Document ID: EPA-HQ-OAR-2010-0544-0179
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2012-02-14T05:00Z

MEMORANDUM

From:	Donna Lee Jones, Ph.D., U.S. Environmental Protection Agency,
Office of Air Quality Planning and Standards, Research Triangle Park, NC
(D243-02)

	  HYPERLINK "mailto:Jones.DonnaLee@epa.goc"  Jones.DonnaLee@epa.go v 

Date:		September 30, 2009

Subject:	Rule Improvements for Secondary Aluminum Production NESHAP 

(40 CFR Part 63 Subpart RRR)

1.	Definitions and Applicability

Clean Charge 

Add more quantitative measure of “clean” charge/scrap. 

Add specific methods to be used to prove scrap is entirely free of
contaminants (see Operation & Monitoring, below).

Add specifications for cleaning processes (e.g., for runaround scrap),
such as:

Minimum residence time and temperature for thermal drying process.

Minimum RPM speed and residence time for centrifuging processes.  

Add that sows, ingots, and t-bars with only paint markings are still
considered clean charge.

Add OECA clarification on how to ‘know’ if it is clean and/or
entirely free of paints, coatings, and lubricants:

Must have some knowledge of the processes applied to the scrap material
by maintaining direct control of the scrap or by knowing the processes
utilized by outside entities that have supplied the scrap.  

Must have some knowledge of the history of that scrap material such that
they may know that the material is “entirely free of paints, coatings,
and lubricants.”  “Entirely free” indicates that the scrap must
contain no paints, coatings, or lubricants.  This knowledge can be
gained through several methods.  One method would be to maintain direct
control of the scrap material being processed and only process scrap
generated within the facility or from other facilities within the same
company that the owner or operators knows has not been subjected to
paints, coatings and lubricants or where they know paints, coatings or
lubricants have been removed consistent with the definition of “Clean
charge”.  Similarly, the owner or operators may also process scrap
from outside entities where they are familiar with the history of the
scrap and therefore, know that the scrap meets the definition of
“clean charge.”   

Add OECA clarification on methods that would not allow owners or
operators to “know” scrap is clean:

Secondary aluminum production facilities may receive bales of aluminum
scrap from scrap vendors.  The scrap is accumulated from a variety of
sources and the owner or operator may conduct a cursory inspection of
the scrap bales to determine whether the material is “entirely free of
paints, coatings, and lubricants.”  This type of inspection is
insufficient and does not provide the owner or operator sufficient
information regarding the scrap such that they may know that the scrap
is “entirely free of paints, coatings, and lubricants.”  Even more
thorough inspections of the scrap may be insufficient, since the scrap
may contain clear coated materials or lubricants not visible on the
outside of the scrap.  Consequently, scrap inspection alone may not
provide owners or operators sufficient knowledge of the scrap such that
they can know that the scrap is “entirely free of paints, coatings,
and lubricants.”

Anodized Aluminum Scrap

Exclude anodized aluminum scrap from the clean charge definition since
dyes may be used as part of the anodizing process, which could
volatilize in the furnace and contribute to THC or D/F emissions.

Secondary Aluminum Processing Unit (SAPU) - Existing vs. New

Clarify definitions to indicate that there can only be ONE existing SAPU
and ONE new.  The existing/new SAPU includes all existing/new Group 1
furnaces and all existing new inline fluxers at a single facility.

Scrap Shredders  

Clarify that all scrap shredders processing other than clean scrap are
subject to the rule.

Clarify that all scrap shredders that generate visible emissions as
determined by EPA Method 22 are subject to the rule regardless of
whether scrap is considered clean or not.

Exempt shredders that always process clean scrap and don’t generate
visible emissions as determined by EPA Method 22.  Minimally, exempt
from periodic testing.

Thermal Chip Dryers

Clarify that a device that uses heat to evaporate water, oil, or
oil/water mixtures from unpainted/uncoated aluminum chips is subject to
subpart RRR.

Furnaces that Are Affected Sources

Identical Furnaces - Identify criteria under which furnaces may be
defined as “identical.”

Examples of possible criteria:  temperature, processing rate, design,
scrap materials charged to the furnaces, etc. 

Stationary Furnace with Internal Heaters - Clarify that a furnace that
is not portable and has internal heaters and is used to hold molten
aluminum is a furnace under subpart RRR.

Furnaces that are Not Affected Sources

Transport Pots - Clarify that pots used to transport metal to customers
are not furnaces.

Diecaster Holding Furnace - Clarify that a furnace used by a diecaster
that only metals or holds clean charge is not a subpart RRR furnace
(diecaster does not have a sweat furnace or thermal chip dryer or scrap
dryer, and does not use flux or only uses nonreactive nonHAP flux)

Sweat Furnace

Clarify that any furnace that charges objects containing aluminum and is
tipped to pour out molten aluminum is a sweat furnace. (Does this mean
that tapping to get the melted aluminum out makes a furnace a Group 1 or
2 furnace?)

Bale Breaker 

Clarify that this is a device used to break the ties holding a bale of
aluminum scrap before it is fed into the shredder and which is not also
a scrap shredder. 

Scalpers

Clarify that scalpers used to remove rough spots from ingots prior to
rolling into various product shapes are not subject to subpart RRR and
are considered to be equipment in aluminum product manufacturing. 

Capture and Collection System -- Add definition.

Residence Time of an Afterburner 

Clarify that this is the total time required for gases to pass through
the afterburner combustion chamber, which does not include the furnace,
ductwork, or stack.

Fluxes

Cover Flux in Rotary or Other Agitated Furnaces 

Clarify that any flux used in a rotary furnace is by design agitated;
therefore, any flux used for “cover” or otherwise in this type of
furnace is considered reactive

Add definitions for agitated and non-agitated furnaces.

Cover Flux Used to Also Remove Impurities

Clarify how to distinguish between cover flux that only prevents
oxidation vs. cover flux that also removes impurities (and is therefore
reactive?) which can result in HAP emissions at a later point.

Continuous vs., Batch (intermittent) Flux Additions

Add definitions so that different monitoring strategies can be set (see
below).

Feed/charge Rate

Clarify that the feed/charge rates obtained during performance tests
should be used to calculate the emission limit for each pollutant from
each SAPU

Thermal Delaminating of Aluminum Scrap and Mechanical Granulation of
Recovered Metal are Affected Sources under Subpart RRR

Heat is used to separate aluminum foil from paper and plastic in scrap, 

Chambers operate at a maximum temperature of 900F and no melting of the
recovered aluminum occurs in the chamber

Subsequent melting of recovered aluminum need not occur at the same
facility that conducts the recovery operation.

2.	Reporting

Area Sources:  Add annual compliance certification reports (currently
exempt from Title V permits).  Similar to requirements in EPA’s 40 CFR
part 63 area source program.

Semi-annual Report Formats.  Add minimum requirements to be included in
these reports.

3.	Operating and Monitoring Requirements 

Add/expand Monitoring Requirements for:

Capture and collection systems 

Reactive flux injection rate

Lime injection rate (lb/hr) verification during daily operation

Feed/charge weight at scrap dryers/delacquering kilns and decoating
kilns

Establish feed/charge weight parameters during performance test

Reactive flux injection furnaces “charge and top” operations

Include alternative process control monitoring?

Scrap inspection

Add how to collect representative sample for oil content.

Add how to correlate visual inspections with physical measurements

Ceramic candle filter control devices

Molten level at passage between sidewell and hearth during reactive
fluxing

Specify how to establish molten level

Specify different monitoring intervals for continuous charging
(@15 minutes) vs., batch (@batch charge addition)

Control measures not required by rule but used during performance test
to control pollutants with emission limits under the rule.

For example, ammonia or carbon injection rates used to control D/F.

Reduce Monitoring Requirements:

Solid flux  

Add monitoring only when solid flux is added for batch/intermittent flux
additions; keep monitoring for every 15 minutes with continuous flux
additions.

O&M Plan Revisions

Require submission for approval of ANY changes and forbid operation
before plan is approved.  

Require minimum time (3 months?) to submit for approval prior to a
planned change in operation.

Clarify options under 63.1510(o) (Site-specific monitoring for Group 1
furnace without add-on air pollution control devices) 

Clarify that 63.1510 does NOT apply to a SAPU that has already
demonstrated compliance on an individual unit basis, as per 63.1510(u).

Require repeat testing of actual volumetric flowrates of hoods during
annual inspection of hood operational integrity

Allowable Operating Conditions 

Clarify feed/charge rate in operation vs. during performance tests

Clarify that can exceed performance test charge weight as long as the
performance test is still representative of facility operation at
highest emission level of all pollutants.  For example, if clean charge
is added to regular charge in Group 2 furnace and final weight is above
performance test rate but not if clean charge is excluded, or if all
clean charge us used in a Group 2 furnace at feed rate higher than the
test rate. 

NOT Allowable Operating Conditions 

[Add any situations that need to be listed]

Thermocouple Calibration for Afterburners

Clarify that a second thermocouple can be used in a dual calibration
system instead of the rule required calibration; if minimally weekly
checks are done for agreement of the dual thermocouples.

4.	Performance Testing 

Feed/charge Rate 

Clarify requirements to determine feed/charge rate used during
performance test that will be used to calculate emissions for each
pollutant. 

Clarify that all the feed/charge rate during ALL performance testing is
required to be the level that is likely to create the highest emissions
(of pollutant known to be the highest emitters, or all pollutants, if
possible)

Frequency of Testing

Clarify that testing needs to be done every five years to show
compliance regardless of level of emissions.

Multiple Emission Units:

Clarify for SAPU and non-SAPU ducted to a common control device.

Clarify for identical furnaces (to reduce individual testing).

Temporary Enclosures for Collection of Fugitive Emissions

Add requirement to capture fugitive emissions during testing

Add requirement to account for fugitives that could be lost from furnace
or other doors being opened during tests.

Add requirement for temporary enclosure to be used if not possible to
capture fugitives otherwise.

Additional Data to be Collected during Performance Tests

Require documentation of the type of scrap processed during performance
test.

Require testing/documentation of flow rate for each hood and
capture/collection system.

Require testing/documentation operating levels of control measures used
during performance test to reduce emissions although not explicitly
required by rule (e.g., ammonia or carbon injection to control D/F).

Exemptions from Performance Tests

Scrap shredders that always process clean scrap and don’t generate
visible emissions (due to low speed and or other parameters) as
determined by EPA Method 22 should be exempt from periodic testing, if
not exempt from rule.

Group 1 furnaces operated <130oF (as measured at the inlet and outlet)
should be exempted from afterburner testing for dioxin/furans 

D/F formation temperature is >130 oF.

Hood Performance Tests

Clarify that the volumetric flowrate ENTERING the hood should be used
and not the stack exit flow.

Clarify that testing of hood flowrate can be done BEFORE performance
test is begun (so can readjust before testing whole system); need to
retest hood after adjustments.

Clarify that must measure actual volumetric flowrate of hood during
lowest expected air flow conditions (ambient air damper in most open
position).

Method 22 Testing

Add allowance for testing in three 20 minute intervals, with greater
than 10 minute breaks in between for a total test time of 60 minutes.

5.	Calculations

Hoods

Can only use high canopy hood equation if low canopy equation is not
appropriate, i.e., where the distance between the hood and the hot
source is greater than the diameter of the source or greater than 3
feet, which ever is larger.

Multiple Control Devices:

Clarify calculations for individual furnaces ducted to a common control
device.

Emissions Calculations to Meet Limits in Terms of Mass of Product 

[Would this be useful?]

6.	Corrections Where Requirements Are Obsolete or Erroneous  

Ventilation System Requirements:  

Remove ACGIH Ventilation Manual (23rd edition) that is incorporated by
reference.  This manual is no longer available for purchase, is
outdated.  Also, EPA no longer incorporates non-Agency documents such as
operating manuals.  

Bag Leak Detection Systems (BLDS) Requirements:

Remove 1997 guidance document on bag leak detection systems.  Current
BLDS operate digitally, which is not covered in 1997 guidance. 

Add requirement that manufacturer’s operating instructions should be
followed at all times.

7.	Typographical Corrections

§63.1503 Definitions: Clean Charge

Replace comma with semicolon before the phrase: “…and runaround
scrap,” as follows:

Clean charge means furnace charge materials, including 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.

§ 63.1505.  Emission standards for affected sources and emission units;
(k) Secondary aluminum processing.

Correct Equation 1 legend for Tti = feed/charge rate for individual
emission unit I: 

Change “emission unit I” to “emission unit i” to be consistent
with other equations in the rule.. 

§ 63.1510(n)(2).  Sidewell group 1 furnace with add-on air pollution
control devices

Change reference citing § 63.1506(m)(7) to §63.1506(m)(6).  There is
no §63.1506(m)(7) and  §63.1506(m)(6) has the right information..  

  FILENAME  SECAL-ANPR-Amendments-Memo-09-30-09.doc 	Page   PAGE  2  of 
 NUMPAGES  7 

 PAGE   

 PAGE   2