One-Hour Sulfur Dioxide Attainment Modeling Technical Support Document for Hutchinson County, Texas
                                 July 7, 2020
   
 Background
On June 22, 2010, the U.S. Environmental Protection Agency (EPA) promulgated a revised National Ambient Air Quality Standard (NAAQS) for sulfur dioxide (SO2). The level of the revised standard is 75 parts per billion (ppb). 
On August 21, 2015, EPA promulgated the "Data Requirements Rule" (DRR) (80 Fed. Reg. 51,052; codified at 40 CFR Part 51, Subpart BB), which required states to evaluate compliance with the 2010 SO2 NAAQS in areas surrounding certain large SO2 emission sources. Pursuant to the DRR, states could choose to perform area characterizations using either air quality monitoring or air dispersion modeling.
In 2016, the Texas Commission on Environmental Quality (TCEQ) installed one ambient air monitor to collect SO2 emission data in Hutchinson County, Texas (CAMS1073). The monitor data showed that the SO2 standard was exceeded. However, under EPA's September 5, 2019 guidance for Round 4 SO2 area designations, EPA announced that it will consider, on a case-by-case basis, a designation other than nonattainment for areas where the following are present:  1) a source-oriented monitor has a design value above the NAAQS, 2) where the source in question has recently become subject to and is complying with federally enforceable SO2 emission limits, and 3) modeling with those limits shows attainment. 
To support a modeling-based attainment designation, a group of six area companies worked to develop a county-wide dispersion modeling system that shows attainment of the SO2 NAAQS based on the application of existing or new federally-enforceable controls or by taking federally-enforceable reductions to potential to emit emissions.  
 Summary of New Federally Enforceable Emission Limits
Five of the significant SO2 sources in Hutchinson County will be making changes to their air permits/or installing control equipment to meet the requirements of federal consent decrees. For the changes not already required by federal enforceable consent decrees, the companies intend to submit the indicated air permit applications once there is an indication that the proposed approach is acceptable. These air permitting actions have been discussed with TCEQ to assist with streamlining the permitting efforts.
This section describes the emissions limits that provide the inputs for the modeling and how the companies propose to make them federally enforceable, where they are not already.  
2.1 Orion Engineered Carbons
Orion Engineered Carbons LLC is undertaking the following limits:
 Orion will accelerate to August 1, 2020 its submittal of the control device nomination letter to EPA, thereby making enforceable the SO2 and NOx controls at its Borger Facility by December 31, 2022 under its federal consent decree, United States v. Orion Engineered Carbons, LLC, Consent Decree (Case No. 6:17-cv-01660), Section VI, Paragraph 16:  Process System Operation Emission Limits and Control Technology requirements.
      
 Orion will submit a registration under the State Pollution Control Project Standard Permit (30 TAC 116.617), to construct a single flare to control maintenance, startup and shutdown (MSS) emissions during the times at which the Cogeneration Unit at its Borger facility is not operational. Orion will work with TCEQ to receive the approval before August 1, 2020.
      
 Orion will submit a permit alteration (30 TAC 116.116(c)(1)(B)), concurrently with the Standard Permit registration, to include an enforceable permit condition stating that the flare constructed under the Standard Permit must be fully operational by December 31, 2022.  Orion will work with TCEQ to receive the altered permit before August 1, 2020.
   
 Old flares will be removed once the construction of new flare is completed by December 31, 2022.

                                   Stack ID
                            SO2 Emission Rate (g/s)
Stack Height (m)
                    Units 1-3 Reactors/Combined Flare (MSS)
                                     94.5
                                      65
                 Waste Heat Boiler (E6B  -  Normal Operations)
                                     12.23
                                     45.72

2.2 Tokai Carbon CB 
The following is a description of the equipment changes that Tokai Carbon CB will be making and the emission limits they will be including in permits:
 Tokai Carbon CB will submit a permit alteration in accordance with 30 TAC 116.116(c)(1) to include enforceable limits into the Borger Plant NSR permit to make the following changes:
 Reduce the current SO2 cap limit of 3607.88 lbs/hr. To maintain operational flexibility, Tokai Carbon CB may request the TCEQ to permit a lower SO2 cap or, if needed, assign a specific emission rate to a specific emission point. Tokai Carbon CB will work with the TCEQ on these scenarios and ensure that they all meet the NAAQS standard.  This will be the case for all operating scenarios, whether they be normal operations or MSS operations. Only those emission rates and equipment, along with their associated operating scenarios, that have been modeled to meet the NAAQS will be permitted.        
 Increase the heights of two flares from their current heights to a new height of 198 feet for each flare, if Scenario 2 below is implemented
 Eliminate SO2 emissions from the two Dryer Exhaust Bagfilter Stacks (EPNs 1 and 3).
The implementation of these changes will be completed by April 1, 2021, the deadline for the Borger Plant to comply with the EPA Consent Decree (United States v. Sid Richardson Carbon, LDT,  Consent Decree (Civ. Act. No 3:17-cv-01792-SDD-RLB) (Tokai Carbon CB now owns the facility). Tokai Carbon CB will work with the TCEQ to receive the revised permit before August 1, 2020. During the maintenance events for the boilers/cogen unit, the modeling demonstrates the three scenarios below all meet the NAAQS standard. These three operating scenarios are the base scenarios. Tokai Carbon CB may perform additional modeling for other scenarios but only those that meet the NAAQS will be included in the permit alteration request.   
                               Normal Operation
                                   Stack ID
                            SO2 Emission Rate (g/s)
                Boiler Stack (both boilers  -  max conditions)
                                     13.75
                 Boiler Stack (one boiler  -  min conditions)
                                     0.69
                             Plant 1 Dryer Stack 
                                     55.62
                             Plant 2 Dryer Stack 
                                     75.04

        Maintenance Events (Scenario 1  -  Flare 1 Stack at 91.2 feet) 
                                   Stack ID
                            SO2 Emission Rate (g/s)
                                    Flare 1
                                     52.92
                              Plant 1 Dryer Stack
                                     31.53
                              Plant 2 Dryer Stack
                                     50.44
                                       
      Maintenance Events (Scenario 2  -  Higher Flare Stacks at 198 feet)
                                   Stack ID
                            SO2 Emission Rate (g/s)
                                    Flare 1
                                     52.97
                                    Flare 4
                                     40.36
                              Plant 1 Dryer Stack
                                     31.53
                              Plant 2 Dryer Stack
                                     50.44

2.3 Phillips 66 Company (Operator of the Phillips 66 Borger Refinery; the Refinery is owned by WRB Refining LP.)
All significant SO2 sources at the Phillips 66 Borger Refinery are authorized by New Source Review Permit:  9868A/PSDTX102M7 held by Phillips 66 Company.
Phillips 66 is undertaking the following limits:
   1)  Phillips 66 has submitted a permit alteration seeking:
   
 To add the following enforceable permit limits in the Individual Emission Limits section of the "Emission Sources  -  Maximum Allowable Emission Rates" Table:
            
                                      EPN
                              Source Description
                            SO2 Emission Rate
(g/s)
                                     10H1
Crude Oil Heater
                                     0.39 
                                   19B1/19H1
19.2 Charge Furnace
                                     0.57 
                                   19B1/19H2
19.2 No. 2 Reheater
                                     0.33 
                                   19B2/19H4
19.3 Charge Furnace, Reheater and Frac Feed Furnace
                                     0.56
                                     19H3
19.1 Naphtha HDS Charge Heater
                                     0.38
                                     19H5
19.1 No. 1 Reboiler
                                     0.06
                                     19H5
19.1 No. 2 Reboiler
                                     0.05
                                     19H6
19.2 Platformer Reheater No. 1
                                     0.32
                                     22H1
Alky Reboiler Furnace
                                     0.07 
                                     26H1
Unit 26 DeC4 Reboiler
                                     0.26
                                     28H1
Unit 28 Charge Heater
                                     0.64
                                     29H4
Unit 29 DeC4 Reboiler
                                     0.26
                                     29P1
Unit 29 FCCU Stack
                                     22.05
                                      2H1
Unit 2-2 HDS Charge Heater
                                     0.15
                                      2H2
Deoiler Furnace
                                     0.14
                                     34I1
SRU Incinerator
                                     5.65
                                     36H1
HDS Unit Charge Heater
                                     0.19 
                                     40H1
Unit 40 Superheater No. 1
                                     0.12 
                                     40H3
Unit 40 Superheater
                                     0.14
                                     40H4
Unit 40 Preheater Furnace 
                                     0.43
                                     40P1
Unit 40 FCCU Stack
                                     22.05
                                  41H1 (PSD)
Unit 41 Reformer Furnace
                                     2.25
                                  42H1 (PSD)
Unit 42 Reactor Charge Heater
                                     0.27
                                  42H2 (PSD)
Unit 42 Reactor Charge Heater
                                     0.27
                                  43I1 (PSD)
SCOT Unit Incinerator
                                     4.66
                                     50H1
Unit 50 Charge Heater
                                     0.91
                                     51H1
Unit 51 Charge Heater
                                     1.07
                                      5H1
Unit 5-A Feed Heater
                                     0.06
                                    66FL12
GOHDS HC Flare
                                     5.04
                                    66FL13
GOHDS Emergency Sulfur Flare (Derrick Flare)
                                     1.89
                                     7H1-4
Unit 7 Charge Furnace and Reheaters
                                     0.37 
                                     81B17
Boiler 2.4
                                     2.01
                                  85B2 (PSD)
Unit 40 Boiler Stack (8/06)
                                     2.38
                                     98H1
Unit 98 Reformer Furnace
                                     1.02
                                      9H1
Crude Oil Heater
                                     0.41
                                     BLR12
Boiler 12
                                     2.43
                                    SKDBLR
Skid Boiler
                                     1.58
      
         b.  To reduce the SO2 cap to 2 lbs/hr. 
         c.  To remove the sources identified in the table above from the list of emissions contributing to the SO2 Cap.  
         d.  Phillips 66 will also request a stipulation in the permit limiting maintenance meltout to one SRU at a time and to only when the combined emissions of the FCCU emissions and the SRU emissions are less than 375 lbs/hr total.  
         
2.4  IACX Rock Creek LLC
There is one significant SO2 source at the IACX Rock Creek LLC (IACX) gas plant that is authorized by NSR Permit: 3131A, by IACX Rock Creek LLC.
IACX is undertaking the following limits:
 IACX Rock Creek LLC will submit a permit alteration (30 TAC 116.116(c)) to this Permit seeking to reduce the short term Maximum Allowable Emission Rate for the Acid Gas Incinerator (EPN INCIN1) from 441.98 lbs/hr to 165 lbs/hr (equivalent to 20.79 g/s) to align with the modeling scenario represented. The H2S emission rates as well as the SO2 annual emission rate will be revised based on the SO2 hourly emission rate. IACX may also revise stack parameters as part of this permit alteration. Stack parameters such as stack exit temperature and velocity, may be increased at the time of permit alteration if revised data to validate the higher temperature and velocity is available at the time of the permitting action. This is requested to allow the site flexibility to increase the hourly emission rate if modeling results with revised emission rate align with the concentration of the compliant modeling scenario.

 IACX Rock Creek LLC will also incorporate the permit alteration action once finalized into the Title V Permit (30 TAC 122.222(c)).
2.5 Chevron Phillips Chemical Company 
 CPChem will coordinate with the TCEQ on a permitting mechanism to lower hourly and annual emission rates of SO2 from the Sulfolene handling area (i.e. permit alteration to reduce Maximum Allowable Emission Rate limits in New Source Review permit number 21918 or submitting a new PBR to certify the lower emissions and voiding the current one). 
       
 Dispersion modeling description and analysis 
Modeling was performed at the Phillips 66 Company Research Center (Bartlesville, Oklahoma) under the direction of Senior Scientist Shaokai Gao. The following materials were utilized and are referenced throughout this report:
 Guidance for 1-Hour Sulfur Dioxide (SO2) Nonattainment Area State Implementation Plan (SIP) Submissions
 Primary National Ambient Air Quality Standard for Sulfur Dioxide; Final Rule (40 CFR Parts 50, 53, and 58)
 Guideline on Air Quality Models ("Appendix W" to 40 CFR Part 51)
 SO2 NAAQS Designations Modeling Technical Assistance Document (August 2016)
 Air Quality Modeling Guidelines, APDG 6232, TCEQ, Nov. 2019
 AERSURFACE User's Guide (EPA-454/B-08-001)
 Interpretation of "Ambient Air" In Situations Involving Leased Land Under the Regulations for prevention of Significant Deterioration (PSD)" (June 22, 2007)
3.1 Model selection 
The American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) is the preferred regulatory air quality model for the 1-hour SO2 attainment demonstration modeling (Guidance for 1-Hour Sulfur Dioxide (SO2) Nonattainment Area State Implementation Plan (SIP) Submissions, Appendix A (April 23, 2014) (EPA 2014 Guidance)). The 1-hour SO2 attainment demonstration modeling for Hutchinson County, Texas presented in this report was performed using the latest AERMOD version V19191 and in accordance with the EPA 2014 Guidance. AERMOD is the U.S. EPA's recommended model for near-field analysis. AERMOD calculates concentrations in a manner that accounts for changes in dispersion rate with height, allows for a non-Gaussian plume in convective conditions, and accounts for a dispersion rate that is a continuous function of hourly meteorology.  AERMOD also contains advanced algorithms for estimating plume dispersion in the convective and stable boundary layers, plume rise, and buoyancy. Characteristic wind speeds and directions through the plume thickness are estimated to account for the effect of wind shear on pollutant transport.  
There are two input data processors that are regulatory components of the AERMOD modeling system: AERMET (V19191), a meteorological data pre-processor that incorporates air dispersion based on planetary boundary layer turbulence structure and scaling concepts, and AERMAP (V18081), a terrain data preprocessor that incorporates complex terrain using USGS Digital Elevation Data and determines the elevation heights of all buildings, sources, and receptors included in the air quality modeling. Other non-regulatory components of the modeling system include: AERSURFACE (V13016), a surface characteristics preprocessor, and BPIPPRM, a multi-building dimensions program to account for building downwash effects
The regulatory default was selected for all air quality modeling runs. A single processor was utilized for running the AERMAP and AERMOD modeling. The design value was calculated in accordance with the EPA 2014 Guidance by determining the 99[th] percentile (4[th] highest) daily maximum 1-hour concentration at each receptor and then averaging across five years. The modeled results combined with the background concentration was then compared to the revised SO2 primary NAAQS of 75 ppb (196.5 ug/m3) established by EPA on June 2, 2010. (75 FR 35520) 
3.2 Coordinate system 
To ensure accurate placement of sources, buildings, and facility boundaries, each of these elements was geo-coded using a Universal Transverse Mercator (UTM) coordinating system. The zone number where the study took place in UTM coordinates is 14. 
3.3 Modeled SO2 emission sources
The Emissions Inventory for Hutchinson County, Texas was reviewed in order to identify SO2 emission sources. All emission sources having an actual annual emission rate greater than 3.47 tons/year (0.1 g/s) were included in the county-wide modeling, and  for emission sources, such as heaters and boilers, which are usually operated frequently and have emission rates greater than 1.74 tons/year (0.05 g/s), were also included in the modeling, following EPA Region 6's guideline. The sources of six facilities in Hutchinson County - Orion Engineered Carbons LLC, Tokai Carbon CB, Phillips 66 Borger Refinery, Chevron Phillips Chemical Company LLC, Borger Energy Associates, L.P. (BlackHawk Station), and IACX Rock Creek LLC-- were modeled. The facilities were modeled using maximum allowable emission rates (MAER), either federally enforceable now, or which the companies have committed to making federally enforceable by August 1, 2020, as described in Section 2 above, and corresponding stack parameters consistent with the Good Engineering Practice (GEP) Policy per the instructions from the "SO2 NAAQS Designations Modeling Technical Assistance Document" published by the U.S. EPA in February 2016. Emissions were assumed to be the same for each emission source in each modeled year. The modeled MAER for different modeling scenarios are provided in section 3.10 of this report. The emission sources for the six industrial facilities that were included in the most recent National Emission Inventory (NEI) but were considered as minor emission sources that do not significantly impact the attainment demonstrations were excluded from the modeling. Details of those minor emission sources are listed in APPENDIX I in this modeling report. A detailed description of how the emissions were distributed to each of the individual emission sources when the facility has a group of sources with capped emissions is referenced to Section 2 in this report. The details of the sources used in each modeling run are listed with the description of the modeling runs in the following sections. 
3.4 Receptor grids
Ground level concentrations were calculated utilizing five sets of receptor grids as described in TCEQ model guidance. (Air Quality Modeling Guidelines, APDG 6232, TCEQ, Nov. 2019). The centering point of the receptor grid was placed accordingly at the primary emission sources within the Orion Carbon Black plant. The receptors on the fenceline of all facilities had a spatial resolution of 25 meters. The first receptor set was spaced 25 meters apart and extended out to 500 meters. The second receptor set contained receptors spaced 50 meters apart and extended out 1000 meters. The third receptor set contained receptors spaced 100 meters apart and extended out approximately 3000 meters from the facility. The fourth receptor set contained receptors spaced 200 meters apart and extended out to 10000 meters. The fifth receptor set contained receptors spaced 500 meters apart and extended out to 20000 meters (Figure 1). Per EPA Region 6's guidance, a more refined receptor grid with a spatial resolution of 100 meters was placed to the east and south side of the Phillips 66 Borger Refinery-Chevron Phillips Chemical Company LLC-Borger Energy Associates, L.P. complex, which extends from the fenceline to more than 2000 meters away, to better capture the SO2 concentration gradients nearby. Each facility has fenceline that used receptors with 25 meters spatial resolution as boundaries from the public. The Phillips 66 Borger Refinery-Chevron Phillips Chemical Company LLC-Borger Energy Associates, L.P. complex is a security-controlled area with no public access. The outer fenceline that includes the three facilities was used for modeling Scenario#1 (Section 4.1). To understand contributions to SO2 concentration at the TCEQ SO2 monitor (CAMS1073) (+35.676128°, -101.439670°) from different facilities and develop efficient emission reduction plans, a sensitive receptor was also placed at the monitoring location in the modeling system. A total of 25025 discrete receptors were used to capture the SO2 dispersion behaviors within the modeling domain. 
3.5 Terrain dataset
Elevated terrain condition was applied in the modeling system. Source and receptor terrain elevations were developed using the AERMAP processor from National Elevation Dataset (NED) based on the Universal Transverse Mercator (UTM) coordinates for the North American Datum (NAD) 1983. These NED elevation files were downloaded from the United States Geological Survey (USGS) website as recommended by the U.S. EPA modeling guidance. The NED data consists of arrays of regularly spaced elevations at 30-meter intervals. All data obtained from the NED files were spot-checked for accuracy against elevations on corresponding USGS 1:24,000 scale topographic quadrangle maps. The AERMAP terrain preprocessor searches for the terrain height and location that has the greatest influence on dispersion for each individual receptor and defines a ground elevation and an associated hill scale for each receptor.  The hill scale is used by AERMOD to calculate a critical dividing streamline height, which AERMOD then employs to select the correct algorithm to predict the dispersion of each part of the plume at each receptor.  Below the critical dividing streamline height, AERMOD models the pollutant concentration with an algorithm that depicts the portion of the plume dispersing around the base of the hill. Above the critical dividing streamline height, AERMOD models the pollutant with an algorithm that depicts the plume dispersing over the hill. Overall, AERMOD allows impact estimations in terrain ranging from flat to complex in a single modeling run.  
3.6 Urban/Rural determination
In summary, there are two methods of urban/rural classification described in section 7.2.3 of Appendix W.
The first method of urban determination is a land use method. The user analyzes the land use within a 3 km radium of the source using the meteorological land use scheme described by Auer (1978). Using this methodology, a source is considered urban if the land use types, I1 (heavy industrial), I2 (light-moderate industrial), C1 (commercial), R2 (common residential), and R3 (Compact residential) are 50% or more of that area within the 3 km radium circle. Otherwise, the source is considered to be a rural source. 
The second method uses the population density and is described in Section 7.2.3d of Appendix W. As with the land use method, a circle of 3 km radium is used. If the population density within the circle is greater than 750 people/km[2], then the source is considered urban. Otherwise, the source is modeled as a rural source. 
According to the most recent United States census estimate, the City of Borger has a population density of 554.51 people/km[2] (https://worldpopulationreview.com/us-cities/borger-tx-population/). Since modeled industrial facilities are all located outside of the populated area (not within the city boundaries) (Figure 3), "rural" is the most appropriate classification for all modeled emission sources.    
3.7 Meteorological dataset 
The most recent 5-year (2015  -  2019) meteorological data, based on surface observations from the National Weather Service (NWS) station at the Hutchinson County Airport in Borger, Texas (ID 3024) and upper air observations from the NWS station at the Rick Husband Amarillo International Airport, Texas (ID 23047), was prepared by certified meteorologists from a third-party vendor (Lakes Environmental Inc.).  
Typically, the NWS meteorological data contains a number of calm hourly wind speed readings in a year; therefore, the U.S. EPA developed the AERMINUTE program in order to reduce the proportion of calm winds by averaging the 1-minute wind speed and wind direction data. The latest version of AERMET (V19191) was used to process the meteorological data. The latest AERMINUTE (version 15272) was used to process the 1-minute wind speed and wind direction Automated Surface Observing System (ASOS) data.  The recommended default of 0.5 meters per second (m/s) for the calm wind speed threshold was used when processing the 1-minute wind speed and wind direction ASOS data. 
AERSURFACE (V13016) was used to determine the surface characteristics including albedo, Bowen ratio, and surface roughness for the meteorological tower location in Hutchinson County, Texas. Surface characteristics were determined at the NWS location for 12 wind direction sectors with a recommended default radius of one kilometer. 
For determination of surface moisture, the U.S. EPA makes the following recommendation (U.S. EPA's AERSURFACE User's Guide Section 2.3 (page 2-14)):
"The surface moisture condition can be determined by comparing precipitation for the period of data to be processed to the 30-year climatological record. It is recommended the user specify "wet" conditions if precipitation is in the upper 30th-percentile, "dry" conditions if precipitation is in the lower 30th-percentile, and "average" conditions if precipitation is in the middle 40th-percentile. However, the reader should consider that what is normal varies for different regions. A dry (or wet) climate could be more normal for an area, so even if the amount of precipitation is normal for a time period, the area might be more appropriately classified as "dry" (or "wet"). In these cases, the user should justify their categorization."
Following the guidance, the monthly climate normal were pulled out from US National Centers for Environmental Information (NCEI) and were compared to monthly precipitation data from the National Weather Service climate services. For this order, the Hutchinson County airport in Borger did not have monthly precipitation probabilities (only monthly means). A cooperative station in Borger (COOP ID #410958) contains monthly precipitation probabilities for comparison to the recommended percentiles. The 2018-2019 monthly precipitation data from the Borger airport were missing from the NWS NOWData portal.
Below is the table comparing the Wet, Dry, & Average precipitation probabilities to the monthly precipitation totals at the COOP station in Borger:
                                       
                                      75%
                                      25%
                                      50%
                                     Years
                                     Month
                                      Wet
                                      Dry
                                    Average
                                     2015
                                     2016
                                     2017
                                     2018
                                     2019
                                      JAN
                                     1.08
                                     0.11
                                     0.64
                                     1.26
                                     0.17
                                     3.22
                                     0.01
                                     0.02
                                      FEB
                                     1.14
                                     0.15
                                     0.64
                                     0.31
                                      0.4
                                     0.37
                                       0
                                      0.3
                                      MAR
                                     1.98
                                     0.64
                                     1.29
                                     0.26
                                       0
                                     2.74
                                     0.04
                                     1.24
                                      APR
                                     2.82
                                     0.48
                                     1.15
                                      4.4
                                     2.97
                                     2.31
                                     1.09
                                     2.68
                                      MAY
                                     3.76
                                      1.3
                                     2.27
                                     9.28
                                     4.11
                                     1.19
                                     2.51
                                     6.52
                                      JUN
                                     4.57
                                     1.52
                                     3.19
                                      2.8
                                     1.36
                                     0.44
                                     3.15
                                     1.72
                                      JUL
                                      3.7
                                     1.32
                                     2.43
                                     8.65
                                     1.33
                                     3.66
                                     1.67
                                     2.16
                                      AUG
                                     4.42
                                     2.49
                                      3.5
                                     5.77
                                     2.98
                                     6.66
                                     1.39
                                     2.31
                                      SEP
                                      2.9
                                     0.72
                                     2.25
                                     0.59
                                     1.02
                                     2.93
                                     1.06
                                     2.79
                                      OCT
                                     2.78
                                     0.61
                                     1.25
                                     4.06
                                     0.05
                                     2.26
                                     3.63
                                     3.38
                                      NOV
                                      1.3
                                     0.28
                                     0.71
                                     1.33
                                     0.15
                                     0.06
                                     0.27
                                     1.06
                                      DEC
                                     1.19
                                      0.2
                                     0.58
                                     0.84
                                     0.22
                                       0
                                     0.67
                                     0.95
                                       
                                     31.64
                                     9.82
                                     19.9
                                     39.55
                                     14.76
                                     25.84
                                     15.49
                                     25.13
                                       
                                     29.53
                                     11.78
                                       
                                      Wet
                                      Avg
                                      Avg
                                      Avg
                                      Avg

Based on those annual precipitation values, the Average for 2016-2019 was selected as they all fell well within the 30th-70th percentile ranges. Note that the NCEI precipitation probabilities are given as the 25th & 75th percentiles so those values are adjusted to the 30th & 70th in accordance with EPA's recommendation. Detailed surface moisture characteristics for each modeled year are also included in the meteorological data processing report (Appendix II) attached in this modeling report. The NWS wind rose plot for the modeled years 2015-2019 is shown in Figure 4. The wind rose shows the frequency of wind direction every ten degrees for specific wind speed ranges. The plot shows the directions from which the wind is blowing in compass degrees and the wind speeds in meters per second. As can been seen, the prevailing winds at the Hutchinson County, TX, NWS station are from the south for 2015 through 2019.   
3.8 Downwash treatment 
The Building Profile Input Program (BPIP) was used to calculate the wind direction specific building dimensions for input to AERMOD. The output from BPIP is read by AERMOD to calculate the aerodynamic downwash for all modeled stacks. All buildings which may affect the aerodynamic downwash in the wake of each modeled stack were included in the program. The length, width, height, and location of each building and the height and location of each stack are included as inputs to the program.  
Following the GEP policy, for those stacks that are above the GEP stack height, the GEP height was used.  For stacks below the GEP stack height, the actual stack height was used. The GEP stack height policy was followed when using allowable emissions because those emissions limits were set with GEP heights.
3.9 Background data  
SO2 background concentrations were developed in accordance with methodologies recommended by the U.S. EPA Guidance and Appendix W. A temporally varying background concentration following the EPA Tier II approach was developed for the modeling analysis by using the multi-year average of 2[nd] high measured 1-hour concentrations for each season and hour-of-day combination. According to Appendix W 8.2.2.b.:
"Use air quality data in the vicinity of the source to determine the background concentration for the averaging times of concern. Determine the mean background concentration at each monitor by excluding concentrations when the source in question is impacting the monitor... For shorter time periods, the meteorological conditions accompanying concentrations of concern should be identified. Concentrations for meteorological conditions of concern, at monitors, not impacted by the source in question, should be averaged for separate averaging time to determine the average background value. Monitoring sites inside a 90° sector downwind of the source may be used to determine the area of impact".
Following Appendix W, the TCEQ SO2 monitor located to the north of the carbon black plants (CAMS1073; +35.676128°, -101.439670°) was initially selected as the monitor to calculate the background SO2 concentrations. To avoid interferences of SO2 emissions from the modeled emission sources, contributions from those sources were screened out by excluding winds that went through the SO2 emission facilities using the arc as depicted in Figure 5 upon discussion with the EPA Region 6 (dashed line).   
However, several issues associated with using the monitoring data from the TCEQ SO2 monitor CAMS1073 for development of the regional SO2 background concentration were identified and discussed with EPA Region 6.
The CAMS1073 monitor started to collect SO2 concentration and meteorological data in Hutchinson County, TX in November 2016. Therefore, the most recent 3-year (2017-2019) SO2 concentration data was used to develop the regional background concentration. Figure 6 shows the SO2 rose plot, which indicated that using SO2 concentration within the wind sector as suggested by the EPA Region 6 (dashed line in Figure 5) to develop background concentration, might be positively biased due to potential interferences from SO2 emissions from the carbon black plants. Therefore, a wind sector from 200⁰ to 45⁰ (CW) was selected to develop the background concentration to avoid potential interferences from the modeled emission sources within the carbon black plants.  
However, even when the wind sector was narrowed down to 200⁰ - 45⁰ (CW), several issues were identified.  For example: 1) using concentration data within the proposed wind sector led to insufficient data points for development of a representative background concentration (not enough datapoints to cover each season and hour-of-day), and 2) there is compelling evidence that even the limited data from the chosen wind sector is influenced by the major sources in the area due to the proximity of the monitor to the carbon black plants.  
Due to the potential problems of using the CAMS1073 monitor, the Phillips 66 Research Center proposed using an alternative SO2 monitor for the development of background SO2 concentration for Hutchinson County, TX. Upon reviewing the other SO2 monitors in the panhandle/west Texas area, only CAMS1025 (35.236708°, -101.787356°) and CAMS1077 (35.316289°, -101.741756°) appear to be alternates for evaluation. Compared to the CAMS1025 monitor, the CAMS1077 monitor had less data available and is located near a power plant. Some wind sector exclusion would also be required to screen out the impact from the power plant, which could lead to insufficient data for development of a representative SO2 background concentration. Therefore, the CAMS1025 SO2 monitor (Amarillo on 24[th] Ave.) was selected as the alternative background monitor because it has been measuring SO2 concentration for a longer time, and it is further away from the Harrington Generating Station (Xcel Energy), which means wind sector exclusion would be smaller, leaving enough datapoints for development of seasonally-hourly varying background SO2 concentrations following the EPA Tier II approach.
Following guidelines from Appendix W, the impact of the Harrington Generating Station needs to be screened out when using the CAMS1025 monitor. Therefore, the wind directions of 25⁰ +- 45⁰ was omitted as shown in Figure 7, which means the SO2 concentration data with the wind direction between 340⁰ - 70⁰ CW was screened out. The SO2 concentration data within the wind sector 71⁰ - 339⁰ (CW) as shown in the rose plot (Figure 8) was sorted by season and by hour-of-day in each year, then the 2[nd] highest hourly concentration for each season and hour-of-day for each year was selected, and the 3-year average (2017-2019) concentration for each season and hour-of-day was used as the final background concentration for the modeling analysis (Table 1). 
The calculated temporally-varying background concentration values using the most recent 3-year (2017-2019) TCEQ CAMS1025 SO2 monitor dataset (Table 1) have been approved by the EPA Region 6. 
3.10 Modeling scenarios
The only maintenance activities from the Phillips Borger Refinery that generates a significant amount of SO2 are the SRU meltouts. As described in Section 2, a stipulation will be added in the proposed permit alteration to only allow a meltout of one SRU at a time and only when the combined emissions of the FCCU emissions and the SRU emissions are less than 375 lbs/hr total. Because the SRU MSS emissions will be considerably less than the base case emissions that are listed in Section 2.3, a separate MSS model run for the Phillips 66 Borger Refinery was not necessary.
Six different modeling scenarios were conducted to support the modeling demonstration for Hutchinson County, Texas. The first modeling scenario based on the federally enforceable emission limits the companies describe in Section 2 which demonstrates attainment with the 2010 SO2 NAAQS for all receptors in Hutchinson County during normal operations. In this modeling scenario, the merged stack (emission source ID #119) from Tokai Carbon CB has two boilers operating with maximum flow rate and emission rate. The different operating conditions of the merged stack from Tokai Carbon CB were modeled separately. 
The second modeling scenario addressed emissions from the merged stack from Tokai Carbon CB. Three different operating conditions were modeled (Table 3), which included one boiler operating with maximum flowrate and emission rate, one boiler operating with minimum flowrate and emission rate, and one boiler operating at 75% load. Since both boilers are rated at the same capacity, the max flow and max emission rate for Boiler #1 and Boiler #2 are identical. The max flow/velocity for one boiler equals 50% of the max condition for that of 2 boilers. The max emission rate for one boiler equals 50% of the max condition for that of 2 boilers.
The third modeling scenario addressed special conditions related to the MSS events associated with the Cogen/waste heat boiler located at the Tokai Carbon CB facility. Two different cases were modeled. The first case uses one backup flare during the Cogen/Waste heat boiler turnaround while the second case uses two backup flares. 
The fourth modeling scenario addressed the special MSS events associated with the Cogen/waste heat boiler located at the Orion carbon black facility. A new MSS flare will be built to replace the three old flares, which means the gas from 3 reactors during the Cogen/waste heat boiler turnaround will be routed to the new flare. 
For the MSS modeling for both Tokai and Orion, the worst-case scenario was modeled by assuming an 8760-hour operation time of the flares in each year over five years from 2015-2019. Emission rates for all emission sources under the different modeling scenarios were all assumed to be constant over the 5 years. 
For the fifth modeling scenario (facility ambient air modeling), emissions from each facility were zeroed out, and the impact of emissions from all other facilities on that particular facility was evaluated during each modeling analysis. Receptors with a spatial resolution of 50 meters were placed on the modeled facility while other receptors were removed from the modeling. Seven modeling iterations were conducted in total (one modeling for each facility, including Tokai Carbon CB, Orion Engineered Carbons, IACX Rock Creek LLC, Chevron Phillips Chemical Company, Borger Energy Associates, L.P., Phillips 66 Borger Refinery, and Solvay Polymer). According to the EPA memorandum "Interpretation of "Ambient Air" In Situations Involving Leased Land Under the Regulations for prevention of Significant Deterioration (PSD)" (June 22, 2007):
"When two (or more) companies operate sources on property owned by one company and leased in part to the other, and the lessor grants the lessee sole control over who may access the leased property (e.g. leased property with direct access via entrance on outer perimeter of lessor's land):
 The air over the property retained for use by the lessor is not ambient air to the lessor if public access is precluded. 
 The air over the lessor property is ambient air to the lessee.
 The air over the leased property is ambient air to the lessor. 
 The air over the leased property is ambient air to the lessee unless the lessee acts to preclude public access to the leased property"
Chevron Phillips Chemical LLC and Borger Energy Associates both lease their facility site from Phillips 66 Company. Each have sole control over their property and a guard gate precludes public access to the complex. Therefore, one fenceline for the Phillips 66 Borger refinery-Chevron Phillips Chemical Company LLC-Borger Energy Associates, L.P. complex was used in the first modeling scenario (attainment demonstration). This fenceline was replaced with the fenceline for each of the facilities for the ambient air modeling. 
The sixth modeling scenario addressed impact of the IACX stack parameters, namely temperature and velocity at the stack exit. After discussion with modelers at EPA Region 6 and the TCEQ Air Quality Division, it was agreed that the best way to obtain the most reasonable temperature and velocity at the stack exit is to review the most recent stack test data rather than looking up those parameters from the 1999/2000 permit amendment where the incinerator was modeled. However, while there is information on flue gas temperature and flow rate at the sampling port, combustion chamber temperature, and operational data from the stack test, there was not enough data to determine/calculate the temperature loss at the stack exit. To that end, two different sets of modeling parameters were applied to the base case modeling (Modeling Scenario #1), MSS modeling for Orion (Modeling Scenario #4), and Phillips 66 Borger Refinery ambient air modeling (Modeling Scenario #5), to understand the impact of potential variation of temperature and velocity of the incinerator based upon discussion with EPA Region 6 and TCEQ. The first set of parameters has a temperature of 866.48 K, which is based on the most recent stack test results at the sampling port, and a velocity of 12.37 m/s (based on engineering calculation using the temperature). The second set of parameters, which are also the IACX stack parameters used for all the other modeling scenarios, has a temperature of 533.15 K at the stack exit assuming a quick temperature drop from the sampling port to the stack exit and a velocity of 7.5 m/s (based on engineering calculation using the temperature). The velocity at 533.15 K closely aligns with the worst-case estimate of the historical NSR permit documentation.
Parameters for all emission sources under each different modeling scenario are provided in Table 2, Table 3, Table 4, and Table 5. 
 Attainment demonstration modeling results 
The following table shows the design value (2015-2019) for each of the modeling scenarios mentioned in Section 3.10. 
                               Modeling Scenario
                                 Modeling Case
                                  Description
                             Design Value (ug/m3)
                                 Design Value
                                     (ppb)
                             Modeling Scenario #1
                                    Case #1
Normal operation
                                     190.4
                                     72.7
                             Modeling Scenario #2
                                    Case #1
Merged stack modeling for Tokai Carbon CB. One boiler stack operating with minimum flow and velocity 
                                     185.7
                                     70.9
                                       
                                    Case #2
Merged stack modeling for Tokai Carbon CB One boiler stack operating with maximum flow and velocity
                                     188.4
                                     71.9
                                       
                                    Case #3
Merged stack modeling for Tokai Carbon CB. One boiler stack operating with 75% load
                                     187.7
                                     71.6
                             Modeling Scenario #3
                                    Case #1
MSS modeling for Tokai Carbon CB (1 backup flare) 
                                     182.1
                                     69.5
                                       
                                    Case #2
MSS modeling for Tokai Carbon CB (2 backup flares)
                                     188.7
                                     72.0
                             Modeling Scenario #4
                                    Case #1
MSS modeling for Orion Engineered Carbons
                                     196.3
                                     74.9
                             Modeling Scenario #5
                                    Case #1
Facility ambient air modeling for Tokai Carbon CB
                                     81.1
                                     31.0
                                       
                                    Case #2
Facility ambient air modeling for Orion Engineered Carbons
                                     184.4
                                     70.4
                                       
                                    Case #3
Facility ambient air modeling for IACX Rock Creek LLC
                                     88.7
                                     33.9
                                       
                                    Case #4
Facility ambient air modeling for Chevron Phillips Chemical Company
                                     143.8
                                     54.9
                                       
                                    Case #5
Facility ambient air modeling for Borger Energy Associates, L.P.
                                     155.1
                                     51.2
                                       
                                    Case #6
Facility ambient air modeling for Phillips 66 Borger Refinery
                                     108.8
                                     41.5
                                       
                                    Case #7
Facility ambient air modeling for Solvay Polymer
                                     138.2
                                     52.7
                             Modeling Scenario #6
                                    Case #1
Impact of IACX parameters on modeling of normal operation (Temperature = 866.48 K, Velocity = 12.37 m/s)
                                     185.8
                                     70.9

                                    Case #2
Impact of IACX parameters on Orion MSS modeling (Temperature = 866.48 K, Velocity = 12.37 m/s)
                                     190.5
                                     72.7

                                    Case #3
Impact of IACX parameters on facility ambient air modeling of the Philllips 66 Borger Refinery (Temperature = 866.48 K, Velocity = 12.37 m/s)
                                     107.7
                                     41.1
Detailed results for each of the modeling scenarios are listed below. 

4.1 Modeling Scenario #1:  
The purpose of the modeling is to demonstrate that the federally enforceable emission reductions committed to by each of the major contributors results in compliance with the 2010 one-hour SO2 NAAQS. 
To ensure full attainment with the SO2 NAAQS for the entire Hutchinson County, a series of sensitivity analysis for the three major contributors, including Orion Carbon Black plant, Tokai Carbon CB plant, and IACX, was conducted to identify the major SO2 emission units within each of the facility. The specific emission reduction plan is shown in Table 6. The emission reductions will be done through either installation of emission control equipment, e.g. the SCR/Scrubber system or federally enforceable permitting actions approved by the TCEQ. The resulting changes regarding emission parameters, e.g. stack height, temperature, and flowrate etc., due to the installation of emission control equipment can be found in Table 2.
Figure 9 shows the contour plot of the SO2 concentrations using the reduced MAER as shown in Table 2, and the design value (2015-2019) is 190.4 ug/m3 (72.7 ppb), which is less than the SO2 NAAQS. This indicates that the entire county will attain with the SO2 NAAQS using the proposed emission reduction strategy. 
4.2. Modeling Scenario #2
The purpose of the modeling is to understand impact of the different operation conditions for two boilers at Tokai Carbon CB which have emissions merged into one stack. Three different scenarios were considered:  operation one boiler at maximum flowrate and emission rate; operation of one boiler at minimum flowrate and emission rate; and operation of one boiler at 75% load. The modeled parameters for each of the operating scenarios are listed in Table 3.
Figure 10 shows the contour plots of the SO2 concentrations for the single boiler operation scenarios under three different operating conditions (maximum flowrate and emission rate, minimum flowrate and emission rate, and 75% load). The design value (2015-2019) for the three different scenarios were 185.7 ug/m[3] (70.9 ppb), 188.4ug/m[3] (71.9 ppb), and 187.7 ug/m[3] (71.6 ppb), respectively, which are all less than the SO2 NAAQS. The modeling scenario to capture the two boilers operating at maximum flowrate and emission rate is the same as modeling scenario#1 (Figure 9), which shows the design value (2015-2019) is 190.4 ug/m3 (72.7 ppb). This indicates that the entire county will attain with the SO2 NAAQS under all operation scenarios of the two boilers. 
4.3 Modeling Scenario #3 and #4: 
The purpose of the modeling is to understand the impact of MSS events of the Cogen/waste heat boiler from Tokai Carbon CB and Orion Carbon Black plants when emissions are routed to the backup flares. 
The modeling analysis provided guidance on flare emission optimization to ensure attainment of the SO2 NAAQS during the Cogen/waste heat boiler turnaround. A worst-case scenario was modeled for each of the facilities by assuming an 8760-hour flare operation time over the most recent 5 years (2015-2019).  
As described in section 3.10, Tokai carbon CB (Modeling Scenario #2), has two possible cases. For the first case, the emissions during the Cogen/waste heat boiler turnaround will be routed to 1 flare.  The modeled flare emission parameters are listed in Table 4a. Figure 11 shows the MSS Modeling results for Tokai; the design value  is 182.1 ug/m[3] (69.5 ppb), which means that the entire county will still be able to attain the NAAQS during the Cogen/waste heat boiler turnaround using the modeled flare emission parameters from the Tokai Carbon CB. 
For the second case, the emissions during the Cogen/waste heat boiler turnaround will be routed to 2 flares (raised to new heights of 198 feet.  The modeled flare emission parameters for this case are listed in Table 4b. Figure 12 shows the MSS Modeling results for Tokai Carbon CB have a design value (2015-2019) of 188.7 ug/m3 (72 ppb), which means that the entire county will still be able to attain with the NAAQS during the Cogen/waste heat boiler turnaround using the modeled flare emission parameters from Tokai Carbon CB (Figure 12).  
For the Orion Carbon Black plant, gas from the 3 reactors will be routed to a single, new flare during the Cogen/waste heat boiler turnaround.  The emission parameters of the new flare are provided in Table 5. Figure 13 shows the design value (2015-2019) is 196.3 ug/m[3] (74.9 ppb) which means that the entire county will be in attainment with the NAAQS using the flare emission parameters in Table 4.
4.4 Modeling Scenario #5
The purpose of the modeling is to understand the impact of emissions from all other facilities on one particular facility. To do that, as described in Section 3.10, a receptor grid that has a 50-meter spacing was placed on the modeled facility while the rest of the receptors were removed.
For ambient air modeling of the Phillips 66 Borger Refinery, Chevron Phillips Chemical Company LLC, and Borger Energy Associates, L.P., the one fenceline (Figure 1) used for the complex for modeling scenario #1 was replaced with the fenceline for each facility, and receptors were placed on each modeled facility.  
Figure 14 showed the facility ambient air modeling on each of the facilities.  The modeling results showed design values at 81.1 ug/m[3] (31.0 ppb), 184.4 ug/m[3] (70.4 ppb), 88.7 ug/m[3](33.9 ppb), 143.8 ug/m[3] (54.9 ppb), 155.1 ug/m[3] (59.2 ppb), 108.8 ug/m[3] (41.5 ppb), 138.2 ug/m[3] (52.7 ppb), respectively, for the modeling on Tokai Carbon CB, Orion Engineered Carbons, IACX Rock Creek LLC, Chevron Phillips Chemical Company, Borger Energy Associates, L.P., Phillips 66 Borger Refinery, and Solvay Polymer. The results demonstrate that none of the receptors within any facility had concentrations above the SO2 NAAQS, indicating that workers in each facility will not be exposed to SO2 concentration greater than the SO2 NAAQS caused by emissions from other facilities. 
4.5 Modeling Scenario #6
The purpose of the modeling was to understand the impact of the IACX stack parameters, namely temperature and velocity at the stack exit. As discussed in Section 3.10, three modeling cases were conducted to understand the impact on base case modeling (Modeling Scenario #1), MSS modeling for Orion Engineered Carbons (Modeling Scenario #4), and facility ambient air modeling on Phillips 66 Borger Refinery (Modeling Scenario #5). The maximum temperature (866.48 K) and the engineering calculated exit velocity (12.37 m/s) based on that temperature was used for the modeling. 
Figure 15 shows the modeling results for the three modeling cases mentioned above. The design value for these modeling runs is 185.8 ug/m[3] (70.9 ppb), 190.5 ug/m[3] (72.7 ppb), and 107.7 ug/m[3] (41.1 ppb), respectively, indicating that variations of temperature and velocity of the IACX incinerator will not cause design values greater than the SO2 NAAQS. 
   
 Conclusion
This modeling demonstrates that when the actions described in Section 2 are fully implemented, all areas of Hutchison County will meet the one-hour SO2 NAAQS for all operating scenarios.  
                                    TABLES
Table 1. Temporally varying background concentrations for modeling analysis to support the designation of non-attainment areas in Hutchinson County, Texas. All concentrations reported in the table are in ppb.  
                                     Hour
                                    Winter
                                    Spring
                                    Summer
                                     Fall
                                       0
                                     1.20
                                     0.73
                                     0.60
                                     1.07
                                       1
                                     1.20
                                     0.80
                                     0.63
                                     1.10
                                       2
                                     1.03
                                     1.00
                                     0.70
                                     0.97
                                       3
                                     0.90
                                     1.13
                                     0.70
                                     0.83
                                       4
                                     0.97
                                     0.90
                                     0.83
                                     0.77
                                       5
                                     1.13
                                     0.83
                                     1.13
                                     0.87
                                       6
                                     1.17
                                     0.97
                                     1.03
                                     0.87
                                       7
                                     1.07
                                     1.10
                                     1.03
                                     0.97
                                       8
                                     1.07
                                     1.10
                                     1.27
                                     1.20
                                       9
                                     0.97
                                     1.13
                                     1.40
                                     1.20
                                      10
                                     1.27
                                     1.20
                                     1.43
                                     0.83
                                      11
                                     3.07
                                     1.50
                                     1.43
                                     2.40
                                      12
                                     4.00
                                     0.97
                                     1.40
                                     1.00
                                      13
                                     1.83
                                     1.43
                                     1.83
                                     0.97
                                      14
                                     1.20
                                     1.60
                                     1.07
                                     0.93
                                      15
                                     0.83
                                     1.23
                                     1.00
                                     1.03
                                      16
                                     0.97
                                     1.07
                                     0.97
                                     0.93
                                      17
                                     0.93
                                     1.03
                                     1.03
                                     0.87
                                      18
                                     0.87
                                     0.77
                                     0.93
                                     0.83
                                      19
                                     1.50
                                     0.73
                                     0.90
                                     1.03
                                      20
                                     1.23
                                     0.80
                                     0.70
                                     0.77
                                      21
                                     1.30
                                     0.73
                                     0.83
                                     0.90
                                      22
                                     1.13
                                     0.97
                                     0.60
                                     0.77
                                      23
                                     1.47
                                     0.93
                                     0.80
                                     0.83



Table 2. Emission parameters for modeling scenario #1 (attainment demonstration)
                                   Facility
                                      ID
                                  Description
                                     Type
                                 Elevation
(m)
                                  Height
(m)
                                 Diameter
(m)
                                Velocity
(m/s)
                                Temperature
(K)
                                  MAER
(g/s)
                                    UTM (E)
                                    UTM(N)
                               BlackHawk Station
                                    EPN1_1
BLACKHAWK STATION Unit 1, combustion turbine w. HRSG
                                     POINT
                                    926.09
                                     39.60
                                     5.49
                                     19.81
                                    572.04
                                     12.85
                                   286456.22
                                  3952838.42

                                    EPN2_1
BLACKHAWK STATION Unit 2, Combustion Turbine W. HRSG
                                     POINT
                                    925.11
                                     39.60
                                     5.49
                                     19.81
                                    572.04
                                     12.85
                                   286490.25
                                  3952822.50
                                    CPCHEM
                                     FL_1
CPCHEM North Flare
                                     POINT
                                    907.54
                                     60.96
                                     1.47
                                     20.00
                                    1273.00
                                     52.14
                                   287109.47
                                  3953315.88

                                     FL_2
CPCHEM South Flare
                                     POINT
                                    907.55
                                     53.64
                                     1.32
                                     20.00
                                    1273.00
                                     9.88
                                   286937.13
                                  3952991.40

                                    FM2A_2
CPCHEM Sulfolene handling area fugitive (4-trailer storage)
                                     AREA
                                See notes below

                                    FM2A_1
CPCHEM Sulfolene handling area fugitive (Building + 1 trailer)
                                     AREA

                                     IACX
                                   GASINCIN
IACX Acid Gas Incinerator
                                     POINT
                                    922.88
                                     65.00
                                     0.52
                                     7.50
                                    533.15
                                     20.79
                                   281855.64
                                  3950424.17
                                   Tokai CB
                                      119
Tokai Merged Boilers Stack
                                     POINT
                                    959.31
                                     60.35
                                     2.90
                                     16.46
                                    377.00
                                     13.73
                                   279480.06
                                  3949603.20

                                      121
Tokai Plant 1 Dryer Stack
                                     POINT
                                    959.02
                                     60.35
                                     2.30
                                     13.40
                                    700.00
                                     55.60
                                   279534.06
                                  3949484.20

                                      122
Tokai Plant 2 Dryer Stack
                                     POINT
                                    960.23
                                     60.35
                                     2.70
                                     11.80
                                    700.00
                                     75.00
                                   279573.06
                                  3949763.20
                                   Orion CB
                                     E_53P
Orion TPE Bag Filter
                                     POINT
                                    961.12
                                     36.58
                                     1.52
                                     9.14
                                    425.37
                                     0.17
                                   279781.00
                                  3949634.00

                                      E6B
Orion Waste Heat Boiler
                                     POINT
                                    954.53
                                     45.72
                                     2.56
                                     21.34
                                    422.04
                                     12.23
                                   279820.00
                                  3949535.00
                                      P66
                                     10H1
P66 Crude Oil Heater
                                     POINT
                                    924.79
                                     28.47
                                     2.36
                                     3.41
                                     446.9
                                     0.39 
                                   286404.18
                                  3953539.19
                                       
                                   19B119H1
P66 U19.2, Charge Furnace, #2 & #3
                                     POINT
                                    915.49
                                     30.48
                                     1.41
                                     21.64
                                    438.71
                                     0.57 
                                   286240.00
                                  3953442.00
                                       
                                   19B119H2
P66 19.2 #2 Reheater
                                     POINT
                                    915.35
                                     30.48
                                     1.41
                                     21.64
                                    438.71
                                     0.33 
                                   286239.00
                                  3953453.00
                                       
                                   19B219H4
P66 U19.3 Charge. & Fractionator Furnace
                                     POINT
                                    918.28
                                     19.66
                                     1.22
                                     20.57
                                    438.71
                                     0.56
                                   286235.00
                                  3953320.00
                                       
                                     19H3
P66 19.1 Charge Furnace
                                     POINT
                                    915.81
                                     30.5
                                     2.26
                                     4.94
                                    533.15
                                     0.38
                                   286238.00
                                  3953414.00
                                       
                                     19H5
P66 U19.2, #1 Reboiler
                                     POINT
                                    918.37
                                      15
                                     0.82
                                     6.25
                                    616.48
                                     0.06
                                   286249.17
                                  3953336.19
                                       
                                    19H5_2
P66 U19.2, #2 Reboiler
                                     POINT
                                    918.37
                                      15
                                     0.82
                                     6.25
                                    616.48
                                     0.05
                                   286249.17
                                  3953336.19
                                       
                                     19H6
P66 U19.2 #1 Reheater
                                     POINT
                                    915.27
                                     33.53
                                     3.03
                                     4.27
                                    533.15
                                     0.32
                                   286238.00
                                  3953460.00
                                       
                                     22H1
P66 Alky Reboiler Furnace
                                     POINT
                                    922.43
                                     9.14
                                     1.07
                                     4.42
                                    533.15
                                     0.07 
                                   286233.17
                                  3953165.19
                                       
                                     26H1
P66 Unit 26 Debutanizer Reboiler
                                     POINT
                                    923.78
                                     21.34
                                     1.29
                                     8.32
                                    469.26
                                     0.26
                                   286345.17
                                  3953292.19
                                       
                                     28H1
P66 Unit 28 Heater
                                     POINT
                                    922.94
                                     29.3
                                     1.22
                                     4.60
                                    439.00
                                     0.64
                                   286324.71
                                  3953573.76
                                       
                                     29H4
P66 Unit 29 Debutanizer Reboiler
                                     POINT
                                    927.32
                                     41.15
                                      1.6
                                     6.10
                                    479.26
                                     0.26
                                   285971.17
                                  3952912.19
                                       
                                     29P1
P66 Unit 29 FCCU
                                     POINT
                                    928.19
                                     53.6
                                     2.44
                                     12.50
                                    567.00
                                     22.05
                                   286025.00
                                  3952753.00
                                       
                                      2H1
P66 Unit 2-2 HDS Charge Heater
                                     POINT
                                    919.68
                                     30.48
                                     1.44
                                     4.72
                                    533.15
                                     0.15
                                   285373.16
                                  3953033.19
                                       
                                      2H2
P66 Deoiler Furnace
                                     POINT
                                     929.2
                                     20.88
                                     1.52
                                     3.75
                                    505.37
                                     0.14
                                   285783.16
                                  3952891.19
                                       
                                     34I1
P66 Unit 34 Incinerator
                                     POINT
                                    933.31
                                     60.7
                                     1.22
                                     4.94
                                    726.48
                                     5.65
                                   285740.16
                                  3952696.19
                                       
                                     36H1
P66 HDS Unit Charge Heater
                                     POINT
                                      924
                                     27.43
                                     1.52
                                     5.24
                                    533.15
                                     0.19 
                                   286367.18
                                  3953569.19
                                       
                                     40H1
P66 Unit 40 Superheater No. 1
                                     POINT
                                    928.84
                                     33.8
                                     1.05
                                     11.28
                                    718.15
                                     0.12 
                                   285963.17
                                  3953024.19
                                       
                                     40H3
P66 Unit 40 Superheater
                                     POINT
                                    929.45
                                     24.72
                                     1.28
                                     9.33
                                    668.71
                                     0.14
                                   285950.00
                                  3953027.00
                                       
                                     40H4
P66 Unit 40 Preheater Furnace
                                     POINT
                                    927.32
                                     39.62
                                     2.29
                                     7.62
                                    549.82
                                     0.43
                                   286035.00
                                  3953137.00
                                       
                                     40P1
P66 Unit 40 FCCU
                                     POINT
                                     926.6
                                     53.6
                                     0.91
                                      30
                                      544
                                     22.05
                                   286011.00
                                  3952863.00
                                       
                                     42H1
P66 Unit 42 Reactor Charge Heater
                                     POINT
                                     931.4
                                     46.02
                                     0.82
                                     20.12
                                    435.93
                                     0.27
                                   286043.16
                                  3952536.18
                                       
                                     42H2
P66 Unit 42 Reactor Charge Heater
                                     POINT
                                    932.33
                                     46.02
                                     0.82
                                     20.12
                                    435.93
                                     0.27
                                   285972.16
                                  3952554.18
                                       
                                     43I1
P66 Unit 43 Incinerator
                                     POINT
                                     928.4
                                     45.7
                                     1.07
                                     18.29
                                    449.82
                                     4.66
                                   286145.17
                                  3952814.18
                                       
                                     50H1
P66 Unit 50 Charge Furnace
                                     POINT
                                    926.84
                                     57.91
                                     2.13
                                     8.84
                                    516.48
                                     0.91
                                   286268.00
                                  3952967.00
                                       
                                     51H1
P66 VDU Heater
                                     POINT
                                    928.96
                                     57.91
                                     2.29
                                     8.57
                                    472.04
                                     1.07
                                   286416.00
                                  3953058.00
                                       
                                      5H1
P66 Unit 5-A Feed Heater
                                     POINT
                                    927.04
                                     13.36
                                     1.07
                                     3.57
                                    533.15
                                     0.06
                                   285758.17
                                  3953012.19
                                       
                                    66FL12
P66 GOHDS Flare
                                     POINT
                                    905.69
                                     42.7
                                     0.96
                                      20
                                     1273
                                     5.04
                                   285381.16
                                  3953345.19
                                       
                                    66FL13
P66 Derrick Flare
                                     POINT
                                    929.15
                                      65
                                     0.27
                                      20
                                     1273
                                     1.89
                                   286198.17
                                  3952810.18
                                       
                                     7H14
P66 Unit 7 Charge Furnace
                                     POINT
                                    920.91
                                     44.84
                                     2.06
                                     4.51
                                    438.71
                                     0.37 
                                   285395.16
                                  3953042.19
                                       
                                     81B17
P66 Boiler 2.4
                                     POINT
                                    924.04
                                     19.81
                                     1.22
                                     55.78
                                    433.15
                                     2.01
                                   286164.00
                                  3952984.00
                                       
                                     85B2
P66 Unit 40 Boiler
                                     POINT
                                    927.73
                                     75.4
                                     3.58
                                     10.57
                                      472
                                     2.38
                                   285965.00
                                  3952941.00
                                       
                                     98H1
P66 SMR Charge Heater
                                     POINT
                                    932.64
                                     39.62
                                     1.98
                                     15.85
                                    463.71
                                     1.02
                                   285933.00
                                  3952599.00
                                       
                                      9H1
P66 Crude Oil Heater
                                     POINT
                                    922.68
                                     25.79
                                     2.03
                                     5.37
                                    438.71
                                     0.41
                                   286304.18
                                  3953540.19
                                       
                                     BLR12
P66 Boiler 12
                                     POINT
                                    929.23
                                     39.62
                                     2.44
                                     18.29
                                    422.04
                                     2.43
                                   285927.00
                                  3952878.00
                                       
                                    SKDBLR
P66 Skid Boiler
                                     POINT
                                    930.08
                                     23.65
                                     2.74
                                     14.02
                                    417.59
                                     1.58
                                   285891.61
                                  3952883.70
                                       
                                     41H1 
P66 Unit 41 Reformer Furnace
                                     POINT
                                    926.80
                                     45.72
                                     2.43
                                     55.78
                                    435.93
                                     2.25
                                   286005.00
                                  3952800.00
Notes:
 All flare diameters are calculated effective diameters.
 Modeling parameters for the two area sources from CPCHEM are below (X represents UTM Easting, and Y represents UTM northing):
                                      ID
                                 Elevation (m)
                                  Height (m)
                                     MAER
                                   (g/s-m2)
                                      X1
                                      Y1
                                      X2
                                      Y2
                                      X3
                                      Y3
                                      X4
                                      Y4
FM2A_1
                                    922.23
                                     6.06
                                    9.3E-5
                                   286731.00
                                  3953192.00
                                   286704.19
                                  3953192.71
                                   286702.65
                                  3953171.02
                                   286731.09
                                  3953169.63
FM2A_2
                                    912.68
                                     3.05
                                    1.25E-5
                                   287266.00
                                  3952995.00
                                   287343.00
                                  3952929.00
                                   287155.00
                                  3952837.00
                                   287111.00
                                  3952903.00

Table 3. Modeling scenarios to address the merged stack emissions from the boilers from the Tokai Carbon CB
ID
Description
                              Operating Condition
                                 Elevation
(m)
                                  Height
(m)
                                 Diameter
(m)
                                Velocity
(m/s)
                                   Temp
(K)
                                  MAER
(g/s)
                                    UTM (E)
                                    UTM(N)


                                NO. of Boilers
                                Flow Condition
                              Emission Condition
                                       
                                       
                                       
                                       
                                       
                                       
                                       
                                       
119
Tokai merged boilers stack
                                      2 
                                    Maximum
                                    Maximum
                                    959.31
                                     60.35
                                     2.90
                                     16.46
                                    377.00
                                     13.73
                                   279480.06
                                  3949603.20


                                       1
                                    Maximum
                                    Maximum
                                    959.31
                                     60.35
                                     2.90
                                     8.23
                                    377.00
                                     6.87
                                   279480.06
                                  3949603.20


                                       1
Minimum
                                    Minimum
                                    959.31
                                     60.35
                                     2.90
                                     6.57
                                    377.00
                                     0.93
                                   279480.06
                                  3949603.20


                                       1
75% load
                                   75% load
                                    959.31
                                     60.35
                                     2.90
                                     6.17
                                    377.00
                                     5.15
                                   279480.06
                                  3949603.20
Notes:
 Both boilers are rated at the same capacity, the max flow and max emission rate for Boiler #1 and Boiler #2 are identical. The max flow/velocity for one boiler equals 50% of the max condition for that of 2 boilers. The max emission rate for one boiler equals 50% of the max condition for that of 2 boilers.
 The modeling for 2 boilers operating at maximum flowrate and emission rates are the same as the base modeling (scenario#1 for attainment demonstration).
 The stack gas temperature is dictated by the design of the pollution control equipment and not by the boiler loads, therefore, stack temperature was kept the same for different modeling scenarios. 

Table 4. Emission parameters for modeling scenario #2_MSS events from Tokai Carbon CB
 Tokai Carbon CB MSS Case #1, one backup flare at 27.8 m (91.2 ft)) 
                                   Facility
                                      ID
                                  Description
                                     Type
                                 Elevation
(m)
                                  Height
(m)
                                 Diameter
(m)
                                Velocity
(m/s)
                                Temperature
(K)
                                  MAER
(g/s)
                                    UTM (E)
                                    UTM(N)
                                   Tokai CB
119
Tokai Merged Boilers Stack
                                     POINT
                                    959.31
                                     60.35
                                     2.90
                                     16.46
                                    377.00
                                       0
                                   279480.06
                                  3949603.20

121
Tokai Plant 1 Dryer Stack
                                     POINT
                                    959.02
                                     60.35
                                     2.30
                                     13.40
                                    700.00
                                     31.50
                                   279534.06
                                  3949484.20

122
Tokai Plant 2 Dryer Stack
                                     POINT
                                    960.23
                                     60.35
                                     2.70
                                     11.80
                                    700.00
                                     50.40
                                   279573.06
                                  3949763.20

FLARE_1
Tokai MSS Flare#1
POINT
                                    958.64
                                     27.80
                                     2.75
                                     20.00
                                    1273.00
                                     52.92
                                   279493.03
                                  3949448.50
Notes:
 All flare diameters are calculated effective diameters.
 The table above only shows modeling parameters of emission sources from Tokai CB. Modeling parameters for emission sources from other facilities were kept the same as shown in Table 2. 
   
 Tokai Carbon CB MSS Case #2: (two backup flares at 198 ft (60.35 m)) 
                                   Facility
                                      ID
                                  Description
                                     Type
                                 Elevation
(m)
                                  Height
(m)
                                 Diameter
(m)
                                Velocity
(m/s)
                                Temperature
(K)
                                  MAER
(g/s)
                                    UTM (E)
                                    UTM(N)
                                   Tokai CB
119
Tokai Merged Boilers Stack
                                     POINT
                                    959.31
                                     60.35
                                     2.90
                                     16.46
                                    377.00
                                       0
                                   279480.06
                                  3949603.20

121
Tokai Plant 1 Dryer Stack
                                     POINT
                                    959.02
                                     60.35
                                     2.30
                                     13.40
                                    700.00
                                     31.50
                                   279534.06
                                  3949484.20

122
Tokai Plant 2 Dryer Stack
                                     POINT
                                    960.23
                                     60.35
                                     2.70
                                     11.80
                                    700.00
                                     50.40
                                   279573.06
                                  3949763.20

FLARE_4
Tokai MSS Flare#2
POINT
                                    958.28
                                     60.35
                                     2.98
                                     20.00
                                    1273.00
                                     40.32
                                   279497.61
                                  3949739.40

FLARE_1
Tokai MSS Flare#1
POINT
                                    958.64
                                     60.35
                                     2.75
                                     20.00
                                    1273.00
                                     52.92
                                   279493.03
                                  3949448.50
Notes:
 All flare diameters are calculated effective diameters.
 The table above only shows modeling parameters of emission sources from Tokai CB. Modeling parameters for emission sources from other facilities were kept the same as shown in Table 2. 


Table 5. Emission parameters for modeling scenario #3 to address MSS events of the Cogen unit _Orion Engineered Carbons
                                   Facility
ID
Description
                                     Type
                                 Elevation
(m)
                                  Height
(m)
                                 Diameter
(m)
                                Velocity
(m/s)
                                Temperature
(K)
                                  MAER
(g/s)
                                    UTM (E)
                                    UTM(N)
                                   Orion CB
E_53P
Orion TPE bag filter
                                     POINT
                                    961.12
                                     36.58
                                     1.52
                                     9.14
                                    425.37
                                     0.17
                                   279781.00
                                  3949634.00

E6B
Orion Waste Heat Boiler
                                     POINT
                                    954.53
                                     45.72
                                     2.56
                                     21.34
                                    422.04
                                       0
                                   279820.00
                                  3949535.00

FLARECMB
Units 1-3 Reactors/Combined Flare
                                     POINT
                                    958.30
                                     65.00
                                     4.85
                                     20.00
                                    1273.00
                                     94.50
                                   279745.85
                                  3949549.50
Notes:
 All flare diameters are calculated effective diameters.
 The table above only shows modeling parameters of emission sources from Orion Engineered Carbons. Modeling parameters for emission sources from other facilities were kept the same as shown in Table 2. 






Table 6. Proposed emission reduction strategy and timeline for attainment with the SO2 NAAQS in Hutchinson County, Texas. 
                                   Facility
                                      ID
                                  Description
                                   UTM

(E)
                                   UTM

(N)
                             Permitted MAER
(g/s)
                    MAER for Attainment Demonstration
(g/s)
                                Control Measure
                                  Time Frame
                              Emission Reduction










                                Tokai Carbon CB
                                      121
Plant 1 Dryer Stack
                                   279534.06
                                   3949484.2
                                     68.16
                                     55.57
 Lower permit limit
                                April 1, 2021 
                                    68.80%

                                      122
Plant 2 Dryer Stack
                                   279573.06
                                   3949763.2
                                    100.04
                                     74.97
 Lower permit limit
                                April 1, 2021 


                                      119
Boilers Stack
                                   279480.06
                                   3949603.2
                                    274.68
                                     13.73
Install SCR/Scrubber 
                                 April , 2021


                                       1
Plt 1, No. 1 & 2 Dryer Purge filter
                                   279559.06
                                  3949458.19
                                     9.83
                                       0
Fire natural gas or install heat exchanger
                                April 1, 2021 


                                       3
Plt 1, No. 3 & 4 Dryer Purge filter
                                   279551.06
                                   3949458.2
                                     9.83
                                       0
Fire natural gas or install heat exchanger
                                April 1, 2021 

                           Orion Engineered Carbons
                                      E6B
Orion Waste Heat Boiler
                                    279820
                                    3949535
                                    261.19
                                     12.23
Install SCR/Scrubber
                               December 31, 2022
                                    97.66%

                                    E_10FL
Orion Unit 1 Flare
                                    279750
                                    3949343
                                     87.06
                                       0
Retire
                              December 31, 2022 


                                    E_20FL
Orion Unit 2 Flare
                                    279765
                                    3949432
                                     87.09
                                       0
Retire
                              December 31, 2022 


                                    E_40FL
Orion Unit 4 Flare
                                    279743
                                    3949276
                                     87.09
                                       0
Retire
                              December 31, 2022 

                          Phillips 66 Borger Refinery
                                  Flex Permit
Reduced MAER's
                                      NA
                                      NA
                                      NA
                                      NA
NA
                                 July 1, 2020
                                      NA
                             IACX Rock Creek LLC.
                                   GASINCIN
Acid Gas Incinerator 
                                   281855.64
                                  3950424.17
                                     55.69
                                    20.79 
Permit Alteration
                                July 10, 2020 
                                    62.69%
                               Chevron Phillips
                                Chemical Company
                                    FM2A_1
Sulfolene handling area fugitive (Building + 1 trailer)
                               See Table 2 for 
                             detailed information
                                     0.615
                                    0.057 
Permit Alteration
                        Submit week of July 20, 2020 
                                    56.35%
                                       
                                    FM2A_2
Sulfolene handling area fugitive (4-trailer storage)
                                       
                                       
                                     0.21
Permit Alteration
                        Submit week of July 20, 2020 
                                       
Total SO2 emission reduction in Hutchinson County, Texas
                                    81.75%
 
                                    FIGURES
                                       
Figure 1. Receptor grid used in the modeling system.

                                       
Figure 2. Terrain elevations for the modeling analysis. 
                                       
Figure 3. Google map image showing the boundary of the city of Borger. 

                                       
Figure 4. Wind rose plot obtained using the 5-year meteorological data (2015-2019) from the NWS surface meteorological station (ID:  3024) in Hutchinson County, Texas.  
                                       
                                       
Figure 5. Google map showing locations of SO2 emission facilities, SO2 monitor (CAMS1073), and the arc (dashed line) suggested by the EPA Region 6 for calculation of SO2 background concentration. 

                                       
Figure 6. SO2 pollutant rose plot using 3-year SO2 concentration (2017-2019) data from the TCEQ SO2 monitor CAMS1073. The SO2 concentrations within wind sector 200⁰-45⁰ (CW) were used to develop the regional background concentration. 
                                       
Figure 7. Google map showing locations of the Harrington Generating Station and CAMS1025 background SO2 monitor. 

                                       
Figure 8. SO2 pollutant rose plot from the 3-year (2017-2019) SO2 concentration data from the CAMS1025 monitor. The SO2 concentration data within the wind sector arc 71⁰ - 339⁰ (highlighted in yellow) was used to develop the background SO2 concentration for Hutchinson County, TX.  


Figure 9. Base case modeling results using the reduced MAER as shown in Table 2. The design value (2015-2019) is 190.4 ug/m[3]. The merged stack (emission source ID #119) from Tokai Carbon CB has two boilers operating with maximum flow rate and emission rate for the base case modeling scenario. The different operating conditions of the merged stack from Tokai Carbon CB were modeled separately. 



                                       b
b
a
a
                                       c
c
                                       
Figure 10. Modeling results for the merged boiler stack for Tokai CB (2015-2019): a) one boiler operating with maximum flow and emission rate. Since the two boilers are rated at the same capacity, the maximum flowrate and emission rate for each boiler are the same, which is half of those when two boilers are operating at the same time. The design value is 188.4 ug/m[3]; b) one boiler operating with minimum flow and emission rate. The design value is 185.7 ug/m[3] and c) one boiler operating at 75% load. The design value is 187.7 ug/m[3]. 


 
Figure 11. MSS modeling results for Tokai Carbon CB (Case#1). The design value (2015-2019) is 182.1 ug/m[3].







Figure 12. MSS modeling results for Tokai Carbon CB (Case#2). The design value (2015-2019) is 188.7 ug/m[3].



Figure 13. MSS modeling results for Orion Engineered Carbons LLC. The design value (2015-2019) is 196.3 ug/m[3].


b
b
a
a



d
d
c
c



f
f
e
e



g
g


q


Figure 14. Facility ambient air modeling:  a) Tokai Carbon CB; b) Orion Engineered Carbons LLC; c) IACX Rock Creek LLC; d) Phillips 66 Borger Refinery; e) Borger Energy Associates, L.P.; f) Chevron Phillips Chemical Company LLC.; and g) Solvay Polymer. The design values (2015-2019) for the seven facility ambient air modeling scenarios described above are: 88.1 ug/m[3], 184.4 ug/m[3], 88.7 ug/m[3], 100.8 ug/m[3], 155.1 ug/m[3], 143.8 ug/m[3], and 138.2 ug/m[3], respectively. 


                                      cb
cb
b
b
a
a
                                       








Figure 15. Impact of temperature and velocity of the IACX incinerator on a) base case modeling; b) MSS modeling for Orion Engineered Carbons; and c) ambient air modeling for Phillips 66 Borger Refinery. The design values (2015-2019) for the three modeling scenarios are: 185.8 ug/m[3], 190.5 ug/m[3], and 107.7 ug/m[3]. 

                                       
                   APPENDIX I: Minor Emission Source Tables
Table 1. Minor SO2 emission sources _ IACX 
NEI ID
EPN
Source Type
Unit Description
MAER 
(g/s)
UTM (E)
UTM (N)
000010
STK4
Point
Cooper GMV-10
3.78E-03
281762.35
3950350.97
000009
STK5
Point
Superior 8G825
2.52E-03
281785.26
3950350.74
000055
ENG8A
Point
Superior 6G825
2.52E-03
281755.44
3950578.71
000057
PUMP
Point
Caterpillar G-3306
5.18E-05
281836.23
3950456.72
000050
STK7
Point
Gas Turbine 7A
1.76E-02
281740.41
3950593.84
000002
STK6D
Point
31,050 HP GE Gas Turbine Stack
9.32E-02

281762.35
3950350.97
000002
STK6C
Point
31,050 HP GE Gas Turbine Stack

281796.06
3950492.01
000002
STK6B
Point
31,050 HP GE Gas Turbine Stack

281838.26
3950491.53
000002
STK6A
Point
31,050 HP GE Gas Turbine Stack

281838.26
3950491.53
000053
HOH1
Point
North Hot Oil Heater
1.26E-03
281779.36
3950641.61
000054
HOH2
Point
South Hot Oil Heater
1.26E-03
281811.24
3950320.80
000004
HTRSTK3
Point
Regen. Heater Stk. 3
1.26E-03
281890.37
3950407.66
000003
BLRSTK1
Point
18.56 MM BTU/HR Boiler Stack #1
1.26E-03
281867.34
3950373.70
000005
BLRSTK2
Point
25.69 MM BTU/HR Boiler Stack #2
2.52E-03
281878.21
3950373.77
 Notes:
 The emission sources listed above takes ~2% of the total SO2 emissions from IACX.
 IACX only has one 31,000hp Frame V turbine. The four points (NEI ID 000002) are the locations of the four exhaust stacks (2 on each side  -  one before the steam generators and one after on each side).

Table 2. Minor SO2 emission sources _ Chevron Phillips Chemical Company 
                                    NEI ID
                                      EPN
                                  Source Type
                               Unit Description
                                  MAER (g/s)
                                    UTM (E)
                                    UTM (N)
                                    000405
                                   M2A1 MSS
                                     Point
 Sulfolene Flaker Scrubber RTO MSS
                                < 2.88 E-04 
                                   286820.2
                                    3952945
                                    000397
                                    ICE-04
                                     Point
 West Fire Water Engine
                                   2.60E-03
                                   286406.4
                                   3953528.7
                                    000400
                                    ICE-03
                                     Point
 East Fire Water Engine
                                   2.60E-03
                                   286406.4
                                   3953528.7
                                    000024
                                      H-1
                                     Point
 MPU Dutch Oven
                                < 2.88 E-04 
                                   286750.3
                                    3953112
                                    000398
                                    ICE-05
                                     Point
 East Test Engine  -  RON
                                   7.97E-05
                                   286406.2
                                   3953428.8
                                    000399
                                    ICE-06
                                     Point
 West Test Engine  -  MON
                                   7.97E-05
                                   286406.2
                                   3953428.8
                                    000359
                                    G-SB2A
                                     Point
 South Paint Yard Air Compressor (Sandblasting)
                                   1.18E-02
                                   286574.3
                                   3953116.2
                                    000358
                                    G-PB1A
                                     Point
 North Paint Yard Air Compressor (Sandblasting)
                                   6.85E-04
                                   287212.4
                                   3953501.7
                                    000199
                                      n/a
                                      n/a
n/a
                                      n/a
                                      n/a
                                      n/a
                                    000348
                                     SP5C
                                     Point
Vapor Combustor 
                                < 2.88 E-04 
                                   286719.2
                                   3952866.1
                                     00042
                                     F-M2A
                                     Area 
Sulfolene Handling Area fugitives 
                                See notes below
                                    000396
                                    ICE-01
                                     Point
Maintenance Compressor (Painting) 
                                   9.78E-06
                                    287205
                                   3953501.9
                                    000402
                                    ICE-02
                                     Point
Maintenance Compressor (Sandblasting) 
                                   1.84E-04
                                    287205
                                   3953501.9
                                    000404
                                   F-M2A MSS
                                     Area
Sulfolene Process Maintenance (MSS)
                                  2.88 E-04 
                                   286748.2
                                   3952965.8
Notes:
 Source 000199:   No conclusions can be drawn to what this source may be, as the coordinates in the NEI do not represent any facility, or nearby facility.
 The area emission sources were included in the county-wide modeling, and the modeling parameters are listed below:
                                      ID
                                 Elevation (m)
                                  Height (m)
                                     MAER
                                   (g/s-m2)
                                      X1
                                      Y1
                                      X2
                                      Y2
                                      X3
                                      Y3
                                      X4
                                      Y4
FM2A_1
                                    922.23
                                     6.06
                                    9.3E-5
                                   286731.00
                                  3953192.00
                                   286704.19
                                  3953192.71
                                   286702.65
                                  3953171.02
                                   286731.09
                                  3953169.63
FM2A_2
                                    912.68
                                     3.05
                                    1.25E-5
                                   287266.00
                                  3952995.00
                                   287343.00
                                  3952929.00
                                   287155.00
                                  3952837.00
                                   287111.00
                                  3952903.00


Table 3. Minor SO2 emission sources _ Orion Carbon Black Plant 
                                    NEI ID
                                      EPN
Source Type
                               Unit Description
UTM (E)
UTM (N)
MAER (g/s)
n/a
                                     P_60P
Point
FD Fan Vent Stack
                                    279775
                                    3949537
                                    0.02646
n/a
                                     E_5B
Point
Thermal Boiler
                                    279828
                                    3949552
                                    0.00126
000033
                                     E_10D
Point
B-1 Dryers Stack A
                                    279753
                                    3949323
                                    0.00126
000017
                                     E_11D
Point
B-1 Dryers Stack B
                                    279753
                                    3949318
                                    0.00126
000033
                                     E_20D
Point
B-2 Dryers Stack A
                                    279800
                                    3949410
                                    0.00126
000033 
                                     E_21D
Point
B-2 Dryers Stack B
                                    279800
                                    3949415
                                    0.00126
000024
                                     E_40D
Point
B-4 Dryers Stack A
                                    279751
                                    3949312
                                    0.00126
000024
                                     E_41D
Point
B-4 Dryers Stack B
                                    279751
                                    3949308
                                    0.00126
000033
                                     E_10D
Point
B-1 Dryer Bag Filter Stack A
                                    279762
                                    3949343
                                    0.00063
000033
                                     E_11D
Point
B-1 Dryer Bag Filter Stack B
                                    279762
                                    3949338
                                    0.00063
000017
                                     E_20D
Point
B-2 Dryer Bag Filter Stack A
                                    279800
                                    3949410
                                    0.00063
000017
                                     E_21D
Point
B-2 Dryer Bag Filter Stack B
                                    279800
                                    3949415
                                    0.00063
000024 
                                     E_40D
Point
B-4 Dryer Bag Filter Stack A
                                    279754
                                    3949275
                                    0.00063
000024
                                     E_41D
Point
B-4 Dryer Bag Filter Stack B
                                    279764
                                    3949275
                                    0.00063
000014 
                                     E_50R
Point
Thermal Unit 1 Reactor Stack A
                                    279788
                                    3949573
                                    0.08694
000014
                                     E_51R
Point
Thermal Unit 1 Reactor Stack B
                                    279788
                                    3949579
                                    0.08694
000014
                                     E_53P
Point
TPE Bag Filter
                                    279781
                                    3949634
                                    0.17262
000039
                                    E_100H
Point
Main Tank Preheater
                                    279775
                                    3949825
                                  0.000287671
000038
                                    E_101H
Point
Small Tank Preheater
                                    279775
                                    3949825
                                  0.000287671
n/a
                                   FURN_FUG
Area
Furnace Area Fugitives
                                    279734
                                    3949382
                                   0.000100
Note:
E-53P was included in the county-wide modeling considering it has an emission rate greater than 0.1 g/s as recommended by EPA Region 6. 




Table 4. Minor SO2 emission sources _ Solvay Polymer  
                                    NEI ID
                                      EPN
                                  Source Type
                               Unit Description
                                   MAER (g/s)
                                    UTM (E)
                                    UTM (N)
                                    000009
                                    H-08 
                                     point
 No. 1 Dowtherm Furnace
                                   5.52E-02
                                   286984.89
                                  3953348.99
                                    000010
                                     H-09
                                     point
 No. 2 Dowtherm Furnace
                                   5.52E-02
                                   286986.15
                                  3953337.30
                                    000011
                                     H-01
                                     point
 No. 3 Dowtherm Furnace
                                   8.00E-02
                                   286765.83
                                  3953400.53

Table 5. Minor SO2 emission sources _ Phillips 66 Borger Refinery
                                    NEI ID
                                      EPN
                               Unit Description
                                     Type
                                  MAER 
(g/s)
                                   UTM 
(E)
                                   UTM 
(N)
                                  70987413487
                                     51H1
VDU Heater
                                     Point
                                     1.07
                                   286416.00
                                  3953058.00
                                  70987313486
                                     50H1
Unit 50 Charge Furnace 
                                     Point
                                     0.91
                                   286268.00
                                  3952967.00
                                  29585713122
                                   19B1/19H1
Unit 19.2, Charge Heater, #2 & #3
                                     Point
                                     0.57
                                   286240.00
                                  3953442.00
                                  29583313348
                                     7H1-4
Unit 7 Charge Furnace
                                     Point
                                     0.37
                                   285395.16
                                  3953042.19
                                  29589013111
                                     10H1
Crude Oil Heater
                                     Point
                                     0.39
                                   286404.18
                                  3953539.19
                                  29585513124
                                     19H3
Unit 19.1 Charge Furnace
                                     Point
                                     0.38
                                   286238.00
                                  3953414.00
                                  29575513125
                                   19B2/19H4
Unit 19.3 Charge & Fractionator Furnace
                                     Point
                                     0.56
                                   286235.00
                                  3953320.00
                                  29583913127
                                     19H6
Unit 19.2 #1 Reheater
                                     Point
                                     0.32
                                   286238.00
                                  3953460.00
                                  29605013292
                                     42H1
Unit 42 Reactor Charge Heater
                                     Point
                                     0.27
                                   286043.16
                                  3952536.18
                                  29605213294
                                     42H2
Unit 42 Reactor Charge Heater
                                     Point
                                     0.27
                                   285972.16
                                  3952554.18
                                  29594213308
                                     26H1
Unit 26 Debutanizer Reboiler
                                     Point
                                     0.26
                                   286345.17
                                  3953292.19
                                  29611513142
                                     29H4
Unit 29 Debutanizer Reboiler
                                     Point
                                     0.26
                                   285971.17
                                  3952912.19
                                       
                                   19B1/19H2
Unit 19.2 #2 Reheater
                                     Point
                                     0.33
                                   286239.00
                                  3953453.00
                                  29611613143
                                     36H1
HDS Unit Charge Heater
                                     Point
                                     0.19
                                   286367.18
                                  3953569.19
                                  29583813128
                                      2H1
Unit 2-2 HDS Charge Heater
                                     Point
                                     0.15
                                   285373.16
                                  3953033.19
                                  29583713129
                                     22H1
Alky Reboiler Furnace
                                     Point
                                     0.07
                                   286233.17
                                  3953165.19
                                  29584013126
                                     19H5
Unit 19.2, #1 Reboiler
                                     Point
                                     0.06
                                   286249.17
                                  3953336.19
                                  29574213123
                                     19H5
Unit 19.2, #2 Reboiler
                                     Point
                                     0.05
                                   286249.17
                                  3953336.19
                                       
                                    SKDBLR
Skid Boiler
                                     Point
                                     1.58
                                   285891.61
                                  3952883.70
                                       
                                      9H1
Crude Oil Heater
                                     Point
                                     0.41
                                   286304.18
                                  3953540.19
                                       
                                      5H1
Unit 5-A Feed Heater
                                     Point
                                     0.06
                                   285758.17
                                  3953012.19
                                       
                                     40H4
Unit 40 Preheater Furnace 
                                     Point
                                     0.43
                                   286035.00
                                  3953137.00
                                       
                                     40H1
Unit 40 Superheater No. 1
                                     Point
                                     0.12
                                   285963.17
                                  3953024.19
 
                                     40H3
Unit 40 Superheater
                                     Point
                                     0.14
                                   285950.00
                                  3953027.00
                                  29603713293
                                     42H3
Unit 42 Fractionator Feed Heater
                                     Point
                                     0.27
                                   285972.16
                                  3952575.18
                                  70988313496
                                     FWP1
Fire Water Pump 1 - #8 ARDS Fire Water Pump, 67-H463
                                     Point
                                     0.07
                                   285977.00
                                  3953216.00
                                  70988413497
                                     FWP2
Fire Water Pump 2 - #7 ARDS Fire Water Pump, 67-H464
                                     Point
                                     0.07
                                   285987.00
                                  3953216.00
                                  70988513498
                                     FWP3
Fire Water Pump 3 - South NGL Fire Water Pump, 67-H741
                                     Point
                                     0.07
                                   285691.00
                                  3952775.00
                                  70988613499
                                     FWP4
Fire Water Pump 4 - N Refinery Fire Water Pump, 67-V371
                                     Point
                                     0.07
                                   285698.00
                                  3952774.00
                                       
                                     FWP5
Fire Water Pump 5 - S Refinery Fire Water Pump, 67-V372
                                     Point
                                     0.07
                                   285720.00
                                  3952571.00
                                  70992513538
                               Heaters/Furnaces
Decoking
                                     Point
                                     0.70
                                       
                                       
                                        
                                      5H3
Unit 5-C Feed Heater
                                     Point
                                     0.04
                                   285786.00
                                  3952807.00
                                  29580813155
                                      6H1
BHU Reduction Furnace
                                     Point
                                     0.03
                                   285410.00
                                  3952799.00
                                  29611113145
                                      4H2
Unit 4 Dehydrator Heater
                                     Point
                                     0.01
                                   285814.00
                                  3952811.00
                                        
                                     12H1
Mol Sieve Regen Gas Heater
                                     Point
                                     0.01
                                   285848.00
                                  3952467.00
                                  70988013493
                                     50HT1
Coker Heater Tank 1
                                     Point
                                     0.01
                                   287377.00
                                  3953021.00
                                  70988113494
                                     50HT2
Coker Heater Tank 2
                                     Point
                                     0.01
                                   286752.00
                                  3954195.00
                                  70988213495
                                     50HT3
Coker Heater Tank 3
                                     Point
                                     0.01
                                   286859.00
                                  3954189.00
                                  29615213229
                                     93E1
Engine No. 37
                                     Point
                                     0.00
                                   285917.00
                                  3952298.00
                                        
                                     66FL8
100M Sour Brine Flare Pit
                                     Point
                                     0.00
                                   281443.00
                                  3955571.00
                                        
                                    66FL11
30M Swt Brine Flare Pit
                                     Point
                                     0.00
                                   281556.00
                                  3954895.00
                                  29595513114
                                     12E1
Engine
                                     Point
                                     0.00
                                   285900.00
                                  3952460.00
                                  29595413115
                                     12E2
Engine
                                     Point
                                     0.00
                                   285906.00
                                  3952460.00
                                  29595313116
                                     12E3
Engine
                                     Point
                                     0.00
                                   285913.00
                                  3952460.00
                                  29593813117
                                     12E4
Engine
                                     Point
                                     0.00
                                   285919.00
                                  3952459.00
                                  29596413118
                                     12E5
Engine
                                     Point
                                     0.00
                                   285925.00
                                  3952459.00
                                  29594913119
                                     12E6
Engine
                                     Point
                                     0.00
                                   285927.00
                                  3952453.00
                                  29594813120
                                     12E7
Engine
                                     Point
                                     0.00
                                   285933.00
                                  3952453.00
                                  29577313159
                                      7E1
Unit 7 Plat Engine #1
                                     Point
                                     0.00
                                   285464.00
                                  3952877.00
                                  29578913160
                                      7E2
Unit 7 Plat Engine #2
                                     Point
                                     0.00
                                   285460.00
                                  3952877.00
                                  29579013161
                                      7E3
Unit 7 Plat Engine #3
                                     Point
                                     0.00
                                   285455.00
                                  3952877.00
                                  29579113162
                                      7E4
Unit 7 Plat Engine #4
                                     Point
                                     0.00
                                   285451.00
                                  3952877.00
                                  29579213163
                                      7E5
Unit 7 Plat Engine #5
                                     Point
                                     0.00
                                   285446.00
                                  3952877.00
                                  29579313164
                                      7E6
Unit 7 Plat Engine #6
                                     Point
                                     0.00
                                   285442.00
                                  3952877.00
                                        
                                    66FL10
100M Swt Brine Flare Pit
                                     Point
                                     0.00
                                   280864.00
                                  3955107.00
                                       
                                     93E2
Engine No. 38
                                     Point
                                     0.00
                                   285917.00
                                  3952307.00
                                  29608713218
                                    ENG-EB1
Unregistered PBR 106.511 from 2015 
                                     Point
                                     0.01
                                   286139.00
                                  3952652.00
                                        
                                    ENG-EB2
Unregistered PBR 106.511 from 2015 
                                     Point
                                     0.01
                                   285642.00
                                  3952695.00
                                 112968313549
                                    ENG-EB4
Unregistered PBR 106.511 from 2015 
                                     Point
                                     0.01
                                   285395.00
                                  3953013.00
                                 112968413550
                                    ENG-EB6
Unregistered PBR 106.511 from 2015 
                                     Point
                                     0.01
                                   285980.00
                                  3953149.00
                                 112968613552
                                    ENG-EB7
Unregistered PBR 106.511 from 2015 
                                     Point
                                     0.01
                                   285980.00
                                  3953144.00
                                 112968813554
                                    ENG-EB9
Unregistered PBR 106.511 from 2015 
                                     Point
                                     0.01
                                   285639.00
                                  3952696.00
                                        
                                    F-43WHB
Waste Heat Boiler Fugitives
                                     Point
                                     0.00
                                   286180.00
                                  3952609.00
                                        
                                   MISC-MSS
Miscellaneous MSS Activities (Low Emitting Activities)
                                     Point
                                     0.02
                                       
                                       
                                        
                                    MSSFUG
Planned Maintenance Activities
                                     Area
                                     0.001
                                       
                                       

Notes:
 51H1:40H3 were included in the modeling following EPA Region 6's guideline as they have emission rates greater than 0.05 g/s.
 The fire water pumps (FWP1:FWP5) only run 30 min per week, which were considered as infrequent emission sources. Therefore, they were excluded from the modeling.
 42H3 was demolished to make room for the Diesel Vacuum Tower. This emission source will be removed from the cap contributions either via the SO2 attainment alteration or via the renewal permit in the future.
 Decoking MSS (NEI ID: 70992513538) will be removed from permit.
 Sources 7H1-4, 19B1/19H1,19B1/19H2, and 19B2/19H4 represent merged stacks for more than one combustion devise. In each case the combustion devices are associated with the same process and do not operate independently of the other devices sharing the stack.
 Unit of emission rate for MSSFUG is g/s. 

              APPENDIX II: Meteorological Data Processing Report
                                       
                                       













