               GA EPD's Comments on EPA's EtO Modeling Files
                               February 12, 2021

The Georgia Environmental Protection Division (GA EPD) reviewed EPA's EtO modeling files for the following five facilities: Sterigenics, BD-Covington, BD-Madison, Sterilization Services of Georgia (SSG), and Kendall Patient Recovery (KPR).  A summary of our comments for each facility are contained below with details placed in the attached Excel file.

Sterigenics
GA EPD recommends using "Sterigenics" for the facility name instead of "Griffith Micro Science Inc." 

Based on the controls currently installed and operated at the facility and based on the draft permit that is currently out for public comment, GA EPD recommends using the process-level allowable and actual emissions shown in Tables 1 and 2 (total EtO emissions = 0.0419850 TPY = 84.0 lbs/yr).  GA EPD did not have a breakdown for the fugitive emissions associated with ST1 because they were calculated using an assumption of 0.5% of usage.  Therefore, GA EPD applied EPA's ratio (01.25/1.875 = 0.0058571/0.0087857 = 2/3) of emission from the sterilizer room area (Emission Unit ID: CR) to emissions of the shipping or warehouse (Emission Unit ID: S) to the total amount of fugitive emissions sent to ST1 (0.015625 TPY = 31.25 lbs/yr).  Therefore, 40% of the total fugitive emissions sent to ST1 (0.4 * 0.015625 = 0.00625 TPY) are allocated to the sterilizer room area (Emission Unit ID: CR) and 60% of the total fugitive emissions sent to ST1 (0.6 * 0.015625 = 0.009375 TPY) are allocated to the shipping or warehouse (Emission Unit ID: S).  

Table 1. Process-level allowable emissions for Sterigenics.
                            EMISSION RELEASE POINT
                                      ID
                                   EMISSION
                                    UNIT ID
                                  PROCESS_ID
                                Emissions (TPY)
                                     EPA 
                                   Allowable
                                Emissions (TPY)
                                    GA EPD
                                   Allowable
                                       
                                      ST2
                                     AR-1
                                       A
                                   0.0087857
                                   0.0187500
                                      ST1
                                      CR
                                      FUG
                                   0.0058571
                                   0.0062500
                                      ST2
                                      SC
                                      CEV
                                   0.0011955
                                   0.0037500
                                      ST2
                                      SC
                                       S
                                   0.0000123
                                   0.0038600
                                      ST1
                                       S
                                      FUG
                                   0.0087857
                                   0.0093750
                                       
                                       
                                     TOTAL
                                   0.0246362
                                   0.0419850

Table 2. Process-level actual emissions for Sterigenics.
                            EMISSION RELEASE POINT
                                      ID
                                   EMISSION
                                    UNIT ID
                                  PROCESS_ID
                                Emissions (TPY)
                                     EPA 
                                   Allowable
                                Emissions (TPY)
                                    GA EPD
                                   Allowable
                                       
                                      ST2
                                     AR-1
                                       A
                                   0.1250000
                                   0.0187500
                                      ST1
                                      CR
                                      FUG
                                   1.2500000
                                   0.0062500
                                      ST2
                                      SC
                                      CEV
                                   2.1260938
                                   0.0037500
                                      ST2
                                      SC
                                       S
                                   2.9162391
                                   0.0038600
                                      ST1
                                       S
                                      FUG
                                   1.8750000
                                   0.0093750
                                       
                                       
                                     TOTAL
                                   8.2923329
                                   0.0419850
BD-Covington
Based on the most recent permit application under GA EPD's review, GA EPD recommends using the process-level allowable emissions shown in Table 3 (total EtO emissions = 0.2031 TPY = 406.2 lbs/yr).  If actual emissions are used, GA EPD recommends using the process-level actual emissions shown in Table 4 (total EtO emissions = 0.1524 TPY = 304.7 lbs/yr).

Table 3. Process-level allowable emissions for BD-Covington.
                            EMISSION RELEASE POINT
                                      ID
                                   EMISSION
                                    UNIT ID
                                  PROCESS_ID
                                Emissions (TPY)
                                     EPA 
                                   Allowable
                                Emissions (TPY)
                                    GA EPD
                                   Allowable
                                       
                                     RTO-a
                                      AR
                                       A
                                    0.11024
                                   0.010500
                                     STK1
                                      SVR
                                      FUG
                                     1.068
                                   0.008300
                                     RTO-a
                                      SC
                                      CEV
                                     2.67
                                   0.000019
                                     RTO-a
                                      SC
                                       S
                                    2.47966
                                   0.019170
                                     STK2
                                     STOR
                                      FUG
                                     1.602
                                   0.165100
                                       
                                       
                                     TOTAL
                                    7.9299
                                   0.203089

Table 4. Process-level actual emissions for BD-Covington.
                            EMISSION RELEASE POINT
                                      ID
                                   EMISSION
                                    UNIT ID
                                  PROCESS_ID
                                Emissions (TPY)
                                      EPA
                                    Actual
                                Emissions (TPY)
                                    GA EPD
                                    Actual
                                       
                                     RTO-a
                                      AR
                                       A
                                   0.001835
                                   0.007850
                                     STK1
                                      SVR
                                      FUG
                                   0.006810
                                   0.006850
                                     RTO-a
                                      SC
                                      CEV
                                   0.017025
                                   0.000015
                                     RTO-a
                                      SC
                                       S
                                   0.001107
                                   0.014335
                                     STK2
                                     STOR
                                      FUG
                                   0.010215
                                   0.123350
                                       
                                       
                                     TOTAL
                                   0.036992
                                    0.1524

For STK1, GA EPD recommends using 30.282 ft/sec for exit gas velocity (EPA should update gas flow rates accordingly), -83.84093 for X coordinates, and 33.60765 for Y coordinates.  

For STK2, GA EPD recommends using 33.60802 for Y coordinates. 

BD-Madison
GA EPD recommends using "BD (Becton, Dickinson and Company) - Madison" for the facility name instead of "BARD MADISON OPERATIONS". 

GA EPD has not received an updated permit application from BD-Madison yet, but based on the similarities in processes between BD-Covington and BD-Madison, we believe the BD-Covington EtO emissions are the best available estimates for the BD-Madison EtO emissions.  Therefore, GA EPD recommends using the process-level allowable and actual emissions in Tables 1 and 2.  

For STK1, GA EPD recommends using 36.877 ft/sec for exit gas velocity (EPA should update gas flow rates accordingly) and -83.46816 for X coordinates.  

For STK2, GA EPD recommends using 53.084 ft/sec for exit gas velocity (EPA should update gas flow rates accordingly) and -83.46812 for X coordinates. 

For RTO-a, GA EPD recommends using -83.46857 for X coordinates.  

Sterilization Services of Georgia 
Based on the controls currently installed and operated at the facility, GA EPD recommends using the following information for the two "FUG" sources (EPA's emission Unit IDs: CHR and QS).  Although stack testing of the new controls has not been performed yet, we assumed 99% control.

 DBR system in sterilization area (EPA's emission Unit ID: CHR, "Chamber rooms")
 Ambient temperature
 Coordinates: (33.72636, -84.58406)
 Roof height: 28'2"
 Discharge height above roof: 7'10"
 Stack diameter:18"
 Stack flow: 7,450 CFM
 Stack Type: J-type (discharging back toward the roof, recommending the "POINTCAP" type for modeling)
 0.00173222 TPY (1% of EPA's value of 0.173222 TPY)

 DBR system in shipping area (EPA's emission Unit ID: QS, "Quarantine and shipping")
 Ambient temperature
 Coordinates: (33.72632, -84.58465)
 Roof height: 28'2"
 Discharge height above roof: 9'0"
 Stack diameter: 24"
 Stack flow: 15,306 CFM
 Stack Type: J-type (discharging back toward the roof, recommending the "POINTCAP" type for modeling)
 0.00259833 TPY (1% of EPA's value of 0.259833 TPY)

GA EPD recommends updating the actual emissions (tons/year) for OX1 from 0.043028 to 0.000530, DB1 from 0.000277 to 0.006614, and SC1 from 0.038663 to 0.006307.

For EMISSION_RELEASE_POINT_ID OX1, GA EPD recommends using 31.237 ft/sec for exit gas velocity (EPA should update gas flow rates accordingly).  

GA EPD did not provide allowable emissions.  If allowable emissions are modeled, they should not be significantly higher than the actual emissions.

Kendall Patient Recovery (KPR)
This facility is called "Kendall Healthcare Products" by EPA.  

GA EPD recommends excluding FUG_PSC from modeling because EtO is discharged into water in a closed system.  The wastewater to sent offsite to a water treatment facility.  In the modeling files, KPR stated "EtO in condensate is not emitted to the air."

GA EPD recommends modeling FUG_CP as a VOLUME source with sigma_y of 5.81 m and sigma_z of 4.65 m.  If EPA models this source as an AREA source, GA EPD would like to know the reason for this choice.  In addition, GA EPD recommends using 5 ft for the release height and -81.98618 for the X coordinate (what EPA uses will place FUG_CP about 50 m away from where GA EPD recommends).  Based on recent sampling results provided by Alternative Construction & Environmental Solutions, Inc., KPR calculated an average emission rate of 0.025 lbs/yr from the storage shed.  Therefore, the original emission rate shown for FE1 in Appendix A (69 lbs/yr) of the GA EPD modeling memo dated April 28, 2020 was replaced with 2 lbs/yr (a conservative upper-bound estimate for 0.025 lbs/yr) in the modeling.

GA EPD does not believe that FUG_SW emissions should be included since sterilization and aeration occur in the same chamber and any additional fugitive emissions are sent to stacks S-1 through S-8 (see Figure 1).


Figure 1. Locations of stacks and one volume source (FE1) in GA EPD's modeling files for KPR.  "FE1" in the figure is "FUG_CP" in EPA's Excel file.


For stacks S-1 through S-CO, GA EPD recommends using stack diameters listed in Table 5.  EPA should update the gas flow rates accordingly. 


Table 5. Recommended stack diameters and actual emissions for KPR stacks.
                           EMISSION RELEASE POINT ID
                              GA EPD Recommended
                             Stack Diameters (ft)
                                       
                              GA EPD Recommended 
                            Actual Emissions (TPY)
                                      S-1
                                     0.58
                                    0.00006
                                      S-2
                                      1.5
                                    0.00333
                                      S-3
                                     0.58
                                    0.00006
                                      S-4
                                      1.5
                                    0.00333
                                      S-5
                                     3.21
                                    0.00687
                                      S-6
                                     3.21
                                    0.00687
                                      S-7
                                     3.21
                                    0.00687
                                      S-8
                                     2.63
                                    0.00320
                                     S-CO
                                      2.5
                                    0.06930

GA EPD did not provide allowable emissions.  If allowable emissions are modeled, they should not be significantly higher than the actual emissions.


