[Federal Register Volume 77, Number 110 (Thursday, June 7, 2012)]
[Proposed Rules]
[Pages 33812-33857]
[FR Doc No: 2012-13193]

Vol. 77

Thursday,

No. 110

June 7, 2012

Part II

Environmental Protection Agency

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40 CFR Parts 60 and 63

National Emission Standards for Hazardous Air Pollutants for
Reciprocating Internal Combustion Engines; New Source Performance
Standards for Stationary Internal Combustion Engines; Proposed Rule

Federal Register / Vol. 77, No. 110 / Thursday, June 7, 2012 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 60 and 63

[EPA-HQ-OAR-2008-0708, FRL-9679-3]
RIN 2060-AQ58

National Emission Standards for Hazardous Air Pollutants for
Reciprocating Internal Combustion Engines; New Source Performance
Standards for Stationary Internal Combustion Engines

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The EPA is proposing amendments to the national emission
standards for hazardous air pollutants for stationary reciprocating
internal combustion engines under section 112 of the Clean Air Act. The
proposed amendments include alternative testing options for certain
large spark ignition (generally natural gas-fueled) stationary
reciprocating internal combustion engines, management practices for a
subset of existing spark ignition stationary reciprocating internal
combustion engines in sparsely populated areas and alternative
monitoring and compliance options for the same engines in populated
areas. The EPA is also proposing to include a limited temporary
allowance for existing stationary emergency area source engines to be
used for peak shaving and non-emergency demand response. In addition,
the EPA is proposing to increase the hours that stationary emergency
engines may be used for emergency demand response. The proposed
amendments also correct minor mistakes in the pre-existing regulations.

DATES: Comments. Comments must be received on or before July 23, 2012,
or 30 days after date of public meeting if later.
    Public Meeting. If anyone contacts us requesting to speak at a
public meeting by June 14, 2012, a public meeting will be held on June
22, 2012. If you are interested in attending the public meeting,
contact Ms. Pamela Garrett at<PHONE_NUMBER> to verify that a meeting
will be held.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2008-0708, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for
submitting comments.
     Email<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: Air and Radiation Docket and Information Center,
Environmental Protection Agency, Mailcode: 6102T, 1200 Pennsylvania
Ave. NW., Washington, DC 20460. Please include a total of two copies.
The EPA requests a separate copy also be sent to the contact person
identified below (see FOR FURTHER INFORMATION CONTACT).
     Hand Delivery: Air and Radiation Docket and Information
Center, U.S. EPA, Room B102, 1301 Constitution Avenue NW., Washington,
DC. 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-
2008-0708. The EPA's policy is that all comments received will be
included in the public docket without change and may be made available
on-line at 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 www.regulations.gov
or email. The 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
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.
    Public Meeting: If a public meeting is held, it will be held at the
EPA's campus located at 109 T.W. Alexander Drive in Research Triangle
Park, NC or an alternate site nearby.
    Docket: All documents in the docket are listed in the
www.regulations.gov index. The EPA also relies on documents in Docket
ID Nos. EPA-HQ-OAR-2002-0059, EPA-HQ-OAR-2005-0029, EPA-HQ-OAR-2005-
0030, and EPA-HQ-OAR-2010-0295, and incorporated those dockets into the
record for this action. 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 www.regulations.gov or in hard copy at the Air and Radiation Docket,
EPA/DC, EPA West, Room B102, 1301 Constitution Ave. NW., Washington,
DC. The Public Reading Room 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 INFORMATION CONTACT: Ms. Melanie King, Energy Strategies
Group, Sector Policies and Programs Division (D243-01), Environmental
Protection Agency, Research Triangle Park, North Carolina 27711;
telephone number<PHONE_NUMBER>; facsimile number<PHONE_NUMBER>; email
address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Organization of This Document. The following
outline is provided to aid in locating information in the preamble.

I. General Information
    A. Executive Summary
    B. Does this action apply to me?
    C. What should I consider as I prepare my comments for the EPA?
II. Summary of Proposed Amendments
    A. Total Hydrocarbon Compliance Demonstration Option
    B. Emergency Demand Response/Peak Shaving
    C. Non-Emergency Stationary SI RICE Greater than 500 HP Located
at Area Sources
    D. Stationary Agricultural RICE in San Joaquin Valley
    E. Remote Areas of Alaska
    F. Miscellaneous Corrections and Revisions
    G. Compliance Date
III. Summary of Environmental, Energy and Economic Impacts
    A. What are the air quality impacts?
    B. What are the cost impacts?
    C. What are the benefits?
    D. What are the non-air health, environmental and energy
impacts?
IV. Solicitation of Public Comments and Participation
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
    D. Unfunded Mandates Reform Act of 1995
    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 and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations 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. Executive Summary

1. Purpose of the Regulatory Action
    The purpose of this action is to propose amendments to the national
emission standards for hazardous air pollutants (NESHAP) for stationary
reciprocating internal combustion engines (RICE) under section 112 of
the Clean Air Act (CAA). This proposal was developed to address certain
issues that have been raised by different stakeholders through
lawsuits, several petitions for reconsideration of the 2010 RICE NESHAP
amendments and other communications. This proposal also provides
clarifications and corrects minor mistakes in the current RICE NESHAP
and revises the new source performance standards (NSPS) for stationary
engines, 40 CFR part 60, subparts IIII and JJJJ, for consistency with
the RICE NESHAP.
    This action is conducted under the authority of section 112 of the
CAA, ``Hazardous Air Pollutants,'' (HAP) which requires the EPA to
establish NESHAP for the control of hazardous air pollutants (HAP) from
both new and existing sources in regulated source categories.
2. Summary of the Major Provisions of the Regulatory Action
    After promulgation of the 2010 RICE NESHAP amendments, the EPA
received several petitions for reconsideration, legal challenges, and
other communications raising issues of practical implementability, and
certain factual information that had not been brought to the EPA's
attention during the rulemaking. The EPA has considered this
information and believes that amendments to the rule to address certain
of these issues are appropriate. Therefore, the EPA is proposing to
amend 40 CFR part 63, subpart ZZZZ, NESHAP for Stationary RICE. The
current regulation applies to owners and operators of existing and new
stationary RICE at major and area sources of HAP emissions. The
applicability of the rule remains the same and is not changed by this
proposal. The EPA is also proposing to amend the NSPS for stationary
engines to conform with certain of the amendments proposed for the
NESHAP.
    The EPA proposes to add an alternative compliance demonstration
option for stationary 4-stroke rich burn (4SRB) spark ignition (SI)
engines subject to a 76 percent or more formaldehyde reduction. Owners
and operators of 4SRB engines would be permitted to demonstrate
compliance with the 76 percent formaldehyde reduction emission standard
by testing total hydrocarbon (THC) emissions and showing that the
engine is achieving at least a 30 percent reduction of THC emissions.
The alternative compliance option would provide a less expensive and
less complex, but equally effective, method for demonstrating
compliance than testing for formaldehyde.
    Certain stationary RICE are maintained in order to be able to
respond to emergency power needs. The EPA proposes to allow owners and
operators of such stationary emergency RICE to operate their engines as
part of an emergency demand response program within the 100 hours per
year that is already permitted for maintenance and testing of the
engines. The 100 hours per year allowance would ensure that a
sufficient number of hours are permitted for engines to meet
independent system operator (ISO) and regional transmission
organization (RTO) tariffs and other requirements for participating in
various emergency demand response programs and would assist in
stabilizing the grid, preventing electrical blackouts and supporting
local electric system reliability. A temporary limited allowance that
will expire on April 16, 2017 (the date by which full compliance with
the NESHAP From Coal and Oil-Fired Electric Utility Steam Generating
Units (77 FR 9304) is expected), is being proposed for stationary
emergency engines located at area sources of HAP emissions to be used
for up to 50 hours per year for any non-emergency purpose, including
peak shaving. The 50 hours is part of the 100 hours per year total
allowance for all types of emergency engine operation (except during
emergencies where no other power is available, which is not restricted
by the rule). The temporary allowance for peak shaving would give
sources time to address reliability issues and develop solutions to
reliability issues while facilities are coming into compliance with the
National Emission Standards for Hazardous Air Pollutants From Coal and
Oil-Fired Electric Utility Steam Generating Units, which were
promulgated on February 16, 2012 (77 FR 9304).
    The EPA proposes management practices for owners and operators of
existing stationary 4-stroke SI engines above 500 horsepower (HP) that
are area sources of HAP emissions and where the engines are remote from
human activity. A remote area is defined as either a Department of
Transportation (DOT) Class 1 pipeline location,\1\ or, if the facility
is not on a pipeline, if within a 0.25-mile radius of the facility
there are 5 or less buildings intended for human occupancy. The 0.25-
mile radius was chosen as the area would be similar to the area used
for the DOT pipeline Class location. The EPA proposes that these
sources be subject to management practices rather than numeric emission
limits and associated testing and monitoring. This would address
reasonable concerns with accessibility, infrastructure, and staffing
that stem from the remoteness of the engines and higher costs that
would be associated with compliance with the existing requirements. The
EPA proposes that existing stationary 4-stroke SI engines above 500 HP
at area sources that are in populated areas (defined as not in DOT
pipeline Class 1 areas, or if not on a pipeline, if within a 0.25-mile
radius of the facility there are more than 5 buildings intended for
human occupancy) be subject to an equipment standard that requires the
installation of HAP-reducing aftertreatment. The EPA has the discretion
to set an equipment standard as GACT for engines located at area
sources of HAP. Sources would be required to test their engines to
demonstrate compliance initially, perform catalyst activity check-ups,
and either monitor the catalyst inlet temperature continuously or
employ high temperature shutdown devices to protect the catalyst.
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    \1\ A Class 1 location is defined as an offshore area or any
class location unit that has 10 or fewer buildings intended for
human occupancy.
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    To address how certain existing compression ignition (CI) engines
are currently regulated, the EPA proposes to specify that any existing
certified CI engine above 300 HP at an area source of HAP emissions
that was certified to meet the Tier 3 engine standards and was
installed before June 12, 2006, is in compliance with the NESHAP. This
provision would create regulatory consistency between the same engines
installed before and after June 12, 2006. Engines at area sources of
HAP for which construction commenced before June 12, 2006, are
considered existing engines under the NESHAP.

    The EPA is proposing amendments to the requirements for existing
stationary Tier 1 and Tier 2 certified CI engines located at area
sources that are subject to state and locally enforceable requirements
requiring replacement of the engine by June 1, 2018. This is meant to
deal with a specific concern regarding the interaction of the NESHAP
with certain rules for agricultural engines in the San Joaquin Valley
in California. The EPA is proposing to allow these engines to meet
management practices under the RICE NESHAP from the May 3, 2013
compliance date until January 1, 2015, or 12 years after installation
date, but not later than June 1, 2018. This provision would deal with
the issue of owners and operators having to install controls on their
engines in order to meet the RICE NESHAP, and then having to replace
their engines shortly thereafter due to state and local rules
specifying the replacement of engines. Owners and operators will have
additional time to replace their engines without having to install
controls, but will be required to use management practices during that
period.
    The last major change the EPA proposes to make is to broaden the
definition of remote area sources of Alaska in the RICE NESHAP.
Currently, remote areas are those that are not on the Federal Aid
Highway System (FAHS). This change would permit existing stationary CI
engines at other remote area sources in Alaska to meet management
practices as opposed to emission standards likely necessitating
aftertreatment. These remote areas have the same challenges as areas
not on the FAHS, and complying with the current rule would similarly be
prohibitively costly and potentially infeasible. In addition to area
sources located in areas of Alaska that are not accessible by the FAHS
being defined as remote and subject to management practices, the EPA
also proposes that any stationary RICE in Alaska meeting all of the
following conditions be subject to management practices:
    (1) The only connection to the FAHS is through the Alaska Marine
Highway System (AMHS), or the stationary RICE operation is within an
isolated grid in Alaska that is not connected to the statewide
electrical grid referred to as the Alaska Railbelt Grid,
    (2) At least 10 percent of the power generated by the stationary
RICE on an annual basis is used for residential purposes, and
    (3) The generating capacity of the area source is less than 12
megawatts, or the stationary RICE is used exclusively for backup power
for renewable energy and is used less than 500 hrs per year on a 10-
year rolling average.
3. Costs and Benefits
    These proposed amendments would reduce the capital and annual costs
of the original 2010 amendments by $287 million and $139 million,
respectively. The EPA estimates that with the proposed amendments, the
capital cost of the rule is $840 million and the annual cost is $490
million ($2010).
    These proposed amendments would also result in decreases to the
emissions reductions estimated in 2013 from the original 2010 RICE
NESHAP amendments. The estimated reductions in 2013 from the 2010 RICE
NESHAP rulemaking with these proposed amendments are 2,800 tons per
year (tpy) of HAP, 36,000 tpy of carbon monoxide (CO), 2,800 tpy of
particulate matter (PM), 9,600 tpy of nitrogen oxide (NOX),
and 36,000 tpy of volatile organic compounds (VOC). The reductions that
were estimated for the original 2010 RICE NESHAP amendments were 7,000
tpy of HAP, 124,000 tpy of CO, 2,800 tpy of PM, 96,000 tpy of
NOX, and 58,000 tpy of VOC.
    The EPA estimates the monetized co-benefits in 2013 of the original
2010 RICE NESHAP amendments with these proposed amendments incorporated
to be $830 million to $2,100 million (2010 dollars) at a 3-percent
discount rate and $740 million to $1,800 million (2010 dollars) at a 7-
percent discount rate. The benefits that were estimated for the
original 2010 RICE NESHAP amendments were $1,500 million to $3,600
million (2010 dollars) at a 3-percent discount rate and $1,300 million
to $3,200 million (2010 dollars) at a 7-percent discount rate.

B. Does this action apply to me?

    Regulated Entities. Categories and entities potentially regulated
by this action include:

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                                                  Examples of regulated
             Category               NAICS \1\           entities
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Any industry using a stationary           2211  Electric power
 internal combustion engine as          622110   generation,
 defined in the proposed                         transmission, or
 amendments.                                     distribution.
                                                Medical and surgical
                                                 hospitals.
                                         48621  Natural gas
                                                 transmission.
                                        211111  Crude petroleum and
                                                 natural gas production.
                                        211112  Natural gas liquids
                                                 producers.
                                         92811  National security.
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\1\ North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be regulated by this
action. To determine whether your engine is regulated by this action,
you should examine the applicability criteria of this proposed rule. If
you have any questions regarding the applicability of this action to a
particular entity, consult the person listed in the preceding FOR
FURTHER INFORMATION CONTACT section.

C. What should I consider as I prepare my comments for the EPA?

    1. Submitting CBI. Do not submit this information to the EPA
through regulations.gov or email. 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 so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2. Send or deliver information
identified as CBI to only the following address: Ms. Melanie King, c/o
OAQPS Document Control Officer (Room C404-02), U.S. EPA, Research
Triangle Park, NC 27711, Attention

Docket ID No. EPA-HQ-OAR-2008-0708.
    2. Tips for Preparing Your Comments. When submitting comments,
remember to:
    (a) Identify the rulemaking by docket number and other identifying
information (subject heading, Federal Register date and page number).
    (b) Follow directions. The EPA may ask you to respond to specific
questions or organize comments by referencing a Code of Federal
Regulations (CFR) part or section number.
    (c) Explain why you agree or disagree; suggest alternatives and
substitute language for your requested changes.
    (d) Describe any assumptions and provide any technical information
and/or data that you used.
    (e) If you estimate potential costs or burdens, explain how you
arrived at your estimate in sufficient detail to allow for it to be
reproduced.
    (f) Provide specific examples to illustrate your concerns, and
suggest alternatives.
    (g) Explain your views as clearly as possible, avoiding the use of
profanity or personal threats.
    (h) Make sure to submit your comments by the comment period
deadline identified.
    Docket. The docket number for this proposed rule is Docket ID No.
EPA-HQ-OAR-2008-0708.
    World Wide Web (WWW). In addition to being available in the docket,
an electronic copy of this proposed rule will be posted on the WWW
through the Technology Transfer Network Web site (TTN Web). Following
signature, the EPA will post a copy of this proposed rule on the TTN's
policy and guidance page for newly proposed or promulgated rules at
http://www.epa.gov/ttn/oarpg. The TTN provides information and
technology exchange in various areas of air pollution control.

II. Summary of Proposed Amendments

    This action proposes amendments to the NESHAP for RICE in 40 CFR
part 63, subpart ZZZZ. This action also proposes amendments to the NSPS
for stationary engines in 40 CFR part 60, subparts IIII and JJJJ. The
NESHAP for stationary RICE to regulate emissions of HAP was developed
in several stages. The EPA initially addressed stationary RICE greater
than 500 HP located at major sources of HAP emissions in 2004 (69 FR
33473). The EPA addressed new stationary RICE less than or equal to 500
HP located at major sources and new stationary RICE located at area
sources in 2008 (73 FR 3568). Most recently, requirements for existing
stationary RICE less than or equal to 500 HP located at major sources
and existing stationary RICE located at area sources were finalized in
2010 (75 FR 9648 and 75 FR 51570).
    The EPA is proposing to address a number of issues that have been
raised by different stakeholders through lawsuits, several petitions
for reconsideration of the 2010 RICE NESHAP amendments, and other
communications. The EPA is also proposing to revise 40 CFR part 60,
subparts IIII and JJJJ for consistency with the RICE NESHAP and to make
minor corrections and clarifications. The following sections present
the issues that the EPA is addressing in this action, background
information as to why these issues are causing concern among affected
stakeholders, and how the EPA proposes to resolve the issues.

A. Total Hydrocarbon Compliance Demonstration Option

1. Background
    Currently, SI 4SRB non-emergency engines greater than 500 HP
located at major sources and existing SI 4SRB non-emergency engines
greater than 500 HP located at area sources have the option of meeting
either a formaldehyde percent reduction or a formaldehyde concentration
standard. Formaldehyde was established in the original 2004 RICE NESHAP
as an appropriate surrogate for HAP emissions from 4SRB engines based
on industry test data available at that time. Based on testing of
stationary lean burn engines conducted at Colorado State University
(CSU), the EPA was able to establish CO as a surrogate for HAP for lean
burn engines. Rich burn engines were not tested at CSU and the data the
EPA had available at the time that were used to set the standards for
rich burn engines did not support the same relationship between CO and
HAP reductions for rich burn engines. Therefore, the EPA was unable to
establish CO as a surrogate for HAP emissions for rich burn engines and
the emission standard for rich burn engines was specified in terms of
formaldehyde, the hazardous air pollutant emitted in the largest
quantity from stationary engines.
    The EPA has previously acknowledged that it is significantly more
expensive and difficult to test for formaldehyde than for CO, but has
been unable in the past to support the same flexibility for rich burn
engines as is currently in the rule for lean burn engines with the
option to meet the standards in terms of either formaldehyde or CO. For
these reasons, and expecting that new data for rich burn engines may
become available in the future for the EPA to review and reassess
possible surrogates for HAP, the EPA requested comment on this issue
when proposing NESHAP for stationary existing engines less than or
equal to 500 HP at major sources and all stationary existing engines at
area sources in 2009 (74 FR 9698). Specifically, the EPA solicited
comment on whether it would be appropriate to include an alternative
standard in terms of VOC and asked that commenters submit data
supporting the relationship between HAP and VOC. Comments the EPA
received back on the proposed rule asked that the formaldehyde
standards for rich burn engines be replaced with emission standards for
THC. The EPA determined at the time that it was not appropriate to
adopt an alternative standard in terms of THC (or VOC) for rich burn
engines and discussed the reasons why in the 2010 responses to
comments.\2\ Compliance with the formaldehyde standard in the rule is,
therefore, currently demonstrated by initial and continuous performance
testing for formaldehyde.
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    \2\ Memorandum from Melanie King, EPA Energy Strategies Group to
EPA Docket EPA-HQ-OAR-2008-0708. Response to Public Comments on
Proposed National Emission Standards for Hazardous Air Pollutants
for Existing Stationary Reciprocating Internal Combustion Engines
Located at Area Sources of Hazardous Air Pollutant Emissions or Have
a Site Rating Less Than or Equal to 500 Brake HP Located at Major
Sources of Hazardous Air Pollutant Emissions. August 10, 2010. EPA-
HQ-OAR-2008-0708-0557.
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    On October 19, 2010, engine manufacturer Dresser-Waukesha submitted
a petition for reconsideration of the formaldehyde requirements. The
EPA granted the petition for reconsideration on January 5, 2011. (In
addition, on November 3, 2010, the Engine Manufacturers Association
submitted a petition for judicial review of these requirements.) In the
petition for reconsideration, Dresser-Waukesha argued that formaldehyde
is difficult and costly to measure. The petition requested that the HAP
surrogate for 4SRB engines should be THC rather than formaldehyde.
Dresser-Waukesha submitted data from testing it conducted illustrating
that THC reduction across the catalyst is an appropriate surrogate for
HAP reduction across the catalyst.\3\ According to the petitioner,
testing for THC is easier and less costly and would substantially
reduce the burden of the rule for owners and operators of these
engines. Testing for formaldehyde emissions could cost more than double
that of testing for THC emissions and on

a nationwide basis the EPA estimates that replacing formaldehyde
testing with THC testing would result in substantial compliance cost
savings annually while achieving the same reduction in HAP emissions.
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    \3\ Letter from Dresser-Waukesha to Melanie King. Follow-up to
November 18, 2010 Teleconference. December 6, 2010. EPA-HQ-OAR-2008-
0708-0662.
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    The EPA has reviewed the data submitted by Dresser-Waukesha. The
data provided indicate that a strong relationship exists between
percentage reductions of THC and percentage reductions of formaldehyde
(the surrogate for HAP emissions in the NESHAP) on rich burn engines
using non-selective catalytic reduction (NSCR). Data analyzed by the
EPA indicate that if the NSCR is reducing THC by at least 30 percent
from 4SRB engines, formaldehyde emissions are guaranteed to be reduced
by at least 76 percent, which is the percentage reduction required for
the relevant engines. Indeed, the percentage reduction of formaldehyde
is invariably well above the 76 percent level, and is usually above 90
percent. Therefore, the EPA agrees with the petitioner that for SI 4SRB
engines using NSCR and meeting the NESHAP by showing a percentage
reduction of HAP, it would be appropriate to allow sources to
demonstrate compliance with the NESHAP by showing a THC reduction of at
least 30 percent. Including an optional THC compliance demonstration
option would reduce the cost of compliance significantly while
continuing to achieve the same level of HAP emission reduction because
the emission standards would remain the same. Consequently, the EPA is
proposing amendments to allow owners and operators of certain
stationary 4SRB engines (i.e., the ones currently subject to a
formaldehyde percent reduction requirement) to show compliance with an
optional THC compliance demonstration option. The specific amendments
the EPA is proposing are presented below.
2. Proposed Amendments
    The EPA is proposing to add an alternative method of demonstrating
compliance with the NESHAP for stationary 4SRB non-emergency engines
greater than 500 HP that are located at major sources of HAP emissions
and for existing stationary 4SRB non-emergency engines greater than 500
HP that are located at area sources of HAP emissions that choose to
meet the formaldehyde percent reduction requirement of 76 percent or
more.
    Based on the arguments and evidence presented in the petition
discussed above, the EPA is proposing to add a compliance demonstration
option for stationary 4SRB engines meeting a 76 percent or more
formaldehyde reduction. The compliance demonstration option would be an
alternative to the existing method of demonstrating compliance with the
formaldehyde percent reduction standard, which is to test engines for
formaldehyde. The alternative for owners and operators of 4SRB engines
meeting a 76 percent or more formaldehyde reduction would be to test
their engines for THC showing that the engine is achieving at least a
30 percent reduction of THC emissions.
    Under the proposed amendments, existing and new stationary 4SRB
engines greater than 500 HP and located at major sources would still be
required to reduce formaldehyde emissions by 76 percent or more or
limit the concentration of formaldehyde in the stationary RICE exhaust
to 350 parts per billion by volume, dry basis or less at 15 percent
oxygen (O2). However, owners and operators choosing to meet
the formaldehyde concentration limit would not have the THC
demonstration compliance option, because EPA could not verify a clear
relationship between concentrations of THC and concentrations of
formaldehyde in exhaust from these SI 4SRB engines. For the reasons
discussed in section II.C.1 of this preamble, the EPA is proposing that
existing stationary 4SRB non-emergency engines greater than 500 HP
located at area sources located in populated areas be subject to an
equipment standard and required to install a catalyst. These engines
would be subject to testing to demonstrate initially and on an ongoing
basis that the catalyst is reducing CO by 75 percent or more, or
alternatively that THC emissions are being reduced by 30 percent or
more.
    Owners and operators of existing stationary 4SRB engines less than
or equal to 500 HP who are required to limit the concentration of
formaldehyde in the stationary RICE exhaust to 10.3 parts per million
by volume, dry basis (ppmvd) or less at 15 percent O2 do not
have the option to demonstrate compliance using THC and must continue
to demonstrate compliance by testing for formaldehyde following the
methods and procedures specified in the rule.
    Owners and operators opting to use the THC compliance demonstration
method must demonstrate compliance by showing that the average
reduction of THC is equal to or greater than 30 percent. Owners and
operators of 4SRB stationary RICE complying with the requirement to
reduce formaldehyde emissions and demonstrating compliance by using the
THC compliance demonstration option must conduct performance testing
using Method 25A of 40 CFR part 60, appendix A--Determination of Total
Gaseous Organic Concentration Using a Flame Ionization Analyzer.
Measurements of THC at the inlet and the outlet of the NSCR must be on
a dry basis and corrected to 15 percent O2 or equivalent
carbon dioxide content. To correct to 15 percent O2, dry
basis, owners and operators must measure oxygen using Method 3, 3A or
3B of 40 CFR part 60, appendix A, or ASTM Method D6522-00 (2005) and
measure moisture using Method 4 of 40 CFR part 60, appendix A, or Test
Method 320 of 40 CFR part 63, appendix A, or ASTM D6348-03. Because
owners and operators are complying with a percent reduction
requirement, the method used must be suitable for the entire range of
emissions since pre and post-catalyst emissions must be measured.
Method 25A is capable of measuring emissions down to 5 ppmv and is,
therefore, an appropriate method for measuring THC emissions for
compliance demonstration purposes. The EPA is allowing sources the
option to meet a minimum THC percent reduction of 30 percent by using
Method 25A of 40 CFR part 60, appendix A to demonstrate compliance with
the formaldehyde percent reduction in 40 CFR part 63, subpart ZZZZ.

B. Emergency Demand Response/Peak Shaving

1. Background
    This action also proposes to amend provisions in the RICE NESHAP
that currently allow owners and operators to operate stationary
emergency engines for up to 15 hours per year as part of a demand
response program if the RTO or equivalent balancing authority and
transmission operator have determined there are emergency conditions
that could lead to a potential electrical blackout, such as unusually
low frequency, equipment overload, capacity or energy deficiency, or
unacceptable voltage level. The final rule did not allow emergency
engines to be used for purposes of peak shaving or other non-emergency
purposes as part of a financial arrangement. These provisions were
included in the RICE NESHAP when requirements for existing stationary
CI engines were finalized on March 3, 2010 (75 FR 9648). Following the
completion of that portion of the rule, the EPA received three main
petitions for reconsideration. One petition was from CPower, Inc.,
EnergyConnect, Inc., EnerNOC, Inc., and Innoventive Power, LLC.
(EnerNOC et al.)(EPA-HQ-OAR-2008-0708-0404).

Another petition was received from the Delaware Department of Natural
Resources and Environmental Control (DE DNREC) (EPA-HQ-OAR-2008-0708-
0400). The third petition was from the National Rural Electric
Cooperative Association (NRECA) (OAR-2008-0708-0580). In addition to
these main petitions the EPA received a substantial number of letters
from others in the electric generation industry.
    The petition from EnerNOC, et al., asked that EPA increase the
period of time permitted for emergency demand response operation in the
rule to 60 hours per year, or the minimum number of hours required by
the emergency demand response program. By contrast, the DE DNREC
petition asked EPA to reconsider the emergency demand response
provision because of the adverse effects that it believes would result
from increased emissions from these engines. The petition from NRECA
requested that the EPA eliminate the restriction on the use of
stationary emergency engines for demand response purposes. The EPA
granted the petitions from EnerNOC, et al., DE DNREC and NRECA, and
issued a notice on December 7, 2010 (75 FR 75937), requesting comments
on whether to amend the 15 hours per year limitation on the operation
of stationary emergency RICE participating in emergency demand response
programs.
    The EPA received more than 120 comments from a number of different
entities including various state agencies, utilities, electric
cooperatives and industry organizations. Many commenters expressed that
15 hours per year is not sufficient to meet current emergency demand
response requirements for participation. For example, several emergency
demand response programs have ISO tariff requirements greater than 15
hours per year, including the Electric Reliability Council of Texas
emergency demand response program, which has a tariff requirement of 24
hours per year; the Pennsylvania Jersey Maryland (``PJM'')
Interconnection, known as the Emergency Load Response Program, which
has a tariff requirement of 60 hours per year; and the ISO New England
(``ISO-NE''), which forecasts that backup resources would be expected
for 55 hours over a 12-month period. Tariff requirements are developed
to specify the mandatory time load resources (engines) must be willing
and able to operate if the units are enrolled in the program.
Conversely, some commenters urged the EPA to allow stationary emergency
engines to only operate during true emergencies or when voltage or
frequency varies beyond specified parameters.
    Based on the EPA's review of the petitions and comments that the
EPA has received, the EPA has found it appropriate to propose to amend
the current rule to increase the allowance for stationary emergency
engine participation in emergency demand response programs to up to 100
hours per year, which would be included as part of the pre-existing
allowance of 100 hours for owners of emergency engines to test and
maintain their emergency engines. The EPA believes that the emergency
demand response programs that exist across the country are important
programs that protect the reliability and stability of the national
electric service grid. Allowing stationary emergency engines to operate
as part of emergency demand response programs can help prevent grid
failure or blackouts, by allowing these engines to be used in
circumstances of grid instability prior to the occurrence of blackouts.
Preventing stationary emergency engines from being able to qualify and
participate in emergency demand response programs without having to
apply aftertreatment could force owners and operators to leave their
engines out of these programs, which will impair the ability of ISOs
and RTOs to use these relatively small, quick-starting and reliable
sources of energy to protect the reliability of their systems. The EPA
does not wish to potentially jeopardize electrical reliability or
create a disincentive for stationary emergency engines to participate
in these programs. The circumstances during which the EPA would allow
stationary emergency engines to operate for emergency demand response
purposes include periods during which the regional transmission
authority or equivalent balancing authority and transmission operator
has declared an Energy Emergency Alert Level 2 (EEA Level 2) as defined
in the North American Electric Reliability Corporation Reliability
Standard EOP-002-3, Capacity and Energy Emergency, plus during periods
where there is a deviation of voltage or frequency of 5 percent or more
below standard voltage or frequency. During EEA Level 2 alerts there is
insufficient energy supply and a true potential for electrical
blackouts. System operators must call on all available resources during
EEA Level 2 alerts in order to stabilize the grid to prevent failure.
Therefore, this situation is a good indicator of severe instability on
the system. Consistent normal voltage provided by the utility is often
called power quality and is an important factor in local electric
system reliability. Reliability of the system requires electricity
being provided at a normal expected voltage. The American National
Standards Institute standard C84.1-1989 defines the maximum allowable
voltage sag at below 5 percent. On the local distribution level local
voltage levels are therefore important and a 5 percent or more change
in the normal voltage or frequency is substantial and an indication
that additional resources are needed to ensure local distribution
system reliability. This situation would be indicative of severe
instability on the system. The EPA has revised the language identifying
the emergency conditions that currently appears at 40 CFR 63.6640(f)
because that language is not as specific as the newly proposed
language. The EPA believes that the newly proposed language, along with
the preexisting language in the definition of emergency engine
describing non-demand response emergency situations, will address all
emergency events, including all those that would be recognized solely
by the local system operators, such as local weather events. The EPA
requests comments on the scope of the new language.
    Emergency demand response programs rely on agreements under which
owners of engine agree to make their engines available to be called
upon for a specific number of hours per year, as required by the
relevant ISO or RTO tariff, under specified circumstances considered to
indicate emergencies. In order to be enrolled in an emergency demand
response program, participants must qualify their engines and must be
able to use their emergency engines for the number of hours the program
requires. Engines are not generally called upon for the maximum hours
required by the tariffs. However, even though the engine may not be
called at all or may run for fewer hours than the program requires it
to be available in a particular year, the engine must still be
available for those theoretical number of hours in order to join the
program. Demand response contracts require more hours than the 15 hours
per year that is currently in the regulations, and the commenters state
that the 15 hours per year is not a sufficient amount of time to ensure
the reliability of the program; some programs require up to 60 hours
per year, as discussed earlier in this preamble. For these reasons, the
EPA believes it is appropriate to allow additional hours for emergency
demand response operation in order for such

programs to be accessible to stationary emergency engines.
Consequently, the EPA is proposing amendments to the rule to increase
the limitation on emergency demand response operation to 100 hours per
year for stationary emergency engines. It is expected that owners and
operators of stationary emergency engines that seek to qualify their
units as demand resources would with the proposed increase to 100 hours
per year be able to meet the operational and qualification requirements
of the different ISOs and RTOs in the country.
    As stated, stationary emergency engines that participate in demand
response programs may not be called upon at all, but must nonetheless
be available to operate for the required amount stipulated by the
specific program. The purpose of the limited allowance for emergency
demand response is to respond to emergencies, and the EPA is persuaded
by the information that has been submitted that 15 hours per year is an
insufficient amount of time to allow for emergency demand response
needs, given past experience. The EPA believes 100 hours per year is
sufficient to cover any potential demand response operation as well as
the required maintenance and testing that is also included within the
100 hours of operation.
    The EPA has previously determined that stationary emergency engines
typically operate well below 50 hours per year and more commonly about
1 to 2 hours per month. A survey conducted by the California Air
Resources Board (CARB) indicated the average yearly operation for
emergency diesel engines was 31 hours over a period of 3 years. The
majority of those hours were for the purpose of maintenance and
testing; less than 5 hours was for interruptible service contracts, and
the remaining amount for emergency/standby operation (EPA-HQ-OAR-2005-
0029-0011). Data from demand response programs in ISO-NE and PJM
territories show that backup generation was dispatched for less than 30
hours during the summers of 2008, 2009 and 2010.\4\
---------------------------------------------------------------------------

    \4\ Memorandum from Stacy Angel, Synapse Energy Economics, Inc.
to Doug Hurley, Synapse Energy Economics. Sample Revenue for a 1 MW
Backup Generation Unit. June 27, 2011.
---------------------------------------------------------------------------

    However, again, emergency units must be available to operate more
than that in most cases to qualify for demand response programs. For
instance, PJM requires a minimum ISO tariff of 60 hours per year of
engine availability for program participation. Consequently, in order
to ensure that a sufficient amount of operating time is available for
maintenance and readiness testing, and for demand response operation,
the EPA is proposing 100 hours of operation. A number of commenters
requested that an allowance of 100 hours per year be allowed in order
to provide adequate hours consistent with minimum required hours that
customers must be available to operate and to address local
distribution system emergencies. For instance, in Hawaii, the emergency
demand response program operated by the Hawaiian Electric Company
requires that emergency engines be able to operate for 100 hours per
year in the event of an emergency in order to participate in the
program. In order to provide a sufficient amount of time to cover
annual maintenance and testing, which is typically more than 20 hours
per year according to the survey conducted by CARB (see EPA-HQ-OAR-
2005-0029-0011), plus to cover hours necessary for qualifying for
emergency demand response programs or local distribution system
emergencies, EPA believes an allowance of 100 hours per year would be
appropriate for these activities. Taking into account that there may be
situations where annual maintenance and testing could exceed the
typical 1 to 2 hours per month and accounting for other emergency
demand response programs that require more than 60 hours per year for
program participation (e.g., the Hawaiian Electric Company), the EPA
believes that 100 hours per year is appropriate for emergency demand
response plus maintenance and testing.
    The proposed amendment to the rule would mean that stationary
emergency engines could operate for a total of 100 hours per year for
emergency demand response operation as part of the 100 hours already
permitted for maintenance and readiness testing while maintaining their
status as emergency units, rather than non-emergency units, and
continue to meet the requirements that apply to emergency engines.
    On the issue of peak shaving and non-emergency demand response, the
EPA is proposing to include a temporary limited allowance for peak
shaving and other types of non-emergency use as part of a financial
arrangement for existing stationary emergency engines at area sources
of HAP, if the peak shaving is done as part of a peak shaving (or load
management) program with the local distribution system operator. The
power generated under this allowance can only be used at the facility
or towards the local system.
    The EPA has determined that it is appropriate to include the option
for existing stationary emergency engines at area sources to operate
for a small number (50) of hours per year for any non-emergency reason
and not be penalized or considered a non-emergency engine and
subsequently required to install aftertreatment that could be
prohibitively costly for these sources in the near term. The EPA is
proposing that the 50-hour allowance for peak shaving for emergency
engines at area sources be allowed for a limited period of time, but
then removed after April 16, 2017. The peak shaving would also be
limited to operation as part of a peak shaving (load management
program) with the local distribution system operator. Owners would
still have the pre-existing 50 hours per year allowance for non-
emergency operation after April 16, 2017, but those 50 hours could no
longer be used for peak shaving. The temporary allowance for peak
shaving would give sources an additional resource for maintaining
reliability while facilities are coming into compliance with the NESHAP
From Coal and Oil-Fired Electric Utility Steam Generating Units (77 FR
9304). While the EPA does not expect the NESHAP From Coal and Oil-Fired
Electric Utility Steam Generating Units to cause regional reliability
problems, this limited allowance would allow the owners and operators
of these engines more flexibility to run reliability critical units in
order to minimize potential grid-related interruptions as coal- and
oil-fired baseload power plants may be temporarily shut down to install
emission controls to comply with the NESHAP From Coal and Oil-Fired
Electric Utility Steam Generating Units.
    Including this allowance is important for small electric
cooperatives and other entities located at area sources that use these
engines to maintain voltage and electric reliability. Many rural
electric cooperatives enter agreements with owners of small emergency
engines and rely on the engines to reduce demand on the central power
supply during periods of high demand, which reduces the cost of power
during periods of high demand for the members of the cooperative.
Commenters promoting the continued use of peak shaving programs said
that maintaining the cost of power as low as possible is important
across the country, but is particularly of significant importance to
rural electric cooperatives that, according to the commenter, service
customers in the most economically depressed areas of the country,
where options are the most limited. The commenters argued that if small
emergency engines would no longer be permitted to operate for peak
shaving purposes without having to be reclassified as non-emergency
engines

and subsequently subject to costly emissions controls, owners could no
longer afford to participate in such programs. Cooperatives argued that
this would lead to increased costs that would ultimately be passed
along to the customers. Commenters also maintained that keeping peak
shaving programs would not lead to additional public health risks or
emissions because the operation for peak shaving is minimal. If peak
shaving is not allowed under the rule, commenters said that this would
lead to an increase in central power station capacity and possibly more
transmission and distribution line capacity to accommodate the increase
in demand resulting from eliminating small emergency engines from being
used. This could lead to a larger impact on the environment and public
health than allowing a small number of hours for peak shaving purposes.
Certain small and remote facilities also rely on financial programs to
generate additional income in order to maintain their engines and stay
in operation. The additional funds can be essential for many smaller
facilities and operations. Providing a limited allowance for peak
shaving and non-emergency demand response could generate sufficient
income to prevent small facilities and owners from ceasing operation
where these engines are in service. In order to further limit the
operation of these engines to small, remote facilities, the EPA is
proposing that the power generated under this allowance can only be
used at the facility or towards the local system. In addition, while
the EPA is proposing this allowance until the end of April 16, 2017,
the EPA does not believe it is appropriate to continue the program
beyond that time. Generators receive considerable compensation for
their availability in peak shaving programs and the EPA believes that
it is not appropriate to allow these engines to continue receiving
compensation for this non-emergency use beyond 2017 without having to
reduce their emissions. The generators must by that time decide whether
to restrict their use to emergency or limited non-compensated non-
emergency use or to reduce the emissions from their engines. The EPA
also encourages engine owners and operators, as well as larger system
planners, to consider the use of alternative peak shaving options, such
as load curtailments, lower emitting distributed generation, combined
heat and power, and reduced line losses on the electricity grid.
    The previous estimate of emissions from stationary emergency
engines is not expected to change due to this proposed limited
allowance. To estimate emissions from stationary emergency engines, the
EPA has previously estimated that emergency engines would on average
operate for 50 hours per year. There is a wide range in how much these
engines operate (some well below 50 hours per year), but on average and
to be conservative, the EPA believes that 50 hours per year is still
representative and consequently the environmental impact the EPA has
calculated previously remains appropriate. In consideration of all
these issues, the EPA is proposing amendments to the rule to provide a
limited allowance for peak shaving for existing stationary emergency
engines at area sources of HAP. The specific amendments the EPA is
proposing are discussed below.
2. Proposed Amendments
    a. Emergency Demand Response. Based on the discussion in section
II.B.1 of this preamble, the EPA is proposing to revise the current
provisions for stationary engines used for emergency demand response
operation. The provisions the EPA is proposing to amend are in
Sec. Sec.  63.6640(f) and 63.6675 of 40 CFR part 63, subpart ZZZZ.
Currently, Sec.  63.6640(f)(1)(iii) allows a maximum of 15 hours per
year to be spent towards demand response operation under certain
qualifying conditions. Also, Sec.  63.6640(f)(1)(ii) currently includes
an allowance of 100 hours per year for purposes of maintenance checks
and readiness testing. The EPA is proposing that owners and operators
of stationary emergency RICE be permitted to operate their engines as
part of an emergency demand response program within the 100 hours per
year that is permitted for maintenance and testing in Sec.
63.6640(f)(1)(ii). Owners and operators of stationary emergency engines
can operate for emergency demand response during periods in which the
regional transmission authority or equivalent balancing authority and
transmission operator has declared an EEA Level 2 as defined in the
North American Electric Reliability Corporation Reliability Standard
EOP-002-3, Capacity and Energy Emergency and during periods where there
is a deviation of voltage or frequency of 5 percent or greater below
standard voltage or frequency. The hours spent for emergency demand
response operation are added to the hours spent for maintenance and
testing purposes and counted towards the 100 hours per year. If the
total time spent for demand response operation and maintenance and
testing exceeds 100 hours per year the engine will not be considered an
emergency engine under this subpart and will need to meet all
requirements for non-emergency engines. The EPA is recognizing that
these engines may be called to operate not only by the regional
transmission operator or equivalent to maintain the reliability of the
bulk power system, but also by the local transmission and distribution
system operators to support the local power systems.
    For stationary emergency engines above 500 HP that were installed
prior to June 12, 2006, there is currently no emergency demand response
allowance and there is no time limit on the use of emergency engines
for routine testing and maintenance in Sec.  63.6640(f)(2)(ii). Those
engines were not the focus of the 2010 RICE NESHAP amendments;
therefore, the EPA did not make any changes to the requirements for
those engines as part of the 2010 amendments. For consistency, the EPA
is now also proposing that owners and operators of stationary emergency
engines installed prior to June 12, 2006, be permitted to operate their
engines as part of a demand response program as well for a total of 100
hours per year, including time spent for maintenance and testing.
    The EPA is also proposing to amend the NSPS for stationary CI and
SI engines in 40 CFR part 60, subparts IIII and JJJJ, respectively, to
provide the same allowance for stationary emergency engines for
emergency demand response operation as for engines subject to the RICE
NESHAP. The NSPS regulations currently do not include such an allowance
for emergency demand response operation. For the reasons discussed in
section II.B of this preamble as to why the EPA finds it appropriate to
allow stationary emergency engines to participate in emergency demand
response programs and remain being considered emergency units, and for
consistency across engine regulations, the EPA is proposing to add an
emergency demand response allowance under the NSPS regulations.
Consequently, the EPA is proposing to revise the existing language in
Sec. Sec.  60.4211(f) and 60.4219 of 40 CFR part 60, subpart IIII, and
Sec. Sec.  60.4243(d) and 60.4248 of 40 CFR part 60, subpart JJJJ, to
specify that emergency engines may participate in demand response
programs for up to 100 hours per year, including hours spent towards
maintenance and testing of the emergency engines.
    b. Peak Shaving and other Non-emergency Use as Part of a Financial
Arrangement. In addition to the changes the EPA is proposing related to
emergency demand response operation, the EPA is also including a
further

provision for owners and operators of existing stationary emergency
RICE located at area sources for the reasons discussed in section
II.B.1 of this preamble. Paragraph Sec.  63.6640(f) currently allows
owners and operators of emergency stationary RICE to operate their
engine for 50 hours per year in non-emergency situations. As currently
written, the 50 hours per year for non-emergency situations cannot be
used for peak shaving or to generate income for a facility to supply
power to an electric grid or otherwise supply power as part of a
financial arrangement with another entity; except that owners and
operators of certain emergency engines may operate the engine for a
maximum of 15 hours per year as part of an emergency demand response
program. As discussed, the 15 hours per year allowance for emergency
engines to participate in emergency demand response programs is being
increased to 100 hours per year, but will also include hours spent
towards maintaining and conducting readiness testing of the emergency
engines. However, additionally, the EPA is also proposing that
stationary emergency engines located at area sources be permitted to
apply the 50 hours per year that is currently allowed under Sec.
63.6640(f) for non-emergency operation towards any non-emergency
operation, including operation as part of a financial agreement with
another entity. The peak shaving allowance would expire in 2017. The
EPA is specifying that the power can only be used at the facility or
towards the local system, and the engine can only be operated for peak
shaving as part of a program with the local distribution system
operator. The EPA is also clarifying that an engine that exceeds the
calendar year limitations on non-emergency operation, including
emergency demand response or peak shaving, will be considered a non-
emergency engine and subject to the requirements for non-emergency
engines for the remaining life of the engine.

C. Non-Emergency Stationary SI RICE Greater Than 500 HP Located at Area
Sources

1. Background
    The EPA is also proposing to amend the requirements that apply to
existing stationary non-emergency 4 stroke SI RICE greater than 500 HP
located at area sources of HAP emissions, which are generally natural
gas fired engines. Currently, the RICE NESHAP requires owners and
operators of such engines to (1) either meet a CO concentration limit
of 47 parts ppmvd at 15 percent O2 or reduce emissions of CO
by 93 percent or more, if the engines are 4SLB; and (2) to meet a
formaldehyde concentration limit of 2.7 ppmvd at 15 percent
O2 or reduce formaldehyde emissions by 76 percent or more,
if the engines are 4SRB. In both cases, the EPA expects that the
standards would be met using aftertreatment; oxidation catalysts for
4SLB engines and NSCR for 4SRB engines. In addition to these emission
requirements, owners and operators of existing stationary 4-stroke
engines greater than 500 HP at area sources are also subject to
monitoring, testing, recordkeeping and reporting requirements.
    After the final requirements for existing stationary SI engines
greater than 500 HP at area sources were published on August 20, 2010
(75 FR 51570), the EPA received petitions from Exterran (EPA-HQ-OAR-
2008-0708-0581), the American Petroleum Institute (EPA-HQ-OAR-2008-
0708-0582), the Interstate Natural Gas Association of America (EPA-HQ-
OAR-2008-0708-0584), and the Gas Processors Association (EPA-HQ-OAR-
2008-0708-0587) requesting that the EPA reconsider the requirements of
the final rule. The petitioners expressed many similar concerns. As
relevant to this rulemaking, petitioners stated that the EPA did not
take into account the difference in population density and subsequently
did not consider the difference in health impacts in remote versus more
heavily populated locations. In the petitioners' opinion, there should
be less concern about engines that are located farther away from
people; the petitioners believed that the EPA has substantial latitude
in requiring less stringent standards for owners and operators of
stationary engines in remote areas.
    While the EPA does not share all of the views of the petitioners
regarding the difference between engines based on their location, the
EPA does believe that it is reasonable to create a subcategory of
existing stationary SI 4SLB and 4SRB engines above 500 HP located in
areas remote from human activity. Engines located in remote areas that
are not close to significant human activity may be difficult to access,
may not have electricity or communications, and may be unmanned most of
the time. The costs of the emission controls, testing, and continuous
monitoring requirements may be unreasonable when compared to the HAP
emission reductions that would be achieved, considering that the
engines are in sparsely populated areas. The EPA believes that
establishing a subcategory for SI engines at area sources of HAP
located in sparsely populated areas accomplishes the agency's goals and
is adequate in protecting public health.
    The EPA is proposing to subcategorize sparsely populated engines
using criteria based on the existing DOT classification system for
natural gas pipelines. This system classifies locations based on their
distance to natural gas pipelines covered by the Pipeline and Hazardous
Materials Safety Administration safety regulations. The DOT system
defines a class location unit as an onshore area that extends 220 yards
or 200 meters on either side of the centerline of any continuous 1-mile
(1.6 kilometers) length of natural gas pipeline. The DOT approach
further classifies pipeline locations into Class 1 through Class 4
locations based on the number of buildings intended for human
occupancy. A Class 1 location is defined as an offshore area or any
class location unit that has 10 or fewer buildings intended for human
occupancy. The DOT classification system also has special provisions
for locations that lie within 100 yards (91 meters) of either a
building or a small, well-defined outside area (such as a playground,
recreation area, outdoor theater, or other place of public assembly)
that is occupied by 20 or more persons on at least 5 days a week for 10
weeks in any 12-month period. To be considered remote under this
proposal, a source could not fall under this special provision and, in
addition, must be in a Class 1 location. The EPA requests comment on
whether engines located in class location units where buildings with
four or more stories above ground are prevalent (Class 4 areas under
the DOT classification system) should also specifically not be
considered remote.
    Stakeholders from the oil and gas industry have indicated to the
EPA that the DOT system is well-established and there would be
substantial overlap between engines on natural gas pipelines affected
by the rule and covered by the DOT pipeline classification system.
Incorporating this approach would also create harmonization between the
EPA and DOT and would reduce the implementation and enforcement burden
for states. Implementation for affected sources would also be less
burdensome because the system is already in place and used by the
natural gas pipeline industry and covers the majority of these engines.
Stakeholders have indicated they are required to review the class
location status of natural gas pipeline segments annually. The EPA
believes this approach is reasonable for defining the subcategory

of remote engines for those engines that are associated with natural
gas pipelines. For those engines not associated with pipelines, the EPA
is using similar criteria. An engine would be considered to be in
sparsely populated areas if within 0.25 mile radius of the engine there
are 5 or fewer buildings intended for human occupancy. EPA requests
comment on whether, to be considered remote, an engine not associated
with a natural gas pipeline should also need to be farther than 100
yards (91 meters) of either a building or a small, well-defined outside
area (such as a playground, recreation area, outdoor theater, or other
place of public assembly) that is occupied by 20 or more persons on at
least 5 days a week for 10 weeks in any 12-month period.
    The EPA is proposing management practices as generally available
control technologies for existing stationary SI 4SLB and 4SRB area
source non-emergency engines located in sparsely populated areas. Given
the remote location of the engines from human activity, the EPA
believes that it is appropriate not to include requirements that would
necessitate aftertreatment and extensive testing and monitoring. The
EPA has previously estimated that the costs of oxidation catalyst for
existing 4SLB and 4SRB engines above 500 HP at area sources are $310
and $150 million, for capital and annual costs, respectively. The
capital and annual costs of the RICE NESHAP for existing 4SLB and 4SRB
engines above 500 HP at area sources would be $30 million and $12
million, respectively, if these proposed amendments are incorporated
into the rule. Creating a subcategory of these engines for the ones
located in sparsely populated areas and not mandating emission controls
would significantly reduce the cost of the rule for such engines.
    For existing stationary SI 4SLB and 4SRB area source non-emergency
engines that are located in populated areas, the EPA is proposing an
equipment standard that requires the installation and operation of a
catalyst that will have to be tested initially and annually to ensure
that the catalyst is working properly and reducing emissions as
required. In addition, these units will be required to have devices to
shut down the engine if the catalyst is exposed to dangerous
temperatures or have continuous monitoring equipment installed to
record catalyst inlet temperatures. The EPA is proposing shorter test
duration and less rigorous methods than currently required while still
ensuring that HAP reductions remain at expected levels for these
engines located in populated areas. The specific amendments the EPA is
proposing are discussed below.
2. Proposed Amendments
    Owners and operators of engines in sparsely populated areas would
have to conduct a review of the surrounding area every 12 months to
determine if the nearby population has changed. If the engine no longer
meets the criteria for a sparsely populated area the owner and operator
must within 1 year comply with the emission standards specified below
for populated areas. The EPA requests comment on whether engines that
are not associated with pipelines should be required to conduct the
review less frequently than every 12 months.
    Owners and operators of existing stationary 4SLB and 4SRB greater
than 500 HP at area sources that are in sparsely populated areas as
described above would be required to perform the following:
     Change oil and filter every 1,440 hours of operation or
annually, whichever comes first;
     Inspect spark plugs every 1,440 hours of operation or
annually, whichever comes first, and replace as necessary; and
     Inspect all hoses and belts every 1,440 hours of operation
or annually, whichever comes first, and replace as necessary.

Sources have the option to use an oil analysis program as described in
Sec.  63.6625(i) of the rule in order to extend the specified oil
change requirement. The oil analysis must be performed at the same
frequency specified for changing the oil in Table 2d of the rule. The
analysis program must at a minimum analyze the following three
parameters: Total Acid Number, viscosity, and percent water content.
The condemning limits for these parameters are as follows: Total Acid
Number increases by more than 3.0 milligrams of potassium hydroxide per
gram from Total Acid Number of the oil when new; viscosity of the oil
has changed by more than 20 percent from the viscosity of the oil when
new; or percent water content (by volume) is greater than 0.5. If all
of these condemning limits are not exceeded, the engine owner or
operator is not required to change the oil. If any of the limits are
exceeded, the engine owner or operator must change the oil within 2
days of receiving the results of the analysis; if the engine is not in
operation when the results of the analysis are received, the engine
owner or operator must change the oil within 2 days or before
commencing operation, whichever is later. The owner or operator must
keep records of the parameters that are analyzed as part of the
program, the results of the analysis, and the oil changes for the
engine. The analysis program must be part of the maintenance plan for
the engine.
    Owners and operators of existing stationary 4SLB and 4SRB area
source engines above 500 HP in sparsely populated areas would also have
to operate and maintain the stationary RICE and aftertreatment control
device (if any) according to the manufacturer's emission-related
written instructions or develop their own maintenance plan which must
provide to the extent practicable for the maintenance and operation of
the engine in a manner consistent with good air pollution control
practice for minimizing emissions.
    For engines in populated areas, i.e., existing stationary 4SLB and
4SRB non-emergency engines greater than 500 HP at area sources that are
located on DOT Class 2 through Class 4 pipeline segments or, for
engines not associated with pipelines, that do not meet the 0.25 mile
radius with 5 or less buildings criteria, the EPA is proposing to adopt
an equipment standard requiring the installation of a catalyst to
reduce HAP emissions. Owners and operators of existing area source 4SLB
non-emergency engines greater than 500 HP in populated areas would be
required to install an oxidation catalyst. Owners and operators of
existing area source 4SRB non-emergency engines greater than 500 HP in
populated areas would be required to install NSCR. Owners and operators
must conduct an initial test to demonstrate that the engine achieves at
least a 93 percent reduction in CO emissions or a CO concentration
level of 47 ppmvd at 15 percent O2, if the engine is a 4SLB
engine. Similarly, owners and operators must conduct an initial
performance test to demonstrate that the engine achieves at least a 75
percent CO reduction or a 30 percent THC reduction, if the engine is a
4SRB engine. The initial test must consist of three test runs. Each
test run must be of at least 15 minute duration, except that each test
run conducted using the proposed appendix A to 40 CFR part 63, subpart
ZZZZ must consist of one measurement cycle as defined by the method and
include at least 2 minutes of test data phase measurement. To measure
CO, emission sources must use the CO methods already specified in
subpart ZZZZ, or the proposed appendix A to 40 CFR part 63, subpart
ZZZZ. The THC testing must be conducted using EPA Method 25A.

    The owner or operator of both engine types must also use a high
temperature shutdown device that detects if the catalyst inlet
temperature is too high, or, alternatively, the owner or operator can
monitor the catalyst inlet temperature continuously and maintain the
temperature within the range specified in the rule. For 4SLB engines
the catalyst inlet temperature must remain at or above 450 [deg]F and
at or below 1,350 [deg]F. For 4SRB engines the temperature range must
be greater than or equal to 750 [deg]F and less than or equal to 1,250
[deg]F at the catalyst inlet.
    Owners and operators must in addition to the initial performance
test conduct annual checks of the catalyst to ensure proper catalyst
activity. The annual check of the catalyst must at a minimum consist of
one 15-minute run using the methods discussed above, except that each
test run conducted using the proposed appendix A to 40 CFR part 63,
subpart ZZZZ must consist of one measurement cycle as defined by the
method and include at least 2 minutes of test data phase measurement.
Owners and operators of 4SLB engines must demonstrate during the
catalyst activity test that the catalyst achieves at least a 93 percent
reduction in CO emissions or that the engine exhaust CO emissions are
no more than 47 ppmvd at 15 percent O2. Owners and operators
of 4SRB engines must demonstrate that their catalyst is reducing CO
emissions by 75 percent or more, or alternatively, that THC emissions
are being reduced by at least 30 percent during the catalyst activity
check.
    If the emissions from the engine do not exceed the levels required
for the initial test or annual checks of the catalyst, then the
catalyst is considered to be working properly. If the emissions exceed
the specified pollutant levels in the rule, the exceedance(s) is/are
not considered a violation, but the owner or operator would be required
to shut down the engine and take appropriate corrective action (e.g.,
repairs, clean or replace the catalyst, as appropriate). A follow-up
test must be conducted within 7 days of the engine being started up
again to demonstrate that the emission levels are being met. If the
retest shows that the emissions continue to exceed the specified
levels, the stationary RICE must again be shut down as soon as safely
possible, and the engine may not operate, except for purposes of start-
up and testing, until the owner/operator demonstrates through testing
that the emissions do not exceed the levels specified.

D. Stationary Agricultural RICE in San Joaquin Valley

    In the 2010 amendments to the RICE NESHAP, the EPA required
existing non-emergency CI engines above 300 HP to meet a standard of
either 70 percent reduction of CO emissions or 49 ppmvd CO, for engines
between 300 and 500 HP, or 23 ppmvd CO for engines above 500 HP. The
requirements also included testing and monitoring provisions. As with
all requirements for existing engines in that rule, owners and
operators were required to meet the requirements within 3 years of the
effective date of the regulations (May 3, 2013).
    Since the finalization of the rule for existing stationary CI
engines, stakeholders from the agricultural industry in the San Joaquin
Valley area of California have expressed concern regarding the effect
of certain of these requirements on engines in the San Joaquin Valley.
The San Joaquin Valley Air Pollution Control District (APCD) has
indicated that there are 17 stationary CI engines at area sources in
San Joaquin Valley certified to the Tier 3 standards in 40 CFR part 89
that were installed between January 1 and June 12, 2006. Under the
NESHAP, stationary CI engines at area sources are existing if
construction of the engine commenced prior to June 12, 2006. These 17
Tier 3 engines in the San Joaquin Valley, which were built to meet
stringent emission standards, would not be able to comply with the
applicable RICE NESHAP emission standards for existing engines without
further testing and monitoring, and possible retrofit with further
controls, due to differences in the emission standards and testing
protocols in the RICE NESHAP versus the Tier 3 standards in 40 CFR part
89. However, an identical engine certified to the Tier 3 standards (or
Tier 2 standards for engines above 560 kilowatts (kW)) in 40 CFR part
89 that was installed after June 12, 2006, would not have to be
retrofit in order to comply with the NESHAP. Stationary CI engines
installed after June 12, 2006, at area sources of HAP are required to
comply with the NSPS for stationary CI engines, which requires engines
to be certified to the standards in 40 CFR parts 89, 94, 1039, and
1042, as applicable. Thus, a 2006 model year stationary CI engine
installed after June 12, 2006, that is certified to the applicable
standards would meet the requirements of the NESHAP without further
controls or testing. While the EPA does not know if other certified
Tier 3 engines besides these 17 engines in the San Joaquin Valley were
installed prior to June 12, 2006, EPA believes the same rationale
should apply to any such engine.
    The EPA believes that the Tier 3 standards (Tier 2 for engines
above 560 kW) are technologically stringent regulations and believes it
is unnecessary to require further regulation of engines meeting these
standards. Engines meeting the Tier 3 standards typically employed
emission control technologies such as combustion optimization and
better fuel control to meet the Tier 3 standards. In order to address
the concerns raised by the engine owners in the San Joaquin Valley, the
EPA is proposing changes to amend the requirements for any certified
Tier 3 (Tier 2 for engines above 560 kW) stationary CI engine located
at an area source and installed before June 12, 2006. The EPA is
proposing amendments to specify that any existing certified Tier 3
(Tier 2 for engines above 560 kW) CI engine that was installed before
June 12, 2006, is in compliance with the NESHAP. This amendment would
include any existing stationary Tier 3 (Tier 2 for engines above 560
kW) certified CI engine located at an area source of HAP emissions.
    Another concern brought to the EPA's attention by the San Joaquin
Valley agricultural industry is that due to state and local
requirements in the San Joaquin Valley, many of the Tier 1 and Tier 2
stationary CI engines that are regulated as existing sources under the
NESHAP must be replaced in the next few years, only a short time after
the emission standards for existing engines must be met. Specifically,
the San Joaquin Valley APCD rule for internal combustion engines (Rule
4702) requires Tier 1 and Tier 2 certified engines to meet Tier 4
standards by January 1, 2015, or 12 years after the installation date,
but no later than June 1, 2018. The concern is that owners and
operators of these engines would have to install aftertreatment by 2013
to meet the emission standards of the RICE NESHAP and then only a few
years later be required to replace their engines per San Joaquin Valley
APCD Rule 4702. The San Joaquin Valley APCD has identified 49 Tier 1
engines and 360 Tier 2 engines that are scheduled to be replaced under
the local rule. The EPA has not identified any engines outside the San
Joaquin Valley APCD area that are in the same or similar situation
(i.e., required to be replaced shortly after the compliance date for
existing engines), but the EPA does not preclude the possibility that
there are such engines in other areas, and requests comment and
information on other areas that may have similar concerns.

    The EPA does not think it is appropriate to require emission
controls on a stationary CI engine that is going to be retired only a
short time after the rule goes into effect. Stationary CI engines would
have to comply with this rule by May 3, 2013, and owners of engines
above 300 HP are expected to have to install aftertreatment on their
engines in order to meet the emission standards. The EPA estimates that
the one-time cost to equip a 500 HP stationary CI engine with the
controls necessary to meet the emission standards under this rule is
close to $14,000 and more than $3,000 on a yearly basis, not accounting
for additional costs associated with monitoring, testing, recordkeeping
and reporting. These engines (equipped with aftertreatment) could end
up being in operation for less than 2 years or at most only 5 years
before having to be replaced with a certified Tier 4 engine, as
required by San Joaquin Valley District Rule 4702. It would not be
reasonable to require the engine owner to invest in costly controls and
monitoring equipment for an engine that will be replaced shortly after
the installation of the controls.
    Consequently, the EPA is proposing amendments to existing
stationary CI engines located at area sources of HAP emissions to
address this concern. The EPA is proposing to amend the requirements
for existing stationary Tier 1 and Tier 2 certified CI engines located
at area sources that are greater than 300 HP that are subject to a
state or local rule that requires the engine to be replaced. The EPA is
proposing to allow these engines to meet management practices from the
applicable May 3, 2013, compliance date until January 1, 2015, or 12
years after installation date (whichever is later), but not later than
June 1, 2018. This proposed change would provide owners enough time to
replace their engines without mandating a possibly cost prohibitive
requirement to change all of the engines in a short amount of time,
while still requiring that replacement of the engine or a retrofit of
the engine occur relatively quickly after the owner would have to
comply with the NESHAP. The EPA is proposing that these engines be
subject to management practices until January 1, 2015, or 12 years
after installation date (whichever is later), but not later than June
1, 2018, after which time the CO emission standards discussed above
(and that are in Table 2d of the rule) apply. The management practices
include requirements for when to inspect and replace the engine oil and
filter, air cleaner, hoses and belts. The complete details of which
management practices are required are shown in Table 2d of the rule.
Owners and operators of these existing stationary CI engines located at
area sources of HAP emissions that intend to meet management practices
rather than the emission limits prior to January 1, 2015, or 12 years
after installation date, but not later than June 1, 2018, must submit a
notification by March 3, 2013, stating that they intend to use this
provision and identifying the state or local regulation that the engine
is subject to.

E. Remote Areas of Alaska

1. Background
    The RICE NESHAP currently specifies less stringent requirements for
existing non-emergency CI engines at area sources located in remote
areas of Alaska. Remote areas are defined as those not accessible by
the FAHS. The FAHS includes areas with year-round ferry service that
are not on the contiguous road system. Under the current regulation,
stationary non-emergency CI engines at area sources in areas of Alaska
that are not accessible by the FAHS are subject to management practices
as opposed to numerical emission standards.
    Following the publication of the final rule in 2010, the EPA
received requests to expand the definition of remote areas of Alaska.
Stakeholders asserted that facilities in areas that are accessible by
the FAHS but are not connected to the Alaska Railbelt grid face the
same challenges as those in areas not accessible by the FAHS. The
Alaska Railbelt Grid refers to the service areas of the six regulated
public utilities that extend from Fairbanks to Anchorage and the Kenai
Peninsula. These utilities are the Golden Valley Electric Association,
Chugach Electric Association, Matanuska Electric Association, Homer
Electric Association, Anchorage Municipal Light & Power, and the City
of Seward Electric System. According to the stakeholders, one reason
for broadening the definition of remote areas in Alaska is high energy
costs, which provide a natural incentive to run CI engines as little as
possible. The cost of energy is utilities' greatest concern in Alaska.
Also, the stakeholders indicated that extreme weather conditions in
certain areas of Alaska is another reason for including additional
areas in the definition of remote areas of Alaska. The climate issue is
unique to remote areas of Alaska that experience some of the most
extreme temperatures in the country. Heavy snowfall and high winds are
not uncommon in several areas that are accessible by the FAHS. For
instance, Copper Valley Electric Association (CVEA) is a utility
accessible by the FAHS, but it includes areas that face the same
challenges as other communities not accessible by the FAHS. The utility
operates on an isolated grid and relies on diesel power generation. In
one of CVEA's territories, Valdez, Alaska, CVEA indicated that this
area experiences brutal conditions and stated that Valdez is considered
to have the greatest snowfall (326 inches per winter) in any city of
the United States. Also, winds at more than 100 miles per hour are not
uncommon for Valdez, Alaska, according to CVEA. Temperatures between 40
and 50 below zero are also not abnormal, which emphasizes the extreme
reliance on power, CVEA asserted. Travel times and accessibility are
issues on a regular basis, but can be additionally exacerbated due to
severe weather, which in some cases may lead to avalanches and road
closings. In particular, even if a site is on the FAHS, in the event of
poor weather conditions and road closings, there are in many cases no
alternate roads to travel on. Further, access to specific isolated
sites can also be problematic in particular remote areas of Alaska and
the problems are unique to Alaska because of the infrastructure and
environment. For example, communities made the case that sources along
the AMHS that are only accessible by the AMHS should be treated the
same way as communities not accessible by the FAHS. The AMHS primarily
serves passengers and vehicles, and is not intended for transporting
goods. Therefore, the same methods used to bring in goods to
communities not on the FAHS are the same as those Alaskan villages
served only by the AMHS. Goods are typically brought in to remote
communities by barge and this is another example of a scenario that is
unique to Alaska. Other arguments for expanding the definition of
remote areas of Alaska beyond those not accessible by the FAHS include
very low population density in many other remote areas although
accessible by the FAHS, and the fact that many of these areas are not
connected to the electric grid and rely on back up diesel generation to
support fluctuating renewable energy systems. The energy supply system
is another area that is particularly different in Alaska compared to
the rest of the country where the majority of customers are connected
to the grid. Therefore, for the reasons discussed, the EPA is proposing
expansion of the remote area source category. This proposal is
supported by the Alaska Department of

Environmental Conservation and communities with whom the EPA has
discussed this issue.
2. Proposed Amendments
    The EPA is proposing to expand the current definition of remote
areas of Alaska to extend beyond areas that are not accessible by the
FAHS. Specifically, the EPA is proposing that areas of Alaska that are
accessible by the FAHS and that meet all of the following criteria are
also considered remote and subject to management practices under the
rule:
     The stationary CI engine is located in an area not
connected to the Alaska Railbelt Grid,
     At least 10 percent of the power generated by the engine
per year is used for residential purposes, and
     The system capacity is less than 12 megawatts, or the
engine is used exclusively for backup power for renewable energy and is
used less than 500 hours per year on a 10-year rolling average.

The EPA is proposing limiting the remote classification to engines that
are used at least partially for residential purposes, where the impact
of higher energy costs is of greatest concern. The classification is
further limited to sources that are used infrequently as backup for
renewable power, or that are at smaller capacity facilities, which are
generally in more sparsely populated areas.

F. Miscellaneous Corrections and Revisions

    The EPA is making some minor corrections to the stationary engine
rules to address miscellaneous issues. The EPA is making some minor
revisions in the rules to correct mistakes in the current rules or to
clarify the rules. The revisions are as follows:
     Revising Tables 1b and 2b of 40 CFR part 63, subpart ZZZZ
to correct language requiring the pressure drop to be at plus or minus
10 percent 100 percent load for all engines. The engines that were
regulated in 2010 are not subject to the load requirements and
therefore the EPA is correcting these tables to make this clear.
     Adding a footnote to Table 1b of 40 CFR part 63, subpart
ZZZZ stating that sources can petition the Administrator for a
different temperature range consistent with Table 2b of the rule.
     Correcting rows 8 and 10 in Table 2d of 40 CFR part 63,
subpart ZZZZ to indicate that the requirements apply to non-emergency,
non-black start stationary RICE greater than 500 HP that are 4SLB and
4SRB that operate more than 24 hours per year, as intended in the
original rule.
     Revising the language in Sec.  63.6625(b) of 40 CFR part
63, subpart ZZZZ that states ``* * * in paragraphs (b)(1) through (5)
of this section'' to ``in paragraphs (b)(1) through (6) of this
section.''
     Changing Tables 2c and 2d of 40 CFR part 63, subpart ZZZZ,
where it currently specifies to inspect air cleaner, to also specify
that it must be replaced as necessary.
     Revising Sec.  63.6620(b) of 40 CFR part 63, subpart ZZZZ
to indicate that testing must be conducted within plus or minus 10
percent of 100 percent load for stationary RICE greater than 500 HP
located at a major source (except existing non-emergency CI stationary
RICE greater than 500 HP located at a major source) that are subject to
testing.
     Specifying that, as was intended in the rule adding these
requirements, the operating limitations (pressure drop and catalyst
inlet temperature) in Tables 1b and 2b of 40 CFR part 63, subpart ZZZZ
do not have to be met during startup.
     For consistency, and as provided in the original RICE
NESHAP for other stationary RICE, clarifying in 40 CFR part 63, subpart
ZZZZ that the existing stationary RICE regulated in 2010 (i.e., engines
constructed before June 12, 2006 that are less than or equal to 500 HP
located at major sources or engines located at area sources) must burn
landfill or digester gas equivalent to 10 percent or more of the gross
heat input on an annual basis in order to qualify as a landfill or
digester gas engine under the rule.
     Clarifying Sec.  60.4207(b) of 40 CFR part 60, subpart
IIII to specify that owners and operators of stationary CI engines less
than 30 liters per cylinder that are subject to the subpart that use
diesel fuel must use diesel fuel that meets the requirements of 40 CFR
80.510(b), except owners and operators may use up any diesel fuel
acquired prior to October 1, 2010, that does not meet the requirements
of 40 CFR 80.510(b) for nonroad diesel fuel.
     Adding appendix A to 40 CFR part 63, subpart ZZZZ, which
includes procedures that can be used for measuring CO emissions from
existing stationary 4SLB and 4SRB stationary RICE above 500 HP located
at area sources of HAP that are complying with the emission limits in
Table 2d of 40 CFR part 63, subpart ZZZZ.
     Reinstating the footnotes for Table 2 of 40 CFR part 60,
subpart JJJJ. The footnotes were inadvertently removed when the rule
was amended on June 28, 2011 (76 FR 37954).
     Adding ``part 60'' in Table 4 of the NESHAP, in row 2
where it refers to 40 CFR appendix A.
     Clarifying in Sec.  63.6625(a) of 40 CFR part 63, subpart
ZZZZ that a continuous emission monitoring system is only required to
be installed at the outlet of the control device for engines that are
complying with the requirement to limit the concentration of CO.
     Clarifying that, as was intended in the rule adding these
requirements, all of the standards for stationary SI RICE in Sec.
60.4231(b) of 40 CFR part 60, subpart JJJJ are for stationary SI RICE
that use gasoline.
     Clarifying that, as was intended in the rule adding these
requirements, all of the standards for stationary SI RICE in Sec.
60.4231(c) of 40 CFR part 60, subpart JJJJ are for stationary SI RICE
that are rich burn engines that use LPG.
     Clarifying that, as was intended in the rule adding these
requirements, all of the standards for stationary SI RICE in Sec.
60.4231(d) of 40 CFR part 60, subpart JJJJ are for stationary SI RICE
that are not gasoline engines or rich burn engines that use LPG.

G. Compliance Date

    The EPA has received questions regarding whether the compliance
dates for engines impacted by the 2010 amendments and this proposed
reconsideration will be extended. Affected sources that may be impacted
by this action have expressed concern about having sufficient time to
comply with the rule by the compliance date, which is May 3, 2013, for
existing stationary CI RICE and October 19, 2013, for existing
stationary SI RICE. Sources impacted by this reconsideration are
particularly concerned with compliance in the event that the EPA does
not finalize changes that are substantially similar to the changes
being proposed in this action. The EPA does not intend to extend the
May 3, 2013, and October 19, 2013, compliance dates, because there are
many engines that must meet those compliance dates that are not
impacted by this reconsideration. However, the EPA notes that sources
that are affected by the reconsideration and that may need additional
time to install controls to comply with the applicable requirements can
request up to an additional year to install controls, as specified in
40 CFR 63.6(i). The EPA requests comment regarding whether special
consideration should be given to engines whose requirements would be
reduced by this proposal if, in the final rule, the EPA does not
finalize the proposed reduced requirements.

III. Summary of Environmental, Energy and Economic Impacts

A. What are the air quality impacts?

    The EPA estimates that the rule with the proposed amendments
incorporated will reduce emissions from existing stationary RICE as
shown in Table 1 of this preamble. The emissions reductions the EPA
previously estimated for the 2010 amendments to the RICE NESHAP are
shown for comparison. Reductions are shown for the year 2013, which is
the first year the final RICE NESHAP will be implemented for existing
stationary RICE.

                           Table 1--Summary of Reductions for Existing Stationary RICE
----------------------------------------------------------------------------------------------------------------
                                                                  Emission reductions (tpy) in the year 2013
                                                             ---------------------------------------------------
                                                                   2010 Final rule        2010 Final rule with
                          Pollutant                          --------------------------      these proposed
                                                                                amendments
                                                                   CI           SI     -------------------------
                                                                                CI           SI
----------------------------------------------------------------------------------------------------------------
HAP.........................................................        1,014        6,008        1,005        1,778
CO..........................................................       14,342      109,321       14,238       22,211
PM..........................................................        2,844          N/A        2,818          N/A
NOX.........................................................          N/A       96,479          N/A        9,648
VOC.........................................................       27,395       30,907       27,142        9,147
----------------------------------------------------------------------------------------------------------------

    The EPA estimates that more than 900,000 stationary CI engines will
be subject to the rule in total, but only a small number of stationary
CI engines are affected by the proposed amendments in this action. It
is estimated that approximately 330,000 stationary SI engines will be
subject to the rule in total; however, only a subset of stationary SI
engines are affected by the proposed amendments in this action. The
decrease in estimated reductions for SI engines is primarily due to
proposed amendments to the requirements for existing 4SRB and 4SLB SI
engines larger than 500 HP at area sources of HAP that are in remote
areas. Those engines were required by the 2010 rule to meet emission
limits that were expected to require the installation of aftertreatment
to reduce emissions; under these proposed amendments, those engines are
required to meet management practices that would not require the
installation of aftertreatment. Further information regarding the
estimated reductions of this final rule can be found in the memorandum
titled, ``RICE NESHAP Reconsideration Amendments--Cost and
Environmental Impacts,'' which is available in the docket (EPA-HQ-OAR-
2008-0708). The EPA did not estimate any reductions associated with the
minor changes to the NSPS for stationary CI and SI engines.

B. What are the cost impacts?

    The proposed amendments are expected to reduce the overall cost of
the original 2010 RICE NESHAP amendments. The EPA estimates that with
these proposed amendments incorporated the cost of the rule for
existing stationary RICE will be as shown in Table 2 of this preamble.
The costs the EPA previously estimated for the 2010 amendments to the
RICE NESHAP are shown for comparison. The costs that were previously
estimated are shown in the original year ($2008 for CI and $2009 for
SI), as well as updated to 2010 dollars.

                          Table 2--Summary of Cost Impacts for Existing Stationary RICE
----------------------------------------------------------------------------------------------------------------

----------------------------------------------------------------------------------------------------------------
Engine                             2010 Final rule.....       2010 Final rule with these proposed amendments
----------------------------------------------------------------------------------------------------------------
                                                Total Annual Cost
----------------------------------------------------------------------------------------------------------------
SI...............................  $253 million ($2009)  $251 million ($2010)  $115 million ($2010).
CI...............................  $373 million ($2008)  $375 million ($2010)  $373 million ($2010).
----------------------------------------------------------------------------------------------------------------
                                               Total Capital Cost
----------------------------------------------------------------------------------------------------------------
SI...............................  $383 million ($2009)  $380 million ($2010)  $103 million ($2010).
CI...............................  $744 million ($2008)  $748 million ($2010)  $740 million ($2010).
----------------------------------------------------------------------------------------------------------------

Further information regarding the estimated cost impacts of the
proposed amendments, including the cost of the proposed amendments in
2010 dollars, can be found in the memorandum titled, ``RICE NESHAP
Reconsideration Amendments--Cost and Environmental Impacts,'' which is
available in the docket (EPA-HQ-OAR-2008-0708). The EPA did not
estimate costs associated with the changes to the NSPS for stationary
CI and SI engines. The changes to the NSPS are minor and are not
expected to impact the costs of those rules.

C. What are the benefits?

    Emission controls installed to meet the requirements of these rules
will generate benefits by reducing emissions of HAP as well as criteria
pollutants and their precursors, including CO, NOX and VOC.
NOX and VOC are precursors to PM2.5 (particles
smaller than 2.5 microns) and ozone. The criteria pollutant benefits
are considered co-benefits for these rules. For these rules, we were
only able to quantify the health co-benefits associated with reduced
exposure to PM2.5 from emission reductions of NOX
and directly emitted PM2.5.
    The EPA previously estimated that the monetized co-benefits in 2013
of the stationary CI NESHAP would be $940 million to $2,300 million
(2008 dollars) at a 3-percent discount rate and $850 million to $2,100
million (2008 dollars)

at a 7-percent discount rate.\5\ For stationary SI engines, EPA
previously estimated that the monetized co-benefits in 2013 would be
$510 million to $1,200 million (2009 dollars) at a 3-percent discount
rate) and $460 million to $1,100 million (2009 dollars) at a 7-percent
discount rate.\6\
---------------------------------------------------------------------------

    \5\ U.S. Environmental Protection Agency. 2010. Regulatory
Impact Analysis (RIA) for Existing Stationary Compression Ignition
Engines NESHAP: Final Draft. Research Triangle Park, NC. February.
http://www.epa.gov/ttn/ecas/regdata/RIAs/CIRICENESHAPRIA2-17-0cleanpublication.pdf.
    \6\ U.S. Environmental Protection Agency. 2010. Regulatory
Impact Analysis (RIA) for Existing Stationary Spark Ignition (SI)
RICE NESHAP: Final Report. Research Triangle Park, NC. August.
http://www.epa.gov/ttn/ecas/regdata/RIAs/riceriafinal.pdf.
---------------------------------------------------------------------------

    The proposed amendments are expected to reduce the overall emission
reductions of the rules. In addition to revising the anticipated
emission reductions, we have also updated the methodology used to
calculate the co-benefits to be consistent with methods used in more
recent rulemakings, which is summarized below and discussed in more
detail in the Regulatory Impact Analysis (RIA). We estimate the
monetized co-benefits of the proposed amendments of the CI NESHAP in
2013 to be $770 million to $1,900 million (2010 dollars) at a 3-percent
discount rate and $690 million to $1,700 million (2010 dollars) at a 7-
percent discount rate. For SI engines, we estimate the monetized co-
benefits of the proposed amendments in 2013 to be $62 million to $150
million (2010 dollars) at a 3-percent discount rate and $55 million to
$140 million (2010 dollars) at a 7-percent discount rate.
    Using alternate relationships between PM2.5 and
premature mortality supplied by experts, higher and lower co-benefits
estimates are plausible, but most of the expert-based estimates fall
between these two estimates.\7\ A summary of the monetized co-benefits
estimates for CI and SI engines at discount rates of 3 percent and 7
percent is in Table 3 of this preamble.
---------------------------------------------------------------------------

    \7\ Roman, et al., 2008. Expert Judgment Assessment of the
Mortality Impact of Changes in Ambient Fine Particulate Matter in
the U.S., Environ. Sci. Technol., 42, 7, 2268-2274.

 Table 3--Summary of the Monetized PM2.5 Co-Benefits for Proposed Amendments to the NESHAP for Stationary CI and
                                                   SI Engines
                                         [Millions of 2010 dollars] a,b
----------------------------------------------------------------------------------------------------------------
                                                                 Total monetized co-       Total monetized co-
            Pollutant                 Emission reductions       benefits  (3 percent      benefits  (7 percent
                                        (tons per year)               discount)                 discount)
----------------------------------------------------------------------------------------------------------------
                                          Original 2010 Final Rules \c\
----------------------------------------------------------------------------------------------------------------
Stationary CI Engines:
    Total Benefits...............  2,844 PM2.5..............  $950 to $2,300..........  $860 to $2,100.
                                   27,395 VOC...............
Stationary SI Engines:
    Total Benefits...............  96,479 NOX...............  $510 to $1,300..........  $470 to $1,100.
                                   30,907 VOC...............
----------------------------------------------------------------------------------------------------------------
                                 2010 Final Rules with these Proposed Amendments
----------------------------------------------------------------------------------------------------------------
Stationary CI Engines:
    Directly emitted PM2.5.......  2,818....................  $770 to $1,900..........  $690 to $1,700.
Stationary SI Engines:
    NOX..........................  9,648....................  $62 to $150.............  $55 to $140.
----------------------------------------------------------------------------------------------------------------
\a\ All estimates are for the analysis year (2013) and are rounded to two significant figures so numbers may not
  sum across rows. The total monetized co-benefits reflect the human health benefits associated with reducing
  exposure to PM2.5 through reductions of PM2.5 precursors, such as NOX and directly emitted PM2.5. It is
  important to note that the monetized co-benefits do not include reduced health effects from exposure to HAP,
  direct exposure to NO2, exposure to ozone, ecosystem effects or visibility impairment.
\b\ PM co-benefits are shown as a range from Pope, et al. (2002) to Laden, et al. (2006). These models assume
  that all fine particles, regardless of their chemical composition, are equally potent in causing premature
  mortality because the scientific evidence is not yet sufficient to allow differentiation of effects estimates
  by particle type.
\c\ The benefits analysis for the 2010 final rules applied out-dated benefit-per-ton estimates compared to the
  updated estimates described in this preamble and reflected monetized co-benefits for VOC emissions, which
  limits direct comparability with the monetized co-benefits estimated for these proposed rules. In addition,
  these estimates have been updated from their original currency years to 2010$, so the rounded estimates for
  the 2010 final rules may not match the original RIAs.

    These co-benefits estimates represent the total monetized human
health benefits for populations exposed to less PM2.5 in
2013 from controls installed to reduce air pollutants in order to meet
these rules. To estimate human health co-benefits of these rules, the
EPA used benefit-per-ton factors to quantify the changes in
PM2.5-related health impacts and monetized benefits based on
changes in directly emitted PM2.5 and NOX
emissions. These benefit-per-ton factors were derived using the general
approach and methodology laid out in Fann, Fulcher, and Hubbell
(2009).\8\ This approach uses a model to convert emissions of
PM2.5 precursors into changes in ambient PM2.5
levels and another model to estimate the changes in human health
associated with that change in air quality, which are then divided by
the emission reductions to create the benefit-per-ton estimates.
However, for these rules, we utilized air quality modeling of emissions
in the ``Non-EGU Point other'' category because we do not have modeling
specifically for stationary engines.9 10

The primary difference between the estimates used in this analysis and
the estimates reported in Fann, Fulcher, and Hubbell (2009) is the air
quality modeling data utilized. While the air quality data used in
Fann, Fulcher, and Hubbell (2009) reflects broad pollutant/source
category combinations, such as all non-EGU stationary point sources,
the air quality modeling data used in this analysis has narrower sector
categories. In addition, the updated air quality modeling data reflects
more recent emissions data (2005 rather than 2001) and has a higher
spatial resolution (12-km rather than 36-km grid cells). The benefits
methodology, such as health endpoints assessed, risk estimates applied,
and valuation techniques applied did not change. As a result, the
benefit-per-ton estimates presented herein better reflect the
geographic areas and populations likely to be affected by this sector.
However, these updated estimates still have similar limitations as all
national-average benefit-per-ton estimates in that they reflect the
geographic distribution of the modeled emissions, which may not exactly
match the emission reductions in this rulemaking, and they may not
reflect local variability in population density, meteorology, exposure,
baseline health incidence rates, or other local factors for any
specific location.
---------------------------------------------------------------------------

    \8\ Fann, N., C.M. Fulcher, B.J. Hubbell. 2009. The influence of
location, source, and emission type in estimates of the human health
benefits of reducing a ton of air pollution. Air Qual Atmos Health
(2009) 2:169-176.
    \9\ U.S. Environmental Protection Agency. 2012. Technical
support document: Estimating the benefit per ton of reducing PM2.5
precursors from other point sources. Research Triangle Park, NC.
    \10\ Stationary engines are included in the other non-EGU point
source category. If the affected stationary engines are more rural
than the average of the non-EGU sources modeled, then it is possible
that the benefits may be somewhat less than we have estimated here.
The TSD provides the geographic distribution of the air quality
changes associated with this sector. It is important to emphasize
that this modeling represents the best available information on the
air quality impact on a per ton basis for these sources.
---------------------------------------------------------------------------

    We apply these national benefit-per-ton estimates calculated for
this sector separately for directly emitted PM2.5 and
NOX and multiply them by the corresponding emission
reductions. The sector modeling does not provide estimates of the
PM2.5-related benefits associated with reducing VOC
emissions, but these unquantified benefits are generally small compared
to other PM2.5 precursors. More information regarding the
derivation of the benefit-per-ton estimates for this category is
available in the technical support document, which is available in the
docket.
    These models assume that all fine particles, regardless of their
chemical composition, are equally potent in causing premature mortality
because the scientific evidence is not yet sufficient to allow
differentiation of effects estimates by particle type. The main
PM2.5 precursors affected by these rules are directly
emitted PM2.5 and NOX. Even though we assume that
all fine particles have equivalent health effects, the benefit-per-ton
estimates vary between precursors depending on the location and
magnitude of their impact on PM2.5 levels, which drive
population exposure. For example, directly emitted PM2.5 has
a lower benefit-per-ton estimate than direct PM2.5 because
it does not form as much PM2.5; thus, the exposure would be
lower, and the monetized health benefits would be lower.
    It is important to note that the magnitude of the PM2.5
co-benefits is largely driven by the concentration response function
for premature mortality. Experts have advised the EPA to consider a
variety of assumptions, including estimates based both on empirical
(epidemiological) studies and judgments elicited from scientific
experts, to characterize the uncertainty in the relationship between
PM2.5 concentrations and premature mortality. We cite two
key empirical studies, one based on the American Cancer Society cohort
study \11\ and the extended Six Cities cohort study.\12\ In the RIA for
this proposed amendments rule, which is available in the docket, we
also include benefits estimates derived from the expert judgments and
other assumptions.
---------------------------------------------------------------------------

    \11\ Pope, et al., 2002. Lung Cancer, Cardiopulmonary Mortality,
and Long-term Exposure to Fine Particulate Air Pollution. Journal of
the American Medical Association 287:1132-1141.
    \12\ Laden, et al., 2006. Reduction in Fine Particulate Air
Pollution and Mortality. American Journal of Respiratory and
Critical Care Medicine 173:667-672.
---------------------------------------------------------------------------

    The EPA strives to use the best available science to support our
benefits analyses. We recognize that interpretation of the science
regarding air pollution and health is dynamic and evolving. After
reviewing the scientific literature, we have determined that the no-
threshold model is the most appropriate model for assessing the
mortality benefits associated with reducing PM2.5 exposure.
Consistent with this finding, we have conformed the previous threshold
sensitivity analysis to the current state of the PM science by
incorporating a new ``Lowest Measured Level'' (LML) assessment in the
RIA accompanying these rules. While an LML assessment provides some
insight into the level of uncertainty in the estimated PM mortality
benefits, the EPA does not view the LML as a threshold and continues to
quantify PM-related mortality impacts using a full range of modeled air
quality concentrations.
    Most of the estimated PM-related co-benefits for these rules would
accrue to populations exposed to higher levels of PM2.5. For
this analysis, policy-specific air quality data are not available due
to time or resource limitations, and thus, we are unable to estimate
the percentage of premature mortality associated with this specific
rule's emission reductions at each PM2.5 level. As a
surrogate measure of mortality impacts, we provide the percentage of
the population exposed at each PM2.5 level using the source
apportionment modeling used to calculate the benefit-per-ton estimates
for this sector. Using the Pope, et al. (2002) study, 77 percent of the
population is exposed to annual mean PM2.5 levels at or
above the LML of 7.5 micrograms per cubic meter ([micro]g/m\3\). Using
the Laden, et al. (2006) study, 25 percent of the population is exposed
above the LML of 10 [micro]g/m\3\. It is important to emphasize that we
have high confidence in PM2.5-related effects down to the
lowest LML of the major cohort studies. This fact is important,
because, as we model avoided premature deaths among populations exposed
to levels of PM2.5, we have lower confidence in levels below
the LML for each study.
    Every benefit analysis examining the potential effects of a change
in environmental protection requirements is limited, to some extent, by
data gaps, model capabilities (such as geographic coverage) and
uncertainties in the underlying scientific and economic studies used to
configure the benefit and cost models. Despite these uncertainties, we
believe the benefit analysis for these rules provides a reasonable
indication of the expected health benefits of the rulemaking under a
set of reasonable assumptions. This analysis does not include the type
of detailed uncertainty assessment found in the 2006 PM2.5
National Ambient Air Quality Standard (NAAQS) RIA because we lack the
necessary air quality input and monitoring data to run the benefits
model. In addition, we have not conducted air quality modeling for
these rules, and using a benefit-per-ton approach adds another
important source of uncertainty to the benefits estimates. The 2006
PM2.5 NAAQS benefits analysis \13\ provides an indication of
the sensitivity of our results to various assumptions.
---------------------------------------------------------------------------

    \13\ U.S. Environmental Protection Agency, 2006. Proposed
Amendments Regulatory Impact Analysis: PM2.5 NAAQS. Prepared by
Office of Air and Radiation. October. Available on the Internet at
http://www.epa.gov/ttn/ecas/ria.html.
---------------------------------------------------------------------------

    It should be noted that the monetized co-benefits estimates
provided above do not include benefits from several important benefit
categories, including exposure to HAP, NOX, ozone exposure,
as well as ecosystem effects and visibility impairment. Although we do

not have sufficient information or modeling available to provide
monetized estimates for these proposed amendments, we include a
qualitative assessment of these unquantified benefits in the RIA for
these proposed amendments.
    For more information on the benefits analysis, please refer to the
RIA for these proposed amendments, which is available in the docket.

D. What are the non-air health, environmental and energy impacts?

    The EPA does not anticipate any significant non-air health,
environmental or energy impacts as a result of these proposed
amendments.

IV. Solicitation of Public Comments and Participation

    The EPA seeks full public participation in arriving at its final
decisions, and strongly encourages comments on all aspects of this
proposed rule from all interested parties. Whenever applicable, full
supporting data and detailed analysis should be submitted to allow the
EPA to make maximum use of the comments. The agency invites all parties
to coordinate their data collection activities with the EPA to
facilitate mutually beneficial and cost-effective data submissions. A
redline/strikeout version of the complete NESHAP for stationary RICE,
which shows the changes that are being proposed in this action, is
available from the rulemaking docket.
    The EPA is seeking specific comment on the proposal to temporarily
allow stationary emergency engines located at area sources to apply the
50 hours per year that is currently allowed under Sec.  63.6640(f) for
non-emergency operation towards any type of non-emergency operation,
including peak shaving and non-emergency demand response if the peak
shaving is done as part of a peak shaving (load management) program
with the local distribution system operator. The EPA is proposing that
the allowance be removed after April 16, 2017.
    The EPA recognizes that the electricity grid achieves demand
response and grid stability with and without the use of emergency
stationary RICE. Alternative approaches include reductions or shifts in
energy use, electricity storage, distribution automation, microgrids,
natural gas-fired combustion turbines, and grid-connected distributed
generation, including non-emergency engines and combined heat and
power. Many of these approaches can provide additional benefits, such
as additional energy efficiency, lower costs, shorter electricity
outage times, and better integration of renewable energy generation
into the electricity grid. Several studies project a significant future
potential for using less energy in homes, buildings, and industry
during times of peak electricity demand. The EPA seeks comment on how
these investments may affect the number of hours which emergency
stationary RICE are needed in the future to address electricity peak
shaving and grid stability.
    The EPA is also specifically seeking comment on the proposed
criteria for expanding the current definition of remote areas of Alaska
beyond areas that are not accessible by the FAHS. The EPA requests
comment on whether the proposed system capacity limitation of 12
megawatts and the alternative 500 hour cap on annual usage (based on a
10-year rolling average) are the appropriate criteria for
distinguishing the areas of Alaska that, while accessible by the FAHS,
have the same unique challenges as the areas that are not accessible by
the FAHS.
    The EPA is also seeking information related to irrigation pump
engine sizes. During the 2010 rulemaking, the EPA relied upon several
sources to determine the potential number of irrigation engines that
may be impacted by the rule. Using these sources, the EPA estimated
that the vast majority of the existing irrigation engines were less
than or equal to 300 HP. The EPA received several comments confirming
this estimation. The EPA seeks comprehensive, nationwide information on
the size of existing irrigation engines to either confirm or refute our
understanding of existing irrigation engine sizes; this information
will assist EPA in assessing the impacts of the 2010 rule on existing
irrigation engines. The EPA has placed information in the docket for
this rulemaking (see EPA-HQ-OAR-2008-0708-0495) on the number of
irrigation engines provided by the U.S. Department of Agriculture after
the 2010 RICE NESHAP amendments were finalized.

V. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review

    Under section 3(f)(1) of Executive Order 12866 (58 FR 51735,
October 4, 1993), this action is an ``economically significant
regulatory action'' because it is likely to have an annual effect on
the economy of $100 million or more. Accordingly, the EPA submitted
this action to the Office of Management and Budget (OMB) for review
under Executive Order 12866 and Executive Order 13563 (76 FR 3821,
January 21, 2011), and any changes made in response to OMB
recommendations have been documented in the docket for this action. In
addition, the EPA prepared a RIA of the potential costs and benefits
associated with this action.
    A summary of the monetized benefits, compliance costs and net
benefits for the 2010 rule with the proposed amendments to the
stationary CI engines NESHAP at discount rates of 3 percent and 7
percent is in Table 4 of this preamble. The summary for stationary SI
engines is included in Table 5 of this preamble. OMB Circular A-4
recommends that analysis of a change in an existing regulatory program
use a baseline that assumes ``no change'' in the existing regulation.
For purposes of this rule, however, the EPA has decided that it is
appropriate to assume a baseline in which the original 2010 rule did
not exist. The EPA feels that this baseline is appropriate because full
implementation of the final rule has not taken place as of yet (it will
take place in 2013). In addition, this assumption is consistent with
the baseline definition applied in the recently proposed NESHAP for
Industrial, Commercial, and Institutional Boilers (76 FR 80532) and
NSPS for Commercial/Industrial Solid Waste Incineration Units (76 FR
80452).

    Table 4--Summary of the Monetized Benefits, Compliance Costs and Net Benefits for the 2010 Rule With the
                         Proposed Amendments to the Stationary CI Engine NESHAP in 2013
                                         [Millions of 2010 dollars] \a\
----------------------------------------------------------------------------------------------------------------