[Federal Register Volume 77, Number 200 (Tuesday, October 16, 2012)]
[Proposed Rules]
[Pages 63537-63601]
[FR Doc No: 2012-22348]

Vol. 77

Tuesday,

No. 200

October 16, 2012

Part III

 Environmental Protection Agency

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40 CFR Part 98

 Greenhouse Gas Reporting Program: Proposed Amendments and
Confidentiality Determinations for Subpart I; Proposed Rule

Federal Register / Vol. 77 , No. 200 / Tuesday, October 16, 2012 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 98

[EPA-HQ-OAR-2011-0028; FRL-9726-7]
RIN 2060-AR61

Greenhouse Gas Reporting Program: Proposed Amendments and
Confidentiality Determinations for Subpart I

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule; Grant of Reconsideration.

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SUMMARY: This action proposes amending the calculation and monitoring
methodologies for the Electronics Manufacturing, of the Greenhouse Gas
Reporting Rule. Proposed changes include revising certain calculation
methods and adding a new method, amending data reporting requirements,
and clarifying terms and definitions. This action also proposes
confidentiality determinations for the reporting of the new and revised
data elements. Many of these proposed actions are in response to a
petition to reconsider specific aspects of our regulations. This
document also proposes amendments to the General Provisions of the
Greenhouse Gas Reporting Rule to reflect proposed changes to the
reporting requirements for the Electronics Manufacturing sector.

DATES: Comments. Comments must be received on or before December 17,
2012.
    Public Hearing. The EPA does not plan to conduct a public hearing
unless requested. To request a hearing, please contact the person
listed in the FOR FURTHER INFORMATION CONTACT section by October 23,
2012. Upon such request, the EPA will hold the hearing on October 31,
2012 in the Washington, DC area starting at 9 a.m., local time. The EPA
will provide further information about the hearing on its Web page if a
hearing is requested.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2011-0028, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov.
Follow the online instructions for submitting comments.
     Email<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: Environmental Protection Agency, EPA Docket Center
(EPA/DC), Mailcode 6102T, Attention Docket ID No. EPA-HQ-OAR-2011-0028,
1200 Pennsylvania Avenue NW., Washington, DC 20460.
     Hand Delivery: EPA Docket Center, Public Reading Room, EPA
West Building, Room 3334, 1301 Constitution Avenue NW., Washington, DC
20004. Such deliveries are only accepted during the Docket's normal
hours of operation, and special arrangements should be made for
deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2011-0028. The EPA's policy is that all comments received will be
included in the public docket without change and may be made available
online at http://www.regulations.gov, including any personal
information provided, unless the comment includes information claimed
to be confidential business information (CBI) or other information
whose disclosure is restricted by statute.
    Do not submit information that you consider to be CBI or otherwise
protected through http://www.regulations.gov or email. Send or deliver
information identified as CBI to only the mail or hand/courier delivery
address listed above, attention: Docket ID No. EPA-HQ-OAR-2011-0028.
The http://www.regulations.gov Web site is an ``anonymous access''
system, which means the EPA will not know your identity or contact
information unless you provide it in the body of your comment. If you
send an email comment directly to the EPA without going through http://www.regulations.gov, your email address will be automatically captured
and included as part of the comment that is placed in the public docket
and made available on the Internet. If you submit an electronic
comment, the EPA recommends that you include your name and other
contact information in the body of your comment and with any disk or
CD-ROM you submit. If the EPA cannot read your comment due to technical
difficulties and cannot contact you for clarification, the EPA may not
be able to consider your comment. Electronic files should avoid the use
of special characters, any form of encryption, and be free of any
defects or viruses.
    Docket: All documents in the docket are listed in the http://www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in http://www.regulations.gov or in hard copy at the Air Docket, EPA/
DC, EPA West, Room B102, 1301 Constitution Ave. NW., Washington, DC.
This Docket Facility is open from 8:30 a.m. to 4:30 p.m., Monday
through Friday, excluding legal holidays. The telephone number for the
Public Reading Room is<PHONE_NUMBER>, and the telephone number for the
Air Docket is<PHONE_NUMBER>.

FOR FURTHER GENERAL INFORMATION CONTACT: Carole Cook, Climate Change
Division, Office of Atmospheric Programs (MC-6207J), Environmental
Protection Agency, 1200 Pennsylvania Ave. NW., Washington, DC 20460;
telephone number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>; email
address<EMAIL_ADDRESS>For technical information, contact
the Greenhouse Gas Reporting Rule Hotline at: http://www.epa.gov/climatechange/emissions/ghgrule_contactus.htm Alternatively, contact
Carole Cook at<PHONE_NUMBER>.

SUPPLEMENTARY INFORMATION: Additional information on submitting
comments: To expedite review of your comments by agency staff, you are
encouraged to send a separate copy of your comments, in addition to the
copy you submit to the official docket, to Carole Cook, U.S. EPA,
Office of Atmospheric Programs, Climate Change Division, Mail Code
6207-J, Washington, DC 20460, telephone<PHONE_NUMBER>, email address:
<EMAIL_ADDRESS>    Worldwide Web (WWW). In addition to being available in the docket,
an electronic copy of this proposal, memoranda to the docket, and all
other related information will also be available through the WWW on the
EPA's Greenhouse Gas Reporting Rule Web site at http://www.epa.gov/climatechange/.
    Acronyms and Abbreviations. The following acronyms and
abbreviations are used in this document.

BAMM best available monitoring methods
CAA Clean Air Act
CO2e carbon dioxide equivalent
CBI confidential business information
CFR Code of Federal Regulations
CVD chemical vapor deposition
DRE destruction or removal efficiency
EIA Economic Impact Analysis
EPA U.S. Environmental Protection Agency
F-GHG fluorinated greenhouse gas
FDL field detection limit
FTIR Fourier transform infrared
GHG greenhouse gas
GWP global warming potential
HTF heat transfer fluid
ICR Information Collection Request
IPCC Intergovernmental Panel on Climate Change
ISBN International Standard Book Number
ISMI International SEMATECH Manufacturing Initiative

LCD liquid crystal display
MEMS micro-electro-mechanical systems
mtCO2e metric ton carbon dioxide equivalent
NAICS North American Industrial Classification System
N2O nitrous oxide
NTTAA National Technology Transfer and Advancement Act of 1995
OMB Office of Management & Budget
PFC perfluorocarbon
POU point of use
ppbv parts per billion by volume
QMS quadrupole mass spectroscopy
RFA Regulatory Flexibility Act
RSASTP random sampling abatement system testing program
RSD relative standard deviation
SEMATECH SEmiconductor MAnufacturing TECHnology
SIA Semiconductor Industry Association
UMRA Unfunded Mandates Reform Act of 1995
U.S. United States
VCS voluntary consensus standard
WWW Worldwide Web

    Organization of This Document. The following outline is provided to
aid in locating information in this preamble.

I. General Information
     A. What is the purpose of this action?
     B. Does this action apply to me?
     C. Legal Authority
     D. What should I consider as I prepare my comments to the EPA?
 II. Background for Proposed Amendments to GHG Monitoring and
Calculation Methodologies and Other Technical Revisions
     A. Background for Proposed Amendments
     B. How would these amendments apply to 2012 and 2013 reports?
 III. Summary and Rationale for Proposed Amendments to GHG
Monitoring and Calculation Methodologies and Other Revisions
     A. Summary of Proposed Rule Amendments in Response to Petition
for Reconsideration
     B. Rationale for Proposed Amendments
     C. Proposed Rule Changes to Reporting and Recordkeeping
Requirements
     D. Proposed Changes to Remove BAMM Provisions and Language
Specific to Reporting Years 2011, 2012, and 2013.
 IV. Background for Confidentiality Determinations for Subpart I of
Part 98
     A. Overview and Background
     B. Approach to Proposed CBI Determinations for New or Revised
Subpart I Data Elements
     C. Proposed Confidentiality Determinations for Individual Data
Elements in Two Direct Emitter Data Categories
     D. Request for Comments on Proposed Confidentiality
Determinations
 V. Statutory and Executive Order Reviews
     A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
     B. Paperwork Reduction Act
     C. Regulatory Flexibility Act (RFA)
     D. Unfunded Mandates Reform Act (UMRA)
     E. Executive Order 13132: Federalism
     F. Executive Order 13175: Consultation and Coordination with
Indian Tribal Governments
     G. Executive Order 13045: Protection of Children from
Environmental Health Risks and Safety Risks
     H. Executive Order 13211: Actions that Significantly Affect
Energy Supply, Distribution, or Use
     I. National Technology Transfer and Advancement Act
     J. Executive Order 12898: Federal Actions to Address
Environmental Justice in Minority Populations and Low-Income
Populations

I. General Information

A. What is the purpose of this action?

     The EPA is proposing amendments to the calculation and monitoring
methodologies for Subpart I, Electronics Manufacturing, of the
Greenhouse Gas Reporting Rule (``subpart I''). In addition, the EPA is
proposing conforming changes to the reporting and recordkeeping
requirements of subpart I. Changes include revising certain calculation
methods and adding a new method, amending data reporting requirements,
and clarifying terms and definitions. The EPA is proposing these
amendments to (1) Modify calculation methods and data requirements to
better reflect new industry data and current practice; (2) provide
additional calculation methods to allow individual facilities to choose
the method best suited for their operations; (3) reduce the burden
associated with existing requirements; and (4) address sensitive
business information concerns raised by members of the Semiconductor
Industry Association (SIA). Amendments being proposed today affect all
facilities that manufacture electronics including those that
manufacture semiconductors (including light emitting diodes), micro-
electro-mechanical systems (MEMS), liquid crystal displays (LCDs), or
photovoltaic (PV) cells. Because we are planning an effective date of
January 1, 2014 for the final amendments, we are also proposing to
remove the rule language for certain provisions that will not apply
after 2013. Sections II and III of this preamble contain more detailed
information on the background and rationale for these proposed
amendments. Many of the proposed changes are in response to a petition
to reconsider specific aspects of subpart I.
     The EPA is also proposing confidentiality determinations for the
new and revised data elements under the proposed amendments to subpart
I. Section IV of this preamble provides the background and rationale
for these proposed confidentiality determinations. Finally, Section V
of this preamble describes the statutory and executive order
requirements applicable to this action.

B. Does this action apply to me?

    This proposal affects entities that are required to submit annual
greenhouse gas (GHG) reports under subpart I of 40 CFR part 98 (``Part
98''). The Administrator determined that this action is subject to the
provisions of Clean Air Act (CAA) section 307(d). See CAA section
307(d)(1)(V) (the provisions of CAA section 307(d) apply to ``such
other actions as the Administrator may determine''). Part 98 and this
action affect owners and operators of electronics manufacturing
facilities. Affected categories and entities include those listed in
Table 1 of this preamble.

            Table 1--Examples of Affected Entities by Category
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                                                  Examples of affected
             Category                 NAICS            facilities
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Electronics Manufacturing........       334111  Microcomputers
                                                 manufacturing
                                                 facilities.
                                        334413  Semiconductor,
                                                 photovoltaic (solid-
                                                 state) device
                                                 manufacturing
                                                 facilities.
                                        334419  Liquid crystal display
                                                 unit screens
                                                 manufacturing
                                                 facilities.
                                        334419  Micro-electro-mechanical
                                                 systems manufacturing
                                                 facilities.
------------------------------------------------------------------------

     Table 1 of this preamble lists the types of entities that
potentially could be affected by the reporting requirements under the
subpart covered by this proposal. However, this list is not intended to
be exhaustive, but rather provides a guide for readers regarding
facilities likely to be affected by this action. Other types of
facilities not listed in the table could also be subject to reporting
requirements. To determine whether you are affected by this action,

you should carefully examine the applicability criteria found in 40 CFR
part 98, subpart A as well as 40 CFR part 98, subpart I. If you have
questions regarding the applicability of this action to a particular
facility, consult the person listed in the FOR FURTHER INFORMATION
CONTACT section of this preamble.

C. Legal Authority

    The EPA is proposing rule amendments to Part 98 under its existing
CAA authority, specifically authorities provided in CAA section 114. As
stated in the preamble to the 2009 final rule (74 FR 56260, October 30,
2009) and the Response to Comments on the Proposed Rule, Volume 9,
Legal Issues, CAA section 114 provides the EPA broad authority to
obtain the information in Part 98, including subpart I, because such
data would inform and are relevant to the EPA's carrying out a wide
variety of CAA provisions. As discussed in the preamble to the initial
Part 98 proposal (74 FR 16448, April 10, 2009), CAA section 114(a)(1)
authorizes the Administrator to require emissions sources, persons
subject to the CAA, manufacturers of control or process equipment, or
persons whom the Administrator believes may have necessary information
to monitor and report emissions and provide such other information the
Administrator requests for the purposes of carrying out any provision
of the CAA.
    In addition, the EPA is proposing confidentiality determinations
for proposed data elements in subpart I, under its authorities provided
in sections 114, 301, and 307 of the CAA. As mentioned, CAA section 114
provides the EPA authority to obtain the information in Part 98,
including those in subpart I. Section 114(c) requires that the EPA make
publicly available information obtained under section 114 except for
information (excluding emission data) that qualify for confidential
treatment.
    The Administrator has determined that this action (proposed
amendments and confidentiality determinations) is subject to the
provisions of section 307(d) of the CAA.

D. What should I consider as I prepare my comments to the EPA?

1. Submitting Comments That Contain CBI
    Clearly mark the part or all of the information that you claim to
be CBI. For CBI information in a disk or CD-ROM that you mail to the
EPA, mark the outside of the disk or CD-ROM as CBI and then identify
electronically within the disk or CD-ROM the specific information that
is claimed as CBI. In addition to one complete version of the comment
that includes information claimed as CBI, a copy of the comment that
does not contain the information claimed as CBI must be submitted for
inclusion in the public docket. Information marked as CBI will not be
disclosed except in accordance with procedures set forth in 40 CFR part
2.
    Do not submit information that you consider to be CBI or otherwise
protected through http://www.regulations.gov or email. Send or deliver
information identified as CBI to only the mail or hand/courier delivery
address listed above, attention: Docket ID No. EPA-HQ-OAR-2011-0028.
    If you have any questions about CBI or the procedures for claiming
CBI, please consult the person identified in the FOR FURTHER
INFORMATION CONTACT section.
2. Tips for Preparing Your Comments
    When submitting comments, remember to:
    Identify the rulemaking by docket number and other identifying
information (e.g., subject heading, Federal Register date and page
number).
    Follow directions. The EPA may ask you to respond to specific
questions or organize comments by referencing a CFR part or section
number.
    Explain why you agree or disagree, and suggest alternatives and
substitute language for your requested changes.
    Describe any assumptions and provide any technical information and/
or data that you used.
    If you estimate potential costs or burdens, explain how you arrived
at your estimate in sufficient detail to allow us to reproduce your
estimate.
    Provide specific examples to illustrate your concerns and suggest
alternatives.
    Explain your views as clearly as possible, avoiding the use of
profanity or personal threats.
    Make sure to submit your information and comments by the comment
period deadline identified in the preceding section titled DATES. To
ensure proper receipt by the EPA, be sure to identify the docket ID
number assigned to this action in the subject line on the first page of
your response. You may also provide the name, date, and Federal
Register citation.
    To expedite review of your comments by agency staff, you are
encouraged to send a separate copy of your comments, in addition to the
copy you submit to the official docket, to Carole Cook, U.S. EPA,
Office of Atmospheric Programs, Climate Change Division, Mail Code
6207-J, Washington, DC, 20460, telephone<PHONE_NUMBER>, email
<EMAIL_ADDRESS>You are also encouraged to send a separate
copy of your CBI information to Carole Cook at the provided mailing
address in the FOR FURTHER INFORMATION CONTACT section. Please do not
send CBI to the electronic docket or by email.

II. Background for Proposed Amendments to GHG Monitoring and
Calculation Methodologies and Other Technical Revisions

A. Background for Proposed Amendments

    The GHG reporting requirements for subpart I were finalized on
December 1, 2010 (75 FR 74774, hereafter referred to as ``final subpart
I rule''). Following the publication of the final subpart I rule in the
Federal Register, the SIA (hereafter referred to as ``the Petitioner'')
submitted on January 31, 2011 an administrative petition titled
``Petition for Reconsideration and Request for Stay Pending
Reconsideration of Subpart I of the Final Rule for Mandatory Reporting
of Greenhouse Gases'' (hereafter referred to as the ``Petition for
Reconsideration'', available in docket EPA-HQ-OAR-2009-0927),
requesting reconsideration of numerous provisions in the final subpart
I rule. Since that petition was filed, the EPA has published five
actions related to subpart I.
     Additional Sources of Fluorinated GHGs: Extension of Best
Available Monitoring Provisions for Electronics Manufacturing (76 FR
36339, published June 22, 2011). Granted the Petition for
Reconsideration with respect to the provisions for the use of Best
Available Monitoring Methods (BAMM). Extended three of the deadlines in
subpart I related to using the BAMM provisions from June 30, 2011 to
September 30, 2011.
     Changes to Provisions for Electronics Manufacturing to
Provide Flexibility (76 FR 59542, published September 27, 2011).
Amended the calculation and monitoring provisions for the largest
semiconductor manufacturing facilities to provide flexibility through
the end of 2013 and extended two deadlines in the BAMM provisions.
     Proposed Confidentiality Determinations for Subpart I and
Proposed Amendments to Subpart I Best Available Monitoring Methods
Provisions (77 FR 10434, published February 22, 2012). Re-proposed
confidentiality determinations for data elements in subpart I and
proposed amendments to the provisions regarding

the calculation and reporting of emissions from facilities that use
BAMM.
     Revisions to Heat Transfer Fluid Provisions (77 FR 10373,
published February 22, 2012). Amended the definition of fluorinated
heat transfer fluids (fluorinated HTFs) and the provisions to estimate
and report emissions from fluorinated HTFs.
     Final Confidentiality Determinations for Nine Subparts and
Amendments to Subpart A and I under the Mandatory Reporting of
Greenhouse Gases Rule; Final Rule (77 FR 48072, published August 13,
2012). Final confidentiality determinations for data elements in
subpart I and final amendments to the provisions regarding the
calculation and reporting of emissions from facilities that use BAMM.

B. How would these amendments apply to 2012 and 2013 reports?

    The EPA intends to address the comments on these proposed
amendments and publish any final amendments in 2013. Facilities would
be required to follow one of the new or revised methods to estimate
emissions beginning in 2014. The first reports of emissions estimated
using the new methods would be submitted in 2015. For the reports for
reporting years 2012 and 2013, reporters would be expected to calculate
emissions and other relevant data using the existing requirements under
Part 98. These existing requirements include the flexibility for the
largest semiconductor manufacturing facilities added in the September
27, 2011 rule titled ``Changes to Provisions for Electronics
Manufacturing to Provide Flexibility.''
    Given the timing and extent of the proposed changes, and the
likelihood that the final rule will not be published until the second
half of 2013, we have determined that it is not feasible for sources to
implement these changes for reporting year 2013. The proposed revisions
would change and replace existing calculation methods and regulatory
requirements, and would greatly affect how emissions are calculated and
the data that would be reported. For example, we are proposing to add a
new stack testing option to measure and calculate fab-level fluorinated
greenhouse gas (F-GHG) emissions, revise process categories and
associated gas utilization rates and by-product formation rates, and
eliminate existing methods that require using recipe-specific gas
utilization rates and by-product formation rates to calculate
emissions. Because of the different data collection requirements
compared to the current subpart I requirements, we do not anticipate
that facilities would have enough time after the final rule is
published to schedule stack tests, revise their current tracking and
monitoring methods, or revise the data collection methods for reporting
year 2013.
    Thus, reporters using the current methods in subpart I would
continue to use these methods for collecting data and calculating
emissions for 2013 that are reported in 2014. Reporters would be
required to select calculation methods based on any final revisions to
the rule to calculate the emissions for 2014 that are reported in 2015.

III. Summary and Rationale for Proposed Amendments to GHG Monitoring
and Calculation Methodologies and Other Revisions

A. Summary of Proposed Rule Amendments in Response to Petition for
Reconsideration

    In this action, we are granting reconsideration on all issues in
the Petition for Reconsideration not already addressed in the final
rules published June 22, 2011 (Additional Sources of Fluorinated GHGs:
Extension of Best Available Monitoring Provisions for Electronics
Manufacturing); September 27, 2011 (Changes to Provisions for
Electronics Manufacturing to Provide Flexibility); and August 13, 2012
(Confidentiality Determinations for Subpart I and Amendments to Subpart
I Best Available Monitoring Methods Provisions). Those final rules are
described in Section II.A of this preamble. Section III.B of this
preamble discusses the specific issues raised in the Petition for
Reconsideration that are addressed in this action and the changes the
EPA is proposing in response to the petition. The EPA intends to
complete its response to the Petition for Reconsideration through this
rulemaking.
    Following consideration of the issues raised in the Petition for
Reconsideration and data presented by the Petitioner, the EPA is
proposing certain amendments to subpart I. Table 2 of this preamble
presents a summary of the outstanding issues raised by the Petitioner
and the corresponding proposed changes to the rule. Section III.B of
this preamble provides further detail including the EPA's rationale for
each proposed change.

       Table 2--Proposed Changes to the Rule Based on Petition for
 Reconsideration and the Petitioner's May 26, 2011 Letter Supporting the
    Development of the Rule Changes To Provide Flexibility That Were
                      Finalized September 27, 2011
------------------------------------------------------------------------
           Technical issue                  Proposed changes to rule
------------------------------------------------------------------------
Rows 2 and 12 apply to semiconductor facilities only. All other rows
 apply to all electronics manufacturing facilities.
------------------------------------------------------------------------
1. Addition of an emission estimation  Revising 40 CFR 98.93 to provide
 method as an alternative to recipe-    an option for using stack
 specific emission factors. (See        testing as an alternative method
 Section III.B.1).                      for determining fab-level
                                        emission factors for determining
                                        fab-level F-GHG emissions for
                                        all electronics manufacturing
                                        facilities.
                                       Revising 40 CFR 98.94 to 98.98 to
                                        include the monitoring methods,
                                        QA/QC, missing data, reporting,
                                        recordkeeping, and definition
                                        requirements for the stack
                                        testing alternative.
2. Revision of default gas             Revise 40 CFR 98.92(a) and 40 CFR
 utilization rates and by-product       98.93(a)(2) and (a)(4) to
 formation rates for the plasma etch    combine wafer cleaning and
 process type for semiconductor         plasma etch emission processes
 manufacturing. (See Section III.B.2).  and associated gas utilization
                                        rates and by-product formation
                                        rates. Revise Tables I-3 and I-4
                                        for semiconductor manufacturing
                                        with new gas utilization rates
                                        and by-product formation rates
                                        based on gas type and process
                                        type or sub-type using
                                        additional data submitted by the
                                        Petitioner.

3. Removing recipe-specific emission   Revising 40 CFR 98.93, 98.94,
 factors: Requirements for (1)          98.96, and 98.97 to remove
 Largest semiconductor manufacturing    provisions to use recipe-
 facilities (defined as those           specific gas utilization rates
 facilities with annual manufacturing   and by-product formation rates
 capacity of greater than 10,500 m\2\   and to combine the wafer
 of substrate) to use recipe-specific   cleaning process type with the
 gas utilization rates and by-product   plasma etch process type. Under
 formation rates to estimate            this proposal, all semiconductor
 emissions from plasma etch             manufacturing facilities,
 processes; and (2) semiconductor       regardless of manufacturing
 facilities using wafers greater than   capacity, would have the option
 300 mm diameter to estimate all of     to use default gas utilization
 their emissions from processes that    rates and by-product formation
 use fluorinated GHGs using recipe-     rates to estimate emissions from
 specific gas utilization rates and     the plasma etching/wafer
 by-product formation rates. (See       cleaning process type and from
 Section III.B.3).                      the following three subtypes of
                                        the chamber cleaning process
                                        type: in-situ plasma chamber
                                        cleaning, remote plasma chamber
                                        cleaning, and in-situ thermal
                                        chamber cleaning.
4. Calculation for determining         Revising the terminology and
 manufacturing capacity. (See Section   definition of maximum designed
 III.B.4).                              substrate starts in 40 CFR 98.98
                                        to be maximum substrate starts,
                                        meaning for the purposes of
                                        Equation I-5 in subpart I, the
                                        maximum quantity of substrates,
                                        expressed as surface area, that
                                        could be started each month in a
                                        reporting year based on the
                                        equipment installed in that
                                        facility and assuming that the
                                        equipment were fully utilized.
                                        Manufacturing equipment would be
                                        considered installed when it is
                                        on the manufacturing floor and
                                        connected to the required
                                        utilities.
5. Reporting provisions for            Facilities would be allowed to
 facilities that have integrated        report integrated production and
 production and research and            R&D emissions and, if doing so,
 development (R&D) activities. (See     would be required to provide an
 Section III.B.5).                      estimate of the fraction of
                                        total emissions from their R&D
                                        activities under 40 CFR 98.96.
6. Requirements for the accuracy and   Removing the requirement for one
 precision of the equipment measuring   percent of full-scale accuracy
 gas consumption. (See Section          for ``all flow meters, weigh
 III.B.6).                              scales, pressure gauges and
                                        thermometers* * *'' in 40 CFR
                                        98.93(i) and referencing the
                                        calibration accuracy
                                        requirements in 40 CFR 98.3(i)
                                        for all measurement devices used
                                        to measure quantities that are
                                        monitored in subpart I.
7. Provisions for re-calculating the   Revising the criteria for an
 facility-wide gas specific heel        ``exceptional circumstance'' in
 factor and handling exceptional        40 CFR 98.94(b)(4) from 20
 circumstances. (See Section III.B.7).  percent of the original trigger
                                        point for change out to 50
                                        percent for small cylinders
                                        (containing less than 9.08
                                        kilograms (20 pounds) of gas).
                                        For large containers, the
                                        ``exceptional circumstance''
                                        would remain as a change out
                                        point that differs by 20 percent
                                        of the trigger point used to
                                        calculate the gas specific heel
                                        factor. Clarifying the
                                        requirements for recalculating
                                        the facility-wide heel factor.
8. Requirements for verifying the      Revising 40 CFR 98.94(c) to allow
 model used to apportion gas            for development of apportioning
 consumption. (See Section III.B.8).    factors by using direct
                                        measurements using gas flow
                                        meters or weigh scales, to
                                        measure process sub-type,
                                        process type, stack system, or
                                        fab-specific input gas
                                        consumption.
                                       Revising 40 CFR 98.94(c)(2)(i) to
                                        allow reporters to select a
                                        period of the reporting year and
                                        its duration that is
                                        representative of normal
                                        operations for the model
                                        verification. The representative
                                        period would be at least 30 days
                                        in duration, and may be as long
                                        as one year. The model would be
                                        verified using the F-GHG used in
                                        the greatest quantity, and would
                                        be corrected if it does not meet
                                        the verification requirements. A
                                        facility would be able to use
                                        two F-GHG for model verification
                                        if they both meet the criteria
                                        and if at least one of them is
                                        used in the greatest quantity.
                                       Increasing the maximum allowed
                                        difference between the modeled
                                        and actual gas consumption in
                                        the verification process from 5
                                        percent to 20 percent.
9. Provisions for calculating N2O      Revising 40 CFR 98.93(b), 40 CFR
 emissions. (See Section III.B.9).      98.96(c)(3) and 40 CFR 98.96(k)
                                        to clarify that facilities must
                                        calculate annual fab-level N2O
                                        emissions from the chemical
                                        vapor deposition (CVD) process
                                        type and from the aggregate of
                                        other electronics manufacturing
                                        production processes using
                                        default emission factors
                                        (facilities are not required to
                                        report emissions from each CVD
                                        process and from each other N2O
                                        using process).
10. Provisions for reporting           Revising 40 CFR 98.94(f) to allow
 controlled emissions from abatement    facilities to use either revised
 systems. (See Section III.B.10).       default destruction or removal
                                        efficiency (DRE) values or to
                                        establish a site-specific DRE
                                        value for each combination of
                                        input gas or by-product gas and
                                        process type or sub-type using
                                        directly measured DREs.
                                        Providing alternative methods
                                        for a facility to directly
                                        measure DRE.

11. Provisions for determining and     Revising Equation I-15 to allow
 calculating abatement system uptime.   reporters to calculate the
 (See Section III.B.11).                average uptime for the group of
                                        systems for each combination of
                                        input gas or by-product gas and
                                        process type or sub-type, using
                                        the same process categories in
                                        which F-GHG use and emissions
                                        are calculated. Abatement system
                                        uptime monitoring and
                                        calculation would be simplified
                                        by assuming that connected
                                        process tools operate with F-
                                        GHGs or N2O flowing continuously
                                        once they are installed; this
                                        would apply for all methods
                                        (both default emission factors
                                        and stack testing).
12. Absence of a method for updating   Revising the data reporting
 gas utilization rates and by-product   requirements in 40 CFR 98.96 to
 formation rates and DRE values for     require certain semiconductor
 semiconductor manufacturing. (See      manufacturing facilities to
 Section III.B.12).                     provide a report to the EPA
                                        every 3 years covering
                                        technology changes at the
                                        facility that may affect gas
                                        utilization rates and by-product
                                        formation rates or DRE values.
------------------------------------------------------------------------

    The EPA is not staying subpart I pending reconsideration as
requested in the Petition for Reconsideration because the EPA believes
that the concerns prompting the stay request have been addressed
through the BAMM process and through the September 27, 2011 final rule
(Changes to Provisions for Electronics Manufacturing to Provide
Flexibility), which amended the calculation and monitoring provisions
for the largest semiconductor manufacturing facilities to provide
flexibility through the end of 2013. As stated in the preamble to the
September 27, 2011 final rule, the EPA intends to finalize revisions to
subpart I in 2013 so that semiconductor manufacturing facilities can
implement the revised subpart I beginning in 2014. The EPA is not
reopening the entirety of subpart I for comment but is taking comment
only on the remaining issues raised by the Petitioner, as listed in
Table 2 of this preamble, and the proposed amendments described in
Section III.B of this preamble, with the exception that we request
comment on whether new data are available to update the default gas
utilization rates and by-product formation rates for the facilities
that manufacture MEMS, LCDs, or PV cells (see Section III.B.2 of this
preamble), and whether new data are available on measured DRE values
for abatement systems used at MEMS, LCD, or PV cell manufacturing
facilities (see Section III.B.10 of this preamble).
    In summary, the major changes we are proposing are to revise the
calculation methods to provide all electronics manufacturing facilities
the choice of two methods to calculate annual emissions and to remove
the option for electronics manufacturing facilities to determine and
use recipe-specific gas utilization rates and by-product formation
rates. The proposed rule would provide the option for reporters to use
either default gas utilization rates and by-product formation rates,
which the EPA is proposing to revise for semiconductor manufacturing
facilities to reflect new industry data provided to the EPA, or to
conduct stack testing to establish site-specific emission factors for
F-GHGs that would be used to calculate F-GHG emissions. The proposed
amendments would ensure that the EPA receives accurate and current
facility-specific data. The proposed amendments also include provisions
for the periodic review of industry advances and changes that may
impact the default gas utilization rates and by-product formation rates
and default DRE values used to estimate emissions, to encourage the
continued collection of data that represent current industry practices.
Additionally, the proposed stack testing approach allows for estimation
of emissions based on periodic direct measurements of stack emissions
from facilities. These proposed amendments would allow the EPA to
accurately characterize and analyze GHG emissions from facilities in
the electronics manufacturing industry while reducing burden to the
industry.

B. Rationale for Proposed Amendments

1. Stack Testing as an Alternative Emission Monitoring Method for
Facilities that Manufacture Electronics
    After subpart I was promulgated, the Petitioner expressed interest
in developing a method to use stack testing to quantify F-GHG emissions
from electronics manufacturing facilities as an alternative to the
recipe-specific method in the final subpart I rule. Specifically, the
Petitioner proposed an approach in which they would (1) develop
emission factors by measuring emissions from their stacks over a
certain period and dividing them by an activity metric (e.g., gas
consumption) measured over the same period; and (2) estimate annual
emissions by multiplying the emission factors by the appropriate annual
activity. They noted that stack testing is already widely accepted in
the industry and commonly used to quantify non-F-GHG emissions for
compliance with other state and federal air programs. They also noted
that in most facilities, a large number of tools using F-GHGs are
exhausted through a relatively small number of stacks, and stack
testing in such a situation could be at least as accurate as the other
methods in the final subpart I rule, and could be more cost-effective
for the facility depending on how often testing is conducted (see
``Technical Support for the Stack Test Option for Estimating
Fluorinated Greenhouse Gas Emissions from Electronics Manufacturing
Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-2011-0028).
    The EPA recognizes that stack testing is an important tool that has
historically been required for specified non-F-GHG pollutants to
determine a facility's compliance with emission limits, capture or
control efficiencies, or monitoring parameters established pursuant to
certain provisions of the CAA. Stack testing performed and verified
according to the procedures in validated EPA methods is considered a
reliable method to quantify facility emissions as long as a robust and
predictable relationship is found between emissions and the selected
activity metric. Because stack testing is a direct measurement of
facility emissions, it has the potential to provide a high-quality
characterization

of the emissions from the electronics manufacturing industry.
Electronics manufacturers are already using stack testing to comply
with other air rules and operating permit requirements. For example,
semiconductor manufacturers subject to 40 CFR part 63, subpart BBBBB,
National Emission Standards for Hazardous Air Pollutants for
Semiconductor Manufacturing, are already required to perform stack
testing using EPA Method 320 at 40 CFR part 63, appendix A (hereafter
``EPA Method 320''), among others, to comply with subpart BBBBB,
although they are not required to use EPA Method 320 to quantify F-GHG
emissions.
    To determine whether stack testing might be appropriate to quantify
F-GHG emissions from electronics manufacturing, EPA evaluated whether
it demonstrates (1) The ability of a method and technology to
accurately measure F-GHG emissions from electronics manufacturing
facilities during the test; (2) the ability to accurately measure a
corresponding activity metric during the test; and (3) the existence of
a reasonably constant and predictable relationship between F-GHG
emissions and the chosen activity metric. The first and third factors
were particularly important given the relatively low concentrations of
F-GHGs in exhaust streams at electronics facilities and the potential
variability of emission factors over time at those facilities as the
mix of products and processes changed over time.
    The Petitioner provided data from stack testing and supporting data
on F-GHG consumption and production to demonstrate that that stack
testing can be used to estimate annual emissions. These data were
provided to the EPA in support of the Petitioner's request in the
petition for reconsideration to add a stack testing option to subpart I
for semiconductor manufacturing. The data were collected using EPA
Method 320, ``Measurement Of Vapor Phase Organic And Inorganic
Emissions By Extractive Fourier Transform Infrared (FTIR)
Spectroscopy'' (40 CFR part 63, appendix A), at three companies
manufacturing a variety of semiconductor products on different sized
wafers. The data provided to the EPA demonstrated that F-GHG emissions
are a direct and reasonably constant function of F-GHG consumption over
the test period. Moreover, data from multiple tests at two facilities
showed that emission factors (kg gas emitted/kg gas consumed) did not
vary widely in the absence of significant technology and abatement
level changes, even though the mix of products at one of the facilities
appeared likely to have changed during the months since the previous
test. This indicates that emissions from one period at a facility, when
converted to emission factors based on F-GHG consumption, can be used
to determine emissions at the same facility over an extended period of
time (i.e., one year, and longer under certain circumstances), and can
be scaled to estimate annual F-GHG emissions.
    The data provided by the Petitioner (see ``Technical Support for
the Stack Test Option for Estimating Fluorinated Greenhouse Gas
Emissions from Electronics Manufacturing Facilities under Subpart I,''
Docket ID No. EPA-HQ-OAR-2011-0028) demonstrated that current FTIR
methods, such as EPA Method 320, have sufficient sensitivity, when used
in conjunction with detectors optimized to detect F-GHGs, to provide
accurate measurements of F-GHG emissions. EPA Method 320 can be used to
measure concentrations of the commonly emitted F-GHGs down to a few
parts per billion by volume (ppbv), and the field detection limits for
the same F-GHGs can be as low as 1 or 2 ppbv.
    The same data provided by the Petitioner provided evidence that F-
GHG consumption can be accurately measured or estimated over the
proposed test period of 8 hours as long as varying temperatures, non-
ideal gas behavior, and low drawdown rates are appropriately accounted
for. (Methods for accounting for these are discussed in ``Stack testing
requirements'' in Section III.B.1 of this preamble.) This ensures that
gas consumption can be accurately determined, either directly for the
test period or by interpolating from longer-term consumption data.
Accurate gas consumption measurements ensure that gas consumption can
be used with the stack emission measurements as the basis for emission
factors to calculate annual emissions.
    Finally, the data provided by the Petitioner demonstrated that
emissions estimated from stack testing were in agreement with emissions
for the same facilities estimated using other methods, such as the
default gas utilization rates and by-product formation rate method in
subpart I (see ``Technical Support for the Stack Test Option for
Estimating Fluorinated Greenhouse Gas Emissions from Electronics
Manufacturing Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-
2011-0028).
    The EPA is proposing to revise subpart I to include a stack testing
option for estimating annual F-GHG emissions at 40 CFR 98.93(i). This
option would apply to all electronic manufacturing facilities,
including those making semiconductors, MEMS, LCDs, and PV cells. We are
not proposing this option for estimating N2O emissions; a
review of the stack test data provided to the EPA revealed inconsistent
results for stack measurements of N2O emissions for which
the cause could not be determined (see ``Technical Support for the
Stack Test Option for Estimating Fluorinated Greenhouse Gas Emissions
from Electronics Manufacturing Facilities under Subpart I,'' Docket ID
No. EPA-HQ-OAR-2011-0028). Therefore, we do not have sufficient data to
show that stack testing is appropriate for development of
N2O emission estimates. However, the rule already includes
an option based on default emission factors for estimating
N2O emissions (see 40 CFR 98.93(b)). (Proposed amendments to
the provisions and emission factors for estimating N2O
emissions are discussed in Section III.B.9 of this preamble.)
    In this action, we are also proposing to allow all electronics
manufacturing facilities to use separate methods (i.e., stack testing
or default utilization and by-product formation rates) to estimate
emissions from each fab within a single facility. Facilities would
report GHG emissions on a fab basis. Many electronics manufacturing
facilities are divided into separate fabs, which generally consist of
separate buildings constructed at different times in which the
processing tools are located. Most facilities have only one fab, but
some facilities have two or more fabs. Each fab may be dedicated to a
different product type, or may represent different generations of
manufacturing technology because they were built at different times. In
the semiconductor manufacturing industry, separate fabs may use
different size wafers.
    Because of differences among fabs (e.g., differences in the number
of stacks), a reporter may wish to use different methods to estimate
emissions from each fab. We are proposing to allow reporters to use
different methods for separate fabs, but would also require that
emissions be reported at the fab level. We are proposing to define a
``fab'' in 40 CFR 98.98 as ``the portion of an electronics
manufacturing facility located in a separate physical structure that
began manufacturing on a certain date.''
    Selection of Stack Systems for Testing. The EPA recognizes that
given the diversity of facility designs among electronics
manufacturers, some facilities may have some stacks that account for
only a small percent of total facility emissions. In order to avoid the
burden of testing a large number of stacks, the proposed amendments

would not require that all stacks be tested. Instead, the reporter
would develop a preliminary estimate of the annual emissions from each
``stack system'' in a fab and would not be required to test those stack
systems that account for relatively small emissions. A stack system
would be considered to be one or more stacks that are connected by a
common header or manifold, through which a fluorinated GHG-containing
gas stream originating from one or more fab processes is, or has the
potential to be, released to the atmosphere. For purposes of subpart I,
stack systems would not include emergency vents or bypass stacks
through which emissions are not usually vented under typical operating
conditions.
    Under the proposed rule, the reporter would develop a preliminary
estimate of F-GHG emissions from each stack system on a metric ton
carbon dioxide equivalent (mtCO2e) basis using the gas
consumption in the tools associated with the stack system and gas
utilization rates and by-product formation rates in proposed Tables I-
11 through I-15, and accounting for the DRE of the ``point of use''
(POU) abatement systems and the uptime (the fraction of time the system
is operating within manufacturer's specifications) of the POU systems.
The gas utilization rates and by-product formation rates in proposed
Tables I-11 through I-15 are based on the 2006 Intergovernmental Panel
on Climate Change (IPCC) Tier 2a factors.\1\ The factors in proposed
Tables I-11 and I-12 for semiconductor manufacturing facilities were
updated from the 2006 IPCC factors based on additional data collected
by the Petitioner (see ``Technical Support for Modifications to the
Fluorinated Greenhouse Gas Emission Estimation Method Option for
Semiconductor Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-
2011-0028).
---------------------------------------------------------------------------

    \1\ 2006 IPCC Guidelines for National Greenhouse Gas
Inventories, Prepared by the National Greenhouse Gas Inventories
Programme, Eggleston H.S., Buendia L., Miwa K., Ngara T. and Tanabe
K. (eds). Hayama, Kanagawa, Japan.
---------------------------------------------------------------------------

    In the preliminary estimate, reporters would be required to use
data from the previous reporting year for the DRE of abatement and the
total uptime of all abatement systems in each stack system. The
consumption of each F-GHG in each stack system would be estimated as
the total gas consumption of that F-GHG times the ratio of the number
of tools using that F-GHG that are feeding to that stack system to the
total number of tools in the fab using that F-GHG. The reporter would
convert the F-GHG emissions to CO2e using the global warming
potential (GWP) values for F-GHG in Table A-1 of subpart A of Part 98.
For F-GHG in Tables I-11 through I-15 for which Table A-1 of subpart A
of Part 98 does not list a GWP value, reporters would use a default
value of 2,000 for the GWP. Based on this preliminary estimate, the
reporter would rank the F-GHG emitting stack systems at the facility
from the lowest to highest emitting. The reporter would not have to
test emissions from low-emitting stack systems, defined as those F-GHG
emitting stack systems meeting all of the following three criteria:
    (1) The sum of the F-GHG emissions from all combined stack systems
in the fab that are not tested is less than 10,000 mtCO2e
per year;
    (2) Each of the stack systems that are not tested are within the
fab's lowest F-GHG emitting stack systems that together emit 15 percent
or less of total CO2e F-GHG emissions from the fab; and
    (3) The F-GHG emissions from each of the stack systems that are not
tested can be attributed to only one particular collection of process
tools during the test (i.e., the stack cannot be used as a bypass from
other tools that are normally vented through a stack system that does
not meet these criteria).
    For those low-emitting stack systems that are not tested, the
reported F-GHG emissions would be the preliminary estimate made using
the gas consumption and the gas utilization rates and by-product
formation rates in proposed Tables I-11 through I-15 in subpart I,
accounting for the DRE and uptime of the POU abatement systems. The
default emission factors in proposed Tables I-11 through I-15 are
simplified default emission factors based on just F-GHG species, and do
not account for different rates by process type or sub-type. This
approach minimizes reporting burden to industry because it does not
require allocation of gas consumption between process types or sub-
types (e.g., etch and chamber clean), as is required for the default
emission factor based method. However, we recognize that there may be a
need for facilities to reconfigure low-emitting stack systems following
testing for production reasons. As a result, we are specifically
requesting comment on how often such stack flow configuration changes
occur. In addition, we are specifically requesting comment on whether
reporters should be allowed to calculate emissions for low-emitting
stack systems that are not tested using average fab-specific emission
factors developed for the stack systems that are tested. We are
specifically requesting comment on how such a provision would affect
emission calculations from differences in gas and process types, and in
DRE abatement system uptime between stack systems that are tested and
stack systems that are not tested.
    Stack testing requirements. For those higher-emitting stack systems
in each fab that are not exempt from measurement, the reporter would
measure each F-GHG concentration (parts per million by volume, ppmv)
and the total stack flow to determine the hourly mass flow rate (kg/hr)
of each F-GHG emitted from each applicable stack system. If a stack
system has more than one stack from a common header, the reporter would
be required to measure F-GHG concentration and flow in each stack from
that header because it is known from prior testing that F-GHG
concentrations and flow rates are not consistent in such systems
because of incomplete mixing. The reporter would use EPA Method 320 or
another validated method to measure F-GHG concentration, and EPA
Methods 1 through 4 at 40 CFR part 60, appendices A-1, A-2, and A-3 to
measure other stack gas parameters needed to convert F-GHG
concentration to mass emissions for the test period. Reporters would
also be required to measure the fab-specific consumption of each F-GHG
for the test period.
    Reporters would be required to determine the F-GHGs expected to be
emitted from the stack system, including by-product F-GHG, based on a
facility analysis of all F-GHGs consumed or emitted in the previous
reporting year, and all F-GHGs expected to be consumed or emitted in
the current reporting year by process tools vented to the stack system.
Documented results of the analysis would be kept as a record by the
facility. The facility would not be required to test for all F-GHG
consumed in the previous year if they are no longer being used, but
only to consider the use of those F-GHG in the analysis of the F-GHG
previously consumed or emitted and expected to be consumed or emitted.
The reporter would also need to consider in the analysis the by-product
gases that are included in Tables I-3 to I-7 that are applicable to the
reporter's industry segment (semiconductors, PV, MEMS, or LCD). Based
on this analysis, reporters would be required to measure emissions for
all F-GHG used as input gases and any expected by-product F-GHG, except
for any intermittent low-use F-GHG. Intermittent low-use F-GHGs would
be defined as F-GHG that meet all of the following:
    (1) The F-GHG is used by the fab but was not used on the day of the
actual stack testing;

    (2) The emissions of that F-GHG do not constitute more than 5
percent of the total annual F-GHG emissions from the fab on a
CO2e basis; and
    (3) The sum of all F-GHG that are considered intermittent low-use
F-GHGs does not exceed 10,000 mtCO2e for that year.
    We are proposing that reporters would specifically test for
CF4 and C2F6 as by-product F-GHG from
all stack systems that are subject to testing. These two F-GHG are
commonly formed by-product gases in the electronics manufacturing
industry from the plasma etch and chamber cleaning process types, and
some may also be formed in the abatement systems.
    We are also considering an option that would require testing for
all F-GHGs that have been identified as by-products of any input gas in
previous testing throughout the electronics industry. This set would
include C3F8, C4F6,
C4F8, and CHF3 in addition to
CF4 and C2F6. We are considering this
option because the identities and quantities of by-products generated
at a particular facility at a particular time can be difficult to
predict, and the costs of testing for additional by-products are
expected to be modest. In the one set of semiconductor facility stack
tests that tested for the full range of potential by-products listed
above, a perfluorocarbon (PFC) by-product was found,
C3F8, which accounted for up to 40 percent of the
GWP-weighted by-product emissions of the fab (and up to two percent of
the total GWP-weighted emissions). If unexpected by-products occur in
similar proportions at other facilities, failing to measure for them
could lead to routine underestimates of emissions at those facilities.
This option is discussed further in the memorandum ``Technical Support
for the Stack Test Option for Estimating Fluorinated Greenhouse Gas
Emissions from Electronics Manufacturing Facilities under Subpart I,''
Docket ID No. EPA-HQ-OAR-2011-0028. We are specifically requesting
comment on the option of requiring facilities to test for the six by-
products listed above.
    Reporters would calculate annual emissions of intermittent low-use
F-GHGs using the gas consumption and the gas utilization rates and by-
product formation rates in proposed Tables I-11 through I-15 in the
rule, accounting for the DRE and uptime of the POU systems during the
year for which emissions are being estimated.
    The testing period would be 8 hours for each stack, with the option
for a longer duration. The EPA understands that a 24-hour testing
duration may be burdensome and may increase testing costs; however,
reporters could elect to conduct longer testing to improve the accuracy
of gas consumption and F-GHG concentration measurements for gases used
in smaller quantities.
    Reporters would not be required to measure all stacks
simultaneously, but reporters would be required to certify there are no
changes between tests in the stack flow configuration (i.e., the
relationship between sets of process tools and any connected POU
systems and their corresponding waste streams that are ultimately
vented through the stack). Reporters would also be required to certify
there are no changes in the centralized abatement systems; if any are
present. The tests would have to be conducted during a period in which
the fab is operating at a representative operating level and with the
POU abatement systems connected to the stack being tested operating
with at least 90 percent uptime during the 8-hour (or longer) period,
or at no less than 90 percent of the average uptime measured during the
previous reporting year. The representative operating level would be
considered to be operating the fab, in terms of substrate starts for
the period of testing, at no less than 50 percent of installed
production capacity or no less than 70 percent of the average
production rate for the reporting year, where production rate for the
reporting year is represented in average monthly substrate starts. For
the purposes of stack testing, the period for determining the
representative operating level must be the 30-day period ending on the
same date on which testing is concluded.
    To convert the measured F-GHG emission rates into fab-specific
emission factors, the reporter would measure the consumption of each F-
GHG used in the tools associated with the stack systems being tested,
excluding gas consumption allocated to tools venting to low-emitting
stack systems that are not tested. Consumption could be measured using
gas flow meters, weigh scales, or pressure measurements (corrected for
temperature and non-ideal gas behavior). For gases with low volume
consumption for which it is infeasible to measure consumption
accurately over the 8-hour testing duration, short-term consumption
could be estimated by using one or more of the following:
    (1) Drawing from single gas containers in cases where gas is
normally drawn from a series of containers supplying a manifold;
    (2) Increasing the length of the test period to greater than 8
hours; or
    (3) Calculating consumption from long-term consumption (e.g.,
monthly) that is pro-rated to the test duration.
    F-GHGs not detected by Method 320. The EPA is proposing that the
concentrations of F-GHG in stacks systems be measured using EPA Method
320. This has been shown to be a valid method for measuring these
target compounds, but it is expected that some F-GHG may occur in
concentrations that are below the field detection limit (FDL), as
defined in EPA Method 320. Therefore, we are proposing that the
following procedures be followed to account for different scenarios in
which a F-GHG is used, but not detected by Method 320 measurements:
     If a F-GHG is consumed during testing, but emissions are
not detected, the reporter would use one-half of the FDL for the
concentration of that F-GHG in calculations.
     If a F-GHG is consumed during testing and detected
intermittently during the test run, the reporter would use the detected
concentration for the value of that F-GHG when available and use one-
half of the FDL for the value when the F-GHG is not detected.
     If a F-GHG is not consumed during testing but is detected
intermittently as a by-product gas, the reporter would use the measured
concentration when available and use one-half of the FDL for the value
when the F-GHG is not detected.
     If a F-GHG is an expected by-product gas (e.g.,
CF4, C2F6, and other gases listed as
by-products in Tables I-3, I-4, I-5, I-6, I-7, and proposed Tables I-11
to I-15) of the stack system tested and is not detected during the test
run, use one-half of the FDL for the value of that F-GHG.
     If a F-GHG is not used, and is not an expected by-product
of the stack system and is not detected, then assume zero emissions for
that F-GHG for the tested stack system.
    We are specifically requesting comment on the option of listing
specific by-product gases as ``expected'' to be emitted even when they
are not detected. Based on a review of the default emission factor
tables listed above, CF4 and C2F6 are
almost always generated as by-products (that is, they are generated by
a wide range of process types and input gases), and CHF3 is
frequently generated. Other by-products appear to be generated less
frequently. Thus, it may be appropriate to specify CF4 and
C2F6, and possibly also CHF3, as the
set of by-products for which a value of one half of the FDL should be
assumed in calculating emissions during the test. This approach would
simplify the rule, provide certainty for purposes of implementation,
and relieve facilities of the burden of determining

which by-products are ``expected'' to be emitted.
    EPA Method 320 requires the specification of maximum FDLs because
the FDLs achieved by a method and detector can have a significant
impact on the quality of the measurements. For example, if the FDL for
a F-GHG were so high that large emissions of that GHG were never
detected, the uncertainty of the resulting emissions estimate (i.e.,
one-half the FDL), would be correspondingly high. The EPA is proposing
maximum FDLs based on (1) review of the FDLs that have been achieved at
three different semiconductor facilities, and (2) analysis of the
magnitude of the emissions that would occur (in CO2e) at
various possible maximum FDLs. The latter provides an indication of the
uncertainty of emissions measurements using methods and detectors with
those FDLs. The proposed maximum FDLs can be found in proposed Table I-
10 of the regulatory text.
    The EPA expects that the proposed treatment of these non-detect
values using one-half of the FDL will avoid any potential under-
counting of any F-GHGs that are expected to be in the emissions from a
given process and F-GHG input gas combination. At the same time, the
proposed treatment will provide a reasonable estimate of emissions of
F-GHGs that occur in concentrations that are below the FDL. The EPA's
analysis of testing data provided by the Petitioner has shown that
emission measurements of gases known to be used and for which the
concentration was below the FDL accounted for about 0.1 percent of F-
GHG consumption and would account for about 0.1 percent of emissions on
a CO2e basis if the concentration was assumed to be one-half
of the FDL as outlined in this section (see ``Technical Support for the
Stack Test Option for Estimating Fluorinated Greenhouse Gas Emissions
from Electronics Manufacturing Facilities under Subpart I,'' Docket ID
No. EPA-HQ-OAR-2011-0028).
    Alternative stack test methods. To provide flexibility for
facilities utilizing the stack test option, we are proposing that
reporters may use an alternative stack test method to measure the
concentration of F-GHG in each stack provided that the method is
validated using EPA Method 301 of 40 CFR part 63, appendix A (hereafter
``EPA Method 301''), and the EPA approves its use.
    Under the proposed approval process in 40 CFR 98.94(k), the
reporter would be required to notify the Administrator of the intent to
use an alternative test method. The notification would need to include
a test plan describing the alternative method and procedures, the range
of test conditions over which the validation is intended to be
applicable, and also an alternative means of calculating the fab-level
F-GHG emissions if the Administrator denies the use of the results of
the alternative method. The reporter would be required to validate the
alternative method using EPA Method 301 and submit the results of the
Method 301 validation process along with the notification of intention
and a rationale for not using the specified method.
    The Administrator would review and determine whether the validation
of the proposed alternative method is adequate and issue an approval or
disapproval of the alternative test plan within 120 days of the
reporter submitting the notification and test plan. The reporter would
be required to respond to any of the Administrator's questions on the
test plan before obtaining approval and take into account the
Administrator's comments on the test plan in conducting the test using
the alternative method. The reporter would be required to respond to
the Administrator's questions or request for additional information on
the plan during the 120-day review period and the Administrator's
questions or request for additional information would not extend that
review period. Therefore, it would be the reporter's obligation to
respond in a timely manner. If an alternative test plan were not
approved, a reporter would need to begin the process to have an
alternative test method approved starting with the notification of
intent to use an alternative test method.
    The reporter would report the results of stack testing using the
alternative method and procedure specified in the approved test plan.
The report would include all methods, calculations and data used to
determine F-GHG emissions. The Administrator would review the results
of the test using the alternative methods and procedure and then
approve or deny the use of the results of the alternative test method
and procedure no later than 120 days after they are submitted to the
EPA. During this 120-day period, the reporter would be required to
respond to any of the Administrator's questions on the test report
before obtaining approval of the final test results using the
alternative method. If the Administrator were to find reasonable
grounds to dispute the results obtained by the alternative method, the
Administrator could require the use of the method specified in subpart
I instead of the alternative method.
    Once the Administrator approved the use of the alternative method,
that method could be used by any other facility for the same F-GHGs and
types of stack systems, if the approved conditions apply to that
facility. In granting approval, the Administrator would limit the range
of test conditions and emission characteristics for which that approval
is granted and under which the alternative method could be used without
seeking further approval. The Administrator would specify those
limitations, if any, in the approval of the alternative method.
    Accounting for Abatement System Downtime. To account for the effect
of POU abatement system downtime in estimating emissions using the
stack testing method, reporters would record the abatement system
downtime in each fab during testing and for the entire reporting year.
Using the downtime measured during testing, the reporters would correct
the measured emission factors to assume no abatement system downtime
(i.e., 100 percent abatement system uptime). The downtime measured over
the entire reporting year would be used to calculate the excess F-GHG
emissions that occur as a result of abatement system downtime events.
    The reporter would measure the amount of POU abatement system
downtime (in minutes) during the emission tests for any tools that are
vented to the stacks being tested. For example, if five POU abatement
systems are down for times of 10, 15, 25, 30, and 40 minutes during an
8-hour test, the total POU system downtime would be 120 minutes, or 5.0
percent of the total possible abatement system and tool operating time
for the five tools (2,400 minutes). Using these data and the average
DRE for the POU abatement systems, the emission factor measured during
the testing would be adjusted to an emission factor representing POU
abatement systems with 100 percent uptime (zero percent downtime).
    The downtime measured over the year would be used to determine an
uptime factor that would be an aggregate for all abatement systems in
the fab, and calculated using proposed Equation I-23 in subpart I.
Abatement system downtime would be considered any time during which the
abatement system was not operating according to the manufacturer's
specifications. The reporter would determine the sum of the downtime
for all abatement systems during the year, and divide this sum by the
sum of the possible annual operating time for each of the tools
connected to those abatement systems in the fab to determine the
downtime fraction. The downtime fraction would be the

decimal fraction of operating time that the abatement systems were not
operating according to the manufacturer's specifications. The uptime
fraction used in the emissions calculations would be equal to 1 minus
the downtime fraction.
    The total possible annual tool operating time would be calculated
by assuming that tools that were installed for the whole of the year
were operated for the entire year. The total possible tool operating
time would be prorated to account for the days in which a tool was not
installed; any partial day that a tool was installed would be treated
as a full day of tool operation. For an abatement system with more than
one connected tool, the tool operating time would be equivalent to a
full year if at least one tool was installed at all times throughout
the year. The reporter would also be able to account for time that
tools are idle and no gas is flowing through the tools to the abatement
system.
    It is important to note that the proposed calculation of the uptime
factor is different when a reporter would be using the proposed stack
testing method than when the reporter would be using the default gas
utilization rate and by-product formation rate method. In the proposed
stack testing method, the uptime would not be determined for each gas
and process type combination, as it would be under the proposed
revisions to the default emission factor method. Instead, the uptime
factor would be based on an aggregate for all tools in the fab for
which the stack testing method is being used. This aggregate method is
possible because the emissions measured at the stack already account
for the fact that the emissions have been abated, and the uptime factor
is only needed to account for the relatively small percent of time that
the abatement systems are not operating and excess emissions need to be
calculated. In contrast, the default gas utilization rates and by-
product formation rates in the current rule and in the proposed
amendments are for ``unabated emissions'' and the uptime factor needs
to be determined for each gas and process type combination to determine
the relatively large percent of emissions that have been abated.
    To calculate an unabated emission factor during periods of downtime
in the stack testing method, the reporter would divide the abated
emission factor by (1-dif), where dif is the average weighted fraction
of F-GHG i destroyed or removed in the POU abatement system(s) in the
fab. The factor dif would be calculated using proposed Equation I-24 in
subpart I, based on the gas consumption and destruction and removal
efficiency (DRE) for the abatement system(s) for each gas and process
type combination.
    When calculating annual emissions, the reporter would continue to
collect abatement system downtime data and calculate the fraction of
abatement system uptime for the fab. Excess emissions from abatement
system downtime events would be determined based on the actual amount
of downtime as a percent of the total annual abatement system operating
time for the reporting year. If a fab had 2.0 percent downtime for the
year, then the unabated emission factor would be applied to 2.0 percent
of the gas consumption for the year to calculate the excess emissions.
The abated emission factor would be applied to the other 98 percent of
gas consumption for the fab. The excess emissions and the abated
emissions would be added together to determine the total annual
emission from the fab.
    Calculating an average fab-specific emission factor. The reporter
would calculate an average fab-specific emission factor using proposed
Equation I-19 in subpart I for each input F-GHG and proposed Equation
I-20 for each by-product F-GHG, based on the testing results (average
kg/hr) and the F-GHG gas consumption (average kg/hr). The fab-specific
emission factor for each input F-GHG and each F-GHG formed as a by-
product would take into account the mass emission rate, the gas
consumption, the abatement system uptime, and the F-GHG destroyed or
removed from the abatement systems. The fab-specific emission factor
for input gases would be in units of kg gas emitted per kg of the same
gas consumed (kg/kg).
    For gases generated as by-products, we are proposing that the fab-
specific emission factor would be the mass of the by-product emitted
divided by the summed masses of all the F-GHGs consumed, as presented
in proposed Equation I-20. This equation would apply to those F-GHGs
that are emitted only as by-products and not consumed as input gases.
    The reporter would calculate annual emissions for each F-GHG by-
product gas as the product of the fab-specific emission factor and the
total annual amount of F-GHG consumed, corrected for any POU abatement
system downtime as described in this section of the preamble.
    In some cases, emissions of a particular F-GHG input gas may exceed
consumption of that gas because the F-GHG is generated as a by-product
of the other input gases. This is often the case for CF4. In
these cases, we are proposing that the reporter use 1.0 as the input F-
GHG emission factor and treat the remainder of that F-GHG's emissions
as a by-product of the other input gases. The reporter would use
Equation I-20 to calculate the emission factor for the by-product
emissions. For example, if during the testing, the fab consumed 100 kg
of an F-GHG, but the stack testing measured 300 kg of that gas, the
reporter would assign 100 kg of that F-GHG as an input gas used in
proposed Equation I-19, and 200 kg of that gas as a by-product gas used
in proposed Equation I-20. In this instance, we are also proposing that
the denominator in Equation I-20 would include the consumption of all
other F-GHGs, with the exception of the F-GHG being included in the
numerator. This treatment of the denominator reflects the fact that we
are assuming that the F-GHG in the numerator is formed as a by-product
from all other F-GHGs, while the emissions from the actual consumption
of that F-GHG as an input are being accounted by proposed Equation I-
19. For calculating emissions from an F-GHG with an input emission
factor equal to 1.0 and with a by-product emission factor, the input F-
GHG emissions would be assumed to equal consumption of that F-GHG, and
the by-product emissions would be determined by multiplying the by-
product emission factor by the sum of the consumption of all F-GHGs
excluding the by-product F-GHG.
    The advantage of this approach is that it reflects the physical
mechanism through which emissions of an input gas exceed consumption of
that gas. Because mass is conserved, the emissions of an input gas that
are in excess of consumption of that gas must be attributable to the
other input gases. These ``excess'' emissions are expected to vary with
the facility's consumption of the other input gases rather than with
the facility's consumption of the ``excessively'' emitted gas.
Reflecting this in the by-product emission factor will lead to more
accurate emission estimates and will help to prevent large swings in
emission factors that could result when consumption of the
``excessively'' emitted gas varies from test to test. For example, this
could help a facility to avoid a 20 percent or greater relative
standard deviation in its CF4 emission factor, which would
otherwise prevent the facility from qualifying to skip testing for five
years (see ``Testing frequency'' in Section III.B.1 of this preamble).
    Note that the proposed approach includes a simplification that
would in some cases affect the ``extra'' emissions

that are reassigned as by-products of other input gases. This
simplification, and its potential impacts are discussed in more detail
in the document entitled ``Technical Support for the Stack Test Option
for Estimating Fluorinated Greenhouse Gas Emissions from Electronics
Manufacturing Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-
2011-0028. Although we expect that the effect of this simplification
will generally be small, we are specifically requesting comment on the
simplification.
    We are also specifically seeking comment on the proposed treatment
of F-GHGs whose emissions exceed consumption, and comment on which F-
GHG should be included in the denominator of proposed Equation I-20 for
calculating the emission factor for by-product F-GHG. The currently
proposed equation includes all F-GHG used in the fab in the denominator
for the calculation of all by-product F-GHGs, except when the emission
factor for an input F-GHG exceeds 1.0. If the emission factor for a F-
GHG exceeds 1.0, the emissions greater than 1.0 would be assumed to be
by-product F-GHG instead of un-utilized input F-GHG. This proposed
approach is based on the assumption that all F-GHG used as inputs could
be contributors of fluoride (F) atoms that could be involved in the
formation of F-GHG by-product gases, which are primarily carbon
containing F-GHG, even if those input F-GHG do not contain carbon, such
as SF6 or NF3. An alternative approach on which
the EPA is seeking comment is not to include in the denominator
SF6, NF3, and other F-GHG that do not contain
carbon (C) atoms, assuming that they are less involved in the formation
of carbon containing by-product F-GHG than the F-GHG used as inputs
that contain carbon.
    Testing frequency. Based on the potential for multiple process
changes and numerous R&D activities that may affect emissions at an
individual facility, as discussed in the Petition for Reconsideration,
the EPA is proposing in 40 CFR 98.94(j)(5)(i) to require annual testing
of each stack system and annual calculation of emission factors,
excluding those low-emitting stack systems that are exempt from
testing. However, to offer flexibility, the EPA is also proposing in 40
CFR 98.94(j)(5)(ii) to allow reduced testing frequency based on
variability in measured emission factors. If the reporter meets
criteria for low measured variability in emission factors calculated
from the test results, then testing frequency could be reduced to every
5 years instead of annually. Under this option, a reporter would
conduct a minimum of three emission tests for each non-exempt stack,
with at least 2 months between the tests on a single stack system. All
tests could be done in one year, or the reporter could use three annual
tests for this analysis. If the relative standard deviation (RSD) of
the emission factors calculated from each of the three tests, expressed
as CO2e for all F-GHG combined, was less than or equal to 15
percent, and the RSD of the emission factors for each single F-GHG that
individually accounts for 5 percent or more of CO2e
emissions was less than 20 percent, the facility could use the averages
of the three emission factors for each F-GHG for annual reporting for
that year and the next 4 years without testing, unless conditions
change that affect the emission factors and trigger retesting, as
specified in proposed 40 CFR 98.94(j)(8) and described in this section
of the preamble. If the variability between the three tests did not
meet these criteria, then the facility would use the emission factors
from the most recent testing for reporting for that year and continue
the annual testing. Facilities could repeat the RSD analysis each year
using the previous three sets of data. We anticipate that this
provision will provide additional incentive for careful measurements of
emissions and gas consumption during each stack test to maximize the
repeatability of the results in subsequent tests.
    In addition, previously completed tests that were performed and
verified according to EPA Method 320 or an alternative method validated
using EPA Method 301 could be applied towards the three tests required
under this option, as long as all three tests were completed no earlier
than the date 3 years before the date of publication of the final rule
amendments and they meet the final rule requirements for stack testing,
which are being proposed under 40 CFR 98.94(j). Allowing facilities to
use prior completed tests would allow them to use data that were
collected in support of developing this proposed stack testing option,
and in support of developing the revised default gas utilization rates
and by-product formation rates that are also being proposed in this
action. The reporter would be required to conduct testing of each stack
system, regardless of the results of the most recent stack tests, if
certain changes take place in the reporter's annual consumption of F-
GHGs or in the equipment and processes at the fab. Testing would need
to be repeated to develop a new fab-specific emission factor if
consumption of a specific input gas used during the emissions test
changes by more than 10 percent of total annual gas consumption in
CO2e, relative to gas consumption in CO2e for
that gas during the year in which the most recent emissions test was
conducted. For example, if use of a single gas goes from 25 percent of
CO2e to more than 35 percent of CO2e, that would
trigger the need for a new test. If there is a change in the reporter's
use of an intermittent low-use F-GHG that was not used during the
emissions test and not reflected in the fab-specific emission factor,
such that it no longer meets the proposed definition of intermittent
low-use F-GHG (see ``Stack testing requirements'' in Section III.B.1 of
this preamble), the reporter would also be required to re-test using
that gas. Additionally, if there is: (1) A decrease by more than 10
percent in the fraction of tools with abatement systems, compared to
the fraction of tools with abatement systems during the most recent
emissions test; (2) a change in the wafer or substrate size used by the
fab since the most recent emissions test; or (3) a change in a stack
system that formerly met the criteria for not being subject to testing
such that it no longer meets those criteria, then the reporter would
also be required to re-test.
    Finally, if a reporter is using a F-GHG that was not used during
the emissions test, the reporter would be required to conduct
additional stack tests in that year during a period when that gas is
being used to determine an emission factor for that gas. If a F-GHG is
no longer used or is an intermittent low-use gas, re-testing would not
be required, and F-GHG emissions would be calculated according to the
process for intermittent low-use gases.
    The EPA is specifically soliciting comment on other changes that
may occur at a fab, including the adoption of specific new process
technologies that should be included in the list of activities that
would be expected to affect emissions to the point that those changes
should require a fab to retest the stacks to develop new emission
factors.
    As stacks are re-tested, reporters would update the fab-specific
emission factors with the new data from those stacks, replacing the
data from the earlier testing of the same stack. The reporters would
also be required to annually review the current data for determining
which stacks were exempt from testing to ensure that the low-emitting
stacks still qualify for exemption. If a stack no longer meets the
criteria for exemption from testing as a low-emitting stack, it would
need

to be tested and the fab-specific emission factor would need to be
recalculated including those data. This provision would ensure that the
fab-specific emission factors determined through testing are based on
approximately 85 percent of the F-GHG consumed in the fab on a
CO2e basis. Finally, if a requirement to re-test stacks were
triggered, facilities would also be required to re-evaluate the RSD of
the emission factors including the most recent test results and the
previous two test results to see if they still complied with the
provisions that allow them to skip testing. If they did not meet those
provisions, they would have to resume annual testing for at least the
next 3 years to complete a new RSD analysis. Even if they met those
requirements, they still would be required to resume annual testing no
later than the fifth year after the original RSD analysis that was
performed before the retesting requirement was triggered.
    We specifically request comment on the proposed option to allow
less frequent emission testing (i.e., the 5-year testing exemption).
Commenters are encouraged to supply rationale and any available data in
support of submitted comments.
2. Revise the Default Gas Utilization Rates and By-Product Formation
Rates for the Plasma Etch Process Category for Facilities That
Manufacture Semiconductors
    The EPA is proposing to amend the default plasma etch and chamber
cleaning gas utilization rates and by-product formation rates and the
requirements in 40 CFR 98.93(a)(2) for estimating F-GHG emissions from
plasma etch processes at semiconductor manufacturing facilities. The
EPA is not proposing to amend the default emission factors for other
types of electronics manufacturing facilities. As discussed in this
section of this preamble, the current provisions allow certain
facilities the option to use default plasma etch and chamber cleaning
rates based on wafer size, gas input, and process type/sub-type. The
default emission factors are based on two different wafer size classes
(one set of default emission factors for both 150 mm and 200 mm wafers
combined, and a second set of default emission factors for 300 mm
wafers) and five process types/sub-types (plasma etching; chamber
cleaning including in situ plasma cleaning, remote plasma cleaning, in
situ thermal cleaning; and wafer cleaning).
    As discussed in this section of this preamble, following the
promulgation of the final subpart I rule, the Petitioner submitted
additional utilization and by-product formation data for various size
wafers (200 mm and 300 mm) from semiconductor manufacturing facilities.
The Petitioner requested that the EPA consider revising the default gas
utilization rates and by-product formation rates based on gas input,
process type, and wafer size. They also requested that the rule be
revised to allow all semiconductor manufacturing facilities to use the
revised default emission factors in lieu of requiring certain
manufacturers to develop recipe-specific utilization rates and by-
product formation rates (see ``Technical Support for Modifications to
the Fluorinated Greenhouse Gas Emission Estimation Method Option for
Semiconductor Facilities under Subpart I,'' Docket ID. No EPA-HQ-OAR-
2011-0028).
    The Petitioner, in documents submitted to the EPA after the
Petition for Reconsideration, also questioned the EPA's establishment
of separate default gas utilization rates and by-product formation
rates for the wafer cleaning process type in the final subpart I rule.
The Petitioner stated that the wafer cleaning process represents a very
small fraction of overall semiconductor manufacturing GHG consumption
and emissions. At 12 facilities analyzed by the Petitioner, wafer
cleaning represented 1 percent or less of the gas used at each
facility. The Petitioner also noted that wafer cleaning is basically
the same process as the wafer plasma etch process (see ``Technical
Support for Modifications to the Fluorinated Greenhouse Gas Emission
Estimation Method Option for Semiconductor Facilities under Subpart
I,'' Docket ID No. EPA-HQ-OAR-2011-0028). Plasma etching is defined in
40 CFR 98.98 as ``a process type that consists of any production
process using fluorinated GHG reagents to selectively remove materials
from a substrate during electronics manufacturing.'' Wafer cleaning is
defined in 40 CFR 98.98 as ``a process type that consists of any
production process using fluorinated GHG reagents to clean wafers at
any step during production.'' The Petitioner stated in documents
submitted to the EPA that the tools specifically designated for wafer
cleaning are using the same gases in plasma to remove materials as used
in the tools designated for plasma etching. The Petitioner also noted
that the gas utilization rates for wafer cleaning and plasma etching in
subpart I are similar for the four gases most commonly used in both
plasma etch and wafer cleaning (CF4,
CH2F2, NF3, and SF6),
especially for SF6 and CF4. The Petitioner also
provided additional data to support their recommendation to combine the
wafer cleaning process type with the plasma etch process type (see
``Technical Support for Modifications to the Fluorinated Greenhouse Gas
Emission Estimation Method Option for Semiconductor Facilities under
Subpart I,'' Docket ID No. EPA-HQ-OAR-2011-0028).
    In response to the concerns raised in the Petition for
Reconsideration about the recipe-specific measurements, the EPA is
proposing to amend the default utilization and by-product formation
rates for the semiconductor manufacturing industry. Based on the
amendments in the September 27, 2011 final rule titled ``Changes to
Provisions for Electronics Manufacturing to Provide Flexibility,'' the
larger semiconductor facilities that manufacture wafers measuring 300
mm or less may use the default utilization and by-product formation
rates currently in subpart I to estimate emissions, instead of the
recipe-specific method that would have otherwise been required, only
through December 31, 2013.
    First, the EPA is proposing that all semiconductor manufacturing
facilities, regardless of manufacturing capacity, would have the option
to calculate F-GHG emissions from the plasma etching process type using
the appropriate default gas utilization rates and by-product formation
rates provided in Tables I-3 and I-4 of subpart I. We would no longer
distinguish between ``large'' and ``other'' semiconductor manufacturing
facilities based on the calculated annual manufacturing capacity. That
distinction exists in the current subpart I because the EPA chose not
to require the recipe-specific method for the ``other'' semiconductor
manufacturing facilities. However, the calculation methods we are
proposing in today's action would apply to all semiconductor
manufacturing facilities. Under this proposal, no electronics
manufacturing facility would have the option to determine and use
recipe-specific gas utilization rates and by-product formation rates
for the plasma etch process type, as described in Section III.B.3 of
this preamble. The EPA is proposing to remove the distinction between
large and other semiconductor facilities, such that all semiconductor
manufacturing facilities could use the default gas utilization rates
and by-product formation rates, independent of facility size. The EPA
had required only the largest semiconductor manufacturing facilities to
use the recipe-specific plasma etch method to ensure that smaller
facilities

had a lower burden consistent with their lower expected F-GHG
emissions. However, in proposing to remove the recipe-specific plasma
etch method, the burden on the largest facilities would be reduced
significantly and would eliminate the need to distinguish between
``large'' and ``other'' semiconductor manufacturing facilities.
    Second, we are proposing to revise the default emission factors for
the plasma etch process type in Tables I-3 and I-4 of subpart I. The
proposed revised default emission factors are based on an expanded data
set provided to the EPA by semiconductor manufacturing facilities after
subpart I was originally promulgated in December 2010. The data were
provided to the EPA in support of the Petitioner's request to develop
alternatives to the recipe-specific method. The proposed revised plasma
etch default emission factors are based on 976 data records
(representing additional data submitted after December 1, 2010; see the
EPA's analysis in ``Technical Support for Modifications to the
Fluorinated Greenhouse Gas Emission Estimation Method Option for
Semiconductor Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-
2011-0028), whereas the plasma etch default emission factors in the
final subpart I are based on 93 records. As in the final rule, the
proposed plasma etch default emission factors were developed using data
characterizing un-abated emissions for specific process equipment that
follows a version of the International SEMATECH Manufacturing
Initiative (ISMI) measurement guidelines. Because the set of tool
manufacturers and processes included in the 976 data records is larger
than that included in the 93 records, the proposed revised plasma etch
default emission factors are expected to be more representative of the
F-GHG emitting processes and tools than the default emission factors in
the final subpart I rule promulgated in December 2010. However, please
see the ``Technical Support for Modifications to the Fluorinated
Greenhouse Gas Emission Estimation Method Option for Semiconductor
Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-2011-0028, for
more discussion of this issue and of the estimated uncertainty
associated with the use of the default emission factor approach.
    In developing the proposed revised default emission factors for the
plasma etch process type in semiconductor manufacturing, the EPA
considered alternatives that would reduce the burden compared to the
recipe-specific approach in the current rule, while still providing F-
GHG emission estimates with generally acceptable uncertainty.\2\ The
EPA considered including film type as a variable in the tables of
default emission factors for the plasma etch process type, in addition
to the input gas type and wafer size. However, based on the EPA and the
Petitioner's analysis of the available data, the EPA determined that
including film type would provide only a marginal improvement (about 4
percent) in the uncertainty of the emission estimates, but it would
also introduce a potential for error because F-GHG consumption would
need to be apportioned to plasma etch processes based on the film type
being etched. The potential error introduced by apportioning F-GHG
consumption by film type would offset the reduction in uncertainty by
including the film type. In addition, including film type would also
increase the burden associated with this approach because facilities
would need to apportion gas consumption by film type. The EPA also
considered establishing default emission factors for different sub-
types of the plasma etch process type. However, based on an analysis of
the available data, no difference in default emission factors could be
accurately determined for any identifiable sub-type of the plasma etch
process type. Based on these findings, the EPA concluded that including
only input F-GHG type and wafer size in the default emission factors
for the plasma etch process type would achieve the best balance between
the burden and uncertainty in estimating F-GHG emissions from the
plasma etch process type. (See ``Technical Support for Modifications to
the Fluorinated Greenhouse Gas Emission Estimation Method Option for
Semiconductor Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-
2011-0028.)
---------------------------------------------------------------------------

    \2\ The EPA performed an uncertainty analysis that found that,
depending on the wafer size and gas usage patterns of the fab, the
default emission factor approach would result in estimates with
uncertainties between approximately 10 and 40 percent; see
``Technical Support for Modifications to the Fluorinated Greenhouse
Gas Emission Estimation Method Option for Semiconductor Facilities
under Subpart I,'' Docket ID No. EPA-HQ-OAR-2011-0028.
---------------------------------------------------------------------------

    The EPA also considered two averaging conventions in developing the
proposed revised default by-product emission factors for etch process
input F-GHG for multi-gas processes. The first convention used the
simple arithmetic mean of all available by-product emission factor data
where a non-zero measurement was recorded. This method averaged all
available non-zero by-product emission factor data (by by-product) for
each gas, wafer size, process type or sub-type combination. This
approach is appropriate if zeros indicate that a by-product was not
looked for during the test.
    The second convention used the simple arithmetic mean of all
available by-product emission factor data, but included the use of
zeros when by-product emissions were not recorded. This method averaged
all available by-product emissions factor data (by by-product)
including records that did not indicate by-product emissions (zeros)
for each gas, wafer size, process type or sub-type combination. This
approach is appropriate if zeros indicate that a by-product was looked
for during the test, but was not detected.
    The EPA compared the resulting by-product emission factors from
using both averaging conventions. The comparison showed that including
versus not including the zeros for cases where no detected by-product
was reported resulted, on average, in a 38 to 45 percent difference in
the by-product emission factors (see ``Technical Support for
Modifications to the Fluorinated Greenhouse Gas Emission Estimation
Method Option for Semiconductor Facilities Under Subpart I,'' Docket ID
No. EPA-HQ-OAR-2011-0028).
    Because the EPA was not certain whether zeros indicate that
particular by-products were not looked for or whether they were looked
for but not detected, we are conservatively proposing by-product
emission factors that do not include zeros. We specifically request
comment on whether and to what extent zeros in the emission factor data
indicate that a by-product was looked for, but not detected. We also
specifically request comment on what the detection limits were for such
by-products. To the extent that zeros represent instances where a by-
product was looked for, but not detected, we recognize that not
including zeros in the by-product emission factor development may
result in overstating by-product emissions. Therefore, we are
specifically requesting comment on the method for averaging the
available by-product emission factor data to determine the default by-
product emission factors.
    Third, the EPA is proposing to revise the default by-product
formation rates for the chamber cleaning process type/sub-types in
Tables I-3 and I-4 of subpart I. In developing the proposed default
utilization and by-product emission factors for etch processes, the EPA
also reviewed emissions from chamber cleaning processes for
completeness. The EPA did not receive new data to support revised
default

utilization rates for the chamber cleaning process type/sub-types
established in the final subpart I rule. However, the EPA evaluated the
averaging conventions used to develop the proposed revised default by-
product emission factors for etch processes for use in developing
default by-product emission factors for the chamber cleaning process
type/sub-types. Using data from the final subpart I rule, the EPA
analyzed the emission estimates from chamber cleaning process type/sub-
types using the two averaging conventions described in this section of
this preamble. Again, for simplicity, we are proposing to not include
zeros for the development of by-product emission factors. As with the
proposed revised default etch emission factors, the averaging
comparison showed that including versus not including the zeros for
cases where no detected by-product was reported could result in
overstating by-product emissions. Therefore, we are proposing to follow
the same averaging convention for chamber cleaning process type/sub-
types. The revised default by-product formation rates for the chamber
cleaning process type/sub-types in Tables I-3 and I-4 of subpart I
reflect the simple arithmetic mean of the available by-product emission
factor data, without the use of zeros. As for the revised default etch
emission factors, we are specifically seeking comment on the method for
averaging the available by-product emission factor data to determine
the default by-product emission factors for chamber cleaning process
type/sub-types.
    Finally, the EPA is proposing to combine the semiconductor wafer
cleaning process type with the plasma etch process type; the amended
rule would not have separate default emission factors for semiconductor
wafer cleaning in the revised Table I-3 and I-4 of subpart I. The EPA
has reviewed the available data (see ``Technical Support for
Modifications to the Fluorinated Greenhouse Gas Emission Estimation
Method Option for Semiconductor Facilities under Subpart I,'' Docket ID
No. EPA-HQ-OAR-2011-0028), and believes that it is appropriate to
combine these process types. The same gases are used for plasma etch
and wafer clean, with similar gas utilization rates and by-product
formation rates, and the wafer clean process represents 1 percent or
less of gas consumption at a typical facility. Furthermore, the burden
associated with apportioning gas consumption to the various process
types is expected to be reduced by combining the wafer cleaning and the
plasma etch process types because some gases used for wafer cleaning
are also used in etching processes.
    For the chamber clean process type, we are not proposing any
changes to the three chamber clean sub-types. Under the revised default
emission factors, semiconductor manufacturing facilities would estimate
emissions from chamber clean and plasma etch processes using the
following four process types/sub-types: (1) Plasma etch/wafer cleaning
process type; and (2) chamber cleaning process type, including (2a) in
situ plasma chamber cleaning; (2b) remote plasma chamber cleaning; and
(2c) in situ thermal chamber cleaning.
    If gas utilization rates and by-product formation rates are not
available for a gas/process combination in Tables I-3 or I-4 of subpart
I, we are proposing that reporters would assume that the utilization
and by-product formation rates are zero (i.e., assume that emissions of
a gas equal consumption of that gas). This approach is consistent with
the methodology in the current subpart I rule, except that we are
proposing to remove the option for facilities to develop recipe-
specific factors.
    All other provisions related to the method using default gas
utilization rates and by-product formation rates, such as the wafer
size classes used for the default emission factors in Tables I-3 and I-
4, would remain the same. The only exception would be that the default
emission factors in Table I-4 that apply to 300 mm wafers would also
apply to wafers greater than 300 mm (e.g., 450 mm wafers). As more data
(i.e., utilization and by-product formation rates) become available for
the semiconductor manufacturing industry in the future, the EPA would
consider adding new default emission factors to Tables I-3 and I-4 for
new gas and process type/sub-type combinations, including adding any
new default emission factors specifically for semiconductor
manufacturing facilities using wafers greater than 300 mm diameter
(e.g., 450 mm wafers). However, for this proposal, facilities using
wafers greater than 300 mm diameter would use the same default emission
factors as those using 300 mm wafers. Section III.B.12 of this preamble
describes the proposed process for updating default emission factors as
more information is collected from the electronics manufacturing
industry.
    We request comment on whether new data are available for gas
utilization and by-product formation rates for any of the process types
or sub-types in the semiconductor manufacturing industry that could be
used to further update the default emission factors for semiconductor
manufacturing. Commenters are encouraged to submit available data with
their comments using the ``Electronics Manufacturing Data Request
Sheet'' (see Docket ID No. EPA-HQ-OAR-2011-0028). Commenters can fill
out the ``Electronics Manufacturing Data Request Sheet'' and submit the
data to Docket ID No. EPA-HQ-OAR-2011-0028 for consideration by the EPA
on whether to update the proposed default emission factors for
semiconductor manufacturing. If the EPA does update the proposed
default emission factors using such new data, if approved by the EPA,
for the final rule, it will do so using the same methodologies as
described in the ``Technical Support for Modifications to the
Fluorinated Greenhouse Gas Emission Estimation Method Option for
Semiconductor Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-
2011-0028). The EPA will use the same criteria for accepting new data
that were used in accepting data as specified in that document.
    The EPA has not developed any specific changes to the default gas
utilization rates and by-product formation rates for MEMS, LCD, and PV
in Tables I-5 (MEMS), I-6 (LCD), and I-7 (PV) of subpart I because we
have not received any new utilization and by-product formation rate
data. However, we request comment on whether new data are available to
update the default emission factors for the facilities that manufacture
MEMS, LCD, or PV cells; commenters are encouraged to submit available
data and supporting information with their comments using the
``Electronics Manufacturing Data Request Sheet'' (see Docket ID No.
EPA-HQ-OAR-2011-0028). Commenters can fill out the ``Electronics
Manufacturing Data Request Sheet'' and submit the data to Docket ID No.
EPA-HQ-OAR-2011-0028 for consideration by the EPA on whether to update
the default emission factors for MEMS, LCD, or PV manufacturing. If the
EPA does update the default emission factors using such new data, if
approved by the EPA, it will do so using the same methodologies as
described in the ``Technical Support for Modifications to the
Fluorinated Greenhouse Gas Emission Estimation Method Option for
Semiconductor Facilities under Subpart I,'' Docket ID No. EPA-HQ-OAR-
2011-0028). The EPA will use the same criteria for accepting new data
that were used in accepting data as specified in that document.

3. Removing the Provisions for Using Recipe-Specific Gas Utilization
Rates and By-Product Formation Rates for Facilities That Manufacture
Electronics
    The EPA is proposing to remove the provisions to use recipe-
specific gas utilization rates and by-product formation rates in 40 CFR
98.93(a)(2)(ii)(A), (a)(3), and (a)(4). Under 40 CFR 98.93(a)(2)(ii)(A)
of the final subpart I rule, semiconductor manufacturing facilities
with an annual manufacturing capacity greater than 10,500 square meters
of substrate per year manufacturing wafers with a diameter of 300 mm or
less were required to use recipe-specific gas utilization rates and by-
product formation rates to estimate emissions for the plasma etch
process. However, the September 27, 2011 final rule titled ``Changes to
Provisions for Electronics Manufacturing to Provide Flexibility''
provided these facilities the option to use the default emission
factors in lieu of recipe-specific rates for emissions estimated for
the 2011, 2012, and 2013 reporting years. Under the current provisions
(40 CFR 98.93(a)(3)), all electronics manufacturing facilities
(including PV, MEMS, LCD, and semiconductor manufacturers) are given
the option to estimate their F-GHG emissions using recipe-specific
rates. Under 40 CFR 98.93(a)(4), semiconductor manufacturers are
required to use recipe-specific rates for all F-GHG processes if
manufacturing on wafers that are greater than 300 mm in diameter.
    After subpart I was promulgated on December 1, 2010 (75 FR 75774),
the Petitioner requested the EPA to reconsider and remove the
requirement to develop and use recipe-specific gas utilization rates
and by-product formation rates for certain semiconductor manufacturing
processes and facilities. The Petitioner cited three primary concerns
with using recipe-specific rates in place of other methods:
     The technical burden of determining rates for numerous
recipes used at a facility, which could number in the hundreds.
     The technical and logistical burden of tracking gas
consumption and other facility parameters on a recipe-specific basis to
accurately implement recipe-specific rates.
     Recipe-specific information could be used to reverse
engineer individual recipes and otherwise compromise trade secrets.
    The Petitioner noted that the recipes used at a facility could
number in the hundreds. In the Petition for Reconsideration, the
Petitioner provided industry survey results for 19 facilities each
having over 200 recipes, in which three facilities had over 500
recipes, and two facilities had greater than 800 recipes. For
facilities with R&D activities, the Petitioner noted that the number of
unique recipes could run ``into the thousands.'' The Petitioner
explained in the petition that the EPA defined individual recipes in a
way that presumed that each recipe has a ``specific combination of
gases'' ``used repeatedly'' and ``under specific conditions of reactor
temperature, pressures, flow, radio frequency (RF) power and
duration.'' The Petitioner stated that a manufacturer may have many
complex recipes that are comprised of upwards of 20 or more individual
steps that could each meet the rule definition of ``individual
recipe,'' and that manufacturing facilities may run hundreds to
thousands of such recipes per year. Because of the nature of the
fabrication process, for each step, a recipe could specify a varying
``combination of gases'' or a variety of distinct ``specific
conditions.'' The petition stated that the EPA's definition of
individual recipes could be interpreted to render each step in a
complex recipe as a separate ``individual recipe'' that would need to
be tracked and measured to determine recipe-specific utilization and
by-product formation rates.
    The Petitioner also stated that the EPA's definition of ``similar
recipes'' could result in each step of a complex recipe to be
considered an ``individual recipe'' under subpart I, due to changes in
the chemicals used and the specific conditions for each step.
Furthermore, as discussed in Section III.B.5 of this preamble, the
Petitioner asserted that many facilities integrate research and
development activities into their production lines, and research
requires an iterative process and introduces hundreds of recipe
variations that would need to be accounted for. The Petitioner stated
in the Petition for Reconsideration that the equipment and personnel do
not currently exist in most facilities to perform the measurements,
testing, and data collection that would be required under subpart I to
develop gas utilization rates and by-product formation rates for every
recipe or each recipe step. Specifically, the Petitioner provided an
industry analysis with the Petition for Reconsideration that stated
that only 5 of 24 surveyed facilities had the available equipment, and
only one facility had personnel with the expertise to perform the
testing to quantify emissions from individual recipes.
    The Petitioner further stated in the Petition for Reconsideration
that tracking gas consumption and other facility parameters on a
recipe-specific basis would present technical and logistical challenges
to manufacturers. The Petitioner said that the infrastructure does not
currently exist to perform the data collection and testing that would
be required on a recipe-specific basis. The Petitioner stated in the
petition that many facilities would need to make significant equipment
expenditures in order to have the capability to measure and collect the
gas consumption data at the recipe-specific level.
    In the Petition for Reconsideration, the Petitioner also stated
that it is difficult to estimate the quantities of gas used in
individual production processes and steps, and it is currently not
possible to measure actual consumption because the points at which
gases are used (the individual tools) are widely distributed throughout
a facility. Although each individual process chamber has a mass flow
controller to control the actual flow of each gas introduced in the
chamber, collecting this information would require software
modifications and the implementation of data gathering capability on
the level of each tool at the facility, and then managing the data
collected for all tools across the facility. In subsequent information
provided to the EPA, the Petitioner stated that apportioning gas
consumption to these points on a recipe-specific basis would introduce
significant degrees of error that could affect the uncertainty of
estimated emissions.
    In discussions with the EPA, the Petitioner also suggested that as
an alternative to the recipe-specific approach, facilities may be able
to estimate emissions using the allocation of F-GHG to specific process
types, and an estimate of the overall DRE for those process types.
However, because the Petitioner and EPA developed the other F-GHG
estimation approaches being proposed today, this alternative method was
not developed beyond an initial concept.
    In 2010, the EPA's goal was to publish default utilization rates
and by-product formation rates for the electronics manufacturing
industry that would provide accurate facility-level F-GHG emissions
data. This would avoid the need for facilities to determine these rates
on a recipe-specific basis. At that time, however, the emission data
available to the agency was very limited, particularly with regard to
F-GHG emissions from the plasma etch process for the semiconductor
industry. At the final rule stage, we decided that we still had
insufficient data for estimating

plasma etch process emissions using default emission factors for the
largest facilities. For that reason, we required the largest facilities
to report their facility-specific plasma etch data using a recipe-
specific approach. We intended to use these data to develop emission
factors for incorporation into the rule at a later date. Subsequent to
the publication of the final rule, the Petitioner provided a
substantial amount of plasma etch data as described in this section of
the preamble. We have used these data to develop improved emission
factors for plasma etch processes. Thus, the recipe-specific approach
is no longer a critical part of the rule. As described in Section
III.B.12 of this preamble, we are also proposing a mechanism for
gathering data from facilities on changes to their processes that may
necessitate updates to the default emission factors. We anticipate this
addition will ensure that the default emission factors continue to
reflect facility emissions going forward.
    It is the EPA's position that the recipe-specific requirements in
40 CFR 98.93(a)(2)(ii)(A), (a)(3), and (a)(4) are no longer necessary
given the substantial amount of data submitted by the Petitioner
following promulgation of subpart I, together with today's proposal to
revise the default utilization and by-product formation rate method and
introduce a stack testing method. Furthermore, the EPA believes the
revised and alternative methods proposed today would provide reliable
facility-specific data while avoiding in large part the potential
concerns raised regarding the recipe-specific requirements with respect
to technical difficulty, burden, and the protection of trade secret
information. The EPA is proposing to remove the recipe-specific
requirements and revise corresponding requirements in 40 CFR 98.94,
98.96, and 98.97 to remove recipe-specific provisions.
    As described in Section III.B.2 of this preamble, after subpart I
was promulgated, the EPA received additional data characterizing
emissions from the semiconductor manufacturing industry and supporting
revised default gas utilization and by-product formation rates for the
plasma etch process. As discussed in Section III.B.2 of this preamble,
we are proposing revised default utilization rate and by-product
formation rates for the plasma etch and chamber cleaning process types.
The EPA believes that the revised default emission factors (based on
process type, gas, and wafer size) would provide reliable facility-
specific GHG data. Like other semiconductor manufacturing facilities,
new facilities manufacturing semiconductors on wafers greater than 300
mm diameter would not be required to develop recipe-specific gas
utilization rates and by-product formation rates and would use either
the default factors for 300 mm wafers or stack testing. In the future,
the EPA will likely develop default gas utilization rates and by-
product formation rates specifically for facilities using wafers
greater than 300 mm as that technology is implemented and emissions
data are available and collected by the EPA (see Section III.B.12 of
this preamble).
    As described in Section III.B.1 of this preamble, the EPA is also
proposing to include a method using stack testing to develop fab-
specific F-GHG emission factors for all electronics manufacturing
facilities. The EPA believes that the addition of the stack testing
method would also provide representative facility-specific GHG data for
all types of electronics manufacturing facilities, including new
facilities manufacturing semiconductors on wafers greater than 300 mm
diameter. Allowing a stack test approach in addition to the revised
default emission factor approach would give reporters flexibility to
choose from alternative methods if the recipe-specific approach is
removed as the EPA is proposing. For example, facilities with a large
number of stacks may prefer the default emission factor approach,
whereas a facility with a small number of stacks may desire the stack
test method. Compared to the recipe-specific approach, the default
emission factor and stack test options would reduce or eliminate the
burden, technical, and logistical feasibility concerns raised by the
Petitioner.
    Finally, the proposed default gas utilization rates and by-product
formation rate and stack test alternatives are more compatible with the
existing infrastructure, equipment, data management, and recordkeeping
systems currently used by the industry than the recipe-specific
approach. The proposed approaches would ensure that the EPA would
continue to receive representative data for characterizing the F-GHG
emissions from the industry while reducing burden on reporting
facilities.
    Although the EPA has deferred the mandatory use of recipe-specific
gas utilization rates and by-product formation rates through the end of
2013 (76 FR 59542, September 27, 2011), we are proposing that the
requirements to use recipe-specific rates in 40 CFR 98.93(a)(2)(ii)(A),