## DATE: July 24 , 201 5

**SUBJECT:** Technical Support Document for the Secondary Aluminum Production Source Category Final Rule **FROM:** Mark Bahner , RTI International **TO:** Rochelle Bo yd , U.S. Environmental P rotection A gency (the EPA) The purpose of this memorandum is to document the technical approach and rationale used to develop certain modifications to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for Secondary Aluminum Production (40 CFR Part 63, S ubpart RRR). **1. Capture Efficiency Assumption for Uncontrolled Furnaces**  Test data related to the capture efficiency for uncontrolled furnaces were analy zed. Two tests were available. Both were conducted at Southwire Corpo ration in Hawesville, KY. Testing was performed for PM, HCl and PCDD/PCDF from April 30

– May 02, 2007 at Furnace #5 in Mill 3, and reported on June 26, 2007. The test length was approximately 8 hours, which corresponds to the batch length for Melter/Holder 5. T esting was performed for PM, HCl and PCDD/PCDF from July 17

– 19, 2007 at a Group 1 furnace located in Rod Mill 1 and reported on September 5, 2007. The test length was approximately

3 hours, which corresponds to the Melter 1 batch length 1



## . These tes ts were performed on a furnace stack and also on a temporary canopy h ood, which was installed for the test, to capture emissions not directed through the furnace stack. The results of the two tests are summarized in **Table 1** . From Table 1, for all pollutant s measured via the furnace stack , it can be seen that the mean capture efficiency for the furnace stack was 71 percent, and the median capture efficiency was 7 8 percent . The EPA has considered various potential furnace stack capture eff

i ci enc y assumptions and resultant stack test estimation factors for uncontrolled furnaces in light of the available data . For example, if the furnace capture efficiency of an uncontrolled furnace is assumed to be 50 percent, the furnace test results would need to be mul tiplied by a factor of 2 to calculate total emissions , and if the furnace capture efficiency was assumed to be 66.67 percent (approximately

67 percent), the furnace test results would need to be multiplied by a factor of 1.5 to calculate total emissions
. Choosing a value of 80 percent, close to the median capture efficiency of 7 8 percent and the average capture efficiency for the HAP with the highest capture efficiency, would mean that test results would need to be multiplied by a factor of 1.25. The EPA ha s chosen 80 percent as providing the best estimate of the capture efficiency of uncontrolled furnaces for the pollutants being measured, based on the limited data. Additional tables related to this analysis are included in **Appendix A** to this memorandum. T he tables can be summarized as follows: **Table A1** : This table presents data from the June 26, 2007 report. The data included pollutant emissions in pounds per hour and test sampling time. These are converted into total mass measured, so that the total emissions from the furnace stack can be compared to the total emissions in the canop y hood stack. For example, the during Run 3, hy drogen

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chloride (HCl) emissions in the furnace stack were 5.31 pounds (lb), and 0.84 lb in the canop y hood, for a total of 6. 15 lb. **Table A2** : This table presents data from the June 26, 2007 report. The data are exclusively

in pounds and the table includes a calculation of the percentage of pollutants emitted through the canopy hood stack versus the total mass of pollutants emitted through both the canop y hood stack and the furnace stack. For example, the 3
-run average fraction for HCl in the canopy hood is 0.19, meaning that 19 percent of the HCl passes through the canop y hood. **Table A3** : This table presents data from the September 5 , 2007 report. The data included pollutant emissions in pounds per hour and test sampling time. These are converted into total mass measured, so that the total emissions from the furnace stack can be compared to the total emissions in the canopy hood stack. For example, the during Run 3, hydrogen chloride (HCl) emissions in the furnace stack were 2.18 pounds (lb), and 0.84 lb in the canopy hood, for a total of 3.02 lb. **Table A4 :**  This table presents data from the September 5 , 2007 report. The data are exclusively in pounds and the table includes a calculation of the percentage of pollutants emitted through the canop y hood stack versus the total mass of pollutants emitted through both the canop y hood stack and the furnace stack. For example, the 3
-r un average fraction for HCl in the canopy hood is 0.23, meaning that 23 percent of the HCl passes through the canop y hood. **2. Costs for**  **Lowering the Dioxin/Furan (D/F) Emissions L**  **imit for Group 1 Furnaces** We performed an analys is to evaluate the option of lowering the D/F emissions limit from 15 to 10 μ g TEQ/Mg for group 1 furnaces processing other than clean charge at all facilities . Based on testing reported in information collection request responses , 2 

## and supplemental information received from facilities after the 2012 Proposal , 3 

## there are twelve Group 1 furnaces with emissions above 10 μ g/Mg , as shown in **Table 2** 
. Eleven of the twelve furnaces are presentl y controlled with fabric filters, and it is assumed for the purposes of this analysis that activated carbon injection would be added to increase the level of control of D/F at these furnaces. One furnace is presentl y uncontrolled and it is assumed that a direct lime injection fabric filter would be added. In both cases, it was assumed that D/F emissions would be reduced b y 85%. The total capital cost for adding activated carbon injection on each of the eleven furnaces already equipped with a fabric filter is calculated to be $ 170,578, and the total annualized cost for each furnace is estimated to be $ 112,188 . For the one furnace without a fabric filter, the capital cost of adding a direct injection fabric filter is calculated to be $3,174,419 and the total annualized cost is estimated to be $926,856. These costs are based on costs for similar controls estimated for the Brick and Structural Clay Products (BSCP) rule. 4 

## Therefore, the total annualized cost for the additional controls on all twelve furnaces is estimated to be approximately $2,160,000 (see **Table 3**  ) . The total annual D/F emission reduction s if all furnaces above 10 μ g/Mg reduced emissions by 85% would be 2.826 grams TEQ. Therefore, the calculated cost effectiveness is approximately $ 76 5 ,000 per gram TEQ of D/F (see **Table 4** )
. **3. Compliance**  **with Emission Limits during Startup/Shutdown**  The EPA is promulgating standards for startup and shutdown for all secondary aluminum process units. The subpart RRR standards will apply at all times, including periods of startup and shutdown. Because the scrap processed at secondary aluminum production facilities is the source of emissions, emissions

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during startup and shutdown are expected to be no higher and probably much lower than emissions during normal operations since no scrap would be processed. For production processes in the secondary aluminum production source category where the standards are expressed in units of pounds per ton of feed or similar units (i.e. thermal chip dyers, scrap dryer/delacquering kiln/decoating kilns , dross
- only furnaces, in
- line fluxers using reactive flux and group 1 furnaces), the form of the standard would raise implementation issues if facilities were simply required to demonstrate compliance in the exact same way as they do during normal operations because the equipment is not receiving feed material during startu p and shutdown periods . For example, the startup procedure for a furnace consists of gradually heating the furnace to normal operating temperature, without any addition of feed material. Since the feed rate is zero, the emission rate per ton of feed would be calculated to be infinite. One possibility

would be to have concentration
-based limits. However, these are probabl y not appropriate for the secondary aluminum industry, because hooding draws in large amounts of ambient air in order to increase hooding capture. Therefore, it is expected that emissions during startup and shutdown could be measured and determined under the applicable test method in pounds per hour (lb/hr). T o demonstrate compliance during the startup and shutdown periods, for emissions standards that are in units of lbs per ton, the emissions in units of pounds per hour would be divided by the feed rate in tons per hour (ton/hr) from the most recent or current performance test and compared to the emission limit for the affected source . For example, the PM limit for a new or existing group 1 furnace is 0.4 lb/ton. If, during a startup or shutdown, the emission rate determined under the applicable test method is 2 lb/hr, and the furnace charge rate during the most recent performance te st was 10 tons per hour, the calculated emission rate for that test during a period of startup or shutdown would be 0.2 lb/ton of feed (2 lb/hr of PM divided by 10 tons per hour of feed). This would be in compliance with the PM standard of 0.4 lb/ton of feed. If no performance test results were available, the furnace capacity (tons per hour of feed) could be used. Another possibility would be to demonstrate compliance by keeping records that show that during startup and shutdown no feed/charge or flux was added , and that only clean fuel was used or no fuel was used
. **4. Representativeness for Nine** **- Company HAP Metals and HAP Organics Testing**  The EPA use d a nine
- company ICR to gather testing data that would correlate emissions of THC surrogate to speciated organic HAP s and emissions of PM surrogate to speciated metal HAPs . Testing was limited to nine companies for efficiency and to avoid undue burden to the industry . The nine companies were chosen primarily because they

were large companies operating many facilities, and because the se companies are known to operate major source facilities that have thermal chip dryers or scrap dryer/delacquering/decoating kilns. Thermal chip dryers and scrap dryer/delacquering decoating kilns are the onl y typ es of equipment that have THC limits. Testing for these two pieces of equipment were limiting, in that few companies in the secondary aluminum source category currentl y operate those pieces of equipment. Therefore, the sampling of th e pieces of equipment was quite representative, because the sampling represented a large fraction of the equipment operated by the industry . The sampling for HAP metals in fabric filter dust represented a much smaller fraction of the industry (less than 10 percent of all equipment). However, there were a total of 55 samples analyzed for the full suite of HAP metals (including arsenic, cadmium, total chromium and hexavalent chromium, manganese, mercury, nickel, etc.)
. Because 55 samples were taken from many facilities owned by

nine companies, these results are believed to be representative of metal concentrations in fabric filter dust within the secondary aluminum industry

and are suitable for us e in developing speciated metal HAP emissions estimates from PM emissions for metal HAP that are mainly, or entirel y, in particulate form (such as Pb, Ni, Cr, Mn, and Cd)
. More information regarding the data collected and the methodology to calculate

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emiss ions is available in the memorandum, " Development of the RTR Supplemental Proposal Risk Modeling Dataset for the Secondary Aluminum Production Source Category," which is available in the docket for this action. 3 

## References 1. EPA docket item # EPA
- HQ
- OAR
- 2010
- 0544
- 0204 . Available at: http://www.regulations.gov/#!documentDetail;D=EPA
- HQ
- OAR
- 2010
- 0544
- 0204
. 2. Letter, Peter Tsirigotis (U.S. EPA) to Russell Mayf ield (Mayfield Salvage Company) et al., “Requirement to provide information according to 42 U.S.C 7414 ,” February 7, 2011. This was the cover letter for the all
- company data collection ICR. 3. Memorandum, Mark Bahner (RTI, International) to Rochelle Bo yd (U.S. EPA), “Development of the RTR Supplemental Proposal Risk Modeling Dataset for the Secondary Aluminum Production Source Category” November 12 , 2014. EPA docket item # EPA
- HQ
- OAR
- 2010
- 0544
- 0239 . Available at: http://www.regulations.gov/#!documentDetail;D=EPA
- HQ
- OAR
2010
- 0544
- 0239 . This memorandum also has a table that correlates RTI facility ID numbers with facility names and locations. 4. Memorandum, Thomas Holloway (RTI, International) to Jeff Telander (U.S. EPA), “Methodology

and Assumptions Used to Estimate the Model Costs and Impacts of BSCP Air Pollution Control Devices, ” November 6, 2014.

## 5 

# List of Tables Table 1. Southwire Test Results Summary
................................ ................................ ................................ . 6 Table 2. Group 1 Furnace s with Reported Emissions Greater than 10 μg TEQ/Mg Feed
......................... 6 Table 3. Group 1 Furnace D/F Reduction Options
................................ ................................ ..................... 7 Table 4. Cost
- effectiveness Calculation for D/F Reduction Options
................................ ......................... 7 Table A1. Southwire Testing Reported June 26, 2007: Complete Test Results
................................ ........ 9 Table A2. Southwire Testing Reported on June 26, 2007: Results in Pounds
................................ ........ 10 Table A3. Southwire Testing Reported September 5, 2007: Complete Test Results
.............................. 11 Ta ble A4. Southwire Testing Reported on September 5, 2007: Results in Pounds
................................ . 12

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**Table 1**  **. Southwire Test Results Summary**  **Test Report Date Pollutant** ***** **Three -**  **run Average Fraction in Furnace Stack**  **Three -**  **run Average Fraction in Canopy** 

**Hood Stack** June 26, 2007 PM 0.78 0.22 June 26, 2007 HCl 0.81 0.19 June 26, 2007 D/F 0.97 0.03 Sept. 5, 2007 PM 0.49 0.51 Sept. 5, 2007 HCl 0.77 0.23 Sept. 5, 2007 D/F 0.42 0.58 Mean for all All 0.71 0.29 Median for all All 0.78 0.22 * PM = Particulate Matter; HCl = Hydrogen chloride gas; D/F = Dioxins/Furans


## Table **2 . Group 1 Furnaces with Reported Emissions Greater than 10 μ**  **g TEQ/Mg Feed**

RTI I D Number Faci lity Name Emi ssion Re lea se Point ID 2014 Re porte d Emi ssi ons Up date TEQ (ug/M g) 2014 A ctual

Emi ssions, grams 2014 Emi ssi ons, grams

TEQ, as sumi ng 85% re moval f or

al l fur nace s above 10 u g/Mg TEQ Emi ssi on Re duction, grams TEQ, ass umi ng 85% re moval f or al l fur nace s above 10 u g/Mg 316 Me tal I ndustri es, Inc . 001 14. 98 0. 110 0. 017 0. 094 364 Conti nental Aluminum RV -1 14. 55 0. 224 0. 034 0. 190 269 Novelis Corporati on 760MT 13. 10 0. 376 0. 056 0. 319 347 Hydro A lumi num - Loui sville MELTFURN 0 1 ( 01) 12. 40 1. 055 0. 158 0. 897 389 Aler isRe cy cl in g P905 12. 20 0. 113 0. 017 0. 096 389 Aler isRe cy cl in g P901 11. 30 0. 105 0. 016 0. 089 302 Te nnessee Aluminum Proce ssors, Inc . 2 10. 79 0. 217 0. 033 0. 184 303 Aler isSpe ci fia tion Alloys, Inc . EP -002 10. 77 0. 350 0. 052 0. 298 392 Aler isRe cy cl in g, I nc . Rotary Furnace7 10. 50 0. 351 0. 053 0. 298 364 Conti nental Aluminum RV -2 10. 27 0. 002 0. 000 0. 002 389 Aler isRe cy cl in g P903 10. 20 0. 095 0. 014 0. 080 303 Aler isSpe ci fia tion Alloys, Inc . EP -001 10. 08 0. 327 0. 049 0. 278 3. 324 0. 499 2. 826 Total s

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**Table 3**  **. Group 1 Furnace D/F Reduction Options**  **Option Furnace**  **Status Number of** 

**Furnaces Capital Cost**  **1**

**Each (2011 $) Total**  **Annual ized**  **Cost Each (2011 $)**  **Combined Total Capital Cost (2011$)**  **Combined Total Annualized Cost**  **(2011$)** Limit of 10 μg/Mg TEQ for all Controlled 1 1 170,578 112,188 $5,050 ,000 2,160 ,000 Limit of 10 μg/Mg TEQ for all Uncontrolled 1 3,174,419 926,856 1 

## Controlled furnaces have fabric filters, and are assumed to add activated carbon injection. Uncontrolled furnaces are assumed to add direct injection fabric filters (DIFF)
. **Table 4**  **. Cost** **- effectiveness Calculation for D/F Reduction Options**  **Option Combined Total**  **Annualized Cost (2011$) Annual D/F Emission Reduction**  **(grams TEQ) D/F Removal Cost Effectiveness**  **($/gram TEQ)** Limit of 10 μg/Mg TEQ , assuming additional controls added that reduce D/F emissions by 85% 2,160 ,000 2.826 76 5 ,000

## 8 **Appendix A Southwire Test Results** 

## 9

**Table A**  **1. Southwire Testing Reported June 26, 2007: Complete Test Results** 

* reported as 2378 - TCDD equivalent **Southw ir**  **e Te**  **stin g R** 

**ep or** **ted on J**  **une 2**  **6, 2**  **007 PM**  **PM HCl**  **HCl TOTAL D/F**  ***** **TOTA L D**  **/F** ***** Durat ion(hr) fu rnace stack Run 1 7. 70 0. 56 #/hr 4. 31 lb 0. 71 #/ hr 5. 47 lb 8. 69E -0 8 #/ hr 6. 69E -07 lb Run 2 8. 00 0. 75 6. 00 lb 0. 7 5. 60 lb 7. 72E -0 8 #/ hr 6. 18E -07 lb Run 3 7. 70 0. 57 4. 39 lb 0. 69 5. 31 lb 2. 18E -0 8 #/ hr 1. 68E -07 lb

Durat ion(hr) canopy h ood Run 1 3. 00 0. 32 #/hr 0. 96 lb 0. 51 #/ hr 1. 53 lb 3. 87E -0 9 #/ hr 1. 16E -08 lb Run 2 3. 33 0. 58 1. 93 lb 0. 41 1. 37 lb 4. 92E -0 9 #/ hr 1. 64E -08 lb Run 3 3. 00 0. 41 1. 23 lb 0. 28 0. 84 lb 2. 95E -0 9 #/ hr 8. 85E -09 lb
To ta l Run 1 5. 27 lb 7. 00 lb 6. 81E -07 lb Run 2 7. 93 lb 6. 97 lb 6. 34E -07 lb Run 3 5. 62 lb 6. 15 lb 1. 77E -07 lb av erage 6. 27 lb 6. 71 lb 4. 97E -07 lb

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**Table A** **2. Southwire Testing Reported on June 26, 2007: Results in Pounds**  **Southw ir**  **e Te**  **sti ng Re**  **por ted** **on J une**  **2 6,** **2 007**  **Pollut an**  **t Loc**  **at ion**  **Un its**  **Ru n 1**  **Run 2 Ru**  **n 3 Ave**  **rag e**  PM Fu rnace stack lb 4. 31 6. 00 4. 39 4. 90 PM Canopy h ood lb 0. 96 1. 93 1. 23 1. 37

PM To ta l lb 5. 27 7. 93 5. 62 6. 27 PM Fu rnace stack fraction of to ta l 0. 82 0. 76 0. 78 0. 78 PM Canopy h ood fraction of to ta l 0. 18 0. 24 0. 22 0. 22 22% Avg PM To ta l fraction of to ta l 1. 00 1. 00 1. 00 1. 00 HCl Fu rnace stack lb 5. 47 5. 60 5. 31 5. 46 HCl Canopy h ood lb 1. 53 1. 37 0. 84 1. 25 HCl To ta l lb 7. 00 6. 97 6. 15 6. 71 HCl Fu rnace stack fraction of to ta l 0. 78 0. 80 0. 86 0. 81 HCl Canopy h ood fraction of to ta l 0. 22 0. 20 0. 14 0. 19 19% Avg

HCl To ta l fraction of to ta l 1. 00 1. 00 1. 00 1. 00 To ta l D/ F Fu rnace stack lb 6. 69E -07 6. 18E- 07 1. 68E -07 6. 35E -07 To ta l D/ F Canopy h ood lb 1. 16E -08 1. 64E- 08 8. 85E -09 1. 48E -08 To ta l D/ F To ta l lb 6. 81E -07 6. 34E- 07 1. 77E -07 4. 97E -07 To ta l D/ F Fu rnace stack fraction of to ta l 0. 98 0. 97 0. 95 0. 97 To ta l D/ F Canopy h ood fraction of to ta l 0. 02 0. 03 0. 05 0. 03 3% Avg To ta l D/ F To ta l fraction of to ta l 1. 00 1. 00 1. 00 1. 00

## 11

**Table A** **3 .**  **Southwire Testing Reported September 5, 2007**  **: Complete Test Results So**  **uthw ir** **e Te**  **st ing R** 

**ep or** **te d on S**  **ep te**  **mb er**  **5, 2**  **007 PM**  **PM HCl**  **HCl TOTAL D**  **/F** ***** **TOTA L D**  **/F** ***** Duration( hr) fu rn ace stack Run 1 3. 20 0. 61 #/hr 1. 95 lb 1. 38 #/hr 4. 42 lb 2. 02E -0 9 #/hr 6. 46E -0 9 lb Run 2 3. 20 0. 49 1. 57 lb 0. 81 2. 59 lb 3. 97E -0 9 #/hr 1. 27E -0 8 lb Run 3 3. 20 0. 49 1. 57 lb 0. 68 2. 18 lb 8. 31E -1 0 #/hr 2. 66E -0 9 lb

Duration( hr) canopy h ood Run 1 3. 00 0. 86 #/hr 2. 58 lb 0. 38 #/hr 1. 14 lb 8. 31E -0 9 #/hr 2. 49E -0 8 lb Run 2 3. 00 0. 36 1. 08 lb 0. 25 0. 75 lb 2. 20E -0 9 #/hr 6. 60E -0 9 lb Run 3 3. 00 0. 53 1. 59 lb 0. 28 0. 84 lb 1. 35E -0 9 #/hr 4. 05E -0 9 lb

To ta l Run 1 4. 53 lb 5. 56 lb 3. 14E -0 8 lb Run 2 2. 65 lb 3. 34 lb 1. 93E -0 8 lb Run 3 3. 16 lb 3. 02 lb 6. 71E -0 9 lb av erage 3. 45 lb 3. 97 lb 1. 91E -0 8 lb

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**Table A** **4 .**  **Southwire Testing Reported on September 5**  **, 2007: Results in Pounds** Southw ire Testing Re porte d on Se ptem be r 5 , 2007 **Po llutant**  **Lo ca** **tio n**  **Units Run**  **1 Ru** **n 2 Run**  **3 Ave**  **rag e**  PM Fur na ce stack lb 1. 95 1. 57 1. 57 1. 70 PM Canopy hood lb 2. 58 1. 08 1. 59 1. 75
PM Tota l lb 4. 53 2. 65 3. 16 3. 45 PM Fur na ce stack fracti on of tota l 0. 43 0. 59 0. 50 0. 49 PM Canopy hood fracti on of tota l 0. 57 0. 41 0. 50 0. 51 51% Avg PM Tota l fracti on of tota l 1. 00 1. 00 1. 00 1. 00 HCl Fur na ce stack lb 4. 42 2. 59 2. 18 3. 06 HCl Canopy hood lb 1. 14 0. 75 0. 84 0. 91 HCl Tota l lb 5. 56 3. 34 3. 02 3. 97 HCl Fur na ce stack fracti on of tota l 0. 79 0. 78 0. 72 0. 77 HCl Canopy hood fracti on of tota l 0. 21 0. 22 0. 28 0. 23 23% Avg
HCl Tota l fracti on of tota l 1. 00 1. 00 1. 00 1. 00 Tota l D/F Fur na ce stack lb 6. 46E-09 1. 27E-08 2. 66E- 09 1. 06E-08 Tota l D/F Canopy hood lb 2. 49E-08 6. 60E-09 4. 05E- 09 1. 27E-08 Tota l D/F Tota l lb 3. 14E-08 1. 93E-08 6. 71E- 09 1. 91E-08 Tota l D/F Fur na ce stack fracti on of tota l 0. 21 0. 66 0. 40 0. 42 Tota l D/F Canopy hood fracti on of tota l 0. 79 0. 34 0. 60 0. 58 58% Avg Tota l D/F Tota l fracti on of tota l 1. 00 1. 00 1. 00 1. 00