Question and Answer: National Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production Revised June 22, 2020

Revised - June 22, 2020
Question & Answer
National Emission Standards for Hazardous Air Pollutants for Secondary Aluminum Production
40 CFR part 63, subpart RRR
Question Received:
The purpose of this Question and Answer (Q&A) document is to provide an answer to an inquiry EPA
received on how to streamline the process of requesting and making impracticability determinations for
"group 1 furnaces" under 40 CFR, part 63, subpart RRR: National Emission Standards for Hazardous
Air Pollutants for Secondary Aluminum Production. The EPA is posting a response to this inquiry to
ensure a timely review of these requests and the associated determinations.
EPA's Response:
Background
EPA established emission standards for hazardous air pollutants from secondary aluminum production
facilities at 40 CFR part 63, subpart RRR, referred to in this document as Subpart RRR. EPA originally
promulgated standards for Subpart RRR in 2000,1 conducted a risk and technology that was finalized in
2015,2 and amended the rule through a 2016 direct final rule.3 There were a number of additional rule
amendments promulgated before EPA completed the risk and technology review.
In the 2015 final rule and 2016 direct final rule, EPA finalized amendments to Subpart RRR by adding
requirements for new and existing uncontrolled furnaces that did not comply with ventilation guidelines
as specified under the American Conference of Governmental Industrial Hygienists (ACGIH
Guidelines). Pursuant to Subpart RRR, the owner or operator of each affected source or emission unit
equipped with an add-on air pollution control device must design and install a system for the capture and
collection of emissions to meet the engineering standards for minimum exhaust rates contained in the
ACGIH Guidelines. See 40 CFR 63.1506(c)(1).
Subpart RRR provides new and existing uncontrolled group 1 furnaces with a number of performance
test options. One option is that if the furnace cannot install hooding that meets ACGIH Guidelines, the
source can petition the appropriate permitting authority that such hoods are impractical and propose
testing procedures that will minimize unmeasured emissions during the performance test. See 40 CFR
63.1512(e)(4)(ii) & (e)(5)(ii). Subpart RRR sets out the criteria for a source to demonstrate the hooding
is impractical at 40 CFR 63.1512(e)(6) and considerations for methods of minimizing unmeasured
emissions during performance testing at 40 CFR 63.1512(e)(7).
The Agency provided these compliance options to accommodate the complexities and difficulties of
installing hooding for the purpose of demonstrating compliance. We recognized that there may be
situations (e.g., various furnace configurations or building configurations) where constructing hooding
may be impractical. Therefore, we clarified that existing and reconstructed round top furnaces are
exempt from the testing requirements set forth in 40 CFR 63.1512(e)(4). This exemption is based on our
1 65 Fed. Reg. 15690 (Mar. 23,2000)
2 80 Fed. Reg. 56700 (Sept. 18,2015).
3 81 Fed. Reg. 38085 (June 13, 2016).
1

-------
Revised - June 22, 2020
understanding that the furnaces, as constructed, cannot accommodate the testing equipment. In the 2015
rulemaking, we concluded that the impracticality did not similarly apply to new furnaces; we presumed
that new furnaces could be built without such restrictions, so we did not extend the exemption to new
furnaces. But, in the 2016 direct final rule, we provided additional flexibility for testing for new round
top furnaces by allowing owners or operators of those furnaces to assume an 80% capture efficiency for
the furnace exhaust during testing or, for major sources to petition the permitting authority, or for area
sources to petition the Administrator, for a determination that such hoods are impractical. See 40 CFR
63.1512(e)(5).
Using a recent determination as a reference, this Q&A document elaborates on what a source can and
should include in a petition to a permitting authority for a determination that hooding is impractical
pursuant to 40 CFR 63.1512.
Impracticability Determinations for Testing New Groun 1 Furnaces:
It has come to our attention that the process for obtaining an impracticability determination has been
longer than industry had anticipated, thus causing delays in start-up and submittal of pre-construction
permit applications. Stakeholders asked EPA to provide information regarding how the process could be
streamlined. In response to this question, we are providing information on the procedures and types of
information expected and deemed appropriate for supporting an impracticability determination, which
will help streamline the process. We also note that provision of complete and accurate information is
necessary for EPA to provide a full and timely response. The information in this document is largely
based on an impracticability determination addressing a new round-top furnace that was recently issued
by EPA Region 10 for Kaiser Aluminum Fabricated Products, LLC. The initial impracticability
determination request from Kaiser, subsequent communications, and the EPA's ultimate determination
are provided in the references to this document. This Q&A document was developed in coordination
with EPA Region 10, EPA's Office of Air Quality Planning and Standards (OAQPS) and EPA's Office
of General Counsel (OGC). This document with its example, however, is not intended to be the sole
means by which a source may make an impracticability determination nor to prevent the authorized
decision-making authority from requesting additional information based on the specific facts and
information provided by the source, including but not limited to the configuration or operation of the
furnace or building in which the furnace is located. It is also not intended to address all state, local and
federal regulations associated with the permitting and operation of such an affected source. This Q&A
document discusses an example of a request that was determined to be sufficient in light of the
regulatory criteria to help streamline future requests for and action on hooding impracticability
determinations. Specifically, the demonstration and EPA Region 10's evaluation are informative with
respect to:
(1)	Factors to consider when determining installation of hooding is impracticable for existing
and reconstructed round top furnaces;
(2)	The timing for determining "hooding impracticability" and steps necessary to minimize
unmeasured emissions relative to a construction project, specifically that determinations can
be made prior to construction;
(3)	The duration of validity for such determinations, specifically that any approval granted by the
EPA would be valid as long as the project constructed matches the description provided to
the EPA and the applicable section of the regulation does not change substantively in the
interim; and
2

-------
Revised - June 22, 2020
(4) Examples of measures sufficient to minimize unmeasured emissions during testing under 40
CFR 63.1512(e)(5) and (7).
Owners and operators must adequately address two key sections of Subpart RRR (40 CFR 63.1512(e)(6)
and 40 CFR 63.1512(e)(7)), when applying for impracticability determinations. As outlined in 40 CFR
63.1512(e)(6), installation of hooding that meets ACGIH Guidelines is considered impractical if any of
the following conditions exist:
i.	Building or equipment obstructions (for example, wall, ceiling, roof, structural beams,
utilities, overhead crane or other obstructions) are present such that the temporary hood
cannot be located consistent with acceptable hood design and installation practices;
ii.	Space limitations or work area constraints exist such that the temporary hood cannot be
supported or located to prevent interference with normal furnace operations or avoid unsafe
working conditions for the furnace operator; or
iii.	Other obstructions and limitations subject to agreement of the permitting authority for major
sources, or the Administrator for area sources.
Secondly, as required by 40 CFR 63.1512(e)(5), during compliance testing, new furnaces must be
operated to minimize unmeasured emissions consistent with 40 CFR 63.1512 (e)(7), which reads as
follows:
Testing procedures that will minimize unmeasured emissions may include, but are not limited to, the
following:
i.	Installing a hood that does not entirely meet ACGIH Guidelines;
ii.	Using the building as an enclosure, and measuring emissions exhausted from the building if
there are no other furnaces or other significant sources in the building of the pollutants to be
measured;
iii.	Installing temporary baffles on those sides or top of furnace opening if it is practical to do so
where they will not interfere with material handling or with the furnace door opening and
closing;
iv.	Minimizing the time the furnace doors are open or the top is off;
v.	Delaying gaseous reactive fluxing until charging doors are closed and, for round top
furnaces, until the top is on;
vi.	Agitating or stirring molten metal as soon as practicable after salt flux addition and closing
doors as soon as possible after solid fluxing operations, including mixing and dross removal;
vii.	Keeping building doors and other openings closed to the greatest extent possible to minimize
drafts that would divert emissions from being drawn into the furnace;
viii.	Maintaining burners on low-fire or pilot operation while the doors are open or the top is off;
ix.	Use of fans or other device to direct flow into a furnace when door is open; or
x.	Removing the furnace cover one time in order to add a smaller but representative charge and
then replacing the cover.
3

-------
Revised - June 22, 2020
Hooding Impracticability Determination Requests:
In a request for a hooding impracticability determination, owners or operators of an affected source
should include, at a minimum, the following detailed information, in conjunction with the showing
required by 40 CFR 63.1512(e)(6):
1)	Description of the facility's operations and status as it relates to applicability under Subpart
RRR;
2)	Description of the type of Group I furnace being installed, furnace operation, and type of
materials being processed; and
3)	Description and explanation of obstructions, space limitations or other limitations, which
prohibit the installation of hooding in accordance with 40 CFR 63.1512(e)(6). Submittal of
pictures, diagrams, electronic media and/or other relevant information, and visual inspections
by the permitting or delegated authority, should aid in the review process.
Testing Procedures to Minimize Unmeasured Emissions during a Performance Test:
Also, in a request for a hooding impracticability determination, owners or operators of an affected
source must identify which steps will be taken to minimize emissions pursuant to 40 CFR 63.1512(e)(7)
and this submittal should include, at a minimum:
1)	A detailed discussion of measures that will be applied to minimize unmeasured fugitive
emissions during testing. At a minimum, the request should clearly describe how each
measure in 40 CFR 63.1512(e)(7) relevant to the affected source will be applied. Owners or
operators should be specific regarding the procedures that will be used during all stages of
the process where fugitive emissions are likely to be present. Measures the owner or operator
proposes to use to minimize emissions that are not specified in 40 CFR 63.1512(e)(7) should
also be clearly identified and discussed. Examples of measures not included on this list that
may be appropriate include the use of only salt, and not gaseous, flux; and operating round
top furnaces near neutral pressures during the melting cycle.
2)	As appropriate, a discussion of measures identified in 40 CFR 63.1512(e)(7) that the owner
or operator believes are not appropriate for application during testing.
3)	If applicable, a description of any add-on air pollution control devices for the furnace,
including the pollutant(s) controlled, and any monitoring and operating procedures that will
be used during the test.
4)	General information should also be provided to include the types of feed materials, including
any fluxing agents, parametric monitoring, procedures for charging, mixing and tapping of
molten aluminum and other relevant process information. This information should be
consistent with information to be included in the test plan or testing protocol, and the
performance test/compliance demonstration general requirements listed in 40 CFR 63.1511.
If you have any questions regarding this Q & A document, please contact Rochelle Boyd at (919) 541-
1390.
4

-------
Revised - June 22, 2020
References:
1.	Letter, Bernard P. Leber, Jr, (Kaiser Aluminum Fabricated Products, LLC) to Ms. Gina
McCarthy, (U.S. EPA), "Hooding Impracticability Determination Request," August 19,2016.
2.	Letter, Bernard P. Leber, Jr, (Kaiser Aluminum Fabricated Products, LLC) to Ms. Katharine
Owens, (U.S. EPA), "Hooding Impracticability Determination Request," November 9, 2016.
3.	Letter, Kelly McFadden, (U.S.EPA) to Bernard P. Leber, Jr (Kaiser Aluminum Fabricated
Products, LLC), "Hooding Impracticability Determination under NESHAP RRR for Kaiser
Trentwood in Spokane Valley, Washington," February 8, 2018.
4.	Letter, Kelly McFadden, (U.S.EPA) to Bernard P. Leber, Jr (Kaiser Aluminum Fabricated
Products, LLC), "Potential at Kaiser at Kaiser Trentwood in Spokane Valley, Washington," July
17, 2018.
5.	Letter, Bernard P. Leber, Jr, (Kaiser Aluminum Fabricated Products, LLC) to Kelly McFadden,
(U.S. EPA), "Potential Hooding at Kaiser Trentwood in Spokane Valley, Washington," January
10, 2019.
6.	Letter, Kelly McFadden, (U.S.EPA) to Bernard P. Leber, Jr (Kaiser Aluminum Fabricated
Products, LLC), "Response to Hooding Questions at Kaiser Trentwood in Spokane Valley,
Washington," April 9, 2019.
5

-------