DATE: November 12, 2014

SUBJECT: Supplemental Proposal Technical Support Document for the Secondary Aluminum 

Production Source Category

FROM: Mark Bahner, RTI International

TO: Rochelle Boyd, U.S. Environmental Protection Agency (the EPA)

The purpose of this memorandum is to document the technical approach and rationale used to develop 

certain proposed modifications to the National Emission Standards for Hazardous Air Pollutants 

(NESHAP) for Secondary Aluminum Production (40 CFR Part 63, Subpart RRR). The Supplemental 

Proposal is scheduled for signature in November 2014, and will likely be published in the Federal 

Register a few weeks later.

1. Capture Efficiency Assumption for Uncontrolled Furnaces

Test data related to the capture efficiency for uncontrolled furnaces were analyzed. Two tests were 

available. Both were conducted at Southwire Corporation 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. Testing 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. These tests were performed on a 

furnace stack and also on a temporary canopy hood, which was installed for the test, to capture 

emissions not directed through the furnace stack.

One aspect of this testing, regarding sampling time at the canopy hoods versus the furnace stacks,

potentially affects the results. In the testing reported on June 26, 2007, sampling at the furnace stack was 

performed from 7.7 to 8 hours per run, whereas sampling at the canopy hood was performed for 3.0 to 

3.33 hours per run. This is consistent with the concept that emissions captured by the canopy hood 

would only occur during furnace charging, whereas emissions through the furnace stack would occur 

throughout the cycle (charging, melting, tapping) which presumably lasted 7.7 to 8.0 hours. However, in 

the testing reported on September 5, 2007, testing at the furnace stack was performed for 3.2 hours per 

run, whereas testing at the canopy hood was performed for 3.0 hours per run. This could mean that the 

complete furnace cycle was only 0.2 hours longer than the charging period, or it could be a mistake in 

the testing reported on September 5, 2007, such that the testing at the furnace stack did not occur 

throughout the entire furnace cycle. If the testing reported on September 5th was indeed flawed in that 

the sampling at the furnace stack did not occur throughout the furnace cycle, then the ratio of emissions 

from the canopy hood to total emissions (canopy plus furnace stack emissions) would be biased high. 

The results of the two tests are summarized in Table 1. From Table 1, it can be seen that the average 

capture by the furnace stack, for all pollutants and for both tests, was 71 percent. The EPA has 

considered various potential furnace stack capture effiencies and resultant stack test estimation factors 

for uncontrolled furnaces. For example, if the furnace capture efficiency is assumed to be 50 percent, the 

furnace test results would need to be multiplied by a factor of 2 to calculate total emissions. 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 . The test results in 

Table 1 support multiplying the furnace test results by a factor of 1.5, because the average capture 

efficiency for all tests was 71 percent, which is slightly higher than 67 percent.

Additional tables related to this analysis are included in Appendix A to this memorandum. The 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 canopy hood stack. For example, the during Run 3, hydrogen 

chloride (HCl) emissions in the furnace stack were 5.31 pounds (lb), and 0.84 lb in the 

canopy 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 canopy 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 canopy 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 

canopy hood stack versus the total mass of pollutants emitted through both the canopy hood 

stack and the furnace stack. For example, the 3-run average fraction for HCl in the canopy hood 

is 0.23, meaning that 23 percent of the HCl passes through the canopy hood.

2. Costs for Lowering the Dioxin/Furan (D/F) Emissions Limit for Group 1 Furnaces

To evaluate the potential to reduce D/F emissions, our analysis focused on two options: 1) lower the D/F

emissions limit from 15 to 10 μg TEQ/Mg for group 1 furnaces processing other than clean charge at all 

facilities; and 2) lower the D/F emissions limit for Group 1 furnaces processing other than clean charge 

to 10 μg TEQ/Mg, after applying a subcategorization that only required facilities with a Group 1 furnace 

production capacity of more than 200,000 tons per year (tpy) to meet the lower limit. The lower limit 

could potentially be met with activated carbon injection systems. 

With regard to the first option, based on testing reported in information collection request responses1

, 

and supplemental information received from facilities after the 2012 Proposal2

, there are twelve Group 1 

furnaces with emissions above 10 μg/Mg as shown in Table 2. All twelve furnaces are presently 

controlled with fabric filters, and it is assumed that activated carbon injection would be added. The total 

capital cost for adding activated carbon injection on the 12 furnaces is estimated to be $390,000, and the 

total annualized cost is estimated to be $1,400,000 (see Table 3). The total annual D/F emission 

reductions if all furnaces emitted at 10 μg/Mg are estimated to be approximately 0.49 grams TEQ. 

2
Therefore, the calculated cost effectiveness is approximately $2,900,000 per gram TEQ of D/F (see 

Table 4). 

For the second option, only facilities with combined production capacity of all Group 1 furnaces greater 

than 200,000 tpy would be required to meet the 10 μg TEQ/Mg limit. Of the facilities listed in Table 2, 

Aleris Recycling (RTI #389) and Novelis Corporation (RTI #269) have a production capacity greater 

than 200,000 tpy. The calculated total capital cost to add carbon injection to the three furnaces at RTI 

#389 and the one furnace at RTI #269 is estimated to be $130,000, and the total annualized cost is 

estimated to be $460,000 (see Table 3). The total emission reductions if these four furnaces emitted at

the 10 μg TEQ/Mg limit would be 0.12 grams TEQ. Therefore, the calculated cost effectiveness is 

approximately $3,800,000 per gram TEQ of D/F (see Table 4). 

3. Compliance with Emission Limits during Startup/Shutdown

The EPA is proposing standards for startup and shutdown for all secondary aluminum process units. The 

subpart RRR standards would 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 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 startup 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 probably 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). Under the 2012 proposed rule, to demonstrate compliance during the startup and shutdown 

periods, for the 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 test 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.

4. Representativeness for Nine-Company HAP Metals and HAP Organics Testing

The EPA used a nine-company ICR to gather testing data that would correlate emissions of THC

surrogate to speciated organic HAPs 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 

3
companies were chosen primarily because they were large companies operating many facilities, and 

because these 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 only types 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 currently operate those 

pieces of equipment. Therefore, the sampling of the 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 use in developing speciated metal HAP emissions 

from PM emissions. 

References

References

1. Letter, Peter Tsirigotis (U.S. EPA) to Russell Mayfield (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.

2. Memorandum, Mark Bahner (RTI, International) to Rochelle Boyd (U.S. EPA), “Development 

of the RTR Supplemental Proposal Risk Modeling Dataset for the Secondary Aluminum 

Production Source Category,” July 11, 2014. This memorandum also has a table that correlates 

RTI facility ID numbers with facility names and locations.

4
List of Tables

Table 1. Southwire Test Results Summary................................................................................................. 6

Table 2. Group 1 Furnaces 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

Table A4. Southwire Testing Reported on September 5, 2007: Results in Pounds................................. 12

5
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

Average for all All 0.71 0.29

Table 2. Group 1 Furnaces with Reported Emissions Greater than 10 μg TEQ/Mg Feed

RTI ID 

Number Facility Name

Emission Release 

Point ID

2014 Reported 

Emissions 

Update TEQ 

(ug/Mg)

2014 Actual 

Emissions, 

grams

2014 

Emissions at 

10 ug/Mg, 

grams

Emission 

Reduction at 

10 ug/Mg, 

grams

316 Metal Industries, Inc. 001 14.98 0.110 0.073 0.037

364 Continental Aluminum RV-1 14.55 0.224 0.154 0.070

269 Novelis Corporation 760MT 13.10 0.376 0.287 0.089

347 Hydro Aluminum - Louisville MELTFURN 01 (01) 12.40 1.055 0.851 0.204

389 Aleris Recycling P905 12.20 0.113 0.093 0.020

389 Aleris Recycling P901 11.30 0.105 0.093 0.012

302 Tennessee Aluminum Processors, Inc. 2 10.79 0.217 0.201 0.016

303 Aleris Specifiation Alloys, Inc. EP-002 10.77 0.350 0.325 0.025

392 Aleris Recycling, Inc. Rotary Furnace 7 10.50 0.351 0.334 0.017

364 Continental Aluminum RV-2 10.27 0.002 0.002 0.000

389 Aleris Recycling P903 10.20 0.095 0.093 0.002

303 Aleris Specifiation Alloys, Inc. EP-001 10.08 0.327 0.325 0.003

Totals 3.324 2.830 0.494

6
Table 3. Group 1 Furnace D/F Reduction Options

Option

Furnace 

Status

Number of 

Furnaces

Capital Cost1

Each (2011 $)

Total Annualized 

Cost Each

(2011 $)

Combined Total Capital 

Cost (2011$)

Combined Total 

Annualized Cost (2011$)

Limit of 10 μg/Mg TEQ for all Controlled 12 32,478 115,983

390,000 1,400,000

Limit of 10 μg/Mg TEQ for all Uncontrolled 0 617,000 156,100

Limit of 10 μg/Mg TEQ if 

production >200,000 tpy Controlled 4 32,478 115,983

130,000 460,000

Limit of 10 μg/Mg TEQ if 

production >200,000 tpy Uncontrolled 0 617,000 156,100

1 Controlled furnaces have fabric filters, and are assumed to add activated carbon injection. Uncontrolled furnaces are assumed to add fabric 

filters with activated carbon injection.

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 for all 1,400,000 0.49 2,900,000

Limit of 10 μg/Mg TEQ if 

production >200,000 tpy 460,000 0.12 3,800,000

7
Appendix A

Southwire Test Results

8
Table A1. Southwire Testing Reported June 26, 2007: Complete Test Results 

* reported as 2378-TCDD equivalent

Southwire Testing Reported on June 26, 2007

PM PM HCl HCl TOTAL D/F* TOTAL D/F*

Duration(hr) furnace stack

Run 1 7.70 0.56 #/hr 4.31 lb 0.71 #/hr 5.47 lb 8.69E-08 #/hr 6.69E-07 lb

Run 2 8.00 0.75 6.00 lb 0.7 5.60 lb 7.72E-08 #/hr 6.18E-07 lb

Run 3 7.70 0.57 4.39 lb 0.69 5.31 lb 2.18E-08 #/hr 1.68E-07 lb

Duration(hr) canopy hood

Run 1 3.00 0.32 #/hr 0.96 lb 0.51 #/hr 1.53 lb 3.87E-09 #/hr 1.16E-08 lb

Run 2 3.33 0.58 1.93 lb 0.41 1.37 lb 4.92E-09 #/hr 1.64E-08 lb

Run 3 3.00 0.41 1.23 lb 0.28 0.84 lb 2.95E-09 #/hr 8.85E-09 lb

Total

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

average 6.27 lb 6.71 lb 4.97E-07 lb

9
Table A2. Southwire Testing Reported on June 26, 2007: Results in Pounds

Southwire Testing Reported on June 26, 2007

Pollutant Location Units Run 1 Run 2 Run 3 Average

PM Furnace stack lb 4.31 6.00 4.39 4.90

PM Canopy hood lb 0.96 1.93 1.23 1.37

PM Total lb 5.27 7.93 5.62 6.27

PM Furnace stack fraction of total 0.82 0.76 0.78 0.78

PM Canopy hood fraction of total 0.18 0.24 0.22 0.22 22% Avg

PM Total fraction of total 1.00 1.00 1.00 1.00

HCl Furnace stack lb 5.47 5.60 5.31 5.46

HCl Canopy hood lb 1.53 1.37 0.84 1.25

HCl Total lb 7.00 6.97 6.15 6.71

HCl Furnace stack fraction of total 0.78 0.80 0.86 0.81

HCl Canopy hood fraction of total 0.22 0.20 0.14 0.19 19% Avg

HCl Total fraction of total 1.00 1.00 1.00 1.00

Total D/F Furnace stack lb 6.69E-07 6.18E-07 1.68E-07 6.35E-07

Total D/F Canopy hood lb 1.16E-08 1.64E-08 8.85E-09 1.48E-08

Total D/F Total lb 6.81E-07 6.34E-07 1.77E-07 4.97E-07

Total D/F Furnace stack fraction of total 0.98 0.97 0.95 0.97

Total D/F Canopy hood fraction of total 0.02 0.03 0.05 0.03 3% Avg

Total D/F Total fraction of total 1.00 1.00 1.00 1.00

10
Table A3. Southwire Testing Reported September 5, 2007: Complete Test Results

Southwire Testing Reported on September 5, 2007

PM PM HCl HCl TOTAL D/F* TOTAL D/F*

Duration(hr) furnace stack

Run 1 3.20 0.61 #/hr 1.95 lb 1.38 #/hr 4.42 lb 2.02E-09 #/hr 6.46E-09 lb

Run 2 3.20 0.49 1.57 lb 0.81 2.59 lb 3.97E-09 #/hr 1.27E-08 lb

Run 3 3.20 0.49 1.57 lb 0.68 2.18 lb 8.31E-10 #/hr 2.66E-09 lb

Duration(hr) canopy hood

Run 1 3.00 0.86 #/hr 2.58 lb 0.38 #/hr 1.14 lb 8.31E-09 #/hr 2.49E-08 lb

Run 2 3.00 0.36 1.08 lb 0.25 0.75 lb 2.20E-09 #/hr 6.60E-09 lb

Run 3 3.00 0.53 1.59 lb 0.28 0.84 lb 1.35E-09 #/hr 4.05E-09 lb

Total

Run 1 4.53 lb 5.56 lb 3.14E-08 lb

Run 2 2.65 lb 3.34 lb 1.93E-08 lb

Run 3 3.16 lb 3.02 lb 6.71E-09 lb

average 3.45 lb 3.97 lb 1.91E-08 lb

11
Table A4. Southwire Testing Reported on September 5, 2007: Results in Pounds

Southwire Testing Reported on September 5, 2007

Pollutant Location Units Run 1 Run 2 Run 3 Average

PM Furnace stack lb 1.95 1.57 1.57 1.70

PM Canopy hood lb 2.58 1.08 1.59 1.75

PM Total lb 4.53 2.65 3.16 3.45

PM Furnace stack fraction of total 0.43 0.59 0.50 0.49

PM Canopy hood fraction of total 0.57 0.41 0.50 0.51 51% Avg

PM Total fraction of total 1.00 1.00 1.00 1.00

HCl Furnace stack lb 4.42 2.59 2.18 3.06

HCl Canopy hood lb 1.14 0.75 0.84 0.91

HCl Total lb 5.56 3.34 3.02 3.97

HCl Furnace stack fraction of total 0.79 0.78 0.72 0.77

HCl Canopy hood fraction of total 0.21 0.22 0.28 0.23 23% Avg

HCl Total fraction of total 1.00 1.00 1.00 1.00

Total D/F Furnace stack lb 6.46E-09 1.27E-08 2.66E-09 1.06E-08

Total D/F Canopy hood lb 2.49E-08 6.60E-09 4.05E-09 1.27E-08

Total D/F Total lb 3.14E-08 1.93E-08 6.71E-09 1.91E-08

Total D/F Furnace stack fraction of total 0.21 0.66 0.40 0.42

Total D/F Canopy hood fraction of total 0.79 0.34 0.60 0.58 58% Avg

Total D/F Total fraction of total 1.00 1.00 1.00 1.00

12