3-year average of the 98th percentile 24-hour average concentration (highest eighth high modeled output). (5) The 3-year average of the annual arithmetic average concentration (highest first high modeled output). (6) The 3-year average of the 98th percentile of the daily maximum 1-hr average (highest eighth high modeled output). (7) Annual arithmetic average (highest first high modeled output).

The highest design concentrations out of all given modeling years for each pollutant-averaging time is compared to the SIL level shown in Table 3-1 to determine if the ambient air impact from the proposed project is significant. In the case of 24-hour and annual PM2.5 evaluations, EPA guidance states that the applicant should determine the maximum concentration at each receptor per year, then average those values on a receptor-specific basis over the 5 years of meteorological data prior to comparing with the appropriate SIL.6 However, this assessment is only appropriate for the PM2.5 NAAQS, as the PM2.5 Increment standard is not a statistical standard. Therefore, the maximum 5-year average values for PM2.5 were compared to the applicable SILS to determine if a PM2.5 NAAQS analysis is required, whereas the maximum year by year results for PM2.5 were compared to the applicable SILs for a determination if a refined analysis for PM2.5 Increment is required. For PM10, the impacts were evaluated on a year by year basis for comparison to the SIL for both PSD Increment and the NAAQS.

6 Please note that OPC did not use averaging for developing the PM2.5 SIL results for consideration of the PM2.5 Increment. Maximum annual values were used rather than 5-year average values.


As detailed further in Section 4.5.6, the Significance Analysis for PM2.5 also considered secondary PM2.5 impacts from the projects NOX and SO2 emissions, in accordance with the February 2019 Georgia EPD MERPs guidance. For NO2 NAAQS modeling, a concatenated meteorological data set to derive the appropriate form of the 1-hr NO2 NAAQS standard was utilized. For annual NO2 NAAQS modeling, each individual year was processed separately to evaluate maximum annual anticipated impacts. When modeled design concentrations are less than the applicable SIL, further analyses (NAAQS and PSD Increment) are not required for that pollutant-averaging period. If modeled impacts are greater than the SIL, a full NAAQS and PSD Increment analysis is required for that pollutant and averaging period to demonstrate that the facility neither causes nor contributes to any exceedances.

3.2. AMBIENT BACKGROUND DATA

The background concentrations were selected based on the most recent monitor data published by the Georgia EPD for the county of interest.7 The chosen background values are shown in Table 3-2.

Table 3-2. Selected Background Concentrations

PSD Pollutant

Averaging

Period

2015-2017

Monitor

Background

Concentration8

(g/m3) Metric

Monitor

Location

PM10 24-hour 38.0 3-yr average of

second-high

Statewide Value

as Derived by

EPD

PM2.5 24-hour 16.8 3-yr average of

98th percentile Rossville

Annual 8.4 3-yr arithmetic

mean average

NO2 1-hour 30.3 3-yr average of

98th percentile Statewide Value

as Derived by

EPD Annual 4.8 3-yr arithmetic

mean maximum

3.3. AMBIENT MONITORING REQUIREMENTS

The PSD Significance Analysis is also used to determine whether the applicant is exempt from ambient monitoring requirements. To determine whether pre-construction monitoring should be considered, the maximum modeled impacts attributable to the proposed project are assessed against Significant Monitoring

7 https://epd.georgia.gov/air/documents/georgia-background-data - website indicates data last updated November 26, 2018.

8 PM10 and NO2 values listed as statewide values in available Georgia background values. PM2.5 only data directly specified as 2015-2017 from background data resource.

https://epd.georgia.gov/air/documents/georgia-background-data


Concentrations (SMC). The SMC for the applicable averaging periods for PM10, PM2.5, and NO2 are provided in 40 CFR 52.21(i)(5)(i) and are listed in Table 3-1. A pre-construction air quality analysis using continuous monitoring data may be required for pollutants subject to PSD review per 40 CFR 52.21(m). If either the predicted modeled impact from an emissions increase or the existing ambient concentration is less than the SMC, an applicant may be exempt from pre-construction ambient monitoring. The SMC value for PM2.5 was vacated on January 22, 2013; however, EPA has responded to the vacatur by indicating that existing background monitors should be sufficient to fulfill the ambient monitoring requirements. Georgia EPD maintains an extensive ambient monitoring system in Georgia and publishes available background data for PM2.5 on its website. The Rossville monitor is the selected ambient PM2.5 monitor representative of ambient background concentrations of PM2.5 in Murray County. The Rossville monitor is located in Walker County, Georgia and is part of the Chattanooga, Tennessee/Georgia Metropolitan Statistical Area (MSA). It is the closest ambient PM2.5 monitor in Georgia to the OPC T.A. Smith facility, and it is geographically located in a similar and representative area as the OPC T.A. Smith facility. Therefore, sufficient ambient background monitoring data is available for the region for PM2.5.

3.4. OZONE AMBIENT IMPACT ANALYSIS

Elevated ground-level ozone concentrations are the result of photochemical reactions among various chemical species. These reactions are more likely to occur under certain ambient conditions (e.g., high ground-level temperatures, light winds, and sunny conditions). The chemical species that contribute to ozone formation, referred to as ozone precursors, include NOX and VOC emissions from both anthropogenic (e.g., mobile and stationary sources) and natural sources (e.g., vegetation). Pursuant to 40 CFR 52.21, ambient ozone monitoring is not required unless a project’s emissions increase is greater than 100 tpy of VOC or NOX. EPA recently issued guidance specifying a SIL value for ozone of 1 ppb, and has developed a new demonstration methodology (the MERPs guidance) to provide a framework for a Tier 1 demonstration that can illustrate that a project will not cause or contribute to any violation of ambient ozone standards.9 The February 2019 Georgia EPD guidance document titled Guidance on the Use of EPA’s MERPs to Account for Secondary Formation of Ozone and PM2.5 in Georgia, which is based on the EPA MERPS guidance, was used to provide a Tier 1 demonstration that ozone impacts from the projects will not cause or contribute to ambient air quality levels of ozone. Both VOC and NOX emissions increases from the projects were considered. Details regarding that analysis can be found in Section 4.5.6 of this report.

3.5. CLASS I REQUIREMENTS

Class I areas are federally protected areas for which more stringent air quality standards apply to protect unique natural, cultural, recreational, and/or historic values. Cohutta Wilderness is the closest Class I area to the OPC T.A. Smith facility and is located approximately 30.6 km away from the facility (i.e., within 50 km of the site). The following Class I areas are located within 300 km of the OPC T.A. Smith facility (with the approximate distance to the facility listed)10:

9 Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier I Demonstration Tool for Ozone and PM2.5 under the PSD Permitting Program (Memorandum from Mr. Richard A. Wayland, U.S. EPA, to Regional Air Division Directors, December 2, 2016).

10 All distances approximate and based on data obtained from the Class I Area distance tool as published by the Florida Department of Environmental Protection (FL DEP) at https://floridadep.gov/air/air-business-planning/content/class-i-areas-map

https://floridadep.gov/air/air-business-planning/content/class-i-areas-map



Cohutta Wilderness (30.6 km) Joyce Kilmer-Slickrock Wilderness (111 km) Great Smokey Mountains National Park (123 km) Shining Rock Wilderness (195 km) Sipsey Wilderness (227 km) Mammoth Cave National Park (284 km) Linville Gorge Wilderness (299 km)

All other Class I areas are located at distances greater than 300 km from the Smith Facility. The FLMs have the authority to protect air quality related values (AQRVs) and to consider, in consultation with the permitting authority, whether a proposed major emitting facility or a proposed modification to an existing major emitting facility will have an adverse impact on such values. AQRVs for which PSD modeling is typically conducted include visibility and deposition of sulfur and nitrogen. The ratio of emissions to Class I distance (i.e., Q/D) for these projects for the Class I areas within 300 km was considered in order to determine if the FLM would require a full AQRV analysis. The FLM’s AQRV Work Group (FLAG) 2010 guidance states that a Q/D value of ten or less indicates that AQRV analyses should not be required.11 Further, since one of the Class I areas (Cohutta Wilderness) is located within 50 km of the site, direct discussions and correspondence were held with the FLM responsible for the Cohutta Wilderness (Melanie Pitrolo). A copy of that correspondence has been included in Appendix B of this report. Based on that correspondence, the following was indicated for the Cohutta Wilderness.

No AQRV analysis, such as visibility or deposition, for the Cohutta Wilderness is required. A plume blight analysis (using VISCREEN) for Cohutta, should be conducted. However, no explicit modeling

protocol is required. Based on this correspondence, a VISCREEN analysis for the Cohutta Wilderness has been conducted for these projects, as outlined in Section 4 of this report. Notifications were submitted to the appropriate FLMs for all Class I areas located more than 50 km from OPC T.A. Smith, and located within 300 km of the facility, for concurrence with a finding regarding the requirement for AQRV analysis for these projects.12 The Q/D for all Class I areas located more than 50 km from the facility was evaluated and demonstrated that impacts are less than 10. Documentation regarding the Q/D analyses conducted, can be found in Appendix B. A Significance Analysis was conducted for the Class I areas to determine if an evaluation of PSD Increment impacts upon the Class I area is required. Details regarding the Class I area Significance Analysis are as follows. 1. AERMOD was utilized for all Significance Analyses. All Cohutta Wilderness Class I area receptors are within

50 km of the OPC T.A. Smith Facility. Therefore, the Class I area receptors were placed throughout the

11 U.S. Forest Service, National Park Service, and U.S. Fish and Wildlife Service. 2010. Federal land managers’ air quality related values work group (FLAG): phase I report, revised (2010). Natural Resource Report NPS/NRPC/NRR, 2010/232. National Park Service, Denver, Colorado.

12 Copies of correspondence to date, are included in Appendix B. If EPD is not copied on any future correspondence from the FLM providing concurrence that no AQRV analysis is required, a copy of that correspondence will be provided to the Georgia EPD.


Cohutta Wilderness and directly evaluated in the AERMOD model. As shown in Section 4 of this report, no receptors in the Cohutta Wilderness exceeded the Class I SILs for PM10, PM2.5 or NO2.

2. For all other Class I areas, a screening procedure was utilized evaluating an array of receptors located 50 km from the facility at 1-degree intervals, to compare project emission increase impacts to those receptors at 50 km.13 Within the same modeling file described in #1 above, a 50 km-radius ring of receptors in the AERMOD model was developed. Significance results from those receptors also demonstrated that the Class I SILs for PM10, PM2.5, and NO2 were not exceeded. Results of the analysis can be found in Section 4 of this report.

The Class I area SILs and PSD Increment thresholds utilized are listed below. PM2.5 Class I SILs are taken from recent EPA guidance regarding appropriate recommended significant impact levels for PM2.5.14

Table 3-3. Class I Significant Impact Levels and Increment Thresholds

Pollutant Averaging Period

Class I SIL

(μg/m3)

Class I PSD

Increment

(μg/m3)

PM2.5 24-hour 0.27 2

Annual 0.05 1

PM10 24-hour

Annual

0.3

0.2

8

4

NO2 Annual 0.1 2.5

3.6. REGIONAL INVENTORY DATA

As shown below in Section 4 of this report, the only pollutant (and averaging period) to exceed the Class II SIL was NO2 for the 1-hr average (Class II modeling). No other pollutants (PM10, PM2.5) or averaging periods (annual NO2) exceeded the Class II SILs. No pollutants exceeded the Class I SILs, as referenced above in Section 3.4 and as shown in model results in Section 4. As such, it was necessary to develop regional inventory data for Class II modeling of the 1-hr NO2 NAAQS. The following procedure was followed.

Per consultation with the Georgia EPD as part of the modeling protocol approval process, the regional inventory screening would be limited to an area within 50 km of the OPC T.A. Smith facility. Therefore, the only areas for consideration in the modeling inventory were northern Georgia and southern Tennessee.

Facility source information (including model ready data) was provided by the Tennessee Department of Environment and Conservation (TDEC) for the counties of interest in south Tennessee. Documentation regarding the information received from TDEC can be found in Appendix D.15

Georgia based modeling inventory information, was compiled as follows;

13 Consistent with EPD guidance, this assumes that all applicable FLMs have determined that no AQRV analyses will be required for the projects. While the FLM for the Cohutta Wilderness has indicated that no ARQV analysis will be required, concurrence from all applicable FLMs has not yet been received.

14 Guidance on Significant Impact Levels for Ozone and Fine Particles in the Prevention of Significant Deterioration Permitting Program (Memorandum from Mr. Peter Tsirigotis, U.S. EPA, to Regional Air Division Directors, April 17, 2018).

15 E-mail correspondence from Haidar Alrawi of TDEC dated February 13, 2019, as provided in Appendix D.


a. The Georgia EPD source list was queried and evaluated for all counties in Georgia within 50 km of the

OPC T.A. Smith facility.16

b. The EPD PSD modeling inventory tool was queried for all source information within the counties of

interest within 50 km of the OPC T.A. Smith facility.17 However, this resource only provides detailed

source information for Title V and PSD major sources.

c. The EPD air permits website was queried (per county code) for the counties of interest within 50 km of

the OPC T.A. Smith facility for additional air permits issued since the EPD source list was last updated in

June 2018.18 The permit list was also reviewed for consistency with data provided in the June 2018 EPD

permitted source listing.

d. All resources were cross referenced to create an initial list of sources to consider for screening purposes

via 20D. However, this initial listing was quite large, inclusive of a significant number of minor sources.

The minor sources list was first reduced in two ways.

i. The first method was a desktop review of the EPD permits list and available documentation listed

regarding the physical location/latitude-longitude coordinates provided in EPD information for the

sources of interest. If a minor source site was not discernable based on any of the above three

criteria (e.g., no permit on EPD website, street address and latitude/longitude coordinates from June

2018 permit list did not point to an industrial site), then the site was removed from consideration.

Also, review of online permit narrative information from some minor sources revealed that the sites

of interest were not sources of NO2 emissions (for example, sources only emitting PM). Therefore,

those sites were also removed from consideration.

ii. The second method was a file review at the Georgia EPD for any remaining sources. The file review

included a review of records both for the Title V/PSD major sources already identified (for validity

of data from the PSD inventory tool) as well as for minor sources. The file review indicated the

following for many minor sources;

(a) No permit documentation was available for review at the EPD.

(b) File review indicated the site of interest was not a source of NO2 emissions, and the source was,

therefore, removed from consideration.

(c) File review indicated the site was no longer operational, and the source was, therefore, removed

from consideration.

(d) File review indicated a lack of any usable information for dispersion modeling. Remaining minor sources (not meeting the (b) and (c) criteria above), and previously identified major

sources, outside the Significant Impact Area (SIA) were then screened per the 20D screening procedure, as outlined in Section 5.3.1 of the Georgia EPD PSD Guidance.19 Specifically, all sites within 2 km of each were grouped together for consideration of total emissions. If the total emissions from the individual site (or group of sites) was less than 20 times the distance to the OPC T.A. Smith facility, then the site was considered to be “screened out” and eliminated from the NAAQS modeling evaluation.20 If the site was not

16 https://epd.georgia.gov/air/list-sources-georgia - last updated June 2018.

17 https://psd.georgiaair.org/inventory/

18 http://permitsearch.gaepd.org/

19 PSD Permit Application Guidance Document. Georgia Department of Natural Resources, Environmental Protection Division, Air Protection Branch, Draft, February, 2017.

20 Taking the distance back to the site is appropriate in this instance, since the only pollutant and averaging period of concern for refined modeling is the 1-hr average NO2 NAAQS, a short term averaging period. Any sources (for which information was available) within the SIA were modeled.

https://epd.georgia.gov/air/list-sources-georgia

https://psd.georgiaair.org/inventory/

http://permitsearch.gaepd.org/

http://permitsearch.gaepd.org/

https://psd.georgiaair.org/inventory/


“screened out,” then it was further considered for use in the modeling inventory for the refined 1-hr NO2 NAAQS modeling.21

Some minor sources, which did not screen out, were not able to be modeled as there were no available records for review at the Georgia EPD containing any usable information to conduct a modeling assessment. A listing of those sites identified, but not able to be modeled, is included in Appendix D, as well as the final major and minor source inventory information modeled for the 1-hr NO2 NAAQS analysis. Sites listed in Table D-8 with a “No” for “Present in NOx Inventory?” are the sites in question. A copy of the 20D analysis, is also included in Appendix D.

3.7. ADDITIONAL IMPACTS ANALYSIS

PSD regulations require that three additional impacts be considered as part of a PSD permit action: a soil and vegetation analysis, an economic growth analysis, and a visibility analysis. The effect of the proposed project’s NO2, PM10 and PM2.5 emissions increases on local soils and vegetation is addressed through comparison of modeled impacts to the secondary NAAQS and other relevant screening criteria that have been developed by the U.S. EPA to provide protection for public welfare, including protection against decreased visibility, damage to animals, crops, vegetation and buildings.22 The results of the soil and vegetation analysis are discussed in Section 5.4. An economic growth analysis is intended to assess the amount of new growth that is likely to occur in support of the new projects and to estimate emissions resulting from associated growth. Associated growth relates to any residential and commercial/industrial growth that may result from the proposed projects. Residential growth depends on the number of new employees and the availability of housing in the area, while associated commercial and industrial growth consists of new sources providing services to the new employees and the facility. The proposed projects will not result in a change of the current resources necessary to operate and support the projects. Therefore, additional economic growth impacts from the proposed projects will be minimal. Visibility analyses for Class II areas are not necessary for proposed projects that have no regional airports, state parks, or State Historic Sites located within the project’s SIA. The proposed projects modeled impacts are under the SILs for PM10 and PM2.5, and annual NO2. Although the 1-hr NO2 SIA was large, as shown in a figure illustrating the significant impact area in Appendix A of this report, the SIA was very non-contiguous and only larger in size to the west of the OPC T.A. Smith facility. The immediate contiguous impact area only stretched roughly 1 km from the OPC T.A. Smith facility. Therefore, since no regional airports, state parks, or State Historic Sites were located within the SIA, no Class II visibility assessment is required for the proposed projects.23

21 There is no 1-hr average NO2 PSD Increment standard. Therefore, the only refined modeling analysis included in this modeling report is for the 1-hr average NO2 NAAQS.

22 U.S. EPA, A Screening Procedure for the Impacts of Air Pollution Sources on Plants, Soils and Animals (EPA 450/2-81-078), 1980.

23 The Dalton Municipal Airport is located approximately 4 km northeast of the OPC T.A. Smith facility. However, the airport is not located directly within the area of significant receptors for the 1-hr NO2 averaging period from this modeling analysis. Also, the airport pre-dates the existence and installation of the facility itself in 2000. Therefore, since no plume blight visibility issues have occurred from the OPC T.A. Smith facility influencing the airport in the roughly first two decades of operation, it is highly unlikely that any such issues would occur in the future. Therefore, no Class II visibility assessment for the nearby airport has been conducted.


While not a requirement under the federal PSD regulations, OPC has included an evaluation of toxic pollutant impacts for the facility emission sources as part of this permit application in accordance with Georgia EPD guidelines.24 The post-project facility-wide potential emissions for each listed air toxic were compared to the Minimum Emission Rate (MER) values provided in guidance to determine if modeling for those air toxics was required. Toxic pollutant impacts are discussed in detail in Section 5.5. Also, per 40 CFR 52.21, as the net emissions increase for the proposed projects is greater than 100 tons per year of NOX, an ambient air quality analysis or gathering of ambient air quality data is required for ozone. Additional consideration of ozone is discussed further in Section 4 of this report associated with the recent December 2016 EPA guidance document associated with Modeled Emission Rates for Precursors (MERPs), and Georgia EPD’s state specific guidance regarding the MERPs (Guidance on the Use of EPA’s MERPs to Account for Secondary Formation of Ozone and PM2.5 in Georgia, February 2019).

24 Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions. Georgia Department of Natural Resources, Environmental Protection Division, Air Protection Branch, Revised, May, 2017.


4. MODEL SELECTION AND METHODOLOGY

This section includes a summary of the modeling methodology originally presented in the dispersion modeling protocol previously submitted to25 and approved by26 the Georgia EPD.

4.1. SELECTION OF MODEL

The latest version (version 18081) of the AERMOD modeling system was used to estimate maximum ground-level concentrations in all air pollutant analyses conducted for this application. AERMOD is a refined, steady-state, multiple source, Gaussian dispersion model and was promulgated in December 2005 as the preferred model for use by industrial sources for this type of air quality analysis.27 The AERMOD model incorporates the Plume Rise Modeling Enhancements (PRIME), and the direction-specific building downwash dimensions used as inputs are determined by the Building Profile Input Program, PRIME (BPIP PRIME), version 04274.28 BPIP PRIME is designed to incorporate the concepts and procedures expressed in the Good Engineering Practice (GEP) Technical Support document, the Building Downwash Guidance document, and other related documents, while incorporating the PRIME enhancements to improve prediction of ambient impacts in building cavities and wake regions.29 The AERMOD modeling system is composed of three modular components: AERMAP, the terrain preprocessor; AERMET, the meteorological preprocessor; and AERMOD, the dispersion module. AERMAP is used to extract terrain elevations for selected model objects – emission points, buildings, and receptor points – and to generate the receptor hill heights that are used by AERMOD to drive advanced terrain processing algorithms. National Elevation Database (NED) data available from the U.S. Geological Survey (USGS) are utilized to interpolate surveyed elevations onto user-specified model objects in the absence of more accurate site-specific elevation data. AERMET generates separate surface file and vertical profile file to pass meteorological observations and turbulence parameters to AERMOD. AERMET meteorological data are refined for a particular analysis based on the choice of micrometeorological parameters that are linked to the land use and land cover (LULC) around the particular facility and/or meteorological site. Complete sets of model-ready meteorological data specific are created by feeding raw surface and upper air station NWS observation data to AERMET. The details of the meteorological data used in the modeling evaluation for the proposed projects are provided in Section 4.2. An assessment of the appropriate land use category of the area surrounding the OPC T.A. Smith facility was conducted. This assessment determined that use of the rural dispersion coefficients within the AERMOD model was appropriate for this analysis. Additional information is provided in Section 4.2.

25 Letter from Mr. Justin Fickas (Trinity) to Ms. Di Tian (EPD), dated October 30, 2018. A copy of the modeling protocol can be found in Appendix C.

26 Written approval provided in email correspondence from Ms. Di Tian (EPD) to Mr. Justin Fickas (Trinity) dated November 26, 2018. A copy of the modeling protocol response can be found in Appendix C.

27 40 CFR 51, Appendix WGuideline on Air Quality Models, Appendix A.1 AMS/EPA Regulatory Model (AERMOD).

28 Earth Tech, Inc., Addendum to the ISC3 User’s Guide, The PRIME Plume Rise and Building Downwash Model, Concord, MA.

29 U.S. EPA, Office of Air Quality Planning and Standards, Guidelines for Determination of Good Engineering Practice Stack Height (Technical Support Document for the Stack Height Regulations) (Revised), Research Triangle Park, North Carolina, EPA 450/4-80-023R, June 1985.


4.2. METEOROLOGICAL DATA AND LAND USE REPRESENTATIVENESS

The U.S. EPA’s federal Guideline on Air Quality Models, codified at 40 CFR 51, Appendix W, states in Section 9.3.1.2, “Meteorological Input Data – Recommendations”:

… five years of representative meteorological data should be used when estimating concentrations with an air quality model. Consecutive years from the most recent, readily available 5-year period are preferred. The meteorological data may be collected either onsite or at the nearest National Weather Service (NWS) station.

The meteorological data that are “representative” for a particular facility are typically determined subjectively, and the Guideline offers the following guidance in Section 9.3(a).

The meteorological data … should be selected on the basis of spatial and climatological (temporal) representativeness as well as the ability of the individual parameters selected to characterize the transport and dispersion conditions in the area of concern. The representativeness of the data is dependent on: (1) the proximity of the meteorological monitoring site to the area under consideration; (2) the complexity of the terrain; (3) the exposure of the meteorological monitoring site; and (4) the period of time during which data are collected. The spatial representativeness of the data can be adversely affected by large distances between the source and receptors of interest and the complex topographic characteristics of the area.

The OPC T.A. Smith facility is located in Murray County, Georgia. As outlined in the modeling protocol document (found in Appendix C), 2013-2017 meteorological data for the Lovell Field, Tennessee surface station and the Peachtree City/Falcon Field upper air station, with the use of ADJ_U*, was selected for this modeling analysis. ADJ_U* is a regulatory default option that improves overall model performance during periods of low-wind/stable conditions by adjusting the surface frictional velocity (u*) in AERMET.30

4.2.1. Representativeness Analysis

The Chattanooga Lovell Field Airport meteorological station is located at 35.0335 degrees (latitude) and -85.2016 degrees (longitude) and is approximately 45 km northwest of OPC T.A. Smith. An AERSURFACE analysis was completed to compare the surface characteristics around the facility’s location and the chosen meteorological NWS station. AERSURFACE was executed for both the facility site and the NWS station using monthly temporal resolution and the default 1 km radius domain of twelve 30-degree sectors for the roughness surface length.

30 Per e-mail correspondence with the Georgia EPD, dated October 11, 2018, no specific justification for the use of ADJ_U* is required, as that is now a default option of the AERMET meteorological data processor. Choice of meteorological data provided with modeling protocol approval dated November 26, 2018.


Figure 4-1. Comparison of Land Use Categories around the Facility and the NWS Station

Figure 4-1 and Table 4-1 provide detailed comparison of the land use categories and surface parameters at the facility site and the NWS station. The albedo shows a maximum of 13% difference. The Bowen ratio shows differences ranging from 6 to 56%. The surface roughness is similar in most sectors, with a maximum difference of 148% for any sector. Although comparison values for some sectors differ significantly for surface roughness (as would be expected for an open area such as an airport and a developed facility), the Lovell Field data is considered sufficiently representative for use for the modeling analysis.

9.98%

0.23%

0.00%

1.52%

6.62%

34.03%

6.48%

28.58%

12.13%

0.43%

0.00%

1.55%

6.33%

3.84%

30.57%

0.00%

8.25%

4.79%

12.64%

2.55%

1.32%

28.22%

0% 5% 10% 15% 20% 25% 30% 35% 40%

Open Water

Low Intensity Residential

High Intensity Residential

Commercial/Industrial/Transp

Transitional

Deciduous Forest

Evergreen Forest

Mixed Forest

Pasture/Hay

Row Crops

Urban/Recreational Grasses

Category Frequency

Airport Site


Table 4-1. Comparison of Surface Characteristics between the Facility Site and NWS Locations

4.2.2. Urban versus Rural Dispersion Options

This section describes the performance of land-use analysis for the purpose of determining the type of dispersion coefficients most appropriate for the application. The two sets of dispersion coefficients available in AERMOD are urban and rural. The goal of this land-use analysis is to estimate the percentage of urban and rural types of land cover within the study area. The study area is defined as a region centered on the site and having a radius of 3 km. The land-use types corresponding to urban areas are the “Commercial/Industrial/ Transportation” and “High Intensity Residential” types, where all other land cover types are associated with a rural setting. As specified in Section 7.2.1.1.b.i of the Guideline, a circular area with a 3 km radius centered at the OPC T.A. Smith facility was considered for the land-use analysis. AERSURFACE (version 13016) was used to extract the land-use values in the domain. The results of the land-use analysis evaluation are provided in Table 4-2.

Sector

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)Domain 0.17 0.15 0.16 0.16 0.15 0.15 0.15 0.15 -13% 0% -7% -7%

Moisture

Conditions

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)Average 0.92 0.68 0.53 0.92 0.87 0.63 0.37 0.87 -6% -8% -43% -6%Dry 2.04 1.59 1.2 2.04 1.77 1.41 0.77 1.77 -15% -13% -56% -15%Wet 0.47 0.39 0.36 0.47 0.39 0.31 0.24 0.39 -21% -26% -50% -21%

Sector

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON) 0 - 30 0.026 0.032 0.037 0.032 0.483 0.610 0.761 0.761 95% 95% 95% 96%30 - 60 0.054 0.059 0.061 0.059 0.453 0.637 0.776 0.776 88% 91% 92% 92%60 - 90 0.054 0.064 0.072 0.067 0.415 0.581 0.739 0.739 87% 89% 90% 91%90 - 120 0.049 0.063 0.077 0.067 0.519 0.723 0.924 0.924 91% 91% 92% 93%120 - 150 0.145 0.176 0.196 0.185 0.061 0.071 0.082 0.082 -138% -148% -139% -126%150 - 180 0.144 0.174 0.193 0.181 0.171 0.224 0.333 0.333 16% 22% 42% 46%180 - 210 0.046 0.056 0.064 0.057 0.284 0.393 0.615 0.615 84% 86% 90% 91%210 - 240 0.069 0.088 0.104 0.093 0.218 0.293 0.536 0.536 68% 70% 81% 83%240 - 270 0.105 0.131 0.163 0.152 0.090 0.124 0.317 0.317 -17% -6% 49% 52%270 - 300 0.065 0.085 0.124 0.114 0.227 0.304 0.526 0.526 71% 72% 76% 78%300 - 330 0.043 0.058 0.078 0.068 0.216 0.302 0.540 0.540 80% 81% 86% 87%330 - 360 0.024 0.030 0.036 0.031 0.328 0.418 0.568 0.568 93% 92.8% 94% 95%Average 0.07 0.08 0.10 0.42 0.29 0.39 0.56 0.56 76% 78% 82% 24%

"DJF" means December, January, and February "MAM" means March, April, and May"JJA" means June, July, August"SON" means September, October, November(All AERSURFACE default settings)

Surface Roughness Length (m) Surface Roughness Length (m)Lovell Field Site Difference (%): Site - Lovell Field

Bowen Ratio Bowen RatioLovell Field Site Difference (%): Site - Lovell Field

Albedo AlbedoLovell Field Site Difference (%): Site - Lovell Field


Table 4-2. Land-Use Categories Summary

This summary was generated by AERSURFACE and stored in the run’s log file. The 21 categories were evaluated according to the Guideline in terms of dispersion classes as being of URBAN or RURAL. As the data show, the domain surrounding the Smith Facility is approximately 98.6% rural. Therefore, AERMOD was evaluated considering rural dispersion coefficients.

4.3. RECEPTOR GRID COORDINATE SYSTEM

Modeled concentrations were calculated at ground-level receptors placed along the facility fenceline and on a variable Cartesian receptor grid. Fenceline receptors were spaced no more than 50 meters apart. Beyond the fenceline, receptors were placed with 100 meters spacing on a Cartesian grid extending out to a distance sufficient to resolve the maximum concentration. The assessment of the SIA utilized a 50 km receptor grid for PM10, and PM2.5 (NAAQS), and 10 km for PM2.5 Increment. For annual NO2, an approximately 15 km receptor grid was utilized. However, for the 1-hr NO2 averaging period significance modeling, it was necessary to extend the receptor grid further to the west to encapsulate all receptors which were found to exceed the 1-hr NO2 SIL.

LULC CAT Land Category Description

Number of

Grid Cells Frequency

Dispersion

Class

11 Open Water: 1233 3.9% Rural12 Perennial Ice/Snow: 0 0.0% Rural21 Low Intensity Residential: 338 1.1% Rural22 High Intensity Residential: 7 0.0% Urban23 Commercial/Industrial/Transp: 417 1.3% Urban31 Bare Rock/Sand/Clay: 0 0.0% Rural32 Quarries/Strip Mines/Gravel: 0 0.0% Rural33 Transitional: 330 1.1% Rural41 Deciduous Forest: 8990 28.6% Rural42 Evergreen Forest: 5840 18.6% Rural43 Mixed Forest: 9874 31.5% Rural51 Shrubland: 0 0.0% Rural61 Orchards/Vineyard/Other: 0 0.0% Rural71 Grasslands/Herbaceous: 0 0.0% Rural81 Pasture/Hay: 3687 11.7% Rural82 Row Crops: 608 1.9% Rural83 Small Grains: 0 0.0% Rural84 Fallow: 0 0.0% Rural85 Urban/Recreational Grasses: 67 0.2% Rural91 Woody Wetlands: 0 0.0% Rural92 Emergent Herbaceous Wetlands: 0 0.0% Rural

TOTAL 31391Rural 98.6%

Urban 1.3%


A graphical representation of the significance modeling results and the final significance modeling receptor grid utilized for the 1-hr NO2 Significance Analysis (and significant receptors found) is included in Appendix A.31

In general, the receptors covered a region extending from all edges of the OPC T.A. Smith facility ambient boundary to the point where impacts from the projects are no longer expected to be significant. The boundary is defined as all areas that are fenced, as shown in Figure 2-2.

Please note that per EPA guidance, a reduced receptor grid with only the receptors at which maximum modeled concentrations exceed the SIL is required to be used for 1-hr NO2 NAAQS modeling.32 Therefore, NAAQS modeling results, presented in Section 5 for the 1-hr NO2 NAAQS, are representative of modeled receptors for which the projects impact is significant, as determined via the Significance Analysis.

The air toxics modeling analysis, presented in Section 5 of this report, utilized 50 meter spacing for fenceline receptors and a 5 km grid surrounding the OPC T.A. Smith facility at 100 meter spacing.

Receptor elevations and hill heights required by AERMOD were determined using the AERMAP terrain preprocessor (version 18081). Terrain elevations from the USGS 1-arc second NED were used for AERMAP processing. In all modeling analysis data files, the location of emission points, structures, and receptors were represented in the UTM coordinate system, zone 16, NAD 83.

Input and output AERMAP model runs are provided in Appendix E.33

4.4. BUILDING DOWNWASH

The effects of building downwash for each of the facility’s stack emission points were evaluated in terms of the proximity of the stack to nearby structures. The purpose of this evaluation is to determine if stack discharges might become caught in the turbulent wakes of these structures leading to downwash of the plumes. Wind blowing around a building creates zones of turbulence that are greater than if the building were absent. For these modeling analyses, the direction-specific building dimensions used as input to the AERMOD model were calculated using the U.S. EPA’s BPIP PRIME, version 04274. BPIP PRIME is designed to incorporate the concepts and procedures expressed in the GEP Technical Support document, the Building Downwash Guidance document, and other related documents.34 For the BPIP analysis, the structure elevations (buildings and stacks) were estimating using the AERMAP processor (version 18081) and the 1-arc second NED maps.

31 A large 50 km receptor grid was chosen for PM10 and PM2.5 (NAAQS) to demonstrate that all potential significant receptors in the entire 50 km modeling domain were evaluated. Significant terrain features exist in the area of the facility, as shown in the receptor grid elevation plot in Appendix A. A 50 km receptor grid was not run for NO2 based on limitations of the model when evaluating NO2 versus PM2.5. This required implementation of a step-wise receptor grid addition for 1-hr NO2 compared to the initial annual NO2 15 km grid (where no significant receptors were found).

32 Additional Clarification Regarding Application of Appendix W Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard (Memorandum from Mr. Tyler Fox, U.S. EPA, to Regional Air Division Directors, March 1, 2011).

33 Files provided include the AERMAP input and output files as well as the base NED file used for the assessment.

34 U.S. EPA, Office of Air Quality Planning and Standards, Guidelines for Determination of Good Engineering Practice Stack Height (Technical Support Document for the Stack Height Regulations) (Revised), Research Triangle Park, North Carolina, EPA 450/4-80-023R, June 1985.


EPA has promulgated stack height regulations that restrict the use of stack heights in excess of “Good Engineering Practice” (GEP) in air dispersion modeling analyses. Under these regulations, that portion of a stack in excess of the GEP height is generally not creditable when modeling to determine source impacts. This essentially prevents the use of excessively tall stacks to reduce ground-level pollutant concentrations. This equation is limited to stacks located within five times the lesser dimension (5L) of a building structure. Stacks located at a distance greater than 5L from a building structure are not subject to the wake effects of the structure. The wind direction-specific downwash dimensions and the dominant downwash structures used in this analysis are determined using BPIP. In general, the lowest GEP stack height for any source is 65 meters by default.35 The BPIP evaluation indicates that none of the facility emission unit stacks exceed GEP stack height. Input and output files from the BPIP downwash analysis are provided in the electronic files included with this report in Appendix E.

4.5. MODELED EMISSION SOURCES

As discussed in Section 3 of this report, the Significance Analysis evaluates the emission increases associated with the specific projects, and does not take into consideration any regional off-site emissions sources or other facility emission sources. The NAAQS analysis considers both on-site and off-site sources of the emissions of concern. This section discusses the emission sources considered, emission rates, and modeling methods utilized in the Significance Analysis and NAAQS analysis.

4.5.1. Representation of Emission Sources

OPC T.A. Smith modeled the project-associated sources for the Significance Analysis. This includes emissions increases from the facility’s four combined cycle combustion turbine systems (CCCT1-CCCT4). As outlined in the modeling protocol, emissions from startup/shutdown (SUSD) operations of the turbines were not modeled for the Significance Analysis, as there are no anticipated changes to the facility startup cycle or increases in startup based emissions expected from the projects. Since the 1-hr NO2 Significance Analysis exceeded the SIL, a NAAQS analysis incorporating nearby sources was required (cumulative impact analysis). For the cumulative impact analysis, all sources at the facility (with the exception of the diesel-fired backup generators and diesel-fired emergency fire pump) and the appropriate regional inventory sources were included. The diesel-fired backup generators and diesel-fired emergency fire pump at the facility are intermittent sources and, therefore, do no need to be included as an emission source in the modeling analysis.36,37 OPC T.A. Smith emissions sources modeled for the 1-hr NO2 NAAQS included the facility’s four combined cycle combustion turbine systems (CCCT1-CCCT4) and two auxiliary boilers (AUX1, AUX2). As outlined in Section 4.5.2, modeling for these projects considered operations at 100% load (as the normal site operating condition), and an additional series of SUSD assessments for the 1-hr NO2 NAAQS analysis.

4.5.2. Variable Load Analysis

The source parameters for the combined cycle units (CCCT1-CCCT4) when operating at both 75% load and 100% load were developed and evaluated to determine the worst case modeled impacts for each applicable

35 40 CFR 51.100(ii)

36 Tian, Di. “Modeling Questions for Potential Project in Georgia.” Message to Justin Fickas. October 11, 2018.

37 Additional Clarification Regarding Application of Appendix W Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard (Memorandum from Mr. Tyler Fox, U.S. EPA, to Regional Air Division Directors, March 1, 2011).


pollutant. That load basis (on a pollutant by pollutant basis), as shown below in Section 5, demonstrated that the 100% load basis was the overall worst case modeling condition. Therefore, the 100% load condition was carried through as the normal operating condition in all modeling assessments for the projects, including both SIL and NAAQS evaluations.38 Source parameters for the 100% and 75% load condition, utilized in the modeling assessment, can be found in Appendix D.

4.5.3. Significance Analysis

The Significance Analysis was conducted to determine whether the emissions increases associated with the proposed projects could cause a significant impact on the air quality of the surrounding area. “Significance” is analyzed based on modeling only the emissions increases from new, modified, or associated sources comprising the projects; no existing unmodified or associated sources are included, nor are sources from other regional facilities. “Significant” impacts are defined by design concentration thresholds commonly referred to as the SIL. OPC modeled the projects associated sources for significance. For these projects, significance modeling only included CCCT1-CCCT4 at the facility, as those are the only sources that will experience an emissions increase as a direct result of the proposed projects. There are no associated emissions increases from the facility’s remaining emissions sources (i.e., auxiliary boilers, cooling towers, emergency diesel engines); therefore, those sources were not included in the Significance Analysis. For the PM10 and PM2.5 Significance Analyses, the emissions of each combined cycle system (CCCT1-CCCT4) were evaluated in the model as the difference in the future potential emissions and the past actual emissions (as derived from baseline data).39 For the NO2 Significance Analysis, due to concerns regarding the use of negative emission rates with the Tier 2 modeling options used for this analysis (discussed in Section 4.5.4), separate significance modeling runs were conducted for the future potential emissions following the projects and for the baseline past actual emissions preceding the projects. In both cases, the emissions were modeled as positive emission rates. Model plot file output data were then utilized to subtract the maximum results at each receptor for baseline actual emissions model run from the maximum results at each receptor from the future potential emissions model run for comparison to the SIL, so no negative emission rates were utilized in the dispersion modeling for NO2. Emissions for significance were evaluated as follows: 1. The post-project emissions were derived using the following methodologies:

i. For the PM10 and PM2.5 modeling assessments, potential hourly emissions for the 24-hr and annual averaging periods were based on the proposed BACT emission limit of 19.5 lb/hr per CCCT.

ii. For the 1-hr NO2 and annual NO2 modeling assessment, future potential emissions were based on the maximum hourly capacity of each combined cycle combustion turbine system (CCCT1-CCCT4) following the proposed changes, in conjunction with maximum allowable emission rate (i.e., 3 ppm at 15% O2).

38 50% load is not a normal operating condition for the facility and was, therefore, not evaluated as an operating condition for facility operations.

39 Since the pre- and post-projects stack conditions were conservatively assumed to be the same for the analysis, the difference in emissions (as opposed to using a positive and negative source) was utilized.


2. Past actual emissions were derived through: i. For NO2 modeling, CEMS data, as recorded by existing facility monitoring equipment and reported to

EPA under the Clean Air Markets Program, in combination with actual hours of operation were used to derive hourly emission rates. This data was aligned with the same baseline data as used in the NSR analysis.40

ii. For PM10/PM2.5, heat input data (MMBtu) and actual hours of operation (along with estimated emission rates in lb/MMBtu) were used to derive hourly emissions. As with NOX emissions data, this data was aligned with the same baseline data as used in the NSR analysis.

iii. OPC T.A. Smith is considered a baseline source for PM2.5 PSD Increment, as the facility was an

existing permitted and operational facility as of the PM2.5 baseline date (October 2010) for Murray

County. Therefore, for PM2.5 PSD Increment purposes, the project emissions increase considered

baseline emissions from the facility for 2009-2010 (i.e., the 2 year period preceding the baseline

date) as representative of the baseline period. Information demonstrating the derivation of the baseline source emissions, as well as tables providing the baseline modeling inputs utilized in both the significance (and NAAQS) analyses, can be found in Appendix D.

4.5.4. NO2 Modeling Approach

The revised Guideline indicates Ambient Ratio Method 2 (ARM2) has replaced ARM as the regulatory default Tier 2 NO2 modeling method. OPC has utilized ARM2 for modeling NO2 for the 1-hour and annual SIL and NAAQs modeling assessments, as applicable, using the default conversion ratios. Significance modeling utilizing ARM2 was conducted for future potential emissions and for past actual emissions, both as positive emission rates in separate modeling files, and subtracting the maximum results at each receptor manually using plot file output information. This approach was approved by the Georgia EPD as part of the modeling protocol approval process. All emissions data was input into the AERMOD model as NOX, with the model providing output results in terms of NO2. Electronic modeling files and spreadsheet data for the NO2 modeling analyses are provided in Appendix E.

4.5.5. Startup/Shutdown Modeling (1-hr NO2 NAAQS)

As discussed in Section 4.5.1, SUSD modeling was not conducted for significance modeling, as there are no changes to the facility emission units that would have an influence on the duration of a startup event or an increase in startup emissions. Only normal source operating conditions are expected to change as part of the proposed facility changes. However, modeling of SUSD events was considered for the refined modeling analysis for the 1-hr NO2 NAAQS (which was the only pollutant and averaging period to exceed the SIL). Details regarding the SUSD modeling are as follows.41 1. Two startup times, one at 4 AM and one at 10 AM, were included as separate modeling runs in the modeling

assessment. These are expected high frequency startup times for OPC T.A. Smith. In the assessment, the startup times of each combined cycle block (CCCT1-CCCT2, CCCT3-CCCT4) were assumed to be starting up

40 As noted in Volume I of this application, a historic baseline period was conservatively considered for the NSR analysis (2011-2013). As such, the average actual emissions from the last 2 years of operation were not used for the modeling analysis. Instead, the more conservative actual emissions data from the same baseline period (2011-2013) as the NSR analysis was used to estimate facility actual NOX emissions.

41 SUSD modeling procedures were addressed in the October 30, 2018 modeling protocol submitted to the Georgia EPD.


simultaneously. This is a highly conservative evaluation of the startup emissions; actual site operational practices during cold starts involve no more than two turbines starting simultaneously.

2. A cold startup cycle (approximately 4 hours) was the focus of the SUSD modeling, as it is the worst case SUSD condition based on the emissions and duration of startup.

3. Startup source parameters (velocity/temperature/emissions) were developed for each hour of the startup cycle based on available vendor data.

4.5.6. Tier 1 Analysis - Consideration of Modeled Emission Rates for Precursors (MERPs)

In accordance with the revised and updated 40 CFR 51, Appendix W, precursor emission impacts to ozone and PM2.5 (secondary PM2.5) must be considered as part of the modeling analysis. The precursors to ground-level ozone formation are VOC and NOX, and the precursor emissions for secondary PM2.5 formation are NOX and SO2. Georgia EPD guidance, as part of the February 2019 Guidance on the Use of EPA’s MERPs to Account for Secondary Formation of Ozone and PM2.5 in Georgia was followed, as outlined in the following sections.

4.5.6.1. Ozone MERPS Assessment

As outlined in Table 2 of the EPD February 2019 guidance, the default MERP values (tpy) for Georgia PSD applications are 156 tpy NOX and 3,980 tpy VOC for 8-hr ozone. Per Equation 2 of the EPD guidance, the SIL analysis demonstration for the proposed projects at OPC T.A. Smith is as follows;

(127.5 tpy NOX project emissions increase / 156 tpy NOX 8-hr O3 MERP) + (36 tpy VOC project emissions increase / 3,980 tpy VOC 8-hr O3 MERP) = 0.82 + 0.01 = 0.83

As the predicted ozone value is less than the threshold value of 1, the predicted impact of the projects is less than the ozone SIL (1 ppb). Therefore, there are no adverse impacts associated with precursor emissions for ozone as part of these projects, and a cumulative ozone analysis is not required.

4.5.6.2. PM2.5 MERPS Assessment

As outlined in Table 2 of the EPD February 2019 guidance, the default MERP values (tpy) for Georgia PSD applications are 4,014 tpy NOX, and 667 tpy SO2 for daily PM2.5, and 7,427 tpy NOX and 6,004 tpy SO2 for annual PM2.5. Per Example 1 of the EPD guidance, the SILs analysis demonstration is as follows; For annual PM2.5:

(127.5 tpy NOX project emissions increase / 7,427 tpy NOX Annual MERP) + (14.5 tpy SO2 project emissions increase / 6,004 tpy SO2 Annual MERP) = 0.0172 + 0.0024 = 0.0196 × 100% = 1.96%

This effectively means, that so long as direct modeled impacts of annual PM2.5 are less than 98% of the PM2.5 SIL (0.2 µg/m3), then impacts from the projects are acceptable and less than the SIL when considering the additive secondary PM2.5 on an annual basis for Class II modeling. This also means that there is a default secondary PM2.5 modeled impact of 0.004 µg/m3 (1.96% of 0.2 µg/m3) that could be applied to Class I SIL increment modeling for PM2.5, for the annual averaging period. For daily PM2.5:


(127.5 tpy NOX project emissions increase / 4,014 tpy NOX Daily MERP) + (14.5 tpy SO2 project emissions increase / 667 tpy SO2 Daily MERP) = 0.0318 + 0.0217 = 0.0535 × 100% = 5.35%

This effectively means, that so long as direct modeled impacts of daily PM2.5 are less than 94.65% of the PM2.5 SIL (1.2 µg/m3), then impacts from the projects are acceptable and less than the SIL when considering the additive secondary PM2.5 on an annual basis for Class II modeling. This also means that there is a default secondary PM2.5 modeled impact of 0.064 µg/m3 (5.35% of 1.2 µg/m3) that could be applied to Class I SIL increment modeling for PM2.5, for the daily averaging period. The above considerations of additive effects of secondary PM2.5 to direct primary PM2.5 should be considered highly conservative, since it is highly unlikely that there would be temporal and spatial alignment of primary and secondary PM2.5 impacts, particularly for the short term 24-hr averaging period in the near field of the OPC T.A. Smith facility, where modeled primary PM2.5 impacts are at their highest.

4.5.7. Class I Visibility Analysis

Visibility can be affected by plume impairment (heterogeneous) or regional haze (homogeneous). Plume impairment results when there is a contrast or color difference between the plume and a viewed background (the sky or a terrain feature). Plume impairment is generally only of concern when the Class I area is near the proposed source (i.e., less than 50 km). Since the distance between the Smith facility and the Cohutta Wilderness is less than 50 km plume impairment was considered. Cohutta is the only Class I area within 50 km of the OPC T.A. Smith site. As discussed previously, regional haze (occurs at distances beyond 50 km) was not addressed for these projects given the low Q/D ratios associated with the proposed increases.42

4.5.7.1. Plume Impairment

The Cohutta Wilderness is within 50km of the Smith facility. As such, OPC T.A. Smith utilized the VISCREEN model to estimate plume blight at the nearest Class I receptor location as well as at a distance of 50 km to ensure that plume impairment will remain at acceptable levels. A Level 2 analysis was performed, using the worst-case 1% meteorological conditions along with all other Level 1 default values in VISCREEN as described in U.S. EPA’s Workbook.43 The background visual range used was the average of the monthly values included in Table 10 of the FLAG 2010 Guidance document.44 The worst-case 1% meteorological conditions were determined for over 5 years of representative meteorological data from Chattanooga, TN. Table 4-3 presents the summary of the worst-case meteorological data analysis. As shown, the combination of stability class “C” and wind speed of 3 m/s yields the 1% cumulative frequency condition.

42 See Section 3.5 for information regarding correspondence with the FLM for Cohutta, on this issue.

43 U.S. EPA, Workbook for Plume Visual Impact Screening and Analysis (Revised), Research Triangle Park, North Carolina, EPA-454/R-92-023, October 1992.

44 U.S. Forest Service, National Park Service, and U.S. Fish and Wildlife Service, Federal Land Managers’ Air Quality Related Values Work Group (FLAG) Phase I report – Revised (2010). National Resource Report NPS/NRPC/NRR-2010/232. National Park Service, Denver, Colorado. November 2010.


Table 4-3. Worst-Case Meteorological Conditions

Wind

Stability Speed

Class (m/s) f cf f cf f cf f cf

F 2 0.22% 0.22% 0.02% 0.02% 0.00% 0.00% 0.14% 0.14%

F 3 0.07% 0.29% 0.00% 0.03% 0.00% 0.00% 0.07% 0.21%

E 2 0.01% 0.29% 0.04% 0.06% 0.00% 0.00% 0.04% 0.25%

E 3 0.04% 0.34% 0.02% 0.08% 0.00% 0.01% 0.12% 0.36%

D 2 0.06% 0.39% 0.10% 0.18% 0.04% 0.05% 0.05% 0.42%

E 4 0.03% 0.42% 0.00% 0.18% 0.01% 0.06% 0.06% 0.48%

E 5 0.01% 0.43% 0.00% 0.19% 0.00% 0.06% 0.01% 0.49%

D 3 0.10% 0.53% 0.21% 0.39% 0.18% 0.24% 0.15% 0.64%

D 4 0.05% 0.58% 0.13% 0.53% 0.16% 0.40% 0.11% 0.75%

D 5 0.04% 0.62% 0.07% 0.60% 0.14% 0.54% 0.05% 0.80%

D 6 0.02% 0.64% 0.07% 0.67% 0.20% 0.73% 0.04% 0.84%

C 2 0.00% 0.64% 0.08% 0.74% 0.02% 0.75% 0.02% 0.85%

D 7 0.02% 0.66% 0.03% 0.77% 0.10% 0.86% 0.01% 0.86%

D 8 0.00% 0.66% 0.01% 0.78% 0.04% 0.89% 0.00% 0.86%

C 3 0.00% 0.66% 0.08% 0.86% 0.13% 1.03% 0.00% 0.86%

C 4 0.00% 0.66% 0.05% 0.91% 0.14% 1.16% 0.00% 0.86%

C 5 0.00% 0.66% 0.05% 0.96% 0.18% 1.35% 0.00% 0.86%

B 2 0.00% 0.66% 0.04% 1.00% 0.08% 1.43% 0.00% 0.86%

C 6 0.00% 0.66% 0.05% 1.05% 0.09% 1.52% 0.00% 0.86%

C 7 0.00% 0.66% 0.01% 1.05% 0.02% 1.54% 0.00% 0.86%

C 8 0.00% 0.66% 0.00% 1.06% 0.00% 1.55% 0.00% 0.86%

B 3 0.00% 0.66% 0.08% 1.14% 0.09% 1.64% 0.00% 0.86%

C 9 0.00% 0.66% 0.00% 1.14% 0.00% 1.64% 0.00% 0.86%

C 10 0.00% 0.66% 0.00% 1.14% 0.00% 1.64% 0.00% 0.86%

C 11 0.00% 0.66% 0.00% 1.14% 0.00% 1.64% 0.00% 0.86%

B 4 0.00% 0.66% 0.07% 1.20% 0.13% 1.76% 0.00% 0.86%

C 12 0.00% 0.66% 0.00% 1.20% 0.00% 1.76% 0.00% 0.86%

B 5 0.00% 0.66% 0.03% 1.23% 0.04% 1.80% 0.00% 0.86%

A 2 0.00% 0.66% 0.01% 1.24% 0.02% 1.82% 0.00% 0.86%

Frequency (f) and Cumulative Frequency (cf) of Occurrence (in %)

1-6 7-12 13-18 19-24


5. SUMMARY OF RESULTS

This section summarizes the results of the dispersion modeling analyses. Electronic copies of modeling files are included in Appendix E.

5.1. CCCT LOAD ANALYSIS

As discussed in Section 4.5.2, a load analysis evaluating modeled impacts at 100% and 75% load for facility’s four combined cycle combustion units was conducted. The results of that analysis are shown in Table 5-1.

Table 5-1. CCCT Load Analysis

Based on the results above, although in one of the six potential significance based analyses (evaluation of H1H) 100% load was not the worst case, in 5 of the 6 analyses the 100% load condition was shown to the be worst case modeling condition. Differences shown for PM2.5 and PM10 for 100% load case and 75% load case are a function of the difference in averaging methods between 24-hr PM2.5 and PM10 (i.e., evaluating across five years for the H6H value). As the majority of results tended towards 100% load being the worst case modeled condition for the CCCT units, 100% load was selected as the modeled steady-state operating condition for all significance and NAAQS analyses.

5.2. CLASS II AND CLASS I SIGNIFICANCE ANALYSES

As discussed in Sections 3.1 and 3.5, Significance Analyses for Class II and Class I areas, respectively, were conducted to determine the need for further pollutant modeling. Modeled emission points, parameters, and emission rates for the Significance Analyses are provided in Appendix D. The results of the Significance Analyses for each pollutant are provided in the following tables and represent the maximum modeled concentrations from the significance runs. For pollutants and averaging periods modeled with separate meteorological files for the five year period evaluated, the “Year” listed in the tables corresponds to the individual year for which maximum impacts were observed. All modeled results reported for the Significance Analysis correspond to H1H modeled impacts.

PollutantAveraging

Period

75%

LOAD

100%

LOAD

Is 100%

Worst-

case?

Modeled

Output

Concatenated

MET Data?

75%

LOAD100% LOAD

Is 100%

Worst-

case?

Modeled

Output

Concatenated

MET Data?

1-hour 51.02 61.04 YES H1H Yes 41.00 49.02 YES H8H Yes

Annual 0.53 0.58 YES H1H No

24-hour 3.61 4.19 YES H1H Yes 2.39 2.18 NO H6H Yes

Annual 0.32 0.34 YES H1H No

24-hour 2.67 2.52 NO H1H Yes 1.47 1.63 YES H8H Yes

Annual 0.29 0.31 YES H1H Yes

NO2

PM10

PM2.5


Table 5-2. Class II Significance Results for PM10 and PM2.5

As shown in Table 5-2, all direct modeled PM2.5 impacts, as well as PM10 modeled impacts, are less than the applicable Class II SILs. Further, as noted in the MERPs analysis in Section 4.5.6, the modeled impacts for annual and 24-hr PM2.5 are also below the Class II SILs when conservatively considering both direct and secondary PM2.5 modeled impacts (e.g. less than 98% of the annual SIL, and 94.65% of the 24-hr SIL). As such, by definition, the projects does not cause or contribute to an exceedance of the NAAQS or Class II Increment for PM2.5 or PM10. Also, as can be seen from Table 5-2, PM10 predicted modeled impacts for the projects are below the 10 µg/m3 SMC for the 24-hr averaging period.

Table 5-3. Class II Significance Results for NO2

As shown in Table 5-3, the annual NO2 modeled impacts for the projects were less than the Class II SIL, but the 1-hr average NO2 modeled impacts for the projects exceeded the SIL. As previously described in Section 4.5.3 and 4.5.4, modeled results for the Significance Analysis for NO2 (annual and 1-hr) were evaluated using separate model runs for future potential and for past actual emissions. Those model runs, provided in Appendix E, are annotated along with connotations of “PAST” or “FUTURE” to signify which model run is for which situation. As these model runs utilized ARM2, maximum modeled results were evaluated (FUTURE – PAST), on a receptor by receptor basis, to compare to the significance modeling results. Accompanying spreadsheets in the electronic modeling files within Appendix E include the receptor by receptor analysis (data extracted from NO2 modeling plot files) to derive the final significance results displayed in Table 5-3. 45

45 As shown in spreadsheet documentation in Appendix E, as well as a graphical illustration in Appendix A, significant receptors for the 1-hr NO2 significance analysis extended approximately 31.4 km from the facility. As can be seen in Appendix A, the significant receptors are not contiguous due to the complex terrain features in the area of the facility.

Pollutant

Averaging

Period Year

Modeled Conc.

(µg/m3)

SIL

(µg/m3)

Exceeds

SIL?

Modeled

Percentage

of SIL (%)

24-Hour 5-yr avg. 0.65 1.2 No 54.5%

Annual 5-yr avg. 0.083 0.2 No 41.3%

24-Hour 2017 0.76 1.2 No 63.3%

Annual 2017 0.06 0.2 No 30.0%

24-Hour 2017 1.10 5 No 22.0%

Annual 2017 0.09 1 No 9.0%PM10

PM2.5 (for

NAAQS)PM2.5 (for

Increment)

Pollutant

Averaging

Period Year

Modeled

Conc.

(µg/m3)

SIL

(µg/m3)

Exceeds

SIL?

Modeled

Percentage

of SIL (%)

1-Hour 5-yr avg. 28.74 7.5 Yes 383.2%

Annual 2017 0.27 1 No 27.0%NO2


Table 5-4. Class I Significance Results for PM10, PM2.5, and NO2

As shown in Table 5-4, the direct modeled impacts were below the applicable Class I SILs for both the receptors within the Cohutta Wilderness and along the 50 km-radius ring of receptors evaluated in AERMOD (both within the same model run files, provided in Appendix E). If conservatively accounting for the secondary PM2.5 predicted highest impacts, as outlined previously in Section 4.5.6, in addition to the direct PM2.5 modeled concentrations shown in Table 5-4, the total PM2.5 impacts would still be below the Class I SILs for PM2.5.

5.3. NAAQS ANALYSIS

A NAAQS modeling analysis was only conducted for the 1-hr NO2 NAAQS, as that was the only applicable pollutant and averaging period for which the Significance Analysis results exceeded the Class II SIL. As described above in Section 4.3, the NAAQS analysis for 1-hr NO2 utilized the significant receptors (as derived from the Significance Analysis) for use in the NAAQS modeling analysis for three different cases. 1. Normal site operations at 100% load for the entire day. 2. SUSD for facility CCCT units starting at 4 AM, with normal operation for the remainder of the day. 3. SUSD for facility CCCT units starting at 10 AM, with normal operation for the remainder of the day. SUSD modeling was conducted utilizing the HROFDY functionality of the AERMOD model, conservatively assuming that a SUSD event would occur every day starting at either 4 AM or 10 AM. Modeling source parameters utilized in the NAAQS modeling assessment can be found in Appendix D. The 1-hr NO2 NAAQS analysis included the facility CCCT units, auxiliary boilers, and off-site inventory sources as outlined in Section 3.5 of this report. Modeling results representing the H8H modeled impacts for each of the three cases evaluated are summarized in Table 5-5.

Pollutant

Averaging

Period Year

Modeled

Conc.

(µg/m3)

SIL

(µg/m3)

Exceeds

SIL?

Modeled

Percentage

of SIL (%)

24-Hour 2016 0.20 0.27 No 72.6%

Annual 2013 0.013 0.05 No 26.0%

24-Hour 2016 0.20 0.3 No 65.4%

Annual 2013 0.01 0.2 No 6.5%

0.06 0.1 No 60.0%

PM2.5

PM10

NO2 Annual 2013


Table 5-5. 1-hr NO2 NAAQS Analysis Results

As the data show, predicted modeled impacts for the 1-hr NO2 NAAQS analysis demonstrated that the OPC T.A. Smith facility will not cause or contribute to any violations of the NAAQS.

5.4. SOIL AND VEGETATION IMPACTS

Two comparisons were used to address potential soil and vegetation impacts. First, the significance results for modeled criteria pollutants (PM2.5, PM10, and NO2) were assessed against the secondary NAAQS standards, which provide protection for public welfare, including protection against decreased visibility, damage to animals, crops, vegetation, and buildings. Second, modeled impacts for air toxics impacts were compared against conservative screening levels provided by the EPA specifically to address potential soil and vegetation impacts.46 As shown in Table 5-6, the impacts for each pollutant are below the applicable secondary NAAQS or the EPA screening levels. Thus, there are no adverse impacts expected on soils or vegetation as a result of the proposed projects.

46 U.S. EPA, A Screening Procedure for the Impacts of Air Pollution Sources on Plants, Soils, and Animals (EPA 450/2-81-078), 1981.

Pollutant Scenario Year

Modeled

Conc.

(µg/m3)

Background

Conc.

(µg/m3)

Total Conc.

(µg/m3)

NAAQS

(µg/m3)

Exceeds

NAAQS?

Modeled

Percentage

of NAAQS

(%)

113.5

147.8

113.5 60.4%

5-yr avg.

30.3

188

188

No

No

60.4%

78.6%

100% Load

4 AM Startup 5-yr avg.

30.383.21

117.48 30.3

10 AM Startup 5-yr avg. 83.21 188 No

NO2

NO2

NO2


Table 5-6. Soil and Vegetation Impacts

5.5. TOXIC IMPACT ASSESSMENT

EPD regulates the emissions of toxic air pollutants (TAP) through a program approved under the provisions of GRAQC Rule 391-3-1-.02(2)(a)3(ii). A TAP is defined as any substance that may have an adverse effect on public health, excluding any specific substance that is covered by a State or Federal ambient air quality standard. Procedures governing the EPD’s review of toxic air pollutant emissions as part of air permit reviews are contained in EPD’s Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions (TAP Guideline).47

According to the TAP Guideline, dispersion modeling should be completed for each potentially toxic pollutant having quantifiable emissions above the MER for that pollutant, provided in Appendix A of the TAP Guideline.

47 Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions. Georgia Department of Natural Resources, Environmental Protection Division, Air Protection Branch, Revised, May 2017.

Total Vegetation Sensitivity2

Secondary Minimum

Pollutant

Averaging

Period

Concentration1

(µg/m3)

Sensitive

(µg/m3)

Intermediate

(µg/m3)

Resistant

(µg/m3)

NAAQS

(µg/m3)

Threshold

(µg/m3)

NO24

4-Hour - 3,760 6,400 16,920 N/A 3,760 No

8-Hour - 3,760 7,520 15,040 N/A 3,760 No

1-Month - - 564 - N/A 564 No

Annual 0.27 - 94 - 94 No

PM104

24-hour 1.10 - - - 150 150 No

Annual 0.09 - - - 50 50 No

PM2.54

24-hour 0.65 - - - 35 35 No

Annual 0.08 - - - 15 15 No

SO23 1-hour - 917 - - N/A 917 No

3-hour - 786 2,096 13,100 1,300 786 No

Annual - - 18 - N/A 18 No

CO31-wk - 1,800,000 - 18,000,000 N/A 1,800,000 No

H2S3 4-hour - 28,000 - 560,000 N/A 28,000 No

Ethylene33-hour - - 47 - N/A 47 No

24-hour - - 1.2 - N/A 1.2 No

Fluorine310-Days - - 0.5 - N/A 0.5 No

Beryllium31-Month - - 0.01 - N/A 0.01 No

Lead33-Months - - 1.5 - 0.15 0.15 No

1. Model results from the Significance Analysis.

Threshold

Exceeded?

2. Screening concentrations based on Table 3.1 in "A Screening Procedure for Impact of Air Pollution Sources on Plants, Soil and Animals" , EPA, December 12, 1980.

Minimum values noted if range listed.

3. Modeling was not required for SO2, CO, H2S, ethylene, fluorine, beryllium, and lead for this project. Hence, compliance with these limits is inherent.

4. Results from the PM10 (24-hour and annual), PM2.5 (24-hour and annual), and NO2 (annual) SIL runs were used since a NAAQS analysis was not required.


The TAP Guideline infers that a pollutant is identified as a toxic pollutant if any of the following toxicity-determined values have been established for that pollutant:

EPA Integrated Risk Information System (IRIS) reference concentration (RfC) or unit risk; Occupational Safety and Health Administration (OSHA) Permissible Exposure Limits (PEL); American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Values (TLV); and National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limits (REL); Lethal Dose – 50% (LD50) Standards.

The TAP Guideline specifies that the resources should be referenced in the priority schedule listed above to determine long-term and short-term acceptable ambient concentrations (AACs) based on the exposure limits that are provided. Per the TAP Guideline under “Procedures for Demonstrating Compliance with AAC,” the general procedure for determination of TAPs impact is a simple comparative method:

If the facility-wide emission rate for a given TAP is below the MER established in the table in Appendix A, no further analysis is required for that TAP.

If the facility-wide emission rate for a given TAP is above the MER established in the table in Appendix A, further analysis is required for that TAP.

As described in the Volume I report, the OPC T.A. Smith facility developed a maximum annual emission rate for all listed TAPs for which MER thresholds have been established. Table 5-7 summarizes the facility-wide emission rates for each TAP in comparison to their respective MERs.


Table 5-7. Facility-Wide TAP Emissions and Respective MER

Based on the comparison of TAPs emitted by the facility to the MERs, multiple pollutants required a direct modeling evaluation in comparison to the AACs, as published by the Georgia EPD as part of the current version of Appendix A (revised October 2018) to the TAP Guideline. The modeling assessment was done using the latest version of the EPA AERMOD model (version 18081) with the CCCT parameters at 100% load. Modeled source parameters for the toxics modeling assessment can be found in Appendix D of this report. A summary of the air toxics modeling results, with use of AERMOD, is provided in the following table. Modeling files for the air toxics modeling assessment, can be found in Appendix E.

Annual

Emissions

Annual

Emissions1

Minimum

Emission Rate

(MER)2

(tpy) (lb/yr) (lb/yr) Above MER?

Arsenic 2.02E-03 4.05 5.67E-02 YesAmmonia 3.68E+02 735,840.00 2.43E+04 YesBeryllium 1.21E-04 0.24 0.97 NoCadmium 1.11E-02 22.2 1.35 YesAcrolein 2.08E-01 417 4.87 YesLead -- -- 5.84 No1,3-Butadiene 1.40E-02 28.0 7.30 YesCobalt 8.49E-04 1.70 11.7 NoManganese 3.84E-03 7.69 12.2 NoSelenium 2.43E-04 0.49 23.4 NoChromium 1.42E-02 28.3 24.33 YesBenzene 4.14E-01 829 31.6 YesNickel 2.12E-02 42.5 38.6 YesBarium 4.45E-02 89.0 57.9 YesMercury 2.63E-03 5.26 73.0 NoCopper 8.60E-03 17.2 117 NoSulfuric Acid 4.28 8,556 117 YesFormaldehyde 5.82 11,648 267 YesPropylene Oxide 9.45E-01 1,889 657 YesNaphthalene 4.89E-02 97.8 730 NoAcetaldehyde 1.30 2,606 1,107 YesMolybdenum 1.11E-02 22.2 1,738 NoXylenes 2.09 4,170 24,333 NoHexane 2.87 5,739 170,331 No1,4-Dichlorobenzene 1.21E-02 24.3 194,664 NoPropane 16.2 32,361 208,600 NoEthylbenzene 1.04 2,084 243,330 NoPentane 26.3 52,586 341,858 NoToluene 4.27 8,539 1,216,650 No

2. From EPD's Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions, updated October 2018.

Toxic Air Pollutant

(TAP)

1. Annual Emissions (lb/yr) = Annual Emissions (ton/yr) * 2,000 lb/ton.


Table 5-8. Summary of Toxics Modeling Analysis Results

The maximum 15-min average impact was calculated by adjusting the maximum modeled 1-hour impact using the multiplying factor in the TAP Guideline (factor of 1.32). As shown in Table 5-8, the impacts of toxic air pollutants evaluated from the facility’s operations are below all applicable AACs.

5.6. VISCREEN MODELING ASSESSMENT – COHUTTA WILDERNESS

As discussed in Section 4.5.7, a VISCREEN Level 2 modeling assessment was conducted for the Cohutta Wilderness Class I area. The results of the Level 2 VISCREEN analysis are summarized in Table 5-9, which presents the information shown below:

Background: the background against which the plume is viewed (either sky or terrain) Theta: the sun elevation angle above the horizon (0 degrees is when the sun is on the horizon in front of the

observer, 90 degrees is directly overhead and 180 degrees is when the sun is on the horizon behind the observer.

Azimuth: the angle between the line of sight and the line connecting the source and observer (an azimuth angle of zero implies that the observer is looking directly toward the source)

Distance: the distance from the source to the point at which the observer’s line of sight intersects the plume

Alpha: the angle between the light of sight and the plume centerline E Critical: the perceptibility screening threshold (2.0)48 E Plume: the maximum modeled plume perceptibility Contrast Critical: the contrast screening threshold (0.05)37 Contrast Plume: the maximum modeled plume contrast

48 In some cases, VISCREEN changes critical delta E and contrast depending on input parameters, however, compliance was determined based on the default screening levels of 2.0 and 0.05, respectively.

Maximum

Annual Impact Annual AAC

Maximum

24-Hour Impact 24-Hour AAC

Maximum

1-Hour Impact

Maximum

15-Minute Impact2

15-Minute AAC

µg/m3 µg/m

3% of AAC µg/m3 µg/m3

% of ACC µg/m3 µg/m3 µg/m3% of AAC

Arsenic 1.00E-05 2.33E-04 4% N/A 1.40E-04 1.85E-04 2.00E-01 0%Ammonia 3.42E-01 1.00E+02 0% N/A 1.83E+01 2.42E+01 2.40E+03 1%Cadmium 4.00E-05 5.56E-03 1% N/A 7.50E-04 9.90E-04 3.00E+01 0%Acrolein 2.10E-04 2.00E-02 1% N/A 1.10E-02 1.45E-02 2.30E+01 0%1,3-Butadiene 1.00E-05 3.00E-02 0% N/A 7.40E-04 9.77E-04 1.10E+03 0%Chromium 5.00E-05 1.00E-01 0% N/A N/ABenzene 4.20E-04 1.30E-01 0% N/A 2.19E-02 2.89E-02 1.60E+03 0%Nickel N/A 4.40E-04 7.94E-01 0% N/ABarium N/A 9.30E-04 1.19E+00 0% N/ASulfuric Acid N/A 3.98E-02 2.40E+00 2% 2.28E-01 3.01E-01 3.00E+02 0%Formaldehyde 6.15E-03 1.10E+00 1% N/A 3.11E-01 4.11E-01 2.45E+02 0%Propylene Oxide 9.30E-04 2.70E+00 0% N/A N/AAcetaldehyde 1.29E-03 4.55E+00 0% N/A 1.15E-02 1.52E-02 4.50E+03 0%

1. AAC values from EPD's Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions (Guideline) , updated October 2018.

2. Maximum 15-Minute Impact equals the Maximum 1-Hour Impact multiplied by 1.32 per the Guideline.

Toxic Air Pollutant

(TAP)


Table 5-9. VISCREEN Modeling Results

As shown, the proposed projects will have no adverse effect on visibility at the Cohutta Wilderness. Modeling files for the assessment can be found in Appendix E of this modeling report.

Background Theta Azi Distance Alpha Crit Plume Crit Plume

Sky 10 153 50 16 7.15 0.170 0.14 0.003

Sky 140 153 50 16 3.73 0.052 0.14 -0.002

Terrain 10 84 30 84 8.12 0.355 0.27 0.002

Terrain 140 84 30 84 4.56 0.020 0.27 0

Delta E Contrast

Oglethorpe Power Corporation | Advanced Gas Path/Minimum Load Project PSD Permit Application Volume II Trinity Consultants A

APPENDIX A: FIGURES

Appendix A – List of Figures

Figure No.

Figure Description

Figure A-1

Facility Area Map

Figure A-2

Boundary Receptors

Figure A-3

Facility Layout – Buildings & Sources

Figure A-4

Receptor Grid Elevations

Figure A-5 PM2.5 Maximum 24-Hour Class I Area SIL Impacts (2016)

Figure A-6 PM10 Maximum 24-Hour Class II Area SIL Impacts (2017)

Figure A-7 PM10 Maximum Annual Class II Area SIL Impacts (2017)

Figure A-8 PM2.5 Maximum 24-Hour Class II Area SIL Impacts (5-Year Average)

Figure A-9 PM2.5 Maximum Annual Class II Area SIL Impacts (5-Year Average)

Figure A-10 NO2 Significant Receptor Grid

,..-._

8 '-' bJl = :.a .... ""' 0 z ~ E-< ;::J

Figure A-1. Facility Area Map Thomas A. Smith Energy Facility - Dalton, Georgia

3,846,000

3,845,000

3,844,000

3,843,000

3,842,000

3,84 1,000

3,840,000

3,839,000

3,838,000

3,837,000

3,836,000

3,835,000 I:IIL....l.....l..>.--I.J....W......J..U.......___.Ll.L.JI....C.......s:oi=:...J~L...L ........ l...-:-...1.-~l..o..,;L...l:::l.L........a~~_._..lll.:~>.L.::;....:.J~~....l....;;&~..:....J-L.......J...J.........a.:::::....l.~

682,000 683,000 684,000 685,000 686,000 687,000 688,000 689,000 690,000 691,000 692,000 693,000 694,000 695,000 696,000 697,000

UTM Easting (m)

Coordinates reflect UTM projection Zone 16, NAD83 . Tt . . ~

~ norltyl:.. \_Wnsu tants

3,842,800

s '-" 3,842,750 b1l

= :a -s.. 0 z ~ 3,842,700

;:;

3,842,650

3,842,600

3,842,550

3,842,500

3,842,450

690,450 690,500

Figure A-2. Boundary Receptors Thomas A. Smith Energy Facility - Dalton, Georgia

690,550 690,600 690,650 690,700 690,750

Coordinates reflect UTM projection Zone 16, NAD83. UTM Easting (m)

690,800 690,850

Tt . . !\ n. f).;nty h... UJDSUltahts

'"""' 8 '--' t:>Jl

= :.c .... "" 0 z ~ ~ ;;::>

3,842,700

3,842,650

3,842,600

3,842,550

3,842,500

3,842,450

Figure A-3. Facility Layout- Buildings & Sources Thomas A. Smith Energy Facility -Dalton, Georgia

[RJ II

c=Jo

u 0

~~ c::::::J

D 0 0 D

D D

D D D

D D D D

690,400 690,450 690,500 690,550 690,600 690,650 690,700 690,750


0

0

oO 0

IAUX 1

Tt . . ~

n.. 1!-!fltyh... \...Wnswtants

6 3,850,000 '-" b.() c

:.= ..... 1-0 z 3,840,000

~ f-; ;:l

3,830,000

3,820,000

3,810,000

3,800,000

3,790,000

3,780,000

640,000

Figure A-4. Receptor Grid Elevations Thomas A. Smith Energy Facility - Dalton, Georgia

- -- ,7

~

166 ill 215 ill 232 ill 285 ill 412 ill

650,000 660,000 670,000 680,000 690,000 700,000 710,000 720,000

Coordinates reflect UTM projection Zone 16, NAD83. UTM Easting (ill)

1062 ill

730,000 740,000

li . . ~ n... nn1 1ty~ \...k)nsu rants

8 3,850,000 '-" OJl l:l

:.= ..... l-z 3,840,000

~ E-< ~

3,830,000

3,820,000

3,810,000

3,800,000

3,790,000

3,780,000

0 ug/m3

Figure A-5. PM2.s Maximum 24-Hour Class I Area SIL Impacts (2016) Thomas A. Smith Energy Facility -Dalton, Georgia

. --- --

0.03 ug/m3 0.05 ug/m3 0.08 ug/m3

-1-:' :~

0.11 ug/m3 0.18 ug/m3

640,000 650,000 660,000 670,000 680,000 690,000 700,000 710,000 720,000 730,000 740,000


8 3,850,000 '-" ell c :a ...... loo 0 z 3,840,000

~ E-o ~

3,830,000

3,820,000

3,810,000

3,800,000

3,790,000

3,780,000

640,000

0.01 ug/m3

650,000

Figure A-6. PM10 Maximum 24-Hour Class II Area SIL Impacts (2017) Thomas A. Smith Energy Facility - Dalton, Georgia

··$. - --- - -

~·

"" ' {..

0.07 ug/m3 0.12 ug/m3 0.25 ug/m3 0.50 ug/m3 1.10 ug/m3

660,000 670,000 680,000 690,000 700,000 710,000 720,000 730,000 740,000

Coordinates reflect UTM projection Zone 16, NAD83. UTM Easting (m) Tt . . ~

n... nni tty/.!.. UJDSU tants

s 3,850,000 '-' ~ = :.a -'"' 0 z 3,840,000

~ E-o ~

3,830,000

3,820,000

3,810,000

3,800,000

3,790,000

3,780,000

640,000

0 ug/m3

650,000

FigureA-7. PM10 Maximum Annual Class II Area SIL Impacts (2017) Thomas A. Smith Energy Facility - Dalton, Georgia

---~- - - - -

"' {" . J'.-. -

0.02 ug/m3 0.04 ug/m3 0.05 ug/m3 0.07 ug/m3 0.09 ug/m3

660,000 670,000 680,000 690,000 700,000 710,000 720,000 730,000 740,000

Coordinates reflect UTM projection Zone 16, NAD83 . UTM Easting (m) Tt . . ~

n.. f).!f.lty 1:_ \.JilllSWtahts

8 3,850,000 '-' b.()

I: :.a .....

1-o 0 z 3,840,000

:; ~ ;:l

3,830,000

3,820,000

3,810,000

3,800,000

3,790,000

3,780,000

640,000

Figure A-8. PM2.5 Maximum 24-Hour Class II Area SIL Impacts (5-Year Average) Thomas A. Smith Energy Facility - Dalton, Georgia

Jr~ ---

> .... 0.01 ug/m3 0.06 ug/m3 0.11 ug/m3 0.21 ug/m3 0.3 1 ug/m3 0.65ug/m3

650,000 660,000 670,000 680,000 690,000 700,000 710,000 720,000 730,000 740,000

Coordinates reflect UTM projection Zone 16, NAD83. UTM Easting (m) Tt . . ~

n... nui1tyh.. \..k>llSU tahts

FigureA-9. PM2.5 Maximum Annual Class II Area SIL Impacts (5-Year Average) Thomas A. Smith Energy Facility - Dalton, Georgia

8 3,850,000 '-' tlJl = ~ 0 z 3,840,000

~ E;:J

3,830,000

3,820,000

3,810,000

3,800,000

3,790,000

3,780,000 0 ug/m3

640,000 650,000

0.02 ug/m3 0.03 ug/m3

660,000 670,000 680,000 690,000


0.05 ug/m3 0.6 ug/m3

700,000 710,000 720,000

0.08ug/m3

730,000 740,000

n_ Tritui 'ty& UJllSU tahts

]: ~ c

:.c: t: 0 z

:g E-< ;:J

3,870,000

3,864,000

3,858,000

3,852,000

3,846,000

3,840,000

3,834,000

3,828,000

3,822,000

3,816,000

3,810,000

Figure A-10. N02 Significant Receptor Grid Thomas A. Smith Energy Facility - Dalton, Georgia

•

•

II

' II II

-

Grid A

Grid B

Grids C, D, E

. Grid F

Significant Receptor

3,804,000 '---------------~------------------~---------654,000 660,000 666,000 672,000 678,000 684,000 690,000 696,000 702,000 708,000

Coordinates reflect UTM projection Zone 16, NAD83 . UTM Easting (m) Tt . . ~

{)._ f!9Jtyk.... \...Wl1.Swtahts

Oglethorpe Power Corporation | Advanced Gas Path/Minimum Load Project PSD Permit Application Volume II Trinity Consultants B

APPENDIX B: CLASS I NOTIFICATION DOCUMENTATION AND FLM RESPONSE

1

Justin Fickas

From: Jon HillSent: Tuesday, November 06, 2018 3:31 PMTo: Pitrolo, Melanie -FSCc: Justin FickasSubject: Upcoming PSD - Request for DeterminationAttachments: Class I Area Request for Determination (2018 11 06).doc

Melanie, We have swapped emails regarding a potential PSD project near Cohutta. The project is now proceeding and on behalf of Oglethorpe Power (Oglethorpe), Trinity Consultants (Trinity) has prepared the attached Request for Determination form for you to review to determine Class I modeling requirements associated with the project. Per our earlier emails, we believe that only a near‐field visibility analysis at Cohutta is warranted as the Q/D ratio is well below 10 at all of the potentially‐affected areas. Please confirm receipt of the form and let us know if you have any questions on anything. Best Regards, Jon …………………………………………………………………………………………………. Jonathan Hill Managing Consultant/Meteorologist Trinity Consultants 1 Copley Parkway, Suite 205 | Morrisville, NC 27560

NOTE: SUITE NUMBER HAS CHANGED!

Office: 919‐462‐9693 Email: [email protected] Make sure to sign up for our next Air Permitting course! Air Permitting in NC – Winston‐Salem, NC Nov 9, 2018 Register for our Upcoming Complimentary Lunch Seminars: Are You Ready for 2019? Raleigh, NC – December 4th Greenville, SC – December 6th Norfolk, VA – December 12th

For Additional Information or Questions, Contact Melanie Pitrolo

(828) 257-4213 or [email protected]

Request for Applicability of Class I Area Modeling Analysis Southern Region, U.S. Forest Service

Facility Name (Company Name) Thomas A. Smith Energy Facility (Oglethorpe Power Corporation)

New Facility or Modification? Modification

Source Type/BART Applicability Combined Cycle Power Facility – Online 2002

Project Location (County/State/

Lat. & Long. in decimal degrees) Murray County, Georgia – LAT/LON: 34.709392, -84.917815

Application Contacts

Applicant Consultant Air Agency Permit Engineer

Company Oglethorpe Power

Corporation Company Trinity Consultants, Inc. Agency Georgia EPD

Contact Toni Presnell Contact Jon Hill Contact Di Tian

Address 2100 East Exchange Place,

Tucker, GA 30084 Address

1 Copley Pkwy, Suite 205

Morrisville, NC 27560 Address

4244 International Pkwy,

Suite 120

Atlanta, GA 30354

Phone # 770-270-7740 Phone # 919-462-9693 Phone # 404-362-4851

Email [email protected] Email [email protected] Email [email protected]

Briefly Describe the Proposed Project

Oglethorpe Power Corporation (“Oglethorpe”) owns and operates a natural gas-fired combined-cycle facility

located in Dalton, Georgia (“Thomas A. Smith Energy Facility” or “Smith Facility”). The facility consists of

two “2-on-1” power blocks. Oglethorpe is considering a change to the operational controls at the facility

that, if implemented, would increase the capacity of each block by approximately 28.6 Megawatts (MWs) in

the summer and 31.0 MWs in the winter (Block 1 being CT1/DB1 and CT2/DB2 and steam turbine, and

Block 2 being CT3/DB3 and CT4/DB4 and steam turbine). These control changes would result in an

associated increase in maximum heat inputs and maximum hourly rate of emissions when the duct burners

are used at their full capability.

Emissions shown below are the current estimates of increases in the maximum 24-hr short term emission

rates of the listed pollutants for this project, and the corresponding tpy increases. For NOx emissions, current

facility BACT limits will be maintained. SO2 and H2SO4 emissions are small due to use of natural gas only

as a facility fuel source. Current facility emission units will not increase their existing filterable PM limits,

but will now have a condensable PM component added to the prior filterable PM limit. Project data

regarding emissions may change, and any necessary updates will be provided to the FLM as necessary.

Proposed Emissions and BACT

Criteria Pollutant

Emissions

Emission Factor

(AP-42, Stack Test, Other?) Proposed BACT Maximum

hourly

(lb/hr)

Proposed

Annual

(tons/yr)

Nitrogen Oxides 15.6 68.2 Pre-Existing BACT Limit

Existing facility short term BACT limit

(3-hr avg.) of 3 ppm @ 15% O2 –

Increase shown due to increase in

maximum potential system heat input

Sulfur Dioxide 0.85 3.72 Sulfur Content of Natural

Gas

N/A – Project not triggering BACT for

SO2

Particulate Matter 26.8 117.5

Pre-Existing BACT Limit

with Addition of

Condensables

25 lb/hr (~0.012 lb/MMBtu) filterable

PM existing BACT limit, with addition

of condensable component – Maximum

hourly increase shown with addition of

condensables to existing PM limit

Sulfuric Acid Mist 0.06 0.26 Vendor Data N/A – Project not triggering BACT for

H2SO4

Proximity to U.S. Forest Service Class I Areas

Class I Area Cohutta Wilderness Joyce Kilmer Slick Rock

Wilderness Shining Rock Wilderness

Distance from Facility (km) 30.6 km 111 km 195 km

Class I Area Sipsey Wilderness Linville Gorge Wilderness

Distance from Facility (km) 227 km 299 km

1

Justin Fickas

Subject: FW: Upcoming PSD - Request for Determination

From: Pitrolo, Melanie ‐FS <[email protected]> Sent: Friday, December 21, 2018 4:35 PM To: Jon Hill <[email protected]> Subject: RE: Upcoming PSD ‐ Request for Determination Hi Jon. Thank you for reaching out to me regarding the PSD for Oglethorpe Energy. Because of the close proximity to Cohutta, a near‐field visibility analysis is requested to assess the potential for plume blight at the Class I Area. Additional AQRV modeling will not be requested at this time given the proposed increase in emissions. Melanie

From: Jon Hill [mailto:[email protected]] Sent: Tuesday, December 18, 2018 1:46 PM To: Pitrolo, Melanie ‐FS <[email protected]> Subject: FW: Upcoming PSD ‐ Request for Determination Melanie – we really need some direction on the attached RFD that we submitted on 11/6. If you are not the correct person please let me know and I can reach out to that person and not pester you. Thanks! Jon …………………………………………………………………………………………………. Jonathan Hill Managing Consultant/Meteorologist Trinity Consultants 1 Copley Parkway, Suite 205 | Morrisville, NC 27560



From: Jon Hill Sent: Wednesday, November 28, 2018 11:27 AM To: 'Pitrolo, Melanie ‐FS' <[email protected]> Subject: FW: Upcoming PSD ‐ Request for Determination

2

Melanie, I hope you had a nice Thanksgiving! We have agency meetings coming up on this project so I wanted to check‐in and see what thoughts you had on our RFD form (attached). Thanks! Jon …………………………………………………………………………………………………. Jonathan Hill Managing Consultant/Meteorologist Trinity Consultants 1 Copley Parkway, Suite 205 | Morrisville, NC 27560



1

Justin Fickas

Subject: FW: Upcoming PSD - Request for Determination

‐‐‐‐‐‐‐‐‐‐ Forwarded message ‐‐‐‐‐‐‐‐‐‐ From: "Pitrolo, Melanie ‐FS" <[email protected]> Date: Wed, Jan 30, 2019 at 10:31 AM ‐0500 Subject: RE: Upcoming PSD ‐ Request for Determination To: "Jon Hill" <[email protected]>

Hi Jon. I hope you are doing well. Thank goodness the furlough is over! Regarding nearfield visibility, you can just document the methods and results in the same final report. Thanks, Melanie

From: Jon Hill [mailto:[email protected]] Sent: Friday, December 21, 2018 5:03 PM To: Pitrolo, Melanie ‐FS <[email protected]> Subject: RE: Upcoming PSD ‐ Request for Determination Thanks for the reminder on the shutdown Fingers crossed that doesn’t happen. With regards to the protocol, do you prefer for us to submit a formal document since it will just pertain to near‐field visibility or can we document the methods and results in the final report which you will receive a copy of? Best Regards, Jon …………………………………………………………………………………………………. Jonathan Hill Managing Consultant/Meteorologist Trinity Consultants 1 Copley Parkway, Suite 205 | Morrisville, NC 27560



May 6, 2019 Ms. Cindy Huber Air Program Staff USDA Forest Service (FS) George Washington & Jefferson National Forest 5162 Valleypoint Parkway Roanoke, VA 24019 RE: Oglethorpe Power Corporation – Dalton, Georgia Thomas A. Smith Energy Facility

Project in Reference to FS Class I Area – Sipsey Wilderness Dear Ms. Huber, Trinity Consultants (Trinity) is submitting this letter to your attention on behalf of our client Oglethorpe Power Corporation (OPC). OPC is proposing to modify existing facility combined cycle combustion turbine systems at their facility in Dalton, Georgia (Murray County), the Thomas A. Smith Energy Facility. The proposed project will require a Prevention of Significant Deterioration (PSD) construction permit as emissions from the proposed project are anticipated to exceed the PSD significant emission rate (SER) threshold for particulate matter (PM), particulate matter with an aerodynamic diameter of 10 microns (PM10), particulate matter with an aerodynamic diameter of 2.5 microns (PM2.5), nitrogen oxides (NOX), and GHGs (CO2e). The purpose of this letter is to provide the Federal Land Manager (FLM) with preliminary information on the proposed project and to request concurrence from the FLM on the findings presented.

Q/D SCREENING ANALYSIS

A Q/D screening analysis was performed in a manner consistent with the approach discussed in the most recent Federal Land Managers’ Air Quality Related Values Work Group (FLAG) guidance document (FLAG 2010), which compares the ratio of visibility affecting pollutant emissions to the distance from the Class I area (i.e., referenced herein as the FLAG 2010 Approach).1 “Q” is the sum of the annual NOX, PM10, SO2, and sulfuric acid mist (H2SO4) emissions, in tons per year (tpy)2 and “D” is the distance, in kilometers (km), from the proposed facility to the corresponding Class I area. The total emissions for this project will include emissions from all point sources to be modified as part of this project. A summary of the visibility-affecting pollutant (VAP) emissions resulting from the proposed project are shown in Table 1 using the FLAG 2010 Approach. Emissions shown below are the current estimates of increases in the maximum 24-hr short term emission rates of the listed pollutants for this project, and the corresponding tpy increases. For NOx emissions, current facility BACT limits will be maintained. SO2 and H2SO4 emissions are small due to use of natural gas only as a facility fuel source. Current facility emission units will not increase their

1 Federal Land Managers’ Air Quality Related Values Work Group (FLAG) Phase I Report – Revised 2010, October 7, 2010. 2 It is specified within the Flag 2010 Report that “Q” be calculated as the sum of the worst-case 24-hour emissions converted to an annual basis.

Ms. Huber - Page 2 May 6, 2019

existing filterable PM limits, and will now have a condensable PM component added to their revised filterable PM limit. Project data regarding emissions may change, and any necessary updates will be provided to the FLM as necessary.

Table 1. Summary of Visibility-Affecting Pollutant Emissions

The Sipsey Wilderness is the only Class I Area within 300 km of the proposed project site that is indicated as under your jurisdiction. 3

Table 2. Summary of the Q/D Assessment

Table 2 shows the results of the Q/D screening analysis for the FLAG 2010 Approach. As shown in Table 2, the project has a Q/D well below ten. This suggests that the proposed project will have no adverse impacts to any AQRVs at the Sipsey Wilderness. Therefore, OPC plans no AQRV analyses for the proposed project. Based on Table 2, OPC requests that the FS provide written concurrence of this finding of no impact.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

3 Notifications regarding other FS Class I areas was made to Melanie Pitrolo of the FS.

NOX

Direct Particulate1

SO2

H2SO4

Sum of Emissions (tpy)

1. Direct particulate includes all filterable and condensable PM10.

2. FLAG 2010 Approach: Q = Maximum 24 hour basis * 8,760 /2000.

Pollutant

Facility-Wide Maximum 24-

hr Emissions Increase

(lb/hr)

19.82

11.33

0.14

FLAG 2010 Approach Annual

Emissions2

(tpy)

86.83

49.62

0.62

140.79

0.85 3.72

Responsible

Minimum

Distance

from Site

Sum of

Annualized VAP

Emissions - Q

Flag 2010

Approach

Class I Area FLM (km) (tpy) Q/D

227FSSipsey Wilderness 140.79 0.62

Ms. Huber - Page 3 May 6, 2019

OPC greatly appreciates your feedback on this conclusion regarding no presumptive impacts to AQRVs at Class I areas under your management. Please feel free to contact me at 404-751-0228 with any questions that you have. Sincerely, TRINITY CONSULTANTS

Justin Fickas Managing Consultant

May 6, 2019 Ms. Susan Johnson Air Program Staff National Park Service (NPS) Room 215, 12795 W. Alameda Pkwy. Denver, CO 80225 RE: Oglethorpe Power Corporation – Dalton, Georgia Thomas A. Smith Energy Facility

Project in Reference to NPS Class I Areas – Great Smoky Mountains and Mammoth Cave Dear Ms. Johnson, Trinity Consultants (Trinity) is submitting this letter to your attention on behalf of our client Oglethorpe Power Corporation (OPC). OPC is proposing to modify existing facility combined cycle combustion turbine systems at their facility in Dalton, Georgia (Murray County), the Thomas A. Smith Energy Facility. The proposed project will require a Prevention of Significant Deterioration (PSD) construction permit as emissions from the proposed project are anticipated to exceed the PSD significant emission rate (SER) threshold for particulate matter (PM), particulate matter with an aerodynamic diameter of 10 microns (PM10), particulate matter with an aerodynamic diameter of 2.5 microns (PM2.5), nitrogen oxides (NOX), and GHGs (CO2e). The purpose of this letter is to provide the Federal Land Manager (FLM) with preliminary information on the proposed project and to request concurrence from the FLM on the findings presented.

Q/D SCREENING ANALYSIS

A Q/D screening analysis was performed in a manner consistent with the approach discussed in the most recent Federal Land Managers’ Air Quality Related Values Work Group (FLAG) guidance document (FLAG 2010), which compares the ratio of visibility affecting pollutant emissions to the distance from the Class I area (i.e., referenced herein as the FLAG 2010 Approach).1 “Q” is the sum of the annual NOX, PM10, SO2, and sulfuric acid mist (H2SO4) emissions, in tons per year (tpy)2 and “D” is the distance, in kilometers (km), from the proposed facility to the corresponding Class I area. The total emissions for this project will include emissions from all point sources to be modified as part of the project. A summary of the visibility-affecting pollutant (VAP) emissions resulting from the proposed project are shown in Table 1 using the FLAG 2010 Approach. Emissions shown below are the current estimates of increases in the maximum 24-hr short term emission rates of the listed pollutants for this project, and the corresponding tpy increases. For NOx emissions, current facility BACT limits will be maintained. SO2 and H2SO4 emissions are small due to use of natural gas only as a facility fuel source. Current facility emission units will not increase their existing filterable PM limits, and will now have a condensable PM component added to their revised filterable

1 Federal Land Managers’ Air Quality Related Values Work Group (FLAG) Phase I Report – Revised 2010, October 7, 2010. 2 It is specified within the Flag 2010 Report that “Q” be calculated as the sum of the worst-case 24-hour emissions converted to an annual basis.

Ms. Johnson - Page 2 May 6, 2019

PM limit. Project data regarding emissions may change, and any necessary updates will be provided to the FLM as necessary.

Table 1. Summary of Visibility-Affecting Pollutant Emissions

The Great Smoky Mountain and Mammoth Cave Class I areas are the only Class I Areas within 300 km of the proposed project site that are indicated under the jurisdiction of the NPS. 3

Table 2. Summary of the Q/D Assessment

Table 2 shows the results of the Q/D screening analysis for the FLAG 2010 Approach. As shown in Table 2, the project has a Q/D well below ten. This suggests that the proposed project will have no adverse impacts to any AQRVs at the Great Smoky Mountain or Mammoth Cave Class I areas. Therefore, OPC plans no AQRV analyses for the proposed project. Based on Table 2, OPC requests that the NPS provide written concurrence of this finding of no impact.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

3 Notifications regarding other FS Class I areas within 300 km of the project location were made under separate cover.

NOX

Direct Particulate1

SO2

H2SO4

Sum of Emissions (tpy)

1. Direct particulate includes all filterable and condensable PM10.

2. FLAG 2010 Approach: Q = Maximum 24 hour basis * 8,760 /2000.

Pollutant

Facility-Wide Maximum 24-

hr Emissions Increase

(lb/hr)

19.82

11.33

0.14

FLAG 2010 Approach Annual

Emissions2

(tpy)

86.83

49.62

0.62

140.79

0.85 3.72

Responsible

Minimum

Distance

from Site

Sum of

Annualized VAP

Emissions - Q

Flag 2010

Approach

Class I Area FLM (km) (tpy) Q/D

1.14

Mammoth Cave NPS 284 140.79 0.50

Great Smoky Mountains NPS 123 140.79

Ms. Johnson - Page 3 May 6, 2019

OPC greatly appreciates your feedback on this conclusion regarding no presumptive impacts to AQRVs at Class I areas under your management. Please feel free to contact me at 404-751-0228 with any questions that you have. Sincerely, TRINITY CONSULTANTS

Justin Fickas Managing Consultant

Oglethorpe Power Corporation | Advanced Gas Path/Minimum Load Project PSD Permit Application Volume II Trinity Consultants C

APPENDIX C: MODELING PROTOCOL AND EPD RESPONSE

VIA E-MAIL: [email protected] October 30, 2018 Ms. Di Tian, Ph.D. Georgia Department of Natural Resources Environmental Protection Division Air Protection Branch 4244 International Parkway, Suite 120 Atlanta, GA 30354 RE: Oglethorpe Power Corporation, Dalton, GA Site Modeling Protocol for PSD Application – Advanced Gas Path /

Operating Controls Project Dear Ms. Tian: Oglethorpe Power Corporation (“Oglethorpe”) owns and operates a natural gas-fired combined-cycle facility located in Dalton, Georgia (“Thomas A. Smith Energy Facility” or “Smith Facility”). The facility consists of two “2-on-1” power blocks. Oglethorpe is considering a change to the operational controls at the facility that, if implemented, would increase the capacity of each block by approximately 28.6 Megawatts (MWs) in the summer and 31.0 MWs in the winter (Block 1 being CT1/DB1 and CT2/DB2 and steam turbine, and Block 2 being CT3/DB3 and CT4/DB4 and steam turbine). These control changes would result in an associated increase in maximum heat inputs and maximum hourly rate of emissions when the duct burners are used at their full capability. The proposed project will require a Prevention of Significant Deterioration (PSD) permit as a major modification to an existing major source.1 Projected-related emissions increases are anticipated to exceed the PSD significant emission rate (SER) thresholds for particulate matter (PM), particulate matter with an aerodynamic diameter of 10 microns (PM10), particulate matter with an aerodynamic diameter of 2.5 microns (PM2.5), nitrogen oxides (NOx), and greenhouse gases (GHG) in terms of carbon dioxide equivalents (CO2e).2,

A dispersion modeling protocol has been prepared following the policy and guidance of the Georgia Environmental Protection Division (GAEPD). Trinity Consultants (Trinity), on behalf of Oglethorpe, has prepared this dispersion modeling protocol describing the proposed methodologies and data resources to be used for the modeling compliance demonstration. This protocol includes a brief description of the proposed project, an overview of the required PSD and State modeling analyses, and a detailed description of the methodology proposed to be used in the modeling analyses. The analyses include evaluation and consideration of National Ambient Air Quality Standards (NAAQS), PSD Increment, additional impacts analyses, visibility and non-air quality impacts, ambient impact assessment of toxic air pollutant (TAP) emissions, as well as consideration of impacts to Class I Areas.

1 The Smith Facility is an existing PSD major source as potential facility-wide emissions of volatile organic compounds (VOC), NOx, carbon monoxide (CO), PM, PM10, PM2.5, and sulfur dioxide (SO2) are greater than the major source threshold of 100 tons per year (tpy). The facility is classified as one of the 28 named source categories (fossil fuel fired steam electric plants totaling more than 250 million Btu/hr heat input).

2 CO2e is carbon dioxide equivalents calculated as the sum of the six well-mixed GHGs (CO2, CH4, N2O, HFCs, PFCs, and SF6) with applicable global warming potentials per 40 CFR 98 applied.

mailto:[email protected]

Ms. Di Tian - Page 2 October 30, 2018

PROJECT DESCRIPTION

The Smith Facility consists of two “2-on-1” power blocks, with each power block consisting of two General Electric 7FA combustion turbines (CTs), two heat recovery steam generators (HRSGs), two duct burners (DBs), and one steam turbine (ST). The facility also operates two natural gas-fired auxiliary boilers, each with an annual operational limit of 6,000 hours, two diesel-fired backup generators rated at 704 horsepower (hp) each, and one diesel-fired emergency firewater pump rated at 265 hp. The backup generators and emergency firewater pump are limited to 500 hours per year of operation per engine. Oglethorpe is considering a change to the operational controls at the facility that, if implemented, would increase the capacity of each block by approximately 28.6 MWs in the summer and 31.0 MWs in the winter (Block 1 being CT1/DB1 and CT2/DB2 and steam turbine, and Block 2 being CT3/DB3 and CT4/DB4 and steam turbine). These control changes would result in an associated increase in maximum heat inputs and maximum hourly rate of emissions when the duct burners are used at their full capability. Therefore, for this project, only Block 1 and Block 2 would be considered modified facility units, with no physical change or change in the method of operation anticipated for the emergency backup generator or fire pump, or auxiliary boilers. There would also be no expected associated emissions increase from either the emergency backup generator and fire pump, or auxiliary boilers, as part of this project.

Figure 1 provides a map of the area surrounding the existing proposed project location. The approximate central Universal Transverse Mercator (UTM) coordinates of the Smith Facility (centered around the emissions sources) are 690.687 kilometers (km) East and 3,842.790 km North in Zone 16 (NAD 83). The area surrounding the facility is predominantly rural.


Figure 1. Smith Facility Area Map

Figure 2 depicts the fence line boundary of the Smith Facility. The boundary area indicated below is completely fenced.


Figure 2. Smith Facility Boundaries

Fence


PSD APPLICABILITY

Part C of Title I of the Clean Air Act, 42 U.S.C. §§7470-7492, is the statutory basis for the PSD program. The Environmental Protection Agency (EPA) has codified PSD definitions, applicability, and requirements in 40 CFR Part 52.21. PSD is addressed and implemented through Georgia Rule 391-3-1-.02(7). PSD is one component of the New Source Review (NSR) permitting program applicable in areas that are designated in attainment of the NAAQS. Murray County, where the facility is located, is currently designated as unclassifiable or in attainment for all criteria pollutants.3 It is anticipated that the proposed project at the Smith Facility will be considered a major modification under PSD since the proposed project emissions increases for certain criteria pollutants (i.e., PM, PM10, PM2.5, and NOx) and GHGs are expected to exceed their respective PSD SERs. A preliminary summary of project emissions increases is provided in the following table:

Table 1. Expected Project Emissions Increase4

Pollutant Project Emissions Increase (tpy)

PSD SER Threshold (tpy)

PSD Permitting triggered?

CO <100 100 No

NOX >40 40 Yes

PM >25 25 Yes

PM10 >15 15 Yes

PM2.5 >10 10 Yes

SO2 <40 40 No

VOC <40 40 No

CO2e >75,000 75,000 Yes

PSD MODELING ANALYSES

Trinity has prepared this modeling protocol to describe the modeling methodologies and data resources that will be used under the assumption that the proposed project at the Smith Facility will exceed the significant impact levels (SILs). The dispersion modeling analyses will be conducted in consideration of the following guidance documents:

Guideline on Air Quality Models 40 CFR 51, Appendix W (EPA, Revised, January 17, 2017) User’s Guide for the AMS/EPA Regulatory Model – AERMOD, (EPA, April 2018) AERMOD Implementation Guide (EPA, April 2018) New Source Review Workshop Manual (EPA, Draft, October, 1990) Modeling Procedures for Demonstrating Compliance with PM2.5 NAAQS (EPA, Memorandum from Mr. Stephen

Page, March 23, 2010) GAEPD’s PSD Permit Application Guidance Document (GAEPD, Feb 2017)

3 40 CFR §81.301

4 The project emissions increase estimates for the proposed project are preliminary and are subject to change.


Guidance for PM2.5 Permit Modeling (EPA, Memorandum from Mr. Stephen Page, May 20, 2014) Guidance on the Use of EPA’s MERPs to Account for Secondary Formation of Ozone and PM2.5 in Georgia

(GAEPD, September 19, 2018) Guidance on the Development of Modeled Emission Rates for Precursors (MERPs) as a Tier I Demonstration

Tool for Ozone and PM2.5 under the PSD Permitting Program (EPA, Memorandum from Mr. Richard A Wayland, December 2, 2016) and associated errata document (February 2017)

Guidance on Significant Impact Levels for Ozone and Fine Particles in the Prevention of Significant Deterioration Permitting Program (EPA Memorandum from Mr. Peter Tsirigotis, April 17. 2018)

Additional Clarification Regarding Application of Appendix W Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard (EPA, Memorandum from Mr. Tyler Fox, March 1, 2011); and

Clarification on the Use of AERMOD Dispersion Modeling for Demonstrating Compliance with the NO2 National Ambient Air Quality Standard (EPA, Memorandum from Mr. R. Chris Owen and Roger Brode, September 30, 2014).

A summary of the tasks that are performed in a standard PSD air quality modeling analysis is presented in the flow chart provided as Figure 3.


Figure 3. PSD Modeling Flow Chart


Significance and NAAQS Analysis

The Significance Analysis is conducted to determine whether the emissions associated with the proposed new construction could cause a significant impact upon the area surrounding the facility. “Significance” is analyzed based on modeling only the new, modified, or associated sources comprising the project; no existing unmodified or associated sources are included, neither sources from other regional facilities. “Significant” impacts are defined by design concentration thresholds commonly referred to as the SIL. Oglethorpe will model the project associated sources for significance. For this project, significance modeling will only include Block 1 and Block 2 at the facility, and not include the auxiliary boilers, as the auxiliary boilers are not being modified as part of this project. 5 The future potential emissions of each Block (Block 1/Block 2) will be evaluated in the model as a positive emission rate, where past actual emissions (as derived from project baseline data) will be evaluated in the model as a negative emission rate. 6 Emissions for significance will be evaluated as follows.

1. Future potential emissions will be based on the maximum capacity of each Block (Block 1/Block 2) following the proposed changes, in conjunction with maximum allowable emission rates.

2. Past actual emissions will be derived through; i. For NO2 modeling, CEMS data as recorded by existing facility monitoring equipment, and reported to

EPA under the Clean Air Markets Program, in combination with hours of operation to derive hourly emission rates.

ii. For PM10/PM2.5, MMBtu heat input data and hours of operation (along with allowable emission rates in lb/MMBtu) to derive hourly emissions.

iii. The Smith Facility is considered a baseline source for PM2.5 increment, as the facility was an existing permitted and operational facility as of the baseline date (October 2010) for PM2.5. Therefore, for PM2.5 increment purposes, the project emissions increase for PM2.5 increment will consider baseline emissions from the facility for calendar year 2010 as representative of the baseline period for PM2.5

increment impacts. Table 2 lists the SIL, NAAQS, and Class II PSD Increments for all relevant NSR regulated pollutants for this project which will be undergoing PSD permitting. 7

5 As noted later in this modeling protocol, significance modeling will not consider startup/shutdown (SUSD) as the anticipated startup time, conditions, etc. should not be impacted as only normal operating conditions at high load will be impacted by the proposed changes.

6 In the case of NO2 modeling, concerns have been raised regarding use of negative emission rates with Tier 2/Tier 3 modeling options. As Tier 2 modeling methods (e.g. ARM2) are proposed for use with this project, significance modeling will evaluate both the future potential emissions from the project, as well as the past actual (baseline emissions) in the model as part of separate model runs with positive emission rates. Model plot file output data will then be utilized to subtract the past actual model results from the future potential model results, so as no negative emission rates will be utilized in the dispersion model for NO2 modeling.

7 Class I analyses are addressed in a following section.


Table 2. Significant Impact Levels, NAAQS, Class II PSD Increments, and Significant Monitoring Concentrations for Relevant NSR Regulated Pollutants

Pollutant Averaging

Period

PSD Class II SIL

(µg/m3)

Primary and Secondary

NAAQS (µg/m3)

Class II PSD Increment

(µg/m3)

Significant Monitoring

Concentration (µg/m3)

PM10 24-hour 5 150 (1) 30 10

Annual 1 -- 17 --

PM2.5 24-hour 1.2 (2) 35(4) 9 (3) -- (2)

Annual 0.2 (2) 12(5) 4 (3) --

NO2 1-hour 7.5 188(6) N/A --

Annual 1 100(7) 25 14 (1) Not to be exceeded more than three times in 3 consecutive years (highest sixth high modeled output). (2) EPA promulgated PM2.5 SILs, Significant Monitoring Concentrations (SMCs), and PSD Increments on October 20, 2010 [75 FR

64864, PSD for Particulate Matter Less Than 2.5 Micrometers Increments, Significant Impact Levels (SILs) and Significant Monitoring Concentration (SMC); Final Rule]. The SILs and SMCs became effective on December 20, 2010 (i.e., 60 days after the rule was published in the Federal Register) but the U.S. Court of Appeals decision on January 22, 2013 vacated the SMC and remanded the SIL values back to EPA for reconsideration. EPA has recently provided guidance (August 2016) and a finalized memo (April 2018) which recommended use of a 24-hr PM2.5 SIL of 1.2 µg/m3, and an annual SIL of 0.2 µg/m3. However, the guidance indicated that the permitting authority had the discretion to continue to utilize the previously established annual SIL of 0.3 µg/m3. EPA responded to the vacature of the SMCs by indicating that existing background monitors should be sufficient to fulfill the ambient monitoring requirements for PM2.5.

(3) The above mentioned court decision did not impact the promulgated increment thresholds for PM2.5. (4) The 3-year average of the 98th percentile 24-hour average concentration (highest eighth high modeled output). (5) The 3-year average of the annual arithmetic average concentration (highest first high modeled output). (6) The 3-year average of the 98th percentile of the daily maximum 1-hr average (highest eighth high modeled output). (7) Annual arithmetic average (highest first high modeled output).

The highest design concentrations out of all given modeling years for each pollutant-averaging time is then compared to the SIL level shown in Table 2 to determine if the ambient air impact is significant. In the case of 24-hour and annual PM2.5 evaluations, EPA guidance states that the applicant should determine the maximum concentration at each receptor per year, then average those values on a receptor-specific basis over the 5 years of meteorological data prior to comparing with the appropriate SIL.8 However, this assessment is only appropriate for the PM2.5 NAAQS, as the PM2.5 Increment standard is not a statistical standard. Therefore, the year by year results for PM2.5 will be compared to the applicable SILs for a determination if a refined analysis for PM2.5 increment is required. For NO2 NAAQS modeling, a concatenated meteorological data set to derive the appropriate form of the 1-hr NO2 NAAQS standard will be utilized. For annual NO2 NAAQS modeling, each individual year will be processed separately to evaluate maximum annual anticipated impacts. When modeled design concentrations are less than the applicable SIL, further analyses (NAAQS and PSD Increment) are not required for that pollutant-averaging period.

8 Please note that Oglethorpe will not use averaging for developing the PM2.5 SIL results for consideration of the PM2.5 Increment. Maximum annual values will be used rather than 5-year average values.


If modeled impacts are greater than the SIL, a full NAAQS and PSD Increment analysis is required for that pollutant and averaging period to demonstrate that the project neither causes nor contributes to any exceedances. GAEPD publishes background concentration values on their website and the 2015 background monitors as specified by the Georgia EPD for the county of interest will be utilized. 9 The chosen background values are shown in Table 3.

Table 3. Selected Background Concentrations

PSD Pollutant

Averaging Period

2013-2015 Monitor

Background Concentration

(g/m3) Metric Monitor Location

PM10 24-hour 38.0 3-yr average of

second-high

Statewide Value

as Derived by

EPD

PM2.5 24-hour 16.4 3-yr average of

98th percentile Rossville

Annual 8.6 3-yr arithmetic

mean average

NO2 1-hour 30.3 3-yr average of

98th percentile Statewide Value

as Derived by

EPD Annual 4.8 3-yr arithmetic

mean maximum

Class II Increment Analysis

The PSD regulations were enacted primarily to “prevent significant deterioration” of air quality in areas of the country where the air quality was better than the NAAQS. Therefore, to promote economic growth in areas where attainment of the NAAQS occurs, some deterioration in ambient air concentrations is allowed. To achieve this goal, the U.S. EPA established PSD Increments for PM10, PM2.5, SO2, and NO2. The PSD Increments are further broken into Class I, II, and III Increments. Since all short-term Class II Increments (Table 4) are not to be exceeded more than once per year, the H2H modeled impacts for 24-hour averaging periods for respective pollutants from among the five modeled meteorological years will be compared against the short-term Increment. The highest annual average concentrations will be compared against the annual Increment.

9 https://epd.georgia.gov/air/documents/georgia-background-data. If more up to date background data is available, that information is requested from the Georgia EPD.



Table 4. Class II Increments

Pollutant Averaging Period Class II Increment

(μg/m3)

PM2.5 24-hour 9

Annual 4

PM10 24-hour

Annual

30

17 NO2 Annual 25

Ambient Monitoring Requirements

In addition to determining whether the applicant can forego further modeling analyses, the PSD Significance Analysis is also used to determine whether the applicant is exempt from ambient monitoring requirements. To determine whether pre-construction monitoring should be considered, the maximum impacts attributable to the proposed project are assessed against Significant Monitoring Concentrations (SMC). The SMC for the applicable averaging periods for NO2, PM10, and PM2.5 are provided in 40 CFR §52.21(i)(5)(i) and are listed in Table 2. A pre-construction air quality analysis using continuous monitoring data may be required for pollutants subject to PSD review per 40 CFR §52.21(m). If either the predicted modeled impact from an emissions increase or the existing ambient concentration is less than the SMC, an applicant may be exempt from pre-construction ambient monitoring. The SMC value for PM2.5 was vacated on January 22, 2013, however, EPA responded to the vacature by indicating that existing background monitors should be sufficient to fulfill the ambient monitoring requirements for PM2.5. Oglethorpe will provide an evaluation of the monitors in place and a justification for why additional site specific monitoring should not be required.

Ozone Ambient Impact Analysis

Elevated ground-level ozone concentrations are the result of photochemical reactions among various chemical species. These reactions are more likely to occur under certain ambient conditions (e.g., high ground-level temperatures, light winds, and sunny conditions). The chemical species that contribute to ozone formation, referred to as ozone precursors, include NOX and VOC emissions from both anthropogenic (e.g., mobile and stationary sources) and natural sources (e.g., vegetation). Pursuant to 40 CFR 52.21, ambient ozone monitoring will not be required unless a facility’s emissions increase is greater than 100 tpy of VOC or NOX. EPA has also recently issued guidance specifying a SIL value for ozone of 1 ppb, and has developed a new potential demonstration (the MERPs guidance) to provide a framework for a Tier 1 demonstration that can illustrate that a project will not cause or contribute to any violation of ambient ozone standards. The September 2018 GAEPD guidance document titled Guidance on the Use of EPA’s MERPs to Account for Secondary Formation of Ozone and PM2.5 in Georgia will be used to provide a Tier 1 demonstration that ozone impacts from the project will not cause or contribute to ambient air quality levels of ozone. Both VOC and NOx emissions will be considered. Therefore, an evaluation of the ozone impacts from this project will be conducted through following the EPD September 2018 guidance.


Class I Area Analysis

Class I areas are federally protected areas for which more stringent air quality standards apply to protect unique natural, cultural, recreational, and/or historic values. The Class I area of primary concern for the Smith Facility is the Cohutta Wildernes, as it is the closest Class I area to the facility and within 50 km of the project site. The Cohutta Wilderness is located approximately 30.3 km away from Oglethorpe’s Smith Facility. The following Class I areas are located within 300 km of the Smith Facility (with the approximate distance to the Smith Facility listed) 10:

Cohutta Wilderness (30.6 km) Joyce Kilmer-Slickrock Wilderness (111 km) Great Smokey Mountains NP (123 km) Shining Rock Wilderness (195 km) Sipsey Wilderness (227 km) Mammoth Cave NP (284 km) Linville Gorge Wilderness (299 km)

All other Class I areas are located at distances greater than 300 km from the Smith Facility. The Federal Land Managers (FLM) have the authority to protect air quality related values (AQRVs), and to consider in consultation with the permitting authority whether a proposed major emitting facility will have an adverse impact on such values. AQRVs for which PSD modeling is typically conducted include visibility and deposition of sulfur and nitrogen. The ratio of emissions to Class I distance (e.g., Q/D) for this project for the Class I areas within 300 km will be considered in order to determine if the FLM will require a full AQRV analysis. The FLM’s AQRV Work Group (FLAG) 2010 guidance states that a Q/D value of ten or less indicates that AQRV analyses should not be required.11 A letter will be submitted to the appropriate FLMs (along with the requisite form) for all Class I areas located within 300 km for concurrence with a finding regarding the requirement for AQRV analysis for this project.12 The Q/D for all Class I areas greater than 50 km from the facility will be evaluated and demonstrated that impacts will be less than 10. For the Cohutta Wilderness, direct discussion will occur with the appropriate FLM to determine the applicable modeling requirements. A significance analysis will be required for the Class I areas referenced above, for potential evaluation of PSD increment impacts upon the Class I area. Details regarding the Class I area significance analysis are as follows.

1. AERMOD will be utilized for all significance analyses. All Cohutta Wilderness Class I area receptors are within 50 km of the Smith Facility. Therefore, the Class I area receptors of concern will be directly evaluated in the AERMOD model, for the Cohutta Wilderness. If the Class I SILs are exceeded for any of the Cohutta Wilderness receptors, a refined increment analysis of the Class I area will be performed. If

10 All distances approximate and based on data obtained from the Class I Area distance tool as published by the FL DEP at https://floridadep.gov/air/air-business-planning/content/class-i-areas-map

11 U.S. Forest Service, National Park Service, and U.S. Fish and Wildlife Service. 2010. Federal land managers’ air quality related values work group (FLAG): phase I report, revised (2010). Natural Resource Report NPS/NRPC/NRR, 2010/232. National Park Service, Denver, Colorado.

12 EPD will be copied on all correspondence as provided to the appropriate FLMs. If EPD is not copied on any correspondence from the FLM providing concurrence that no AQRV analysis is required, a copy of that correspondence will be provided to GAEPD.



required, all potential regional inventory sources (e.g. increment consumers) within 50 km of the Cohutta Wilderness will be evaluated in the refined increment analysis.

2. For all other Class I areas, a screening procedure will be utilized evaluating an array of receptors located 50 km from the facility at 1-degree intervals, to compare project emission increase impacts to those receptors at 50 km. 13

The Class I area Significant Impact Levels (SILs) and PSD Increment thresholds are listed in Table 5. PM2.5 Class I SILs are taken from recent EPA guidance (April 2018) regarding appropriate recommended significant impact levels for PM2.5.

Table 5. Class I Significant Impact Levels and Increment Thresholds

Pollutant Averaging Period Class I SIL (μg/m3)

Class I Increment (μg/m3)

PM2.5 24-hour 0.27 2

Annual 0.05 1

PM10 24-hour

Annual

0.3

0.2

8

4 NO2 Annual 0.1 2.5

CLASS II MODELING SETUP

This section of the modeling protocol describes the modeling procedures and data resources utilized in the setup of the Class II Area air quality modeling analyses. The techniques proposed for the air quality analysis are consistent with current EPA guidance.

Modeled Sources

Oglethorpe will model the project-associated sources for the significance analysis. This includes the two power blocks at the facility, where each block is composed of two General Electric 7FA combustion turbines (CTs), two heat recovery steam generators (HRSGs), two duct burners (DBs), and one steam turbine (ST). For any off-site impact calculated in the significance modeling analysis that is greater than the SIL for a given pollutant, a NAAQS analysis incorporating nearby sources is required (cumulative impact analysis). For the cumulative impact analysis, all sources at the facility (with the exception of the diesel-fired backup generators and diesel-fired emergency fire pump) and the appropriate inventory sources will be included. The diesel-fired backup generators and diesel-fired emergency fire pump at the facility are intermittent sources and therefore do no need to be included as an emission source in the modeling analysis.14,15

13 Consistent with EPD guidance, this assumes that the applicable FLMs have determined that no AQRV analyses will be required for the project.

14 Tian, Di. “Modeling Questions for Potential Project in Georgia.” Message to Justin Fickas. 11 October 2018.

15 Additional Clarification Regarding Application of Appendix W Modeling Guidance for the 1-hour NO2 National Ambient Air Quality Standard (Memorandum from Mr. Tyler Fox to Regional Air Division Directors, March 1, 2011)


Model Selection

Dispersion models predict downwind pollutant concentrations by simulating the evolution of the pollutant plume over time and space for specific set of input data. These data inputs include the pollutant’s emission rate, source parameters, terrain characteristics, and atmospheric conditions. According to the 40 CFR 51, Appendix W (the Guideline), the extent to which a specific air quality model is suitable for the evaluation of source impacts depends on (1) the meteorological and topographical complexities of the area; (2) the level of detail and accuracy needed in the analysis; (3) the technical competence of those undertaking such simulation modeling; (4) the resources available; and (5) the accuracy of the database (i.e., emissions inventory, meteorological, and air quality data). Taking these factors under consideration, Oglethorpe will use the AERMOD modeling system to represent all project emissions sources at the facility. AERMOD is the default model for evaluating impacts attributable to industrial facilities in the near-field (i.e., source receptor distances of less than 50 km), and is the recommended model in the Guideline.

AERMOD

The latest version (18081) of the AERMOD modeling system will be used to estimate maximum ground-level concentrations in all Class II Area analyses conducted for this application. AERMOD is a refined, steady-state, multiple source, Gaussian dispersion model and was promulgated in December 2005 as the preferred model for use by industrial sources in this type of air quality analysis.16 The AERMOD model has the Plume Rise Modeling Enhancements (PRIME) incorporated in the regulatory version, so the direction-specific building downwash dimensions used as inputs are determined by the Building Profile Input Program, PRIME version (BPIP PRIME), version 04274.17 BPIP PRIME is designed to incorporate the concepts and procedures expressed in the GEP Technical Support document, the Building Downwash Guidance document, and other related documents, while incorporating the PRIME enhancements to improve prediction of ambient impacts in building cavities and wake regions.18 The AERMOD modeling system is composed of three modular components: AERMAP, the terrain preprocessor; AERMET, the meteorological preprocessor; and AERMOD, the dispersion and post-processing module. AERMAP is the terrain pre-processor that is used to import terrain elevations for selected model objects and to generate the receptor hill height scale data that are used by AERMOD to drive advanced terrain processing algorithms. National Elevation Dataset (NED) data available from the United States Geological Survey (USGS) are utilized to interpolate surveyed elevations onto user specified receptor, building, and source locations in the absence of more accurate site-specific (i.e., site surveys, GPS analyses, etc.) elevation data. AERMET generates a separate surface file and vertical profile file to pass meteorological observations and turbulence parameters to AERMOD. AERMET meteorological data are refined for a particular analysis based on the choice of micrometeorological parameters that are linked to the land use and land cover (LULC) around the meteorological site shown to be representative of the application site.

16 40 CFR Part 51, Appendix W, Guideline on Air Quality Models, Appendix A.1 AMS/EPA Regulatory Model (AERMOD).

17 Earth Tech, Inc., Addendum to the ISC3 User’s Guide, The PRIME Plume Rise and Building Downwash Model, Concord, MA.

18 U.S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Guidelines for Determination of Good Engineering Practice Stack Height (Technical Support Document for the Stack Height Regulations) (Revised), Research Triangle Park, North Carolina, EPA 450/4-80-023R, June 1985.


Oglethorpe will use the BREEZE® graphical interface, developed by Trinity Consultants, to assist in developing the model input files for AERMOD. This software program incorporates the most recent versions of AERMOD (dated 18081) and AERMAP (dated 18081) and provides capability for image-generating. Using the procedures outlined in the Guideline as a reference, the AERMOD dispersion modeling for this project will be performed using only regulatory default options of the model.

Receptor Grid and Coordinate System

Modeled concentrations will be calculated at ground-level receptors placed along the facility fenceline and on a variable Cartesian receptor grid. Fenceline receptors will be spaced no further than 50 meters apart. Beyond the fenceline, receptors will be spaced 100 meters apart on a Cartesian grid extending out to a distance sufficient to resolve the maximum concentration, but at least extending outward to 2 km in all directions. The assessment of the significant impact area (SIA) will utilize a minimum 10 km receptor grid. In general, the receptors will cover a region extending from all edges of the Smith Facility ambient boundary to the point where impacts from the project are no longer expected to be significant. The boundary will be defined as all areas that are fenced and/or not accessible to the general public as shown in Figure 2. Please note that per EPA guidance, a reduced receptor grid with only the receptors at which maximum modeled concentrations exceed the SIL is required to be used for NAAQS and Increment modeling. Oglethorpe is proposing to use this approach.

Receptor elevations and hill heights required by AERMOD will be determined using the AERMAP terrain preprocessor (version 18081). Terrain elevations from the USGS 1-arc second NED will be used for AERMAP processing. In all modeling analysis data files, the location of emission sources, structures, and receptors will be represented in the UTM coordinate system, zone 16, NAD-83.

Urban versus Rural Dispersion Options

This section describes the performance of Land-use analysis for the purpose of determining the type of dispersion coefficients most appropriate for the application. The two sets of dispersion coefficients available in AERMOD are urban and rural. The goal of this land-use analysis is to estimate the percentage of urban and rural types of land cover within the study area. The study area is defined as a region centered on the site and having a radius of 3-km. The land-use types corresponding to urban areas are the “Commercial/Industrial/ Transportation” and “High density residential” types, where all other land cover types are associated with a rural setting. As specified in Section 7.2.1.1.b.i of the Guideline, a 3 km radius centered at the Smith Facility was considered for the land-use analysis. AERSURFACE (v.13016) was used for the extraction of the land-use values in the domain. The results of the land use analysis evaluation were as follows.


Table 6. Land-Use Categories Summary

This summary was generated by AERSURFACE and stored in the run’s log file. Additionally, the 21-categories were evaluated according to the Guideline in terms of dispersion classes as being of URBAN or RURAL. As shown above the domain surrounding the Smith Facility is approximately 98.6% rural. Therefore, AERMOD will be evaluated considering rural dispersion coefficients.

Meteorological Data

The Smith Facility is located in Murray County, GA. EPD has provided the most recent five years of meteorological data on their website.19 Assignment of station pairings to each county was based on distance to the centroid of the county, climatological zone, data collection period, and data completeness criteria. For Murray County, GAEAPD provides surface data from the Chattanooga Lovell Field Airport meteorological station located in Tennessee. The Chattanooga Lovell Field Airport meteorological station is located at 35.0335 degrees (latitude) and -85.2016 degrees (longitude) and is approximately 45 km Northwest of the Smith Facility.

19 https://epd.georgia.gov/air/georgia-aermet-meteorological-data EPD provides prescribed recommended meteorological data on a county by county basis.

LULC CAT Land Category Description

Number of

Grid Cells Frequency

Dispersion

Class

11 Open Water: 1233 3.9% Rural12 Perennial Ice/Snow: 0 0.0% Rural21 Low Intensity Residential: 338 1.1% Rural22 High Intensity Residential: 7 0.0% Urban23 Commercial/Industrial/Transp: 417 1.3% Urban31 Bare Rock/Sand/Clay: 0 0.0% Rural32 Quarries/Strip Mines/Gravel: 0 0.0% Rural33 Transitional: 330 1.1% Rural41 Deciduous Forest: 8990 28.6% Rural42 Evergreen Forest: 5840 18.6% Rural43 Mixed Forest: 9874 31.5% Rural51 Shrubland: 0 0.0% Rural61 Orchards/Vineyard/Other: 0 0.0% Rural71 Grasslands/Herbaceous: 0 0.0% Rural81 Pasture/Hay: 3687 11.7% Rural82 Row Crops: 608 1.9% Rural83 Small Grains: 0 0.0% Rural84 Fallow: 0 0.0% Rural85 Urban/Recreational Grasses: 67 0.2% Rural91 Woody Wetlands: 0 0.0% Rural92 Emergent Herbaceous Wetlands: 0 0.0% Rural

TOTAL 31391Rural 98.6%

Urban 1.3%

https://epd.georgia.gov/air/georgia-aermet-meteorological-data


Meteorological data sets provided by GAEPD covered the time period from 2013 to 2017, and included meteorological data processed both with and without the ADJ_U* option of AERMET.

Representativeness Analysis An AERSURFACE analysis was completed to compare the surface characteristics around the facility’s location and the chosen meteorological National Weather Service (NWS) station. AERSURFACE was executed for both, the project site and the NWS station, with monthly temporal resolution, and the default 1 km radius domain of twelve 30-degree sectors for the roughness surface length.

Figure 4. Comparison of Land Use Categories around the Facility and the NWS station

9.98%

0.23%

0.00%

1.52%

6.62%

34.03%

6.48%

28.58%

12.13%

0.43%

0.00%

1.55%

6.33%

3.84%

30.57%

0.00%

8.25%

4.79%

12.64%

2.55%

1.32%

28.22%

0% 5% 10% 15% 20% 25% 30% 35% 40%

Open Water

Low Intensity Residential

High Intensity Residential

Commercial/Industrial/Transp

Transitional

Deciduous Forest

Evergreen Forest

Mixed Forest

Pasture/Hay

Row Crops

Urban/Recreational Grasses

Category Frequency

Airport Site


Figure 4 and Table 7 provide detailed comparison of the land use categories and surface parameters at the project site and the NWS station. The albedo shows maximum of 13% difference. The Bowen ratio shows differences ranging from 6 to 56%. The surface roughness seems to be similar in most sectors, with a maximum value of 148%. Although comparison values differ significantly for surface roughness (as would be expected for an open area such as an airport and a developed facility), the Lovell Field data is considered sufficiently representative for use for the project modeling analysis.

Table 7. Comparison of Surface Characteristics between the project and NWS locations

Building Downwash Analysis

AERMOD incorporates the Plume Rise Model Enhancements (PRIME) downwash algorithms. Direction specific building parameters required by AERMOD are calculated using the BPIP-PRIME preprocessor (version 04274). Smith Facility structures will be built into the model and downwash influences will be evaluated appropriately.

Sector

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)Domain 0.17 0.15 0.16 0.16 0.15 0.15 0.15 0.15 -13% 0% -7% -7%

Moisture

Conditions

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)Average 0.92 0.68 0.53 0.92 0.87 0.63 0.37 0.87 -6% -8% -43% -6%Dry 2.04 1.59 1.2 2.04 1.77 1.41 0.77 1.77 -15% -13% -56% -15%Wet 0.47 0.39 0.36 0.47 0.39 0.31 0.24 0.39 -21% -26% -50% -21%

Sector

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON)

Winter

(DJF)

Spring

(MAM)

Summer

(JJA)

Fall

(SON) 0 - 30 0.026 0.032 0.037 0.032 0.483 0.610 0.761 0.761 95% 95% 95% 96%30 - 60 0.054 0.059 0.061 0.059 0.453 0.637 0.776 0.776 88% 91% 92% 92%60 - 90 0.054 0.064 0.072 0.067 0.415 0.581 0.739 0.739 87% 89% 90% 91%90 - 120 0.049 0.063 0.077 0.067 0.519 0.723 0.924 0.924 91% 91% 92% 93%120 - 150 0.145 0.176 0.196 0.185 0.061 0.071 0.082 0.082 -138% -148% -139% -126%150 - 180 0.144 0.174 0.193 0.181 0.171 0.224 0.333 0.333 16% 22% 42% 46%180 - 210 0.046 0.056 0.064 0.057 0.284 0.393 0.615 0.615 84% 86% 90% 91%210 - 240 0.069 0.088 0.104 0.093 0.218 0.293 0.536 0.536 68% 70% 81% 83%240 - 270 0.105 0.131 0.163 0.152 0.090 0.124 0.317 0.317 -17% -6% 49% 52%270 - 300 0.065 0.085 0.124 0.114 0.227 0.304 0.526 0.526 71% 72% 76% 78%300 - 330 0.043 0.058 0.078 0.068 0.216 0.302 0.540 0.540 80% 81% 86% 87%330 - 360 0.024 0.030 0.036 0.031 0.328 0.418 0.568 0.568 93% 92.8% 94% 95%Average 0.07 0.08 0.10 0.42 0.29 0.39 0.56 0.56 76% 78% 82% 24%

"DJF" means December, January, and February "MAM" means March, April, and May"JJA" means June, July, August"SON" means September, October, November(All AERSURFACE default settings)

Surface Roughness Length (m) Surface Roughness Length (m)Lovell Field Site Difference (%): Site - Lovell Field

Bowen Ratio Bowen RatioLovell Field Site Difference (%): Site - Lovell Field

Albedo AlbedoLovell Field Site Difference (%): Site - Lovell Field


Source Types and Parameters

The AERMOD dispersion model allows for emission units to be represented as point, area, or volume sources. Point sources with unobstructed vertical releases will be modeled with their actual stack parameters (i.e., height, diameter, exhaust gas temperature, and gas exit velocity). All Smith Facility sources to be evaluated in this modeling assessment will have vertical unobstructed releases, and will therefore be evaluated at their actual release velocity conditions.

GEP Stack Height Analysis

EPA has promulgated stack height regulations that restrict the use of stack heights in excess of “Good Engineering Practice” (GEP) in air dispersion modeling analyses. Under these regulations, that portion of a stack in excess of the GEP height is generally not creditable when modeling to determine source impacts. This essentially prevents the use of excessively tall stacks to reduce ground-level pollutant concentrations. This equation is limited to stacks located within 5L of a structure. Stacks located at a distance greater than 5L are not subject to the wake effects of the structure. The wind direction-specific downwash dimensions and the dominant downwash structures used in this analysis are determined using BPIP. In general, the lowest GEP stack height for any source is 65 meters by default.20 A preliminary evaluation has indicated that none of the facility emission unit stacks will exceed GEP height.

Regional Source Inventory (Class II Modeling)

For any off-site impact calculated in the Significance Analysis that is greater than the SIL for a given pollutant, a NAAQS analysis incorporating nearby sources is required. The initial off-site inventory radius will be the radius of the pollutant-specific largest SIA (except for 1-hour NO2) plus 50 km. Oglethorpe will use EPD’s “PSD Modeling Tool” to obtain the off-site inventory sources necessary for the analysis.21 Oglethorpe will only consider Synthetic Minor or minor sources within 5 km of the Smith Facility for any required refined modeling analysis. Oglethorpe will then apply the “20D” rule to eliminate sources based on their distance from the site in kilometers and quantity of emissions in tons per year. Emissions from all stacks within a single facility and other facilities that are located near one another (within 2 km) will be totaled. For long-term models (annual), if the total emissions for the group of sources calculated are less than twenty times the distance from the source to the SIA distance, the source will eliminated from the modeling analysis. For short-term models (24-hour or shorter), if the total emissions for the group of sources are less than twenty times the distance from the source to the site, the source will be eliminated from the modeling. This approach is consistent with GAEPD’s February 2017 document titled PSD Permit Application Guidance Document. Further refinements may be conducted in consultation with the GAEPD, especially for evaluation of 1-hour NO2. Alternative methods may be used in accordance with Guideline which states that “The number of nearby sources to be explicitly modeled in the air quality analysis is expected to be few except in unusual situations. In most cases, the few nearby sources will be located within the first 10 to 20 km from the source(s) under consideration. Owing to both the uniqueness of each modeling situation and the large number of variables involved in identifying nearby sources, no attempt is made here to comprehensively define a “significant concentration gradient.” Rather,

20 40 CFR §51.100(ii)

21 https://psd.georgiaair.org/inventory

https://psd.georgiaair.org/inventory


identification of nearby sources calls for the exercise of professional judgment by the appropriate reviewing authority…”.22 Therefore, for this project, if the SIL for 1-hr NO2 is exceeded, it is proposed that regional inventory sources no more than 20 km from the facility be included in the refined modeling analysis. 23

NO2 Modeling Approach

The revised Guideline now indicates Ambient Ratio Method 2 (ARM2) has replaced ARM as the regulatory default Tier 2 NO2 modeling method. Oglethorpe proposes to utilize ARM2 for modeling NO2 for the 1-hour and annual SIL and NAAQs modeling assessments, and for the annual PSD increment modeling assessment. Should further refinement be needed with Tier 3 modeling methods, such as the Ozone Limiting Method (OLM) or Plume Volume Molar Ratio Method (PVMRM), Oglethorpe will contact the GAEPD. As discussed in an earlier section of this modeling protocol, significance modeling utilizing ARM2 will model both future potential emissions, and past actual emissions, as positive emission rates in separate modeling files, and subtract the results at each receptor manually using plot file output information.

22 Appendix W, Section 8.3.3.b.iii

23 This assumes the significant impact area distance for the project for 1-hr NO2 will be less than 20 km. If greater than 20 km, the maximum inventory source distance utilized in the refined modeling analysis will be set to the significant impact area distance. At such a distance, it is highly unlikely that there would be temporal or spatial pairing of real world facility emission plumes between Smith Facility sources and regional modeled sources.


Startup/Shutdown Modeling and Variable Load Modeling

As discussed in an earlier section of this modeling protocol, Startup/Shutdown modeling will not be conducted for project significance modeling, as there are no changes to the facility emission units that would have an influence on the startup cycle or expected startup emissions. Only normal source operating conditions are expected to change as part of the proposed facility changes. However, Startup/Shutdown (SUSD) modeling will be considered for any required refined modeling analysis for this project, for all non-annual NAAQS and Increment standards. Details regarding the SUSD modeling are as follows.

1. Two startup times, one at 4 AM and one at 10 AM will be included as separate modeling runs in the modeling assessment. These are the expected startup times of highest frequency for the Smith Facility.

2. As noted above, only short term (non-annual) averaging periods for applicable pollutants will be evaluated in the model.

3. A cold startup cycle (approximately 4 hours) is the worst case startup condition based on the amount of time of startup, and will be the focus of any required SUSD modeling.

4. Startup source parameters (velocity/temperature/emissions) will be developed for each hour of the startup cycle.

From a load basis, the project emissions source (Block 1/Block 2) source parameters for 75% load and 100% load will be developed, and evaluated to determine the worst case modeled impacts for each applicable pollutant. That load basis (on a pollutant by pollutant basis) will be carried through as the normal operating condition in all modeling assessments for the project. 24

Particulate Matter Precursor Emissions Modeling

The September 2018 GAEPD guidance document titled Guidance on the Use of EPA’s MERPs to Account for Secondary Formation of Ozone and PM2.5 in Georgia has established a state-specific Tier 1 procedure for a demonstration that a project will not cause or contribute to ambient air quality impacts of PM2.5 associated with secondary PM2.5 emissions. The modeling report to be provided with the permit application for this project will include a Tier 1 assessment for secondary PM2.5 in accordance with GAEPD’s MERPs guidance. Precursor based emission impacts on all PM2.5 modeling for this project will be considered.

ADDITIONAL IMPACTS MODELING METHODOLOGY

The required additional impacts evaluations for this project will include a growth analysis and a soil and vegetation analysis. It is anticipated that no Class II visibility areas (e.g. state parks) will be within the significant impact areas derived for the project, and therefore no Class II visibility assessment will be evaluated for this project.

TOXIC AIR POLLUTANT MODELING

EPD regulates the emissions of toxic air pollutants through a program approved under the provisions of GRAQC Rule 391-3-1-.02(2)(a)3(ii). A TAP is defined as any substance that may have an adverse effect on public health, excluding any specific substance that is covered by a State or Federal ambient air quality standard. Procedures

24 50% load is not a normal operating condition for the facility, and will therefore not be evaluated as an operating condition for facility operations.


governing the EPD’s review of toxic air pollutant emissions as part of air permit reviews are contained in EPD’s Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions (the Toxics Guideline).25

The Toxics Guideline has established the Allowable Ambient Concentration (AAC) and Minimum Emission Rate (MER) for each TAP, which are included in Appendix A of the Toxics Guideline. The MERs were established by EPD by using worst-case dispersion scenarios and using the SCREEN3 computer air dispersion model. The MERs were stablished considering both short-term and long-term exposures, where the lowest MER calculated for each substance was selected as the MER for that substance. Thus, the facility-wide emission rates in lb/yr for each TAP will be used to compare to the MERs. If a pollutant’s facility-wide emission rate is below the MER, no further analysis will be required for that pollutant. For any pollutant whose emission rate is above its respective MER, Oglethorpe will provide a demonstration that facility-wide emissions for that pollutant will not result in an ambient impact above its respective AAC.

If AERMOD is used for the air toxics analysis, all applicable elements of the modeling methodology outlined for the PSD air dispersion modeling analysis will be utilized as developed for that analysis, including the effects of building downwash. If ISCST3 is used, the refined modeling procedures outlined in the Guideline will be utilized. Meteorological data for use with the ISCST3 model for Chattanooga/Greensboro (1987-1989), as available on the Georgia EPD website, will be used unless otherwise specified.

SUMMARY AND APPROVAL OF MODELING PROTOCOL

Oglethorpe is supplying this written preliminary protocol so that the EPD can formally comment on, and approve the methodologies to be used for this analysis, and request any additional information. Oglethorpe requests a written response to this protocol as soon as possible. All modeling files and reports will be provided electronically, as part of the permit application.

If you have any questions about the material presented in this letter, require additional information, or would like to talk about any of the proposed methods, please do not hesitate to call me at 678-441-9977 Ext. 228. Sincerely, TRINITY CONSULTANTS Justin Fickas Managing Consultant cc: Mr. James Eason (EPD) Mr. Eric Cornwell (EPD)

Ms. Toni Presnell (Oglethorpe)

25 Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions. Georgia Department of Natural Resources, Environmental Protection Division, Air Protection Branch, Revised, May 2017.

Richard E. Dunn, Director Air Protection Branch

4244 International Parkway

Suite 120

Atlanta, Georgia 30354

404-363-7000

November 26, 2018

Mr. Justin Fickas

Trinity Consultants

Tel: 678-441-9977 ext. 228 [email protected]

Subject: Review of PSD Air Dispersion Modeling Protocol

Oglethorpe Power Corporation – Smith Energy Facility, Dalton, Murray County, GA

Dear Mr. Fickas:

We have reviewed the air quality dispersion modeling protocol received on October 31, 2018 for a

major modification project at the Oglethorpe Power Corporation – Smith Energy Facility (OPC-Smith),

Dalton, Murray County, GA. We find that it generally conforms to the procedures and guidelines we use

to assess Prevention of Significant Deterioration (PSD) and air toxic impact modeling projects.

However, we do have the following comments:

1. Class I Increment Analysis: EPA/EPD retain purview over Class I increment consumption, so both

agencies should get a copy of any project correspondence you may have with any Federal Land

Manager (FLM). If the project is not required to assess Air Quality Related Values (AQRVs) at any

Class I area, you may perform Class I area increment screening modeling with AERMOD. The

receptors should be placed approximately 1-km evenly spaced on a 50-km arc from the OPC-Smith

towards the Class I areas being evaluated. If the initial screening modeling indicates the project will

exceed applicable significance levels at any Class I area, the applicant may use CALPUFF or other

Lagrangian models to calculate the air quality impact at the Class I area as the second level

screening modeling. If the impact modeled during the second level screening exceeds the applicable

significance levels at any Class I area, a refined analysis including the offsite inventory is needed. A

modeling protocol should be submitted. Please consult with GA EPD and EPA Region 4 for further

discussion. For the Cohutta Wildness Area located 30.6 km northeast from the OPC-Smith facility,

all receptors of this Wildness area (https://www.nature.nps.gov/air/maps/receptors/) should be

evaluated using AERMOD. Should the modeled impact exceeds the applicable significance levels at

any receptors, a refined analysis including the offsite inventory is needed. In addition, if any of the

PM2.5, NOx, or SO2 emissions are greater than their applicable significant emission rates (SER), the

total impact from the primary PM2.5, and the secondary formation of PM2.5 from precursors NOx and

SO2 should be evaluated in the Class I area increment analysis.

The increment screening modeling should not employ building downwash, nor should it include the

assessment of fugitive emissions.

2. Air Toxics: Air toxics modeling should be conducted in accordance with the GA EPD Guideline for

Ambient Impact Assessment of Toxic Air Pollutant Emissions, 2017. AERMOD (version 18081) is

recommended for the air toxics modeling. Air toxics model receptors should extend to at least 2 km


https://www.nature.nps.gov/air/maps/receptors/

outward from the project site, and there must be sufficient receptors to resolve the Maximum

Ground-Level Concentration (MGLC). If any receptors are located at terrain elevations in excess of

the lowest stack height in the model, AERMOD must be used to assess impacts at those receptors.

The air toxics modeling must be conducted with all on-site sources of the same pollutant.

The GA EPD Stationary Source Permitting Program (SSPP) will determine which TAPs need to be

assessed. The AAC spreadsheet developed by GA EPD can be found at

https://epd.georgia.gov/air/documents/appendix-list-tap-aac-and-mer. Please review the AAC values

at the applicable averaging periods and ensure the use of the most recently updated values.

3. Class II criteria pollutant dispersion modeling should use the latest AERMOD version 18081 and

follow the Revisions to the Guideline on Air Quality Models (Appendix W, EPA 2017). According

to Table 8.2 of Appendix W (2017), the emissions modeled in the significant impact analysis should

reflect the post-project potential emission rates for all modified units

As provided in the AERMOD User’s Guide, any DEFAULT option may be employed in the

modeling. Use of Non-Default options is subject to case-by-case approval by EPA Regional office.

A tiered approach is recommended for determining the air quality impact of NO2 emission from

point sources. GA EPD concurs with the applicant’s proposal to utilize the default AERMOD ARM2

option for all short and long-term analysis of NO2 emissions. The default setting for the NO2/NOx

ratio is a minimum value of 0.5 at the highest NOx levels and a maximum value of 0.9 at the lowest

NOx levels. The applicant should consult with GA EPD and EPA regional office if a Tier 3 approach

such as the Ozone Limited Method (OLM) or Plume Volume Molar Ratio Method (PVMRM) is

used. GA EPD concurs with the applicant’s proposal to evaluate the impact from the post-project

potential emission and past actual emission (also baseline) separately.

As required by the 2017 revisions to EPA’s Guideline on Air Quality Models (Appendix W), the

applicant should evaluate the impact of the secondary formation of PM2.5 from precursors NOx and

SO2, and ozone from NOx and VOC following the EPA’s “Guidance on the Development of

Modeled Emission Rates for Precursors (MERPs) as a Tier l Demonstration Tool for Ozone and

PM2.5 under the PSD Permitting Program” (December 2, 2016), and GA EPD’s “Guidance on the

Use of EPA’s MERPs to Account for Secondary Formation of Ozone and PM2.5 in Georgia”

(September 19, 2018). The impact should be evaluated if the emissions of the PM2.5 precursors (NOx

and/or SO2) are greater than the significant emission rate (SER) of 40 tons per year or primary PM2.5

greater than 10 tons per year.

4. Off-site Inventory, NAAQS and Increment Issues: If the project is significant for any averaging

period of any criteria pollutants, a cumulative air quality analysis (both NAAQS and PSD increment

if applicable) will be required. Please carefully distinguish between NOx and NO2 and provide your

definition of NO2 in the air quality modeling report. Please follow the inventory development and

receptor placement guidance in the Georgia EPD PSD Permit Application Guidance Document

(September, 2012) and Section 8.3.3 of Appendix W (2017). The minor source baseline date

(MSBD) for the annual NO2 is May 5, 1988, statewide, and for PM2.5 is October 20, 2011, statewide.

The SSPP will review and approve your on-site emissions inventory including the stack parameters

and emission rates. For off-site emissions inventories, GA EPD has made available a PSD inventory

tool located at https://epd.georgia.gov/air/permit-modeling-information. Please use this tool to

develop an initial off-site emissions inventory within 50km of the OPC-Smith facility. This

inventory can be supplemented and corrected as necessary with approval from GA EPD. If any

https://epd.georgia.gov/air/documents/appendix-list-tap-aac-and-mer

https://epd.georgia.gov/air/permit-modeling-information

missing inventory information is identified, the applicant should consult GA EPD SSPP regarding

your specific missing data handling technique.

Off-site sources can be screened out from the cumulative analysis using a “20D” approach, provided

they are not located within the significant impact area. The emissions of the sources within 2 km

should be grouped together for the “20D” evaluation. Details can be found at Section 5.3 of GA EPD

PSD Guidance Document at http://epd.georgia.gov/air/georgia-epd-psd-permit-application-guidance-

document. Any sources including synthetic minor or minor sources within the significant impact

distance should be considered in the cumulative modeling. The applicant should also follow Section

8.3.3 and Table 8-2 of Appendix W (2017) to identify the nearby sources. The applicant may

propose to use emissions that are different from that in the Georgia PSD inventory tool (e.g., typical

actual emissions). These requests will be evaluated by GA EPD on a case-by-case basis. Also,

sources in TN that are within 50km of the project location should be considered.

5. Ambient Concentrations: The ambient concentrations for year 2015-2017 period can be found at

GA EPD website https://epd.georgia.gov/air/documents/georgia-background-data. Table 3 of

protocol should list more recent ambient concentrations, i.e. year 2015-2017. The recent PM2.5

background concentration at Rossville is 16.8 g/m3 at 24-hour and 8.4 g/m3 annually.

6. General Modeling considerations: Please use BPIP PRIME (version 04274) to assess building

downwash dimensions and GEP stack heights. Stacks of heights equal to, or in excess of GEP

height should be modeled using the GEP height. Please use AERMAP (version 18081) to assess all

model receptor elevations above sea level with the USGS NED database (all model coordinates,

including building corners, should be referenced using the NAD83 datum). Please assess source

base elevations using AERMAP, if appropriate, otherwise, use plant grade elevations. The latest

version of AERMOD (version 18081) should be used for the air impact modeling of all criteria

pollutants. AERMOD meteorological data set (for the period 2013-2017, with adjusted surface

friction velocity U* option) can be obtained at http://epd.georgia.gov/air/georgia-aermet-

meteorological-data. The data was compiled from Chattanooga Lovell Field Airport, TN, NWS

surface station and Peachtree City Falcon Field, GA, upper air observations. The applicant is

expected to provide the meteorological data representative analysis using AERSURFACE (version

13016).

7. Model Receptors: Model receptors should be spaced along the ambient air boundary and should

extend outward from the facility to ensure that the maximum impact location and the significant

impact distance are located with an area of 100-m meter spacing. Model receptors at 100 meter

spacing should extend outward from the facility at least 2 km in all directions but may need to

extend even further. Larger grid spacing may be used if the ultimate design value is determined by

re-modeling with a fine 100-m grid around a more coarsely resolved design concentration. All

design concentrations equal to or greater than 90% of the design concentrations should be resolved

at the 100-m or less grid resolution.

GA EPD requests that a facility plot showing the facility boundary be submitted in the permit

application. Any areas outside the facility fence-line will be considered ambient air.

8. Preconstruction Monitoring Evaluation: The applicant should submit the Monitoring De Minimis

concentration comparison and Ozone Impact Analysis to determine whether the proposed

application is required to conduct preconstruction monitoring for the applicable criteria pollutants

and/or ozone. Please check the Georgia EPD PSD Permit Application Guidance Document

(September, 2012) for details.

http://epd.georgia.gov/air/georgia-epd-psd-permit-application-guidance-document

http://epd.georgia.gov/air/georgia-epd-psd-permit-application-guidance-document


http://epd.georgia.gov/air/georgia-aermet-meteorological-data

http://epd.georgia.gov/air/georgia-aermet-meteorological-data

9. Additional Impacts: All additional impacts studies will be limited to no more than the largest

significant impact distance from the project site. Additional impacts studies do not include National

Monuments, unless specifically requested by a Federal Land Manager. Please check the Georgia

EPD PSD Permit Application Guidance Document (September, 2012) for details.

10. Worst-Case Scenario Determination: The OPC-Smith should discuss and determine the worst-case

scenario and use that scenario to conduct the air impact modeling assessment for this project.

Please refer to GA EPD PSD Guidance Document Appendix A and B for completeness of your

application. If EPA issues any guidance, or models which you believe may affect the modeling of this

project subsequent to this protocol approval letter, please contact GA EPD to verify the ability to

incorporate such guidance or models in the assessments of this application. If you have specific

questions on issues that develop after you receive this protocol approval letter, please contact EPD too.

This protocol approval is valid for 6 months from today, unless otherwise stipulated. If you have any

question, please contact Yan Huang at [email protected] or 404-363-7072.

Sincerely,

Di Tian, Ph.D.

Manager, Data & Modeling Unit

Georgia Department of Natural Resources

Environmental Protection Division - Air Protection Branch

Attachments: Generally Applicable Modeling References


Generally Applicable Modeling References

1990, Draft New Source Review Workshop Manual.

1995, User's Guide For the Industrial Source Complex (ISC3) Dispersion Models, Volume I - User Instructions,

Volume II - Description of Model Algorithms, EPA-454/B-95-003a & b.

2002, User Instructions for the Revised ISCST3 Model (version 02035).

2004, User's Guide to the Building Profile Input Program (BPIP), Revised with the PRIME algorithm (BPIPPRM,

version 04274), EPA-454/R-93-038.

2010, Federal Land Managers’ (FLMs) Air Quality Related Values Work Group (FLAG) Phase I Report -

Revised, http://www.nature.nps.gov/air/Pubs/pdf/flag/FLAG_2010.pdf

2010, Prevention of Significant Deterioration (PSD) for Particulate Matter Less Than 2.5 Micrometers (PM2.5)--

Increments, Significant Impact Levels (SILs) and Significant Monitoring Concentration (SMC), Final rule,

Federal Register vol. 75, No. 202, pgs. 64863-64907 (October 20, 2010).

2012, Georgia EPD PSD Permit Application Guidance Document, https://epd.georgia.gov/air/georgia-epd-psd-

permit-application-guidance-document

2014, Guidance for PM2.5 Permit Modeling,

https://www3.epa.gov/scram001/guidance/guide/Guidance_for_PM25_Permit_Modeling.pdf

2017, Guideline for Ambient Impact Assessment of Toxic Air Pollutant Emissions,

https://epd.georgia.gov/air/documents/toxics-impact-assessment-guideline

2017, 40 CFR 51, Appendix W, Revisions to the Guideline on Air Quality Models,

https://www3.epa.gov/ttn/scram/appendix_w/2016/AppendixW_2017.pdf

2018, AERMOD Implementation Guide,

https://www3.epa.gov/ttn/scram/models/aermod/aermod_implementation_guide.pdf

2018, User's Guide for the AERMOD Terrain Preprocessor (AERMAP, version18081), EPA-454/B-18-004,

https://www3.epa.gov/ttn/scram/models/aermod/aermap/aermap_userguide_v18081.pdf

2018, User's Guide for the AMS/EPA Regulatory Model (AERMOD, version 18081), EPA-454/B-18-001,

https://www3.epa.gov/ttn/scram/models/aermod/aermod_userguide.pdf

http://www.nature.nps.gov/air/Pubs/pdf/flag/FLAG_2010.pdf

https://epd.georgia.gov/air/georgia-epd-psd-permit-application-guidance-document

https://epd.georgia.gov/air/georgia-epd-psd-permit-application-guidance-document

https://www3.epa.gov/scram001/guidance/guide/Guidance_for_PM25_Permit_Modeling.pdf

https://epd.georgia.gov/air/documents/toxics-impact-assessment-guideline

https://www3.epa.gov/ttn/scram/models/aermod/aermod_implementation_guide.pdf

https://www3.epa.gov/ttn/scram/models/aermod/aermap/aermap_userguide_v18081.pdf

https://www3.epa.gov/ttn/scram/models/aermod/aermod_userguide.pdf

1

Justin Fickas

From: Tian, Di <[email protected]>Sent: Thursday, October 11, 2018 1:55 PMTo: Justin Fickas; Huang, Yan; Boylan, JamesCc: Cornwell, EricSubject: RE: Modeling Questions for Potential Project in Georgia

Hi Justin, Please see our comments below.

1. ADJ_U* ‐ Georgia EPD now has posted (for AERMET data) meteorological data sets developed both with and without use of ADJ_U*. Is any justification needed for use of the ADJ_U* data set? If so, what are EPD’s expectations for a justification for use of the ADJ_U* data set? GA EPD: No justification is needed for the use of the ADJ_U* dataset, as this is default option in AERMOD.

2. Insight on current guidance regarding treatment of emergency generators/intermittent sources in

modeling. For modeling, due to the intermittent nature of emergency units it would be argued that they be excluded from modeling assessments. Would EPD concur with this? GA EPD: GA EPD guidance does not require the modeling of the air impact from emergency generators/intermittent sources.

3. Modeling inventory development. Based on recent EPA rulemaking regarding Appendix W, the standard significant impact area + 50 km methodology for development of modeling inventories is inappropriate, particularly for short term standards such as 1‐hr NO2. Any objection or concern regarding proposal (as part of a modeling protocol) for alternative modeling inventory development methods? One proposed option might include limiting the inventory sources included to a specified distance for 1‐hr NO2 modeling, based on recommendations provided in Appendix W (e.g. 10 km). Is there any new State specific guidance EPD can share regarding this? GA EPD: All sources in the 50 km modeling domain need to be evaluated. If a source has emissions less than 20D, this source doesn’t need to be included in the cumulative analysis. If a source has emissions larger than 20D, it should be included in the cumulative analysis, or please consult with EPD to determine whether this source needs to be included in the cumulative analysis. EPD will make case‐by‐case decision depending on the specific value of Q/D and the specific modeling project. We will following the EPA guidelines: “The number of nearby sources to be explicitly modeled in the air quality analysis is expected to be few except in unusual situations. In most cases, the few nearby sources will be located within the first 10 to 20 km from the source(s) under consideration. Owing to both the uniqueness of each modeling situation and the large number of variables involved in identifying nearby sources, no attempt is made here to comprehensively define a ‘‘significant concentration gradient.’’ Rather, identification of nearby sources calls for the exercise of professional judgment by the appropriate reviewing authority (paragraph 3.0(b)).”

4. Class I Impacts Analysis – Regarding Class I increment area impacts, what would EPD’s stance be regarding the necessary inventory/modeled area range around a Class I area, if Class I significant impact levels would be exceeded for PSD increment? My concern is regarding the alternative modeling approval requirement now present under Appendix W for long range transport models (e.g. CALPUFF). Appendix W has stipulations that CALPUFF can be used for screening purposes (significance analyses), but any refined analyses for Class I areas seeking to use CALPUFF, would require an alternative modeling approval. GA EPD: We recommends to first perform AERMOD modeling to identify the maximum impacts at the 50 km

circle from the facility. If the modeled maximum impacts at the 50 km with AERMOD exceeds the Class I SIL,

2

CALPUFF or other Lagrangian models can be used to model impact at the class I area (>50 km) as part of the

second level screening process. If the impact identified during the second level screening at the class I area

exceeds the Class I SIL, a refined modeling analysis is needed. A modeling protocol should be prepared to discuss

what an alternative model is planned to be used and why, as well as detailed modeling setups. This modeling

protocol should also be sent to EPA Region 4 for approval.

In addition, if emissions of any of the PM2.5, NOx, or SO2 are greater than significant emission rates (SER), the

secondary impact from NOx and SO2 should be considered in the Class I area increment analysis.

“For assessment of the significance of ambient impacts for NAAQS and/or PSD increments, there is not a

preferred model or screening approach for distances beyond 50km. Thus, the appropriate reviewing authority

(paragraph 3.0(b)) and the EPA Regional Office shall be consulted in determining the appropriate and agreed

upon screening technique to conduct the second level assessment.”

“the screening approach to address long‐range transport for purposes of assessing NAAQS and/or PSD

increments; removing CALPUFF as a preferred model in appendix A for such long‐range transport assessments;

and confirming our recommendation to consider CALPUFF as a screening technique along with other Lagrangian

models that may be used as part of this screening approach without alternative model approval”.

In a situation where a facility was within 50 km of a Class I area, would EPD agree that any refined Class I increment analysis be limited to a range of 50 km from the Class I area of interest? This would eliminate the potential need to seek alternative model approval from EPA for use of CALPUFF (or other model) for any refined increment modeling for a Class I area (for evaluations greater than 50 km). GA EPD: If a major source is located within 10km from a class I area, and has an impact of 1 ug/m3 on a 24‐hour basis, both PSD increment and AQRV analysis are required regardless of its emission. A screening analysis with AERMOD is suggested. If a facility is located within 50km of a class I area but beyond 10km, GA EPD recommends that AERMOD be used to calculate the consumption of PSD increment following the Class II increment analysis procedure by modeling the air impact on the Class I area receptors, which can be downloaded from www.nature.nps.gov/air/Maps/Receptors/index.cfm

Please let us know if you have any other questions. Thanks! Di ================================= Di Tian, Ph.D. Manager, Data & Modeling Unit Georgia Department of Natural Resources Environmental Protection Division ‐ Air Protection Branch 4244 International Parkway, Suite 120 Atlanta, GA 30354 Office: 404‐362‐4851 Fax: 404‐363‐7100 E‐mail: [email protected]

From: Justin Fickas [mailto:[email protected]] Sent: Thursday, October 11, 2018 12:39 PM To: Tian, Di; Huang, Yan; Boylan, James Cc: Cornwell, Eric Subject: RE: Modeling Questions for Potential Project in Georgia

3

CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.

DiAnyupdateonanswerstomyquestionsbelow?ThanksJustinFickas,P.E.ManagingConsultantTrinityConsultants3495PiedmontRoad|Building10,Suite905|Atlanta,Georgia30305

Office:678‐441‐9977,ext.228|Direct:404‐751‐0228|Fax:678‐441‐9978Email:[email protected]|www.trinityconsultants.com

From: Tian, Di [mailto:[email protected]] Sent: Monday, October 01, 2018 2:51 PM To: Justin Fickas <[email protected]>; Huang, Yan <[email protected]>; Boylan, James <[email protected]> Cc: Cornwell, Eric <[email protected]> Subject: RE: Modeling Questions for Potential Project in Georgia Hi Justin, We have received your questions and will get back to you later this week or early next week. Di

From: Justin Fickas [mailto:[email protected]] Sent: Thursday, September 27, 2018 4:26 PM To: Tian, Di; Huang, Yan; Boylan, James Cc: Cornwell, Eric Subject: Modeling Questions for Potential Project in Georgia

CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe.

Di/Yan/JimAsafollowuptosomediscussionswithEricCornwellthisweek,IwantedtofollowupwithyouonsomehigherlevelmodelingquestionsregardingafutureupcomingpotentialPSDproject.Icopiedallofyouonthise‐mail,asIfeltyoueachmighthavesomethoughts/insightonthesequestions.Pleaseletmeknowifyouhaveanyfollowupquestionsofyourown,orifeasiertochatcangivemeacallatmycontactinformationinmye‐mailsignatureblockbelow.

1. ADJ_U*‐GeorgiaEPDnowhasposted(forAERMETdata)meteorologicaldatasetsdevelopedbothwithandwithoutuseofADJ_U*.IsanyjustificationneededforuseoftheADJ_U*dataset?Ifso,whatareEPD’sexpectationsforajustificationforuseoftheADJ_U*dataset?

4

2. Insightoncurrentguidanceregardingtreatmentofemergencygenerators/intermittentsourcesinmodeling.Formodeling,duetotheintermittentnatureofemergencyunitsitwouldbearguedthattheybeexcludedfrommodelingassessments.WouldEPDconcurwiththis?

3. Modelinginventorydevelopment.BasedonrecentEPArulemakingregardingAppendixW,thestandardsignificantimpactarea+50kmmethodologyfordevelopmentofmodelinginventoriesisinappropriate,particularlyforshorttermstandardssuchas1‐hrNO2.Anyobjectionorconcernregardingproposal(aspartofamodelingprotocol)foralternativemodelinginventorydevelopmentmethods?Oneproposedoptionmightincludelimitingtheinventorysourcesincludedtoaspecifieddistancefor1‐hrNO2modeling,basedonrecommendationsprovidedinAppendixW(e.g.10km).IsthereanynewStatespecificguidanceEPDcanshareregardingthis?

4. ClassIImpactsAnalysis–RegardingClassIincrementareaimpacts,whatwouldEPD’sstanceberegardingthenecessaryinventory/modeledarearangearoundaClassIarea,ifClassIsignificantimpactlevelswouldbeexceededforPSDincrement?MyconcernisregardingthealternativemodelingapprovalrequirementnowpresentunderAppendixWforlongrangetransportmodels(e.g.CALPUFF).AppendixWhasstipulationsthatCALPUFFcanbeusedforscreeningpurposes(significanceanalyses),butanyrefinedanalysesforClassIareasseekingtouseCALPUFF,wouldrequireanalternativemodelingapproval.Inasituationwhereafacilitywaswithin50kmofaClassIarea,wouldEPDagreethatanyrefinedClassIincrementanalysisbelimitedtoarangeof50kmfromtheClassIareaofinterest?ThiswouldeliminatethepotentialneedtoseekalternativemodelapprovalfromEPAforuseofCALPUFF(orothermodel)foranyrefinedincrementmodelingforaClassIarea(forevaluationsgreaterthan50km).

Asstatedabove,ifyouhaveanyquestionsorwouldliketodiscussdirectlywithme,pleaseletmeknow.ThanksJustinFickas,P.E.ManagingConsultantTrinityConsultants3495PiedmontRoad|Building10,Suite905|Atlanta,Georgia30305

Office:678‐441‐9977,ext.228|Direct:404‐751‐0228|Fax:678‐441‐9978Email:[email protected]|www.trinityconsultants.com

Oglethorpe Power Corporation | Advanced Gas Path/Minimum Load Project PSD Permit Application Volume II Trinity Consultants D

APPENDIX D: EMISSIONS INFORMATION FOR MODELING

Appendix D - Emissions Information For Modeling

Oglethorpe Power Corporation - Thomas A. Smith Energy Facility

Table D-1. CCCT Stack Parameters at 100% Load

Stack Height Temperature Velocity Diameter

Source (ft) (F) (ft/s) (ft)

CCCT1 160 211 60.0 18

CCCT2 160 211 60.0 18

CCCT3 160 211 60.0 18

CCCT4 160 211 60.0 18

100% Load Parameters Trinity Consultants Page 1 of 6



Table D-2. CCCT Stack Parameters at 75% Load

Stack Height Temperature Velocity Diameter

Source (ft) (F) (ft/s) (ft)

CCCT1 160 211 48.0 18

CCCT2 160 211 48.0 18

CCCT3 160 211 48.0 18

CCCT4 160 211 48.0 18

75% Load Parameters Trinity Consultants Page 2 of 6



Table D-3. NOX Emissions for NO2 Significance Modeling

Past Actual Emissions Future Potential Emissions

Source (NOX lb/hr)1

(NOX lb/hr)2

CCCT1 19.30 36.30

CCCT2 18.68 36.30

CCCT3 19.90 36.30

CCCT4 19.05 36.30

1 Past actual NOx emissions derived from facility NOx CEMS data and hourly operations

over the April 2011 to March 2013 baseline period.2 Future potential emissions based on worst case hourly maximum heat input rate

(2,594 MMBtu/hr) and the proposed BACT limit of 3 ppm at 15% O2.

NO2 Emissions Data-Significance Trinity Consultants Page 3 of 6



Table D-4. PM Emissions for PM NAAQS Significance Modeling


Source (PM10/PM2.5 lb/hr)1

(PM10/PM2.5 lb/hr)2

CCCT1 14.30 19.50

CCCT2 14.38 19.50

CCCT3 14.37 19.50

CCCT4 14.31 19.50

1 Past actual PM emissions derived from facility heat input rates over the April 2011

to March 2013 baseline period, and estimated short term emission rates.2 Future potential emissions based on the proposed future BACT limit of 19.5 lb/hr.

PM2.5 Emis Sig NAAQS Trinity Consultants Page 4 of 6



Table D-5. PM Emissions for PM2.5 Increment Significance Modeling


Source (PM2.5 lb/hr)1

(PM2.5 lb/hr)2

CCCT1 16.01 19.50

CCCT2 16.02 19.50

CCCT3 15.94 19.50

CCCT4 15.73 19.50

1 Past actual PM2.5 emissions derived from facility heat input rates over 2009 to 2010

preceding the PM2.5 increment baseline date. The existing facility is a baseline increment

source for PM2.5.2 Future potential emissions based on the proposed future BACT limit of 19.5 lb/hr.

PM25 Emissions Sig Increment Trinity Consultants Page 5 of 6



Table D-6. Site Sources for 1-Hour NO2 NAAQS Modeling

Future Potential Emissions Stack Height Temperature Velocity Diameter

Source (NOX lb/hr) (ft) (F) (ft/s) (ft)

CCCT1 36.30 160 211 60.0 18

CCCT2 36.30 160 211 60.0 18

CCCT3 36.30 160 211 60.0 18

CCCT4 36.30 160 211 60.0 18

Aux Boiler 1 0.76 50 400 51.7 2.0

Aux Boiler 2 0.76 65 400 51.7 2.0

Table D-7. CCCT Source Parameters for SUSD Modeling

Hour Temp (K) Velocity (m/s)

NOX Emissions

(lb/hr)

1 396.93 10.40 120

2 369.57 9.76 120

3 363.27 9.63 120

4 369.36 16.83 120

Non-SUSD Hours 372.59 18.29 36.3

1-hr NO2 NAAQS Site Sources Trinity Consultants Page 6 of 6

Table D-8. 1-hr NO2 Regional Source Inventory - Georgia Major and Minor Source 20D Review

SOURCE DESCRIPTION AIRS # City County

UTM East

(NAD83

Zone 17)

(m)

UTM North

(NAD83

Zone 17)

(m)

Potential Facility

NO2 Emissions

(tpy)

Distance

from

Facility

(km)

W/in 2 km

of another

facility?

NOX 20D

NOX Cluster

Emissions

(tpy)

NOX Exclude

Per 20D

Rule?

Include in NOX

Inventory?

Present in NOX

Inventory?

Shaw Industries Group Inc. - Plant 23 31300074 Dalton Whitfield 686,658 3,843,353 97.20 4.07 Yes N/A 679.85 N/A Yes Yes

Looper Bridge Road Meter Station 21300042 Dalton Murray 689,321 3,843,679 12.97 1.63 Yes N/A 91.87 N/A Yes No

Dalton Utilities-Rive 31300143 Dalton Whitfield 689,610 3,844,559 56.25 2.07 Yes N/A 91.87 N/A Yes No

International Vinyl Company 31300149 Dalton Whitfield 688,615 3,842,988 22.65 2.08 Yes N/A 202.27 N/A Yes No

Apollo Industries - Dalton Plant 31300160 Dalton Whitfield 687,132 3,842,778 0.00 3.56 Yes N/A 509.47 N/A No N/A

ALADDIN MILLS - ANTIOCH ROAD PLANT 31300077 Dalton Whitfield 687,605 3,845,534 72.35 4.13 Yes N/A 744.60 N/A Yes Yes

SHAW INDUSTRIES, INC. - PLANT WD 31300070 Dalton Whitfield 686,636 3,844,377 100.00 4.35 Yes N/A 1131.43 N/A Yes Yes

Shaw Industries Group Inc Plant 4 31300084 Dalton Whitfield 686,168 3,843,658 267.40 4.60 Yes N/A 827.42 N/A Yes Yes

Shaw Industries Group Inc. Plant 80 31300003 Dalton Whitfield 686,013 3,844,802 170.38 5.09 Yes N/A 1118.22 N/A Yes Yes

Mohawk Ind-Durkan Pat 31300124 Dalton Whitfield 687,100 3,845,815 62.90 4.69 Yes N/A 744.60 N/A Yes No

MOHAWK INDUSTRIES INC. 31300096 Dalton Whitfield 686,141 3,845,378 170.21 5.23 Yes N/A 1012.00 N/A Yes Yes

CHEM-TECH FINISHERS INC. 31300126 Dalton Whitfield 686,312 3,846,039 168.76 5.45 Yes N/A 744.60 N/A Yes Yes

US Floors LLC 31300148 Dalton Whitfield 685,192 3,840,587 0.00 5.92 Yes N/A 129.08 N/A Yes No

Roberts Capitol, Inc 31300154 Dalton Whitfield 686,002 3,838,859 18.58 6.12 Yes N/A 21.28 N/A Yes No

Harcros Chemicals, Inc. 31300116 Dalton Whitfield 684,694 3,841,325 10.50 6.17 Yes N/A 119.52 N/A Yes No

C & S Block Inc 31300024 Dalton Whitfield 685,674 3,846,666 0.00 6.34 Yes N/A 572.25 N/A No N/A

Beaulieu Plant 560 31300122 Dalton Whitfield 687,208 3,848,142 141.10 6.38 Yes N/A 57.00 N/A Yes Yes

Textile Coating Ltd 31300093 Dalton Whitfield 685,905 3,847,579 0.00 6.77 Yes N/A 225.76 N/A No N/A

Plastic Creations Inc 31300123 Dalton Whitfield 686,122 3,848,007 0.00 6.93 Yes N/A 225.76 N/A No N/A

Shaw Industries Group, Inc. - Plant 1 & 3 31300081 Dalton Whitfield 686,641 3,848,645 57.00 7.12 Yes N/A 57.00 N/A Yes No

American Emulsions 31300127 Dalton Whitfield 687,630 3,849,404 0.00 7.29 Yes N/A 57.00 N/A No N/A

Textile Rubber & Chem 31300055 Dalton Whitfield 683,697 3,840,455 0.00 7.37 Yes N/A 128.00 N/A No N/A

World Carpets Inc 31300086 Dalton Whitfield 686,410 3,848,955 0.00 7.50 Yes N/A 63.70 N/A No N/A

Hanwha Photovoltaic Module Manufacturing Facility 31300165 Dalton 0 685,027 3,837,781 0.00 7.56 Yes N/A 21.28 N/A No N/A

Solomon White Co 31300080 Dalton Whitfield 686,737 3,849,495 0.00 7.78 Yes N/A 63.70 N/A No N/A

Vulcan Construction Materials, LLC - Dalton Quarry 31300006 Dalton Whitfield 690,746 3,856,675 100.00 13.89 No N/A 100.00 N/A Yes No

Cagle's Farms Inc 31300044 Dalton Whitfield 685,853 3,847,003 0.00 6.41 Yes N/A 458.87 N/A No N/A

Aladdin Mills Bcf 31300065 Dalton Whitfield 684,540 3,841,263 100.00 6.33 Yes N/A 110.50 N/A Yes No

Matthews, C.W., Plt 26 31300111 Dalton Whitfield 690,566 3,856,774 0.00 13.98 No N/A 100.00 N/A No N/A

Murray Mix Concrete I 31300125 Dalton Whitfield 689,921 3,851,308 0.00 8.55 No N/A 0.00 N/A No N/A

Oriental Weavers of A 31300132 Dalton Whitfield 682,674 3,839,870 17.50 8.53 No N/A 17.50 N/A Yes No

Shaw Industries Group Inc Plant 6 31300136 Dalton Whitfield 686,300 3,852,942 0.00 11.06 Yes N/A 295.85 N/A No N/A

Syntrex, LLC 31300138 Dalton Whitfield 687,397 3,842,946 13.21 3.29 Yes N/A 500.45 N/A Yes Yes

Dalton Steam Services 31300107 Dalton Whitfield 688,137 3,850,954 38.50 8.55 Yes N/A 62.03 N/A Yes Yes

Trinseo 31300054 Dalton Whitfield 689,614 3,833,905 25.01 8.95 No N/A 25.01 N/A Yes Yes

Hawthorne Industries 31300088 Dalton Whitfield 685,472 3,850,101 0.00 8.98 Yes N/A 208.11 N/A No N/A

Oldcastle Industrial Minerals Inc 31300062 Dalton Whitfield 686,197 3,850,879 6.70 9.25 Yes N/A 302.93 N/A Yes No

Shaw Industries Group Plt WM 31300029 Dalton Whitfield 686,192 3,851,101 0.00 9.45 Yes N/A 358.26 N/A No N/A

Dalton Utilities-V.D. 31300144 Dalton Whitfield 693,810 3,851,789 47.70 9.53 No N/A 47.70 N/A Yes No

Columbia Recycling Co 31300134 Dalton Whitfield 685,477 3,850,878 0.00 9.62 Yes N/A 302.93 N/A No No

Dalton Foam Division of NCFI Polyurethanes 31300161 Resaca Whitfield 687,702 3,833,445 0.00 9.81 No N/A 25.01 N/A No No

XL Brands 12900080 Dalton Gordon 685,049 3,837,790 2.70 7.54 Yes N/A 21.28 N/A Yes No

Tandus Flooring Inc. 31300090 Dalton Whitfield 687,547 3,852,437 55.33 10.15 Yes N/A 295.85 N/A Yes Yes

Royal Adhesives & Sealants, LLC 31300011 Dalton Whitfield 687,590 3,852,632 0.00 10.32 Yes N/A 295.85 N/A No N/A

Shaw Industries Group Inc. Plant 81 31300001 Dalton Whitfield 686,259 3,851,703 88.70 9.95 Yes N/A 358.26 N/A Yes Yes

Vericol, Inc. 31300031 Dalton Whitfield 685,980 3,852,122 17.52 10.45 Yes N/A 358.26 N/A Yes Yes

Hamilton Medical Center 31300113 Dalton Whitfield 684,512 3,851,702 55.71 10.84 Yes N/A 339.01 N/A Yes No

Brooks C S World Carpets Inc-Bandy Plt 31300120 Dalton Whitfield 686,624 3,852,729 0.00 10.74 Yes N/A 302.55 N/A No N/A

Beaulieu Seretean 31300059 Dalton Whitfield 686,066 3,852,787 134.30 11.01 Yes N/A 358.26 N/A Yes No

Tandus Flooring Inc., Environmental Center 31300156 Dalton Whitfield 683,330 3,852,520 36.08 12.20 Yes N/A 95.59 N/A Yes No

Flexstar Packaging, Inc. 31300072 Dalton Whitfield 682,980 3,853,348 3.80 13.07 No N/A 39.88 N/A Yes Yes

Resaca Coatings 12900081 Resaca Gordon 688,279 3,830,576 100.00 12.45 No N/A 100.00 N/A Yes No

Georgia Carpet Finish 21300011 Chatsworth Murray 700,903 3,850,753 100.00 12.95 Yes N/A 300.00 N/A Yes No

Sustainable Corrugated 31300163 Dalton Whitfield 685,221 3,843,175 9.02 5.48 Yes N/A 654.50 N/A Yes No

Better Backers Inc 21300018 N/A Murray 702,550 3,850,457 100.00 14.12 Yes N/A 412.03 N/A Yes No

Shaw Industries Group, Inc. Plant WE 21300016 Chatsworth Murray 702,201 3,851,686 100.00 14.55 Yes N/A 412.03 N/A Yes No

Almatis, Inc. 31300026 Rocky Face Whitfield 680,637 3,853,344 100.00 14.57 No N/A 100.00 N/A Yes No



UTM East

(NAD83

Zone 17)

(m)

UTM North

(NAD83

Zone 17)

(m)

Potential Facility

NO2 Emissions

(tpy)

Distance

from

Facility

(km)

W/in 2 km

of another

facility?

NOX 20D

NOX Cluster

Emissions

(tpy)

NOX Exclude

Per 20D

Rule?

Include in NOX

Inventory?

Present in NOX

Inventory?

Aladdin Mfg Corp 21300020 Chatsworth Murray 702,712 3,851,988 100.00 15.14 Yes 302.79 312.03 N/A Yes No

O-N Minerals (Filler Products) Company 21300010 Chatsworth Murray 704,618 3,849,241 100.00 15.35 Yes 307.04 200.00 N/A Yes No

Custom Grinders Sales, Inc. #1 21300002 Chatsworth Murray 704,607 3,849,379 100.00 15.40 Yes 308.01 200.00 N/A Yes No

Murray County - U.S. 411 Westside MSW Landfill 21300040 Chatsworth Murray 708,075 3,840,154 100.00 17.59 No 351.73 100.00 N/A Yes No

Mohawk Industries - Sugar Valley 12900082 Sugar Valley Gordon 682,253 3,825,737 100.00 19.03 No 380.50 100.00 N/A Yes No

Pilgrim's Pride Corporation 5700023 Calhoun Gordon 689,734 3,823,777 100.00 19.04 No 380.73 100.00 N/A Yes No

Calhon Plastics & Chemicals Inc 12900076 Calhoun Gordon 693,627 3,822,461 100.00 20.54 No 410.80 100.00 N/A Yes No

REDBONE RIDGES MSW LANDFILL 12900070 Ranger Gordon 703,662 3,826,614 100.00 20.74 No 414.74 100.00 N/A Yes No

Concrete Ready Mix - Calhoun 12900078 Calhoun Gordon 688,006 3,821,934 100.00 21.03 Yes 420.55 651.60 N/A Yes No

Henkel Corporation 12900055 Calhoun Gordon 688,002 3,821,891 100.00 21.07 Yes 421.41 651.60 N/A Yes No

Shaw Industries Group Inc Plt WF 12900069 Calhoun Gordon 688,416 3,821,425 100.00 21.49 Yes 429.71 1151.60 N/A Yes No

Darling Ingredients, Inc. 12900084 Calhoun Gordon 688,414 3,821,404 100.00 21.51 Yes 430.12 1151.60 N/A Yes No

City of Calhoun WTP 12900093 Calhoun Gordon 688,571 3,821,305 100.00 21.59 Yes 431.78 1151.60 N/A Yes No

Willcan Inc 12900013 Calhoun Gordon 688,290 3,820,742 100.00 22.18 Yes 443.56 1202.93 N/A Yes No

City of Calhoun WWTP 12900094 Calhoun Gordon 686,870 3,820,355 0.00 22.76 Yes 455.15 1302.93 N/A No N/A

City of Calhoun 12900067 Calhoun Gordon 686,680 3,820,754 51.60 22.40 Yes 447.95 1302.93 N/A Yes Yes

Astro Dye Works Inc 12900012 Calhoun Gordon 688,142 3,819,802 100.00 23.13 Yes 462.57 1202.93 N/A Yes No

Omnova Solutions Inc. 12900029 Calhoun Gordon 688,142 3,819,802 100.00 23.13 Yes 462.57 1202.93 N/A Yes No

Pliant Corporation 12900058 Calhoun Gordon 688,142 3,819,802 100.00 23.13 Yes 462.57 1202.93 N/A Yes No

Shaw Industries Group Inc., Plant Dd 12900065 Calhoun Gordon 688,142 3,819,802 100.00 23.13 Yes 462.57 1202.93 N/A Yes No

Eddie Wilson Body Shop 12900085 Calhoun Gordon 688,105 3,819,775 100.00 23.16 Yes 463.20 1202.93 N/A Yes No

Masland Carpets, LLC 12900037 Calhoun Gordon 687,524 3,819,126 51.33 23.87 Yes 477.49 902.93 N/A Yes Yes

Calhoun Millworks Inc 12900063 Calhoun Gordon 684,659 3,820,196 100.00 23.38 No 467.69 100.00 N/A Yes No

Mohawk Industries Inc 5500002 Calhoun Gordon 687,113 3,819,099 100.00 23.96 Yes 479.19 802.93 N/A Yes No

Apache Mills Inc 12900038 Calhoun Gordon 687,692 3,818,758 5.70 24.22 Yes 484.35 751.33 N/A Yes Yes

Tommy White's Paint & Body Shop 12900088 Calhoun Gordon 688,101 3,818,538 100.00 24.39 Yes 487.78 851.33 N/A Yes No

Northwest Georgia Paving 12900002 Calhoun Gordon 702,895 3,852,243 12.03 15.44 Yes 308.80 312.03 N/A Yes Yes

Brittany Drive WTP 12900095 Calhoun Gordon 697,632 3,818,249 100.00 25.51 No 510.11 100.00 N/A Yes No

Conagra Poultry Co 31300053 Cohutta Whitfield 685,007 3,868,039 100.00 25.88 No 517.60 100.00 N/A Yes No

Garyn Sims Body Shop 12900089 Calhoun Gordon 687,889 3,816,670 100.00 26.27 Yes 525.39 400.00 N/A Yes No

Mohawk Industries Inc - South Industrial 12900018 Calhoun Gordon 688,600 3,816,118 100.00 26.75 Yes 535.06 500.00 N/A Yes No

Shaw Industries Inc Plt D7 12900035 Calhoun Gordon 688,533 3,816,081 100.00 26.80 Yes 535.91 500.00 N/A Yes No

Faus Group, Inc. 12900047 Calhoun Gordon 690,555 3,815,311 100.00 27.48 Yes 549.59 500.00 N/A Yes No

Mannington Commercial 12900025 Calhoun Gordon 689,755 3,814,854 100.00 27.95 Yes 559.04 700.00 N/A Yes No

Legal Manufacturing, LLC 4700031 Ringgold Catoosa 671,462 3,863,421 100.00 28.20 Yes 564.00 232.22 N/A Yes No

Shaw Industries Group, Inc. - Plant EG 4700030 Ringgold Catoosa 673,176 3,865,439 100.00 28.63 Yes 572.58 232.22 N/A Yes No

Kerry Ingredients 12900092 Calhoun Gordon 688,887 3,814,150 100.00 28.70 Yes 573.92 600.00 N/A Yes No

TDG Operations, LLC - Calhoun Wool 12900077 Calhoun Gordon 690,492 3,813,948 100.00 28.84 Yes 576.85 900.00 N/A Yes No

Childers Auto Frame & Body 12900090 Calhoun Gordon 691,608 3,813,905 100.00 28.90 Yes 577.99 600.00 N/A Yes No

Aladdin Manufacturing - Marine Drive Facility 12900096 Calhoun Gordon 690,605 3,813,610 100.00 29.18 Yes 583.61 900.00 N/A Yes No

Shaw Industries, Inc. - Plant RP 4700029 Ringgold Catoosa 672,542 3,864,343 32.22 28.17 Yes 563.48 332.22 N/A Yes Yes

Alladin Manufacturing- Union Grove facility 12900071 Calhoun Gordon 691,103 3,813,139 100.00 29.65 Yes 593.07 600.00 N/A Yes No

Walter Jackson Chevrolet Inc. 4700024 Ringgold Catoosa 671,208 3,865,152 100.00 29.66 Yes 593.13 434.12 N/A Yes No

North American Container Corporation 12900061 Adairsville Gordon 691,299 3,812,890 100.00 29.91 Yes 598.13 600.00 N/A Yes No

Babb Lumber Company 4700017 Ringgold Catoosa 670,800 3,865,780 1.90 30.40 Yes 607.96 201.90 N/A Yes Yes

SR 151 Municipal Solid Waste Landfill 4700027 Ringgold Catoosa 667,497 3,861,789 100.00 29.98 No 599.59 100.00 N/A Yes No

Pilgrim's Pride Corporation - Ranger Feed MIll 12900097 Ranger Gordon 710,236 3,820,046 7.63 29.99 No 599.83 107.63 N/A Yes Yes

Allied Universal Corporation 12900054 Ranger Gordon 709,835 3,819,688 100.00 30.01 No 600.11 107.63 N/A Yes No

Rick Worley & Son, Inc. 4700025 Ringgold Catoosa 670,853 3,866,166 100.00 30.66 Yes 613.14 201.90 N/A Yes No

Cornerstone Medical Center 4700002 Ringgold Catoosa 673,138 3,867,971 100.00 30.69 No 613.85 100.00 N/A Yes No

Hank Cox Customs 12900091 Adairsville GA Gordon 690,304 3,811,963 100.00 30.83 Yes 616.58 500.00 N/A Yes No

Adams Hot Rod Shop 12900087 Rydal Gordon 699,787 3,811,995 100.00 32.11 No 642.24 100.00 Yes No N/A

Walker Cnty Correctio 29500008 Rock Spring Walker 660,893 3,854,970 100.00 32.19 No 643.75 200.00 Yes No N/A

Nissin Brake Georgia Inc 29500053 Rock Spring Walker 660,396 3,853,940 100.00 32.28 No 645.56 200.00 Yes No N/A

Freightliner of Chattanooga Body Shop 4700021 Ringgold Catoosa 668,882 3,866,885 100.00 32.50 No 649.94 100.00 Yes No N/A

Fortune Mills Inc 29500012 Lafayette Walker 657,531 3,842,785 100.00 33.16 No 663.12 200.00 Yes No N/A

Pine Hall Brick Company, Inc. 12900073 Fairmount Gordon 707,894 3,814,236 100.00 33.34 No 666.76 100.00 Yes No N/A

Elite Custom Paint & Body 29500055 LaFayette Walker 657,152 3,841,664 100.00 33.55 No 671.09 200.00 Yes No N/A

The Toy Shop 12900086 Rydal Gordon 698,259 3,810,076 100.00 33.58 No 671.59 100.00 Yes No N/A

Sutton Lumber Company 21300029 Tennga Murray 706,421 3,873,772 100.00 34.75 No 694.95 100.00 Yes No N/A

Sakai America Inc 1500099 Adairsville Bartow 690,224 3,807,751 100.00 35.04 Yes 700.84 300.00 Yes No N/A

Roper Corporation 29500011 LaFayette Walker 655,598 3,839,542 100.00 35.24 No 704.78 100.00 Yes No N/A

BFI Waste Services, LLC - Adairsville Hauling Facility 1500127 Adairsville Bartow 690,107 3,807,544 100.00 35.25 Yes 705.01 300.00 Yes No N/A

Daniel's Hot Rods 22700018 Talking Rock Pickens 721,337 3,824,612 100.00 35.63 No 712.70 100.00 Yes No N/A

J. M. HUBER CORPORATION SOLEM DIVISION -

FAIRMOUNT PLANT12900028 Fairmount Gordon 711,049 3,813,530 275.41 35.65 No 712.95 315.21 Yes No N/A

Pine Hall Brick Co., Inc. - Plant #7 12900079 Fairmount Gordon 711,007 3,813,499 39.80 35.65 No 712.98 315.21 Yes No Yes

Glenn's Collision Center 4700020 Ringgold Catoosa 667,404 3,870,105 100.00 35.89 No 717.83 100.00 Yes No N/A

Shaw Industries Group, Inc., - Plant T1 1500132 Adairsville Bartow 693,346 3,806,820 100.00 36.07 No 721.36 200.00 Yes No N/A

Faltec America, Inc. 1500136 Adairsville Bartow 692,368 3,806,531 100.00 36.30 Yes 725.96 457.68 Yes No N/A

Dietz Auto Body 4700026 Ringgold Catoosa 664,118 3,868,383 100.00 36.89 No 737.81 200.00 Yes No N/A

Shaw Industries Group Plant 67 29500048 LaFayette Walker 654,581 3,835,121 100.00 36.91 No 738.22 100.00 Yes No N/A

Daiki Corporation 1500085 Adairsville Bartow 690,676 3,805,810 100.00 36.98 Yes 739.60 957.68 No Yes No

Premier Yarn Dyers 1500100 Adairsville Bartow 689,689 3,805,348 100.00 37.46 Yes 749.10 500.00 Yes No N/A

Top Gun Architectural Coatings, Inc. 1500128 Adairsville Bartow 691,936 3,805,339 100.00 37.47 Yes 749.43 557.68 Yes No N/A

Vulcan Construction Materials LLC - Adairsville Quarry 1500058 Adairsville Bartow 690,102 3,805,022 100.00 37.77 Yes 755.45 600.00 Yes No N/A

LG Hausys America Inc 12900075 Adairsville Gordon 690,102 3,805,022 100.00 37.77 Yes 755.45 600.00 Yes No N/A

Certified Collison & Glass LLC 4700019 Ringgold Catoosa 664,468 3,870,019 100.00 37.80 No 756.01 200.00 Yes No N/A

VMC Specialty Alloys 1500115 Adairsville Bartow 692,479 3,805,012 57.68 37.82 Yes 756.42 357.68 Yes No N/A

Vista Progressive Metal 1500125 Adairsville Bartow 689,967 3,804,972 100.00 37.83 Yes 756.50 500.00 Yes No N/A

Airgas USA, LLC 4700028 Ringgold Catoosa 664,991 3,872,102 100.00 38.98 No 779.61 100.00 Yes No N/A

Blue Ridge Mountain Woodcrafts Inc 12300014 Ellijay Gilmer 729,713 3,840,739 100.00 39.08 Yes 781.59 700.00 Yes No N/A

Pilgrim's Pride Corporation 5700023 Calhoun Gordon 689,734 3,823,777 100.00 19.04 No 380.73 100.00 Yes No N/A

Larry's Body Shop, LLC. 12300024 Ellijay Gilmer 704,507 3,847,652 0.00 14.65 Yes N/A 200.00 N/A No N/A

O-N Minerals (Chemstone) Company d/b/a "Carmeuse

Lime & Stone12300018 Ellijay Gilmer 729,336 3,835,883 100.00 39.26 No 785.23 100.00 Yes No N/A

Stuart's Automotive and Body Repair 22700024 Talking Rock Pickens 724,281 3,821,507 100.00 39.77 No 795.37 100.00 Yes No N/A

Blue Ridge Carpet Mil 12300012 Ellijay Gilmer 730,438 3,841,022 100.00 39.79 Yes 795.80 700.00 Yes No N/A

Ellijay Lumber & Wood Preserving Co 12300003 Ellijay Gilmer 730,565 3,842,102 100.00 39.88 Yes 797.67 700.00 Yes No N/A

Vulcan Construction Materials, LLC - Ellijay Quarry 12300013 Ellijay Gilmer 730,565 3,842,102 100.00 39.88 Yes 797.67 700.00 Yes No N/A

Bartow Pallets Inc 12300020 Ellijay Gilmer 730,565 3,842,102 100.00 39.88 Yes 797.67 700.00 Yes No N/A

Mount Vernon Mills 5500001 Trion Chattooga 655,106 3,824,044 983.31 40.22 No 804.34 983.31 No Yes Yes

West N A Block Co Inc 12300002 Ellijay Gilmer 731,023 3,841,761 100.00 40.35 Yes 806.98 700.00 Yes No N/A

Cornerstone Medical Center 4700002 Ringgold Catoosa 673,138 3,867,971 100.00 30.69 No 613.85 100.00 Yes No N/A

Tyson Poultry, Inc. - Fairmount 1500093 Fairmount Bartow 711,334 3,807,257 100.00 41.10 No 821.92 100.00 Yes No N/A

By Pass Collision, LLC. 29500056 Chickamauga Walker 654,941 3,864,313 100.00 41.73 No 834.51 100.00 Yes No N/A

Imerys Marble Inc 22700006 Whitestone Pickens 728,784 3,825,477 0.00 41.85 No 836.92 0.00 Yes No N/A

Pyramid Southern Moul 4700013 Rossville Catoosa 660,203 3,872,032 100.00 42.24 No 844.83 100.00 Yes No N/A

Armuchee Auto Collision 11500111 Armuchee Floyd 667,158 3,806,830 100.00 42.97 No 859.48 200.00 Yes No N/A



UTM East

(NAD83

Zone 17)

(m)

UTM North

(NAD83

Zone 17)

(m)

Potential Facility

NO2 Emissions

(tpy)

Distance

from

Facility

(km)

W/in 2 km

of another

facility?

NOX 20D

NOX Cluster

Emissions

(tpy)

NOX Exclude

Per 20D

Rule?

Include in NOX

Inventory?

Present in NOX

Inventory?

VTI of Georgia 11500081 Rome Floyd 667,133 3,806,757 100.00 43.05 No 860.97 200.00 Yes No N/A

Cox Auto Body 29500057 Rossville Walker 656,179 3,868,907 100.00 43.28 No 865.54 200.00 Yes No N/A

Church Chair Industri 11500080 Shannon Floyd 677,344 3,801,465 100.00 43.43 No 868.51 200.00 Yes No N/A

Storey S I Lumber Co Inc 11500024 Armuchee Floyd 663,007 3,808,933 100.00 43.73 No 874.64 100.00 Yes No N/A

Rossville Paving Co. 29500013 Rossville Walker 655,179 3,869,527 100.00 44.45 No 888.97 200.00 Yes No N/A

Fisher Creek Quarry 22700025 Talking Rock Pickens 731,817 3,825,371 100.00 44.67 No 893.32 100.00 Yes No N/A

CW Matthews Contracting, Co., Inc. 12300017 Ellijay Gilmer 735,306 3,849,513 100.00 45.12 No 902.45 100.00 Yes No N/A

Buster Goss Body Shop 11500112 Rome Floyd 676,439 3,799,902 100.00 45.19 Yes 903.86 620.00 Yes No N/A

US Biofuels Inc 11500108 Rome Floyd 675,432 3,799,995 100.00 45.43 Yes 908.65 520.00 Yes No N/A

Morgan Corp 1500066 Rydal Bartow 710,166 3,801,714 100.00 45.46 No 909.21 100.00 Yes No N/A

Advanced Steel Technology 11500103 Rome Floyd 674,832 3,800,001 100.00 45.63 Yes 912.64 320.00 Yes No N/A

Astec Rossville Plant 29500058 Rossville Walker 656,118 3,872,613 100.00 45.66 Yes 913.11 300.00 Yes No N/A

Tri-Valley Sales Inc 29500051 Flintstone Walker 650,305 3,864,126 100.00 45.67 No 913.45 100.00 Yes No N/A

Jorges Carpet Mills 29500029 Rossville Walker 655,892 3,872,464 100.00 45.73 Yes 914.60 300.00 Yes No N/A

BALL CONTAINER LLC ROME CAN PLANT 11500077 Rome Floyd 674,884 3,799,874 20.00 45.73 Yes 914.67 520.00 Yes No N/A

Rossville Yarn Inc 29500047 Rossville Walker 655,727 3,872,328 100.00 45.77 Yes 915.35 300.00 Yes No N/A

Marglen Industries Ext 11500093 Rome Floyd 676,582 3,798,947 100.00 46.06 Yes 921.13 420.00 Yes No N/A

Marglen Industries In 11500004 Rome Floyd 676,582 3,798,944 100.00 46.06 Yes 921.19 420.00 Yes No N/A

Fabricsamerica Corp 5500012 Summerville Chattooga 652,274 3,816,170 100.00 46.74 No 934.70 200.00 Yes No N/A

YATES BLEACHERY CO. 29500022 Flintstone Walker 651,349 3,868,216 244.40 46.84 No 936.80 244.40 Yes No N/A

Concrete Ready Mix - Ellijay 12300023 Ellijay Gilmer 737,328 3,848,993 0.00 47.05 No 941.02 0.00 Yes No N/A

Blount Construction Company 11500067 Rome Floyd 668,144 3,800,843 100.00 47.62 No 952.41 100.00 Yes No N/A

Mohawk Carpet Corp 5500011 Summerville Chattooga 650,791 3,815,627 100.00 48.27 Yes 965.30 400.00 Yes No N/A

Bearden Auto Body 12300025 Cherry Log Gilmer 737,112 3,856,929 100.00 48.53 No 970.61 100.00 Yes No N/A

Aladdin Manufacturing Corp. 5500016 Summerville Chattooga 650,950 3,814,150 100.00 48.98 Yes 979.64 300.00 Yes No N/A

Transmontaigne Operating Co LP 11500050 Rome Floyd 673,780 3,796,817 100.00 48.98 No 979.67 100.00 Yes No N/A

Signature Interior Wo 5500017 Summerville Chattooga 650,942 3,814,151 100.00 48.99 Yes 979.77 300.00 Yes No N/A

Wunda Weve Carpets In 1500039 White Bartow 707,696 3,795,997 100.00 49.79 Yes 995.77 300.00 Yes No N/A

TransMontaigne Operating Company, L.P. - Lookout

MountainTerminal29500038 Flintstone Walker 650,057 3,871,741 100.00 49.89 No 997.79 100.00 Yes No N/A

Toyo Tire North America Manufacturing, Inc. 1500104 White Bartow 707,539 3,795,822 100.00 49.90 Yes 998.00 300.00 Yes No N/A

Voestalpine Automative Body Parts, Inc. 1500130 White Bartow 707,552 3,795,822 100.00 49.90 Yes 998.08 300.00 Yes No N/A

BFS USA, LLC 1500131 White Bartow 703,193 3,794,392 100.00 49.99 No 999.76 793.79 Yes No N/A



Table D-9. Nearby Major Sources for 1-Hour NO2 Modeling

UTM E UTM N Elev NOX Height Temperature Velocity Diameter

AIRS Name Facility Description Type Address County Stack Stack Description Zone (m) (m) (ft) (lb/hr) (ft) (F) (ft/s) (ft)

1 Boiler #1 16 686,023.00 3,851,928.00 718 22.6 176 500 40 4.5

2 Boiler #2 16 686,023.00 3,851,928.00 718 22.6 176 500 40 4.5

3 Boiler #3 16 686,023.00 3,851,928.00 718 7.2 176 500 40 4.5

4 Boiler #4 16 686,032.00 3,851,980.00 718 6.8 125 740 20 3.9

5 Latex coater # 61 16 686,016.00 3,851,785.00 718 3.36 37 220 27.8 4

6 CDR Dye dryer 16 686,051.00 3,851,836.00 718 3.16 33 220 54.4 2.5

7 Latex coater # 62 16 686,000.00 3,851,824.00 718 2.03 33 185 12.9 2.3

8 Carpet Grinder 16 686,259.00 3,851,703.00 718 — 33 68.00 12.9 2.3

1 Boiler #1 16 686,089.00 3,843,541.00 734 2.16 135 550 40 3.5

2 Boiler #3 16 686,089.00 3,843,541.00 734 1.65 135 550 40 3.5

3 Boiler #4 16 686,107.00 3,843,579.00 734 29.7 90 347 30 5

4 Latex Coater #1 16 686,087.00 3,843,434.00 734 2.35 37 185 12.9 2.3

5 Kuster Dye Range 16 686,006.00 3,843,369.00 734 3.04 37 220 54.4 2.5

31300054 Styron, LLC (Trinseo)Styrene-Butadiene Latex Mfg.

PlantTV

1468 Prosser Drive, SE, Dalton,

Georgia 30721Whitfield 1 Process Boiler No. 3 16 689,614.00 3,833,904.00 656 5.71 30.00 300.00 30.00 3.00

1 Gas boiler #4 16 686,636.00 3,844,377.00 760 7.19 37 550 39 4

2 Gas boiler #5 16 686,679.00 3,844,475.00 760 12.4 45 500 39 4

3 Kuster #2 16 686,659.00 3,844,389.00 760 3.73 35 220 54 2.5

4 Kuster #1 16 686,667.00 3,844,478.00 760 4.27 35 185 12.9 2.3

1 Boiler #1 16 686,821.00 3,842,737.00 752 12.1 110 550 39.9 4.5

2 Boiler #2 16 686,821.00 3,842,737.00 752 12.1 110 550 39.9 4.5

3 Boiler #3 16 686,821.00 3,842,737.00 752 12.8 110 550 39.9 4.5

4 Kemco Water Heater 16 686,657.00 3,843,358.00 752 3.6 30.00 200.00 30.00 3.00

5 Kuster Dye Range 16 686,963.00 3,842,717.00 752 2.97 34.5 220 54.4 2.5

6 Kuster Dye Range 16 686,954.00 3,842,578.00 752 1.94 34.5 220 50.5 1.8

7 Latex Coater #1 16 686,814.00 3,842,693.00 752 4.09 36 185 12.9 2.3

1 Cleaver Brooks Boiler 1 16 688,087.00 3,845,531.00 695 12.3 30 149 40 2.5


3 Continental Boiler 16 688,068.00 3,845,695.00 695 3.42 58 3 3 3


5 Carpet Dye Range 1 16 688,097.00 3,845,381.00 695 4.42 37 149 51.8 4.4

6 Curing Oven 1 16 687,605.00 3,845,533.00 695 1.94 30.00 200.00 30.00 3.00

7 Curing Oven 2 16 687,605.00 3,845,533.00 695 1.71 30.00 200.00 30.00 3.00

8 Curing Oven 3 16 687,605.00 3,845,533.00 695 3.12 30.00 200.00 30.00 3.00

9 Tumble Dryers 16 687,605.00 3,845,533.00 695 1.54 30.00 200.00 30.00 3.00

1 Coal Boiler #1 16 686,262.00 3,843,543.00 740 10.8 42 450 39.9 4.5

2 Coal Boiler #2 16 686,205.00 3,843,530.00 740 10.8 110 112 40 2.5

3 Coal Boiler #3 16 686,213.00 3,843,521.00 740 10.8 110 111 47.7 2.5

4 Boiler #1 16 686,262.00 3,843,543.00 740 8.37 42 450 39.9 4.5

5 Boiler #2 16 686,258.00 3,843,535.00 740 8.37 38 400 39.9 4

6 Kuster continuous dye line 16 686,242.00 3,843,539.00 740 2.96 34 220 54.4 2.5

7 Multi-tech continuous dye line 16 686,312.00 3,843,727.00 740 4 36 72 9.9 2.7

8 Beck dryer 16 686,168.00 3,843,658.00 740 2.01 33 220 54.4 2.5

9 Latex coater 16 686,395.00 3,843,573.00 740 6.1 38 220 27.8 4

10 Latex coater 16 686,393.00 3,843,667.00 740 5.89 38 220 27.8 4

11 Water heater 16 686,247.00 3,843,664.00 740 7.18 36 72 9.9 2.7

Shaw Industries

Group Plant 81Carpets & Rugs Mfg TV

Shaw Industries

Group Inc Plt 23Carpet Finishing TV

Aladdin Mills -

Antioch Road Plant

31300001

31300003

31300070

31300074

31300077

31300084

Shaw Industries, Inc. -

Plant WD

TV2230 South Hamilton Street Ext.,

Dalton, Georgia 30720

Carpet & Scatter Rug

ManufacturingTV

2001 Antioch Road, Dalton, Georgia

30722

201 Springdale Road, Dalton, Georgia

30720

Shaw Industries

Group Inc. Plant 80Carpet Manufacturing

2603 Lakeland Road, Dalton, GA

30721Whitfield

Whitfield

Whitfield

WhitfieldCarpet Finishing Plant TV2305 Lakeland Road, Dalton, Georgia

30720

Whitfield

Shaw Industries

Group Inc Plant 4Carpet Manufacturing TV

2225 South Hamilton Street Ext.,

Dalton, Georgia 30720Whitfield

Major Sources Report Table Trinity Consultants Page 1 of 4



Table D-9. Nearby Major Sources for 1-Hour NO2 Modeling

UTM E UTM N Elev NOX Height Temperature Velocity Diameter

AIRS Name Facility Description Type Address County Stack Stack Description Zone (m) (m) (ft) (lb/hr) (ft) (F) (ft/s) (ft)

1 Boiler #3 (69.2 MMBTU/hr) 16 685,808.00 3,845,068.00 716 10.2 40 425 4.3 4

2 Boiler #5 (75.0 MMBTU/hr) 16 685,808.00 3,845,085.00 716 11.1 40 425 4.3 4

3 Boiler #8 (33.5 MMBTU/hr) 16 686,141.00 3,845,378.00 716 9 40 425 4.3 4

4 Kuster dye range 16 685,824.00 3,845,043.00 716 2.24 33 169 180 2

5 Kuster dye range 16 685,908.00 3,845,211.00 716 2.52 40 169 150 2.5

6 Latex coater 16 686,141.00 3,845,378.00 716 1.23 38 220 27.8 4

7 15 MMBtu/hr Water Heater 16 686,141.00 3,845,378.00 716 1.05 30.00 200.00 30.00 3.00

8 12 MMBtu/hr Water Heater 16 686,141.00 3,845,378.00 716 0.84 30.00 200.00 30.00 3.00

9 Boiler #9 (90.9 MMBTU/hr) 16 686,141.00 3,845,378.00 716 — 1 0 0.1 0.1

1 Boiler 1 – Dye House Boiler 16 686,343.00 3,846,224.00 716 8.45 55 425 15 4

2 Boiler #3 – Dye House Boiler 16 686,350.00 3,846,233.00 716 8.45 55 400 15 4

3 Boiler #4 – Dye House Boiler 16 686,351.00 3,846,242.00 716 10.3 55 400 18 4

4 Global Boiler 16 686,079.00 3,846,287.00 716 1.03 39 400 15 1.7

5 Chem-Tech Beck Dryer 16 686,302.00 3,846,216.00 716 1.18 33 260 400 0.8

6 Latex Coater 16 686,312.00 3,846,039.00 716 1.53 38 220 27.8 4

7 Global Latex Coater 16 686,059.00 3,846,224.00 716 2.2 35 280 58 2

8 Global Foam Coater 16 686,082.00 3,846,230.00 716 5.39 35 280 84 2.4

1 Boiler #1 16 654,909.00 3,824,292.00 627 32.2 165 150 43.4 4

2 Boiler #2 16 654,909.00 3,824,292.00 627 32.2 165 150 43.4 4

3 Boiler #3 16 654,928.00 3,824,292.00 627 50.1 155 128 23.9 4

4 Boiler #4 16 654,928.00 3,824,292.00 627 110 155 139 25.8 5

31300126

05500001

31300096

Whitfield

Chattooga

Mohawk Industries

IncCarpet Manufacturing TV

2100 South Hamilton Street, Dalton,

Georgia 30720Whitfield

Chem-Tech Finishers

IncCarpet Finishing TV

Mount Vernon Mills Textile Finishing TV91 Fourth Street, One Plaza Circle,

Trion, Georgia 30753

1904 South Hamilton, Dalton, Georgia

30722

Major Sources Report Table Trinity Consultants Page 2 of 4

Appendix D - Emissions Information For ModelingOglethorpe Power Corporation - Thomas A. Smith Energy Facility

Table D-10. Nearby Minor Sources for 1-Hour NO2 Modeling

UTM E UTM N NOX Height Temperature Velocity Diameter

AIRS Name Facility Description Type Address County Stack Stack Description Zone (m) (m) (lb/hr) (ft) (F) (ft/s) (ft)

1 BL5 16 687,208.20 3,848,141.50 4.02 26 250 24 2.67

2 LC2 16 687,208.20 3,848,141.50 1.75 26 120 8 2.67

3 CD1 16 687,208.20 3,848,141.50 3.00 26 120 8 2.67

4 BV13 16 687,208.20 3,848,141.50 1.55 35 70 50 0.5

5 BD1 16 687,208.20 3,848,141.50 7.80 35 200 50 1.5

6 BS3 16 687,208.20 3,848,141.50 14.09 26 250 24 2.67

1 B1 16 685,898.50 3,849,378.40 2.37 24 420 12.9 1.99

2 BL2 16 685,898.50 3,849,378.40 0.64 30 425 35.5 2.33

1 HS1 16 686,865.60 3,851,747.80 0.06 25 350 18.9 1.5

2 D1 16 686,865.60 3,851,747.80 0.19 25 350 21.2 2

3 HS2 16 686,865.60 3,851,747.80 0.01 25 350 18.9 1.5

4 D2 16 686,865.60 3,851,747.80 0.04 25 350 31.8 2

1 S01 16 682,949.90 3,853,013.80 0.87 20 750 13 4

2 S02 16 682,949.90 3,853,013.80 0.00 30 68 61 10

1 K1 16 711,006.70 3,813,498.80 4.54 70 400 46.4 4

2 K2 16 711,006.70 3,813,498.80 4.54 70 400 46.4 4

12900038 Apache Mills IncFlexible Polymer Products

ManufacturingSM 417 South River St Gordon 1 ABU1 16 687,692.40 3,818,758.20 1.30 38 454 91.92 2.33

1 SBH1 16 710,236.30 3,820,045.60 0.00 19 68 52.7 2.33

2 SBH2 16 710,236.30 3,820,045.60 0.00 173 68 61.1 0.83

3 SBH3 16 710,236.30 3,820,045.60 0.00 120 68 61.1 0.83

4 SBH4 16 710,236.30 3,820,045.60 0.00 210 68 61.1 0.83

5 SBH5 16 710,236.30 3,820,045.60 0.00 49 78 61.1 2.5

6 SBH6 16 710,236.30 3,820,045.60 0.00 46 78 56.8 1.83

7 SBH7 16 710,236.30 3,820,045.60 0.00 208 68 68.8 0.83

8 SBH8 16 710,236.30 3,820,045.60 0.00 153 68 61.1 0.83

9 SBH9 16 710,236.30 3,820,045.60 0.00 167 68 68.75 0.83

10 SBH10 16 710,236.30 3,820,045.60 0.00 173 68 61.1 0.83

11 SBH11 16 710,236.30 3,820,045.60 0.00 173 68 61.1 0.83

12 SBH12 16 710,236.30 3,820,045.60 0.00 173 68 61.1 0.83

13 SBH13 16 710,236.30 3,820,045.60 0.00 173 68 61.1 0.83

14 SC1 16 710,236.30 3,820,045.60 0.00 103 135 60.1 4.58

15 SC2 16 710,236.30 3,820,045.60 0.00 103 135 60.1 4.58

16 SC3 16 710,236.30 3,820,045.60 0.00 103 135 60.1 4.58

17 SB1 16 710,236.30 3,820,045.60 0.87 30 375 34.4 2.17

18 SB2 16 710,236.30 3,820,045.60 0.87 30 375 34.4 2.17

Whitfield

31300122 Beaulieu Plant 560 Carpet Mill With Coating Minor 950 Riverbend Drive Whitfield

31300138 Syntrex, LLC Industrial Binding Tapes Minor 641 Callahan Rd SE

Whitfield

31300076 Tandus Flooring IncVinyl tile Coating, Tufted Carpet

manufacturing and finishingSM 1000 Vista Drive Whitfield

31300072Flexstar Packaging,

Inc.Graphic Arts Flexographic Plant SM 1902 Kimberly Park Drive

Gordon

12900079Pine Hall Brick Co.,

Inc. - Plant #7Brick manufacturing facility SM 234 Gordon Street Gordon

12900097

Pilgrim's Pride

Corporation -

Ranger Feed MIll

N/A SMHighway 411 (1.5 Miles South of

Ranger)

Minor Sources Report Table Trinity Consultants Page 3 of 4

Appendix D - Emissions Information For ModelingOglethorpe Power Corporation - Thomas A. Smith Energy Facility

Table D-10. Nearby Minor Sources for 1-Hour NO2 Modeling

UTM E UTM N NOX Height Temperature Velocity Diameter

AIRS Name Facility Description Type Address County Stack Stack Description Zone (m) (m) (lb/hr) (ft) (F) (ft/s) (ft)

1 BS1 16 687,530.00 3,819,717.30 6.08 38 350 50.0 2.7

2 BS2 16 687,530.00 3,819,717.30 0.58 38 350 30.0 1.7

3 BS3 16 687,530.00 3,819,717.30 0.58 38 350 30.0 1.7

4 BS4 16 687,530.00 3,819,717.30 0.58 38 350 30.0 1.7

5 BS5 16 687,530.00 3,819,717.30 0.19 38 350 30.0 1

6 OS2 16 687,530.00 3,819,717.30 0.05 33 70 30.0 2

7 OS3 16 687,530.00 3,819,717.30 0.05 33 70 30.0 2

8 OS4 16 687,530.00 3,819,717.30 0.05 33 70 30.0 2

9 OS5 16 687,530.00 3,819,717.30 0.05 33 70 30.0 2

10 OS6 16 687,530.00 3,819,717.30 0.05 33 70 30.0 2

11 OS7 16 687,530.00 3,819,717.30 0.05 33 70 30.0 2

12 DS1 16 687,530.00 3,819,717.30 0.48 33 210 30.0 2.4

13 DS2 16 687,530.00 3,819,717.30 0.48 33 210 30.0 2.2

14 DS3 16 687,530.00 3,819,717.30 0.48 33 210 30.0 1

15 DS4 16 687,530.00 3,819,717.30 0.48 33 210 30.0 1

16 DS5 16 687,530.00 3,819,717.30 0.48 15 150 30.0 1.5

17 DS6 16 687,530.00 3,819,717.30 0.48 33 150 38.0 2

18 BS6 16 687,530.00 3,819,717.30 1.89 33 150 38.0 2

19 OS1 16 687,530.00 3,819,717.30 0.10 33 210 30.0 1.5

12900067 City of Calhoun 260 Kirby Road SM Peak Power Generation Gordon 1 G1 16 686,594.30 3,820,121.30 11.78 45 975 89 8.7

1 BS1 16 688,346.30 3,817,599.50 2.58 30.33 250 85.8 3.66

2 BS2 16 688,346.30 3,817,599.50 0.17 8.5 600 13.6 1

4700017Babb Lumber

Company6652 U.S. 41 B Lumber Producer Catoosa 1 G1 16 671,250.50 3,865,607.10 0.43 35 300 40.5 1.92

1 E1 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

2 E2 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

3 E3 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

4 E4 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

5 E5 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

6 E6 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

7 E7 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

8 E8 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

9 E9 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

10 E10 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

11 E11 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

12 E12 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

13 E17 16 670,904.10 3,864,399.60 2.45 20 80 35.1 2.46

14 E18 16 670,904.10 3,864,399.60 2.45 20 80 35.1 2.46

15 E19 16 670,904.10 3,864,399.60 2.45 20 80 35.1 2.46

16 E20 16 670,904.10 3,864,399.60 0.00 20 80 35.1 2.46

31300107Dalton Steam

Services1605 Underwood St. B Wood Waste Fired Boiler Whitfield 1 S1 16 688,136.70 3,850,953.80 8.80 45 565 39.12 3.5

1 S1 16 685,980.00 3,852,121.90 4.00 60 400 39.1 2

2 S2 16 685,980.00 3,852,121.90 4.00 60 400 25 2.5

Gordon

12900037Masland Carpets,

LLC200 S. Fair St. SM Carpet Dyeing Gordon

12900002Northwest Georgia

Paving501 West May St. B Drum Mix Asphalt Plant

Whitfield

4700029Shaw Industries, Inc.

- Plant RP1015 Industrial Boulevard SM Vinyl tile manufacturing Catoosa

31300031 Vericol, Inc. 1338 Coronet Drive B Dye Penetrants,Wet Agents

Minor Sources Report Table Trinity Consultants Page 4 of 4



Table D-11. NOX Emission Sources in Tennessee within 50 km of OPC Smith (for 1-hr NO2 NAAQS) - As Provided by TDEC

Site Name Address City ZIP Code

X Coordinate

(m)

Y Coordinate

(m)

Distance from OPC

Smith

(km)

NOX Emissions

(tpy)

20D

(km) NOX Emissions > 20D?

Pet Haven, LLC 10088 Standifer Gap Road Collegedale 37363-8547 676,436.10 3,877,180.90 37.23 0.51 744.53 No

McKee Foods Corporation 10260 McKee Road Collegedale 37315 678,657.90 3,880,247.90 39.34 26.39 786.84 No

City of Chattanooga Summit Landfill Woodland Drive Ooltewah 37363 674,458.90 3,880,803.30 41.33 0.83 826.65 No

Hawker Powersource, Inc. 9404 Ooltewah Industrial Drive Ooltewah 37363 677,083.50 3,883,309.60 42.74 2.40 854.84 No

Angelica Textile Services, Inc. 9506 Ooltewah Industrial Drive Ooltewah 37363-6700 677,400.60 3,883,557.70 42.88 1.36 857.56 No

SCI Tennessee Funeral Services, LLC d/b/a

Chattanooga Funeral Home7414 Old Lee Highway Chattanooga 37421 670,915.00 3,881,299.80 43.29 1.23 865.78 No

East Tennessee Natural Gas, LLC 5888 Hunter Road Ooltewah 37363 675,189.30 3,884,089.60 44.11 29.40 882.23 No

Coca-Cola Bottling Company United, Inc. 2111 West Shepherd Road Chattanooga 37421-2315 665,456.00 3,879,356.90 44.43 0.15 888.54 No

AZZ Enclosure Systems - Chattanooga LLC 1919 Polymer Drive Chattanooga 37421-2204 664,553.00 3,879,204.00 44.82 1.00 896.43 No

BASF Corporation (Plant #2) 2120 Polymer Drive Chattanooga 37421-2263 664,888.00 3,879,626.00 44.97 8.20 899.44 No

Volkswagen Group of America Chattanooga

Operations, LLC8001 Volkswagen Drive Chattanooga 37416-1347 670,056.00 3,883,093.30 45.28 13.79 905.54 No

Gestamp Chattanooga, LLC (Plant #1) 3063 Hickory Valley Road Chattanooga 37421 668,068.90 3,882,998.90 46.13 1.83 922.68 No

Hudson Emulsion, LLC 4700 Shallowford Road Chattanooga 37411-1136 663,590.00 3,880,289.00 46.26 0.59 925.29 No

Talley Construction Co., Inc. d/b/a

Southeastern Materials (Shallowford Plant)4700A Shallowford Road Chattanooga 37411 663,590.00 3,880,289.00 46.26 6.71 925.29 No

Wrigley Manufacturing Company, LLC 3002 Jersey Pike Chattanooga 37421-6208 664,506.60 3,881,056.10 46.36 5.35 927.30 No

Gestamp Chattanooga, LLC (Plant #2) 4120 Jersey Pike Chattanooga 37421 664,502.00 3,881,080.90 46.39 3.28 927.76 No

Archer-Daniels-Midland Company --

Sweeteners Terminal5991 Hickory Valley Road Chattanooga 37416-1128 667,925.10 3,883,499.80 46.64 4.95 932.82 No

Magellan Terminals Holdings, L.P. (Terminal

#2)4326 Jersey Pike Chattanooga 37416-3630 664,571.00 3,881,727.90 46.89 3.66 937.70 No

Hiwassee Paving LLC 2 Pelican Drive Chattanooga 37416 664,802.60 3,881,992.40 46.98 2.01 939.54 No

Dooley Chemical LLC 2400 East 24th Street Chattanooga 37407 657,271.10 3,875,995.40 47.11 0.30 942.17 No

Astec, Inc. (R & D) 4101 Jerome Avenue Chattanooga 37407-2915 655,110.00 3,873,769.40 47.17 0.09 943.49 No

Heatec, Inc. 5200 Wilson Road Chattanooga 37410 654,332.00 3,873,042.50 47.30 0.28 945.92 No

Astec Industries, Inc. 4101 Jerome Avenue Chattanooga 37407-2915 655,097.80 3,873,958.90 47.31 0.19 946.17 No

Steward Advanced Materials LLC 1245 East 38th Street Chattanooga 37407 655,260.20 3,874,553.00 47.58 0.71 951.62 No

WestRock CP, LLC 3800 Tag Road Chattanooga 37416-3815 663,600.80 3,882,168.20 47.79 1.12 955.89 No

Dover s Cylinder Head Service, Inc. 2929 Calhoun Avenue Chattanooga 37407 655,558.40 3,875,323.60 47.88 0.02 957.59 No

United Entertech Corp. 3005 South Hickory Street Chattanooga 37407-1425 655,846.50 3,875,797.50 47.99 0.45 959.87 No

Allied Metal Co. 3440 Lightfoot Mill Road Chattanooga 37406-2125 661,973.00 3,881,469.00 48.17 2.80 963.44 No

Parkridge Medical Center, Inc. 2333 McCallie Avenue Chattanooga 37404-3258 658,051.00 3,878,328.10 48.25 0.11 965.00 No

Memorial Hospital 2525 de Sales Avenue Chattanooga 37404-1161 658,599.00 3,879,091.10 48.45 7.08 969.00 No

Archer-Daniels-Midland Company d/b/a

Southern Cellulose Products103 West 45th Street Chattanooga 37410-1602 653,550.80 3,874,041.40 48.54 28.82 970.72 No

Gold Coast Fats & Oils, LLC 4608 Kirkland Avenue Chattanooga 37410-1914 653,637.30 3,874,272.50 48.62 2.17 972.38 No

Covenant Funeral Service, Inc. 4340 Bonny Oaks Drive Chattanooga 37416 663,416.00 3,883,205.00 48.76 0.10 975.11 No

Chattanooga Armature Works, Inc. 1209 East 23rd Street Chattanooga 37408-2399 655,760.00 3,876,967.20 48.87 0.23 977.34 No

dcBLOX-TN, Inc. 807 East 16th Street Chattanooga 37408-2106 655,318.00 3,877,883.10 49.82 0.27 996.49 No

NOX Sources Table Trinity Consultants Page 1 of 1

Oglethorpe Power Corporation | Advanced Gas Path/Minimum Load Project PSD Permit Application Volume II Trinity Consultants E

APPENDIX E: ELECTRONIC MODELING FILES

Documents

Oglethorpe Power Corporation > Thomas A. Smith Energy