Comments of the Aluminum Association on the EPA Issues and Recommendations List 

to Revise the Secondary Aluminum Production NESHAP

(40 CFR Part 63 Subpart RRR)

May 18, 2010

Reference EPA document: SECAL-ANPR-Amendments-Memo-09-30-09.doc

The following list is a compilation of issues for review and consideration with the EPA 

memo addressing a draft list of Secondary Aluminum MACT rule improvements (dated 

9-30-09). Also included at the end of this paper is a list of Aluminum Association 

requested rule changes not included or adequately addressed in the EPA list. The list is 

not presented in order of priority, but follows the listing chronology in the EPA memo.

Issues of Concern

1. Definition of Clean Charge – The current definition of clean charge includes: 

molten aluminum; T-bar; sow; ingot; billet; pig; alloying elements; aluminum 

scrap known by the owner or operator to be entirely free of paints, coatings, 

and lubricants; uncoated/unpainted aluminum chips that have been thermally 

dried or treated by a centrifugal cleaner; aluminum scrap dried at 343 °C (650 

°F) or higher; aluminum scrap delacquered/decoated at 482 °C (900 °F) or 

higher, and runaround scrap. 

Specific types of “runaround scrap” materials (generated on-site by 

aluminum casting, extruding, rolling, scalping, forging, forming/stamping, 

cutting, and trimming operations) were defined as part of clean charge

because this material is routinely processed in furnaces that represent the 

MACT floor and were a component of the MACT floor emissions testing used 

to establish furnace emission standards.

Two elements of the definition for clean charge have created interpretation 

issues. The first is “aluminum scrap known by the owner or operator to be 

entirely free of paints, coatings, and lubricants”. OECA has stated that some 

knowledge of the history of the processes applied to the scrap material is 

necessary for the operator to “know” that scrap material is entirely free of 

paints, coatings, and lubricants. OECA also believes that visual inspection is 

inadequate to determine whether scrap material is entirely free of paints, 

coatings, and lubricants. The Association generally accepts OECA’s position, 

but requests EPA to consider whether some type of sampling and analytical 

procedure could be used to determine if scrap from outside entities is entirely 

free of paints, coatings, and lubricants for processing as clean charge.

The second issue deals specifically with aluminum chips generated by turning, 

milling, boring, and machining of aluminum parts. Aluminum chips are 

considered clean charge if either thermally dried or treated by a centrifugal 

cleaner. The Association is satisfied with this definition for cleaned 
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aluminum chips. Thermal chip drying is already defined under the rule. EPA 

may want to add a definition for “centrifugal cleaner”, although this is 

generally understood by the industry.

2. Anodized aluminum - EPA’s list of improvements for Secondary Aluminum 

MACT includes the need to exclude anodized aluminum scrap from the 

definition of clean charge. We believe this is unnecessary because the process 

of anodizing aluminum simply creates a layer of aluminum oxide on the metal 

surface, which would not result in HAP emissions when the anodized 

aluminum is recycled. Most aluminum anodizing does not include “dyes” as 

referenced in the EPA memo. Eliminating “all” anodized aluminum as clean 

charge will create processing cost increases with no commensurate HAP 

emission benefits.

3. Existing and New Source SAPU – The current definition of “existing SAPU” 

includes all existing group 1 furnaces and all existing in-line fluxers within a 

facility. So, by definition, there can only be one existing source SAPU at each 

facility. However, the rule allows multiple new SAPUs and redesignation of 

existing emission units into new SAPUs to address practical issues associated 

with emissions control systems on secondary aluminum “process trains”. For 

example, in cases where a melter, holder and in-line fluxer are all controlled 

by a single lime-injected baghouse, these three emission units were 

redesignated as a “new SAPU” to allow compliance demonstration for all 

three units by testing of the baghouse stack. Compliance demonstrations for 

this process train would be far more complicated if the facility could only 

have “one new source SAPU” as proposed in the EPA memo. Redesignation 

of existing emission units to form a new SAPU requires prior approval by the 

permitting authority under §63.1505(k)(6), which was added to the rule as part 

of a litigation settlement.

4. Scrap Shredders – It is not clear how the applicability statement for all 

shredders to be subject to the SMACT rule is intended. The current rule 

regulates scrap shredders at major sources. If related to area sources, which 

are D/F related emission concerns, the requirement to regulate area source 

shredders makes little sense since shredders have no combustion related 

processing to contribute to D/F formation. Similarly, the statement that all 

shedders with visible emissions are subject to SMACT is also of concern, as 

there is no correlation with HAP emissions in such a determination. In 

addition, there is the concern with reference to Method 22 for visible 

emissions. The rule currently has no requirements for M22 testing. Finally, 

an exemption should be provided in the rule for low RPM shredders that do 

not exhibit fugitive emissions.

5. Thermal Chip Dryers – The draft proposes to expand the applicability of 

thermal chip dryers to add water-only evaporation from the current definition 

for a thermal chip dryer. This expands the scope of the affected source and as 

such would require a reevaluation of the emission standards and possibly a 

new subcategory. No data are available on HAP emissions, if any, from units 

used to evaporate water only from aluminum chips.
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6. Residence Time of an Afterburner – The draft eliminates as residence time 

any inclusion of the connected ductwork to the afterburner in calculating the 

total period for residence time. This is in direct conflict with the rule which 

allows duct work in the calculation of residence time if a thermal couple 

located in the duct verifies adequate temperature for D/F destruction. Many 

afterburners have high performances with lower residence time to reduce fuel 

consumption. This change would necessitate extra costs, fuel consumption 

and GHG emission increases for no commensurate HAP reduction benefits. 

The rule should provide that the afterburner volume calculation include the 

firing zone plus combustion zone in refractory lined ductwork up to the 

control thermocouple used to demonstrate compliance with the 1,400 degree F 

requirement. 

7. Capture and Collection Systems – The memo is currently blank, but refers 

later to the elimination of the ACGIH Ventilation Manual for guidance on this 

issue. It is therefore a high priority to develop a reasonable definition under 

this issue that is workable and cost effective.

8. SAPU Feed/charge Rate – We disagree that SAPU emission limit should be 

calculated based on feed/charge rates during performance test. The total 

allowable emissions in the numerator of the Emission Limit calculation in 

Equation 1 must change each day based on the throughput of charge material 

processed that day in order to account for group 1 furnaces or filter boxes that 

did or did not operate on any given day. Otherwise, calculated total allowable 

emissions would be higher than allowed under the MACT standard. 

9. O&M Plans: Capture and Collection Systems – This is an area of special 

controversy that requires careful consideration to develop, as noted above, 

workable and cost-effective solutions.

10. O&M Plans: Lime Injection Rate – the draft includes a daily pound per hour 

(lb/hr) inspection/verification which for some systems is entirely unnecessary. 

The current SMACT provisions are adequate.

11. O&M Plans: Scrap inspection – EPA additions to address correlation of 

visual inspection with physical measurements must be workable so as not to 

preclude the viability of the existing scrap inspection programs.

12. O&M Plans: Molten Metal Level – It is not clear in the draft memo what 

additional monitoring is necessary. The current rule to assure the arch of the 

passageway is submerged thus avoiding gas exchange between the side-well 

and furnace hearth is adequate.

13. O&M Plan Revisions – The draft requirements for a 3 month time period for 

approval before any operational changes can be made at a facility is entirely 

unworkable. It adds an unnecessary burden of facilities and the ability to 

work efficiently and competitively in the market place, and also adds extra 

burdens to States and Permit Authorities by expanding their work loads. 

14. O&M Plan Revisions: Hood Flowrates – The draft requirement for volumetric 

flowrate testing of hoods is unworkable for many installations. 

15. Performance Testing: Feed/charge Rate – The draft is not clear in what is 

being proposed. We agree that testing should be performed at the 

scrap/charge rate combination that creates the highest emissions potential. 
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However, operating scenarios with differing scrap charge characteristics 

should not be restricted to the tested charge rate for higher HAP producing 

materials. 

16. Performance Testing: Frequency of Testing – the five year testing period to 

be clarified should not apply to area sources because of the unnecessary 

increase in expense for such requirements.

17. Performance Testing: Temporary Enclosures – The requirement for temporary 

enclosures to capture fugitive emissions is not workable, and indeed may 

create safety issues in conducting such testing. Other means are necessary to 

assess fugitive emissions contribution to the overall emission rate.

18. Testing: Method 22 Testing – Currently there are no Method 22 requirements 

in the rule, and the addition of such requirement is unnecessary and adds 

considerable cost for compliance. 

Requested Additional Changes to the SMACT Rule

40 CFR 63.1506(c)(1) – In line with EPA recommendations, delete the requirement to 

design ventilation systems to ACGIH handbook specifications. 

40 CFR 63.1506(d)(1) – Allow an exception for continuous processes such that the test

period and recordkeeping time can be different.

40 CFR 63.1506(m)(4) and (g)(5) – The lime feeder setting should be adjustable to the 

level required to meet the lime flow rate established by the performance test, and not 

subject to OM&M plan revision requirements.

40 CFR 63.1510(e) - Allow an exception for continuous processes such that the test 

period and recordkeeping time can be different.

40 CFR 63.1510(f)(1)(ii) – Delete the requirement to use “Fabric Filter Bag Leak 

Detector Guidance” (Sept 1997 document as it is out of date. Substitute with provision to 

set up per manufacturer’s instructions, and recommended by EPA.

40 CFR 63.1510(j)((4) and (5) – Allow an exception for continuous processes such that 

the test period and recordkeeping time can be different.

40 CFR 63.1510(k)(1) - Allow an exception for continuous processes such that the test 

period and recordkeeping time can be different.

40 CFR 63.1510(m)(1) – Revise to provide that the measurement of the molten metal 

height is obtained at the low point of the furnace cycle, usually following metal tapping.

40CFR63.1511(b) - Allow 180 days from startup for a new source to conduct the initial 

performance test(s). This would be consistent with the MACT general provisions 

(40CFR63.7(a)(2)). It is often difficult and sometimes impossible to achieve full 

production operation of a regulated source within 90 days.
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40 CFR 63.1511(b)(1) – Delete the requirement that the testing be performed at the 

highest production level. Substitute that the test be conducted at the highest emission/ton 

level combination. Emissions testing should be performed with the scrap/charge believed 

to cause the greatest emissions potential and at a production rate representative for that 

scrap/charge combination. Production rates established during the hypothetical 

maximum emissions test should not be restrictive of other lower emitting scrap/charge 

combinations. 

40 CFR 63.1511(b)(2) – Allow for particulate matter emission test on continuous 

processes to be one-hour duration.

40 CFR 63.1517(2) – Allow that records can be maintained on digital media.

Identical Furnaces – The rule needs to be clarified to allow testing of a representative 

furnace to establish emission rates for furnaces with the same or lower HAP emission 

potential.

Furnace Classifications – furnace classifications are based on the operational 

characteristics of the furnace. As such, a source should be allowed to define alternative 

operating scenarios in the OM&M Plan that permit operation as a Group 1 controlled, 

Group 1 uncontrolled, or group 2 depending on charge type and flux practices so long as 

emission limits compliance is demonstrated in performance testing. 

Fugitive Emissions – EPA should recognize that fugitive emissions were not included in 

the MACT floor emission limits and therefore are not subject to the MACT standard.

Clean Charge – Provide in the rule that a Purchase Order requiring that scrap is “entirely 

free of paints, coatings and lubricants” should be acceptable for demonstrating “Clean 

Charge” material.

Representative Testing – Allow representative testing of equipment with Air Pollution 

Control Devices (APCD).

Control Device Shutdown – Provision is needed to allow the shutdown of a fabric filter 

and/or lime injection system if the furnace is idled and not producing HAP emissions. 

Foe example, after a melting furnace is finished a charging & fluxing cycle, but the unit 

is standing on hold for the weekend without fluxing or additional charging. 

Hood Flows – Measurement of actual hood ventilation flows should only be required as 

part of an emission performance test.

Charge Weight for In-Series Units – Equipment installed in an inter-linked series (e.g. 

shredder/delacquering kiln/reverbatory furnace) should not be required to conduct 

independent input or output charge weight determinations for each piece of equipment. 

In such equipment, calculated weights should be allowed so long as there is 
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demonstration that the calculated weight meets the accuracy requirements in the rule 

based on the input or output measurement at the beginning/end of the unit series of 

equipment. 

Cover Flux Definition – The current definition of cover flux (i.e. salt added to the surface 

of molten aluminum in a group 1 or group 2 furnace, without agitation of the molten 

aluminum, for the purpose of preventing oxidation) must be revised. Incidental 

circulation to disperse the cover flux over the surface of the molten aluminum should not 

be considered agitation. 

Alternative Operating and Testing Scenarios – An approved alternative operating or 

testing scenario should be codified and grandfathered for the facility. 

Consent Decree – Requirements obtained by consent decree for a facility should be 

grandfathered and not subject to changes in subpart RRR.

Production weight vs. charge weight – Revise rule to remove restriction in 63.1506 

(d)(3)(i) and (ii). Rule should allow either feed/charge weight or production weight, as 

long as the same basis is used for performance test and SAPU compliance calculation.