DATE: July 24, 2015

SUBJECT: Technical Support Document for the Secondary Aluminum Production Source Category

Final Rule

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 modifications to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for 

Secondary Aluminum Production (40 CFR Part 63, Subpart RRR).

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. The test length was approximately 8 hours, which corresponds to the batch length for 

Melter/Holder 5. 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. The test length was 

approximately 3 hours, which corresponds to the Melter 1 batch length1. 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.

The results of the two tests are summarized in Table 1. From Table 1, for all pollutants 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 78 percent. The EPA has considered various potential furnace stack 

capture efficiency 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 multiplied 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 78

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 has 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. 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 
2

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

We performed an analysis to evaluate the option of lowering the D/F emissions limit from 15 to 10 μg 

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 μg/Mg, as 

shown in Table 2. Eleven of the twelve furnaces are presently 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 presently 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 by 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.4Therefore, 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 reductions if all furnaces above 10 μg/Mg reduced emissions by 85% 

would be 2.826 grams TEQ. Therefore, the calculated cost effectiveness is approximately $765,000 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 
3

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). To 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 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. 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 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 

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 

estimates from PM emissions for metal HAP that are mainly, or entirely, in particulate form (such as Pb, 

Ni, Cr, Mn, and Cd). More information regarding the data collected and the methodology to calculate 
4

emissions 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 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.

3. 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” November 12, 2014. EPA docket item # EPA-HQ-OAR-2010-

0544-0239. Available at: http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OAR2010-0544-0239. 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 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
6

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 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, grams 

TEQ, assuming 85%

removal for all furnaces 

above 10 ug/Mg TEQ

Emission Reduction, grams 

TEQ, assuming 85% 

removal for all furnaces 

above 10 ug/Mg

316 Metal Industries, Inc. 001 14.98 0.110 0.017 0.094

364 Continental Aluminum RV-1 14.55 0.224 0.034 0.190

269 Novelis Corporation 760MT 13.10 0.376 0.056 0.319

347 Hydro Aluminum - Louisville MELTFURN 01 (01) 12.40 1.055 0.158 0.897

389 Aleris Recycling P905 12.20 0.113 0.017 0.096

389 Aleris Recycling P901 11.30 0.105 0.016 0.089

302 Tennessee Aluminum Processors, Inc. 2 10.79 0.217 0.033 0.184

303 Aleris Specifiation Alloys, Inc. EP-002 10.77 0.350 0.052 0.298

392 Aleris Recycling, Inc. Rotary Furnace 7 10.50 0.351 0.053 0.298

364 Continental Aluminum RV-2 10.27 0.002 0.000 0.002

389 Aleris Recycling P903 10.20 0.095 0.014 0.080

303 Aleris Specifiation Alloys, Inc. EP-001 10.08 0.327 0.049 0.278

Totals 3.324 0.499 2.826
7

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 11 170,578 112,188

$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 2.826 765,000
8

Appendix A

Southwire Test Results
9

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
10

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
11

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
12

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