[Federal Register: March 5, 2009 (Volume 74, Number 42)]
[Proposed Rules]
[Page 9697-9731]
[DOCID:fr05mr09-11]

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Part II

Environmental Protection Agency

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40 CFR Part 63

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National Emission Standards for Hazardous Air Pollutants for
Reciprocating Internal Combustion Engines; Proposed Rule

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2008-0708, FRL-8778-6]
RIN 2060-AP36

National Emission Standards for Hazardous Air Pollutants for
Reciprocating Internal Combustion Engines

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: EPA is proposing national emission standards for hazardous air
pollutants for existing stationary reciprocating internal combustion
engines that either are located at area sources of hazardous air
pollutant emissions or that have a site rating of less than or equal to
500 brake horsepower and are located at major sources of hazardous air
pollutant emissions. In addition, EPA is proposing national emission
standards for hazardous air pollutants for existing stationary
compression ignition engines greater than 500 brake horsepower that are
located at major sources, based on a new review of these engines
following the first RICE NESHAP rulemaking in 2004. In addition, EPA is
proposing to amend the previously promulgated regulations regarding
operation of stationary reciprocating internal combustion engines
during periods of startup, shutdown and malfunction.

DATES: Comments must be received on or before May 4, 2009, or 30 days
after date of public hearing if later. Under the Paperwork Reduction
Act, comments on the information collection provisions must be received
by the Office of Management and Budget (OMB) on or before April 6,
2009.
    Public Hearing. If anyone contacts us requesting to speak at a
public hearing by March 25, 2009, a public hearing will be held on
April 6, 2009. If you are interested in attending the public hearing,
contact Ms. Pamela Garrett at<PHONE_NUMBER> to verify that a hearing
will be held.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2008-0708, by one of the following methods:
     http://www.regulations.gov: Follow the on-line
instructions for submitting comments.
     E-mail<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.
EPA requests a separate copy also be sent to the contact person
identified below (see FOR FURTHER INFORMATION CONTACT). In addition,
please mail a copy of your comments on the information collection
provisions to the Office of Information and Regulatory Affairs, Office
of Management and Budget, Attn: Desk Officer for EPA, 725 17th St.,
NW., Washington, DC 20503.
     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. 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 http://www.regulations.gov, including any personal information
provided, unless the comment includes information claimed to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Do not submit information that you
consider to be CBI or otherwise protected through http://
www.regulations.gov or e-mail. The http://www.regulations.gov Web site
is an ``anonymous access'' system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment. If you send an e-mail comment directly to EPA without
going through http://www.regulations.gov, your e-mail 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, 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 EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, 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 Hearing: If a public hearing is held, it will be held at
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 http://
www.regulations.gov index. We also rely on documents in Docket ID Nos.
EPA-HQ-OAR-2002-0059, EPA-HQ-OAR-2005-0029, and EPA-HQ-OAR-2005-0030,
and incorporate those dockets into the record for this proposed rule.
Although listed in the index, some information is not publicly
available, e.g., CBI or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, will be publicly available only in hard copy. Publicly
available docket materials are available either electronically in
http://www.regulations.gov or in hard copy at the Air 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: Mrs. 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>; e-
mail 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. Does this action apply to me?
    B. What should I consider as I prepare my comments for EPA?
II. Background
III. Summary of This Proposed Rule
    A. What is the source category regulated by this proposed rule?
    B. What are the pollutants regulated by this proposed rule?
    C. What are the proposed standards?
    D. What are the requirements for demonstrating compliance?
    E. What are the reporting and recordkeeping requirements?
IV. Rationale for Proposed Rule
    A. Which control technologies apply to stationary RICE?
    B. How did EPA determine the basis and level of the proposed
standards?
    C. How did EPA determine the compliance requirements?
    D. How did EPA determine the reporting and recordkeeping
requirements?
V. 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?

VI. Solicitation of Public Comments and Participation
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and 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. 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
------------------------------------------------------------------------
Any industry using a stationary            2211  Electric power
 internal combustion engine as                    generation,
 defined in this proposed rule.                   transmission, or
                                                  distribution.
                                         622110  Medical and surgical
                                                  hospitals.
                                          48621  Natural gas
                                                  transmission.
                                         211111  Crude petroleum and
                                                  natural gas
                                                  production.
                                         211112  Natural gas liquids
                                                  producers.
                                          92811  National security.
------------------------------------------------------------------------
\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.

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

    1. Submitting CBI. Do not submit this information to EPA through
regulations.gov or e-mail. 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 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: Mrs. 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. 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, 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. Background

    This action proposes national emission standards for hazardous air
pollutants (NESHAP) from existing stationary reciprocating internal
combustion engines (RICE) with a site rating of less than or equal to
500 horsepower (HP) located at major sources, existing non-emergency CI
engines with a site rating >500 HP at major sources, and existing
stationary RICE of any power rating located at area sources. EPA is
proposing these requirements to meet its statutory obligation to
address hazardous air pollutants (HAP) emissions from these sources
under sections 112(d), 112(c)(3) and 112(k) of the CAA. The final
NESHAP for stationary RICE would be promulgated under 40 CFR part 63,
subpart ZZZZ, which already contains standards applicable to new
stationary RICE and some existing stationary RICE.
    EPA promulgated NESHAP for existing, new, and reconstructed
stationary RICE greater than 500 HP located at major sources on June
15, 2004 (69 FR 33474). EPA promulgated NESHAP for new and
reconstructed stationary RICE that are located at area sources of HAP
emissions and for new and reconstructed stationary RICE that have a
site rating of less than or equal to 500 HP that are located at major
sources of HAP emissions on January 18, 2008 (73 FR 3568). At that
time, EPA did not promulgate final requirements for existing stationary
RICE that are located at area sources of HAP emissions or for existing
stationary RICE that have a site rating of less than or equal to 500 HP
that are located at major sources of HAP emissions. Although EPA
proposed requirements for these sources, EPA did not finalize these

requirements due to comments received indicating that the proposed
Maximum Achievable Control Technology (MACT) determinations for
existing sources were inappropriate and because of a decision by the
U.S. Court of Appeals for the District of Columbia Circuit on March 13,
2007, which vacated EPA's MACT standards for the Brick and Structural
Clay Products Manufacturing source category (40 CFR part 63, subpart
JJJJJ). Sierra Club v. EPA, 479 F.3d 875 (DC Cir 2007). Among other
things, the D.C. Circuit found that EPA's no emission reduction MACT
determination in the challenged rule was unlawful. Because in the
proposed stationary RICE rule, EPA had used a MACT floor methodology
similar to the methodology used in the Brick MACT, EPA decided to re-
evaluate the MACT floors for existing major sources that have a site
rating of less than or equal to 500 brake HP consistent with the
Court's decision in the Brick MACT case. EPA has also re-evaluated the
standards for existing area sources in light of the comments received
on the proposed rule.
    This proposal initiates a separate rulemaking process that focuses
on existing sources. EPA has gathered further information on existing
engines and has considered comments it received on the original
proposed rule and the intervening court decision in creating this
proposed rulemaking. Commenters are advised to provide new comments in
response to this proposal and not to rely on any comments they may have
provided in previous rulemaking actions.
    In addition, stakeholders have encouraged the Agency to review
whether there are further ways to reduce emissions of pollutants from
existing stationary diesel engines. In its comments on EPA's 2006
proposed rule for new stationary diesel engines,\1\ the Environmental
Defense Fund (EDF) suggested several possible avenues for the
regulation of existing stationary diesel engines, including use of
diesel oxidation catalysts or catalyzed diesel particulate filters
(CDPF), as well as the use of ultra low sulfur diesel (ULSD) fuel. EDF
suggested that such controls can provide significant pollution
reductions at reasonable cost. EPA issued an advance notice of proposed
rulemaking (ANPRM) in January 2008, where it solicited comment on
several issues concerning options to regulate emissions of pollutants
from existing stationary diesel engines, generally, and specifically
from larger, older stationary diesel engines. EPA solicited comment and
collected information to aid decision-making related to the reduction
of HAP emissions from existing stationary diesel engines and
specifically from larger, older engines under Clean Air Act (CAA)
section 112 authorities. The Agency sought comment on the larger, older
engines because available data indicate that those engines emit the
majority of particulate matter (PM) and toxic emissions from non-
emergency stationary engines as a whole. A summary of comments and
responses that were received on the ANPRM was added to docket EPA-HQ-
OAR-2007-0995.
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    \1\ ``Standards of Performance for Stationary Spark Ignition
Internal Combustion Engines and National Emission Standards for
Hazardous Air Pollution for Reciprocating Internal Combustion
Engines,'' 71 FR 33803-33855, http://www.epa.gov/ttn/atw/rice/
ricepg.html, June 12, 2006.
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    EPA has taken several actions over the past several years to reduce
exhaust pollutants from stationary diesel engines, but believes that
further reducing exhaust pollutants from stationary diesel engines,
particularly existing stationary diesel engines that have not been
subject to Federal standards, is justified. Therefore, EPA is proposing
emissions reductions from existing stationary diesel engines.

III. Summary of This Proposed Rule

A. What is the source category regulated by this proposed rule?

    This proposed rule addresses emissions from existing stationary
engines less than or equal to 500 HP located at major sources and all
existing stationary engines located at area sources. A major source of
HAP emissions is a stationary source that emits or has the potential to
emit any single HAP at a rate of 10 tons (9.07 megagrams) or more per
year or any combination of HAP at a rate of 25 tons (22.68 megagrams)
or more per year, except that for oil and gas production facilities, a
major source of HAP emissions is determined for each surface site. 42
Sec.  7412(n)(4). An area source of HAP emissions is a source that is
not a major source. This proposed rule also addresses emissions from
existing compression ignition (CI) engines greater than 500 HP located
at major sources.
    This action is a revision to the regulations in 40 CFR part 63,
subpart ZZZZ, currently applicable to existing, new, and reconstructed
stationary RICE greater than 500 HP located at major sources; new and
reconstructed stationary RICE less than or equal to 500 HP located at
major sources; and new and reconstructed stationary RICE located at
area sources. Subpart ZZZZ does not currently cover existing stationary
engines located at area sources of HAP emissions, nor does it apply to
existing stationary engines located at major sources with a site rating
of 500 HP or less. When the subpart ZZZZ regulations were promulgated
(see 69 FR 33474, June 15, 2004), EPA deferred promulgating regulations
with respect to stationary engines 500 HP or less at major sources
until further information on the engines could be obtained and
analyzed. EPA decided to regulate these smaller engines at the same
time that it regulated engines located at area sources. EPA issued
regulations for new stationary engines located at area sources of HAP
emissions and new stationary engines located at major sources with a
site rating of 500 HP or less in the rulemaking issued on January 18,
2008 (73 FR 3568), but did not promulgate a final regulation for
existing stationary engines.
1. Stationary RICE <=500 HP at Major Sources
    This action proposes to revise 40 CFR part 63, subpart ZZZZ, to
address HAP emissions from existing stationary RICE less than or equal
to 500 HP located at major sources. For stationary engines less than or
equal to 500 HP at major sources, EPA must determine what is the
appropriate MACT for those engines under section 112(d)(3) of the CAA.
    EPA has divided the source category into the following
subcategories:
     Stationary RICE less than 50 HP,
     Landfill and digester gas stationary RICE greater than or
equal to 50 HP,
     CI stationary RICE greater than or equal to 50 HP,
    [cir] Emergency
    [cir] Non-emergency and
     Spark ignition (SI) stationary RICE greater than or equal
to 50 HP
    [cir] Emergency
    [cir] Non-emergency
    [dec221] 2-stroke lean burn (2SLB)
      <250 HP
      >=250 HP
    [dec221] 4-stroke lean burn (4SLB)
      <250 HP
      >=250 HP
    [dec221] 4-stroke rich burn (4SRB).
2. Stationary RICE at Area Sources
    This action proposes to revise 40 CFR part 63, subpart ZZZZ, in
order to address HAP emissions from existing stationary RICE located at
area sources. Section 112(d) of the Clean Air Act (CAA) requires EPA to
establish national emission standards for hazardous air pollutants
(NESHAP) for both major and area sources of HAP that are listed for
regulation under CAA section 112(c). As noted above, an area

source is a stationary source that is not a major source.
    Section 112(k)(3)(B) of the CAA calls for EPA to identify at least
30 HAP that, as a result of emissions of area sources, pose the
greatest threat to public health in the largest number of urban areas.
EPA implemented this provision in 1999 in the Integrated Urban Air
Toxics Strategy (64 FR 38715, July 19, 1999). Specifically, in the
Strategy, EPA identified 30 HAP that pose the greatest potential health
threat in urban areas, and these HAP are referred to as the ``30 urban
HAP.'' Section 112(c)(3) requires EPA to list sufficient categories or
subcategories of area sources to ensure that area sources representing
90 percent of the emissions of the 30 urban HAP are subject to
regulation. EPA implemented these requirements through the Integrated
Urban Air Toxics Strategy (64 FR 38715, July 19, 1999). The area source
stationary engine source category was one of the listed categories. A
primary goal of the Strategy is to achieve a 75 percent reduction in
cancer incidence attributable to HAP emitted from stationary sources.
    Under CAA section 112(d)(5), EPA may elect to promulgate standards
or requirements for area sources ``which provide for the use of
generally available control technologies or management practices by
such sources to reduce emissions of hazardous air pollutants.''
Additional information on generally available control technologies
(GACT) or management practices is found in the Senate report on the
legislation (Senate report Number 101-228, December 20, 1989), which
describes GACT as:

* * * methods, practices and techniques which are commercially
available and appropriate for application by the sources in the
category considering economic impacts and the technical capabilities
of the firms to operate and maintain the emissions control systems.

Consistent with the legislative history, EPA can consider costs and
economic impacts in determining GACT, which is particularly important
when developing regulations for source categories, like this one, that
have many small businesses.
    Determining what constitutes GACT involves considering the control
technologies and management practices that are generally available to
the area sources in the source category. EPA also considers the
standards applicable to major sources in the same industrial sector to
determine if the control technologies and management practices are
transferable and generally available to area sources. In appropriate
circumstances, EPA may also consider technologies and practices at area
and major sources in similar categories to determine whether such
technologies and practices could be considered generally available for
the area source category at issue. Finally, as EPA has already noted,
in determining GACT for a particular area source category, EPA
considers the costs and economic impacts of available control
technologies and management practices on that category.
    The urban HAP that must be regulated at stationary RICE to achieve
the section 112(c)(3) requirement to regulate categories accounting for
90 percent of the urban HAP are: 7 PAH, formaldehyde, acetaldehyde,
arsenic, benzene, beryllium compounds, and cadmium compounds. As
explained below, EPA chose to select formaldehyde to serve as a
surrogate for HAP emissions. Formaldehyde is the hazardous air
pollutant present in the highest concentration from stationary engines.
In addition, emissions data show that formaldehyde emission levels are
related to other HAP emission levels. EPA is proposing standards for
area source stationary RICE below.
    The subcategories for area sources are the same as those for major
sources and are listed in section A.1. above.
3. Stationary CI RICE >500 HP at Major Sources
    In addition, EPA is proposing emission standards for non-emergency
stationary CI engines greater than 500 HP at major sources under its
authority to review and revise emission standards as necessary under
section 112(d) of the CAA.

B. What are the pollutants regulated by this proposed rule?

    The rule being proposed in this action would regulate emissions of
HAP. Available emissions data show that several HAP, which are formed
during the combustion process or which are contained within the fuel
burned, are emitted from stationary engines. The HAP which have been
measured in emission tests conducted on natural gas fired and diesel
fired RICE include: 1,1,2,2-tetrachloroethane, 1,3-butadiene, 2,2,4-
trimethylpentane, acetaldehyde, acrolein, benzene, chlorobenzene,
chloroethane, ethylbenzene, formaldehyde, methanol, methylene chloride,
n-hexane, naphthalene, polycyclic aromatic hydrocarbons, polycyclic
organic matter, styrene, tetrachloroethane, toluene, and xylene.
Metallic HAP from diesel fired stationary RICE that have been measured
are: cadmium, chromium, lead, manganese, mercury, nickel, and selenium.
Although numerous HAP may be emitted from RICE, only a few account for
essentially all of the mass of HAP emissions from stationary RICE.
These HAP are: Formaldehyde, acrolein, methanol, and acetaldehyde.
    EPA described the health effects of these HAP and other HAP emitted
from the operation of stationary RICE in the preamble to 40 CFR part
63, subpart ZZZZ, published on June 15, 2004 (69 FR 33474). These HAP
emissions are known to cause, or contribute significantly to air
pollution, which may reasonably be anticipated to endanger public
health or welfare.
    EPA is proposing to limit emissions of HAP through emissions
standards for formaldehyde for non-emergency 4SRB engines, emergency SI
engines, and engines less than 50 HP, and through emission standards
for carbon monoxide (CO) for all other engines. For the RICE NESHAP
promulgated in 2004 (69 FR 33474) for engines greater than 500 HP
located at major sources, EPA chose to select formaldehyde to serve as
a surrogate for HAP emissions. Formaldehyde is the hazardous air
pollutant present in the highest concentration in the exhaust from
stationary engines. In addition, emissions data show that formaldehyde
emission levels are related to other HAP emission levels.
    For the NESHAP promulgated in 2004, EPA also found that there is a
relationship between CO emissions reductions and HAP emissions
reductions from 2SLB, 4SLB, and CI stationary engines. Therefore,
because testing for CO emissions has many advantages over testing for
formaldehyde, CO emissions were chosen as a surrogate for HAP emissions
reductions for 2SLB, 4SLB, and CI stationary engines operating with
oxidation catalyst systems for that rule. However, EPA could not
confirm the same relationship between CO and formaldehyde for 4SRB
engines, so emission standards for such engines were provided in terms
of formaldehyde.
    For the standards being proposed in this action, EPA believes that
previous decisions regarding the appropriateness of using formaldehyde
and CO both in concentration (ppm) levels as has been done for
stationary sources before as surrogates for HAP are still valid.\2\
Consequently, EPA is proposing emission standards for formaldehyde for
4SRB engines and emission standards

for CO for lean burn and CI engines in order to regulate HAP emissions.
Information EPA has received from stationary engine manufacturers
indicate that most SI emergency engines and engines below 50 HP are and
will be 4SRB engines. As discussed above, EPA could not confirm a
relationship between CO and formaldehyde emissions for 4SRB engines.
Therefore, EPA is proposing standards for formaldehyde for those
engines. EPA is interested in receiving comments on the use of
formaldehyde as a surrogate for HAP and information on any other
surrogates that may be better indicators of total HAP emissions and
their reductions.
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    \2\ In contrast, mobile source emission standards for diesel
engines (both nonroad and on-highway) are promulgated on a mass
basis rather than concentration.
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    We recognize that stationary diesel engines emit trace amounts of
metal HAP that remain in the particle phase. EPA believes that
formaldehyde and CO are reasonable surrogates for total HAP. Although
metal HAP emissions from existing diesel engines are very small--a
total of about 200 tons per year--we are interested in receiving
comments and data about more appropriate surrogates, if any, for the
metallic HAP emissions.
    In addition to reducing HAP and CO, the proposed rule would likely
result in the reduction of PM emissions from existing diesel engines.
The aftertreatment technologies expected to be used to reduce HAP and
CO emissions also reduce emissions of PM from diesel engines.
Furthermore, this proposed rule would also result in nitrogen oxides
(NOX ) reductions from rich burn engines since these engines
would likely need to install non-selective catalytic reduction (NSCR)
technology that helps reduce NOX in addition to CO and HAP
emissions. Also, we propose the use of ULSD for diesel-fueled
stationary non-emergency CI engines greater than 300 HP with a
displacement of less than 30 liters per cylinder. This will result in
lower emissions of sulfur oxides (SOX) and sulfate
particulate from these engines by reducing the sulfur content in the
fuel.

C. What are the proposed standards?

1. Existing Stationary RICE at Major Sources
    The emission standards that are being proposed in this action for
stationary RICE less than or equal to 500 HP located at major sources
and stationary CI RICE greater than 300 HP located at major sources are
shown in Table 1 of this preamble. Note that EPA is also co-proposing
that the same standards apply during both normal operation and periods
of startup and malfunctions.

   Table 1--Emission Standards for Existing Stationary RICE Located at
                              Major Sources
------------------------------------------------------------------------
                              Emission standards at 15 percent O2 (parts
                                 per million by volume on a dry basis)
                             -------------------------------------------
         Subcategory              Except during       During periods of
                               periods of startup,       startup, or
                                 or malfunction          malfunction
------------------------------------------------------------------------
Non-Emergency 2SLB            85 ppmvd CO.........  85 ppmvd CO.
 50>=HP<=249.
Non-Emergency 2SLB            8 ppmvd CO or 90% CO  85 ppmvd CO.
 250>=HP<=500.                 reduction.
Non-Emergency 4SLB            95 ppmvd CO.........  95 ppmvd CO.
 50>=HP<=249.
Non-Emergency 4SLB 250        9 ppmvd CO or 90% CO  95 ppmvd CO.
 >=HP<=500.                    reduction.
Non-Emergency 4SRB            200 ppbvd             2 ppmvd
 50>=HP<=500.                  formaldehyde or 90%   formaldehyde.
                               formaldehyde
                               reduction.
All CI 50>=HP<=300..........  40 ppmvd CO.........  40 ppmvd CO.
Emergency CI 300>HP<=500....  40 ppmvd CO.........  40 ppmvd CO.
Non-Emergency CI >300 HP....  4 ppmvd CO or 90% CO  40 ppmvd CO.
                               reduction.
<50 HP......................  2 ppmvd formaldehyde  2 ppmvd
                                                     formaldehyde.
Landfill/Digester             177 ppmvd CO........  177 ppmvd CO.
 50>=HP<=500.
Emergency SI 50>=HP<=500....  2 ppmvd formaldehyde  2 ppmvd
                                                     formaldehyde.
------------------------------------------------------------------------

    In addition, certain existing stationary RICE located at major
sources are subject to fuel requirements. Owners and operators of
existing stationary non-emergency diesel-fueled CI engines greater than
300 HP with a displacement of less than 30 liters per cylinder located
at major sources that use diesel fuel must use only diesel fuel meeting
the requirements of 40 CFR 80.510(b). This section requires that diesel
fuel have a maximum sulfur content of 15 parts per million (ppm) and
either a minimum cetane index of 40 or a maximum aromatic content of 35
volume percent.
2. Existing Stationary RICE at Area Sources
    The emission requirements that we are proposing in this action for
existing stationary RICE located at existing area sources are shown in
Table 2 of this preamble. Note that EPA is also co-proposing that the
same standards apply during both normal operation and periods of
startup and malfunctions.

  Table 2--Emission Standards and Requirements for Existing Stationary
                      RICE Located at Area Sources
------------------------------------------------------------------------
                                Emission standards at 15 percent O2, as
                                  applicable, or management practice
                             -------------------------------------------
         Subcategory              Except during       During periods of
                               periods of startup,       startup, or
                                 or malfunction          malfunction
------------------------------------------------------------------------
Non-Emergency 2SLB            Change oil and        Change oil and
 50>=HP<=249.                  filter every 500      filter every 500
                               hours; replace        hours; replace
                               spark plugs every     spark plugs every
                               1000 hours; and       1000 hours; and
                               inspect all hoses     inspect all hoses
                               and belts every 500   and belts every 500
                               hours and replace     hours and replace
                               as necessary.         as necessary.
Non-Emergency 2SLB HP>=250..  8 ppmvd CO or 90% CO  85 ppmvd CO.
                               reduction.

Non-Emergency 4SLB            Change oil and        Change oil and
 50>=HP<=249.                  filter every 500      filter every 500
                               hours; replace        hours; replace
                               spark plugs every     spark plugs every
                               1000 hours; and       1000 hours; and
                               inspect all hoses     inspect all hoses
                               and belts every 500   and belts every 500
                               hours and replace     hours and replace
                               as necessary.         as necessary.
Non-Emergency 4SLB HP>=250..  9 ppmvd CO or 90% CO  95 ppmvd CO.
                               reduction.
Non-Emergency 4SRB HP>=50...  200 ppbvd             2 ppmvd
                               formaldehyde or 90%   formaldehyde.
                               formaldehyde
                               reduction.
Emergency CI 50>=HP<=500....  Change oil and        Change oil and
                               filter every 500      filter every 500
                               hours; inspect air    hours; inspect air
                               cleaner every 1000    cleaner every 1000
                               hours, inspect all    hours, inspect all
                               hoses and belts       hoses and belts
                               every 500 hours and   every 500 hours and
                               replace as            replace as
                               necessary.            necessary.
Emergency CI HP>500.........  40 ppmvd CO.........  40 ppmvd CO.
Non-Emergency CI 50>=HP<=300  Change oil and        Change oil and
                               filter every 500      filter every 500
                               hours; inspect air    hours; replace
                               cleaner every 1000    spark plugs every
                               hours; and inspect    1000 hours; and
                               all hoses and belts   inspect all hoses
                               every 500 hours and   and belts every 500
                               replace as            hours and replace
                               necessary.            as necessary.
Non-Emergency CI HP>300.....  4 ppmvd CO or 90% CO  40 ppmvd CO.
                               reduction.
HP<50.......................  Change oil and        Change oil and
                               filter every 200      filter every 200
                               hours; replace        hours; replace
                               spark plugs every     spark plugs every
                               500 hours; and        500 hours; and
                               inspect all hoses     inspect all hoses
                               and belts every 500   and belts every 500
                               hours and replace     hours and replace
                               as necessary.         as necessary.
Landfill/Digester Gas         Change oil and        Change oil and
 50>=HP<=500.                  filter every 500      filter every 500
                               hours; replace        hours; replace
                               spark plugs every     spark plugs every
                               1000 hours; and       1000 hours; and
                               inspect all hoses     inspect all hoses
                               and belts every 500   and belts every 500
                               hours and replace     hours and replace
                               as necessary.         as necessary.
Landfill/Digester Gas HP>500  177 ppmvd CO........  177 ppmvd CO.
Emergency SI 50>=HP<=500....  Change oil and        Change oil and
                               filter every 500      filter every 500
                               hours; replace        hours; replace
                               spark plugs every     spark plugs every
                               1000 hours; and       1000 hours; and
                               inspect all hoses     inspect all hoses
                               and belts every 500   and belts every 500
                               hours and replace     hours and replace
                               as necessary.         as necessary.
Emergency SI HP>500.........  2 ppmvd formaldehyde  2 ppmvd
                                                     formaldehyde.
------------------------------------------------------------------------

3. New or Reconstructed Stationary RICE >500 HP at Major Sources, New
or Reconstructed 4SLB Stationary RICE >=250 HP at Major Sources and
Existing 4SRB Stationary RICE >500 HP at Major Sources.
    The EPA is co-proposing, in the alternative, as explained below, to
amend the existing regulations for new and reconstructed non-emergency
2SLB and CI stationary RICE >500 HP at major sources, new and
reconstructed non-emergency 4SLB stationary RICE >=250 HP at major
sources, and existing 4SRB stationary RICE >500 HP at major sources, in
order to set limits during periods of startup and malfunction. These
emission limitations are shown in Table 3 of this preamble. Note that
EPA is also co-proposing that the same standards apply during both
normal operation and periods of startup and malfunctions.

   Table 3--Emission Standards for New or Reconstructed Non-Emergency
Stationary RICE >500 HP at Major Sources and Existing Non-Emergency 4SRB
  Stationary RICE >500 HP at Major Sources During Periods of Startup or
                               Malfunction
------------------------------------------------------------------------
                                             Emission standards at 15
              Subcategory                           percent O2
------------------------------------------------------------------------
New or reconstructed non-emergency 2SLB  Limit concentration of CO in
 >500 HP located at a major source of     the stationary RICE exhaust to
 HAP emissions.                           259 ppmvd or less at 15
                                          percent O2 during periods of
                                          startup or malfunction.
New or reconstructed non-emergency 4SLB  Limit concentration of CO in
 >=250 HP located at a major source of    the stationary RICE exhaust to
 HAP emissions.                           420 ppmvd or less at 15
                                          percent O2 during periods of
                                          startup or malfunction.
Existing non-emergency 4SRB >500 HP      Limit concentration of
 located at a major source of HAP         formaldehyde in the stationary
 emissions; or New or reconstructed non-  RICE exhaust to 2 ppmvd or
 emergency 4SRB >500 HP located at a      less at 15 percent O2 during
 major source of HAP emissions.           periods of startup or
                                          malfunction.
New or reconstructed non-emergency CI    Limit concentration of CO in
 >500 HP located at a major source of     the stationary RICE exhaust to
 HAP emissions.                           77 ppmvd or less at 15 percent
                                          O2 during periods of startup
                                          or malfunction.
------------------------------------------------------------------------

4. Operating Limitations
    The EPA is proposing operating limitations for existing stationary
non-emergency 2SLB, 4SLB, 4SRB, and CI RICE that are greater than 500
HP and are located at an area source, and existing stationary non-
emergency CI RICE that are greater than 500 HP and are located at a
major source. These are large engines that are subject to proposed
standards that would require the use of aftertreatment. Owners and
operators of engines that are equipped with oxidation catalyst or NSCR
must

maintain the catalyst so that the pressure drop across the catalyst
does not change by more than 2 inches of water from the pressure drop
across the catalyst that was measured during the initial performance
test. Owners and operators of these engines must also maintain the
temperature of the stationary RICE exhaust so that the catalyst inlet
temperature is between 450 and 1350 degrees Fahrenheit ([deg]F) for
engines with an oxidation catalyst and 750 to 1250 [deg]F for engines
with NSCR. Owners and operators of engines that are not using oxidation
catalyst or NSCR must comply with any operating limitations approved by
the Administrator.
5. Management Practices
    As shown in Table 2 above, the EPA is proposing management
practices for several subcategories of engines located at area sources.
Such management practices include maintenance requirements that are
expected to ensure that emission control systems are working properly.
EPA asks for comments on these management practices and requests
suggestions of additional maintenance requirements that may be needed
for some of these engine subcategories.
6. Fuel Requirements
    In addition to emission standards and management practices, certain
stationary CI RICE located at existing area sources are subject to fuel
requirements. These fuel requirements are proposed in order to reduce
the potential formation of sulfate compounds that are emitted when high
sulfur diesel fuel is used in combination with oxidation catalysts and
to assist in the efficient operation of the oxidation catalysts. Thus,
owners and operators of stationary non-emergency diesel-fueled CI
engines greater than 300 HP with a displacement of less than 30 liters
per cylinder located at existing area sources must only use diesel fuel
meeting the requirements of 40 CFR 80.510(b), which requires that
diesel fuel have a maximum sulfur content of 15 ppm and either a
minimum cetane index of 40 or a maximum aromatic content of 35 volume
percent.

D. What are the requirements for demonstrating compliance?

    The following sections describe the requirements for demonstrating
compliance under the proposed rule.
1. Existing Stationary RICE at Major Sources
    Owners and operators of existing stationary non-emergency RICE
located at major sources that are less than 100 HP and stationary
emergency RICE located at major sources must operate and maintain their
stationary RICE and aftertreatment control device (if any) according to
the manufacturer's emission-related written instructions or develop
their own maintenance plan. Owners and operators of existing stationary
non-emergency RICE located at major sources that are less than 100 HP
and existing stationary emergency RICE located at major sources do not
have to conduct any performance testing.
    Owners and operators of existing stationary non-emergency RICE
located at major sources that are greater than or equal to 100 HP and
less than or equal to 500 HP must conduct an initial performance test
to demonstrate that they are achieving the required emission standards.
    Owners and operators of existing stationary non-emergency RICE
greater than 500 HP located at major sources must conduct an initial
performance test and must test every 8,760 hours of operation or 3
years, whichever comes first, to demonstrate that they are achieving
the required emission standards.
    Owners and operators of stationary non-emergency CI RICE that are
greater than 500 HP and are located at a major source must continuously
monitor and record the catalyst inlet temperature if an oxidation
catalyst is being used on the engine. The pressure drop across the
catalyst must also be measured monthly. If an oxidation catalyst is not
being used on the engine, the owner or operator must continuously
monitor and record the operating parameters (if any) approved by the
Administrator.
2. Existing Stationary RICE at Area Sources
    Owners and operators of existing stationary RICE located at area
sources, that are subject to management practices, as shown in Table 2
of this preamble, must develop a maintenance plan that specifies how
the management practices will be met. Owners and operators of existing
stationary RICE that are subject to management practices do not have to
conduct any performance testing.
    Owners and operators of existing stationary RICE subject to
numerical emission standards and that are located at area sources, as
shown in Table 2 of this preamble, must conduct an initial performance
test to demonstrate that they are achieving the required emission
standards.
    Owners and operators of existing stationary non-emergency RICE that
are greater than 500 HP and located at area sources must conduct an
initial performance test and must test every 8,760 hours of operation
or 3 years, whichever comes first, to demonstrate that they are
achieving the required emission standards.
    Owners and operators of existing stationary non-emergency 2SLB,
4SLB, 4SRB, and CI RICE that are greater than 500 HP and are located at
an area source must continuously monitor and record the catalyst inlet
temperature if an oxidation catalyst or NSCR is being used on the
engine. The pressure drop across the catalyst must also be measured
monthly. If an oxidation catalyst or NSCR is not being used on the
engine, the owner or operator must continuously monitor and record the
operating parameters (if any) approved by the Administrator.

E. What are the reporting and recordkeeping requirements?

    The following sections describe the reporting and recordkeeping
requirements that are required under the proposed rule.
    Owners and operators of existing stationary emergency RICE that do
not meet the requirements for non-emergency engines are required to
keep records of their hours of operation. Owners and operators of
existing stationary emergency RICE must install a non-resettable hour
meter on their engines to record the necessary information. Emergency
stationary RICE may be operated for the purpose of maintenance checks
and readiness testing, provided that the tests are recommended by the
Federal, State or local government, the manufacturer, the vendor, or
the insurance company associated with the engine. Maintenance checks
and readiness testing of such units are limited to 100 hours per year.
Owners and operators can petition the Administrator for additional
hours, beyond the allowed 100 hours per year, if such additional hours
should prove to be necessary for maintenance and testing reasons. A
petition is not required if the engine is mandated by regulation such
as State or local requirements to run more than 100 hours per year for
maintenance and testing purposes. There is no time limit on the use of
emergency stationary engines in emergency situations, however, the
owner or operator is required to record the length of operation and the
reason the engine was in operation during that time. Records must be
maintained documenting why the engine was operating to ensure the 100
hours per year limit for maintenance and testing operation is

not exceeded. In addition, owners and operators are allowed to operate
their stationary emergency RICE for non-emergency purposes for 50 hours
per year, but those 50 hours are counted towards the total 100 hours
provided for operation other than for true emergencies and owners and
operators may not engage in income-generating activities during those
50 hours. The 50 hours per year for non-emergency purposes cannot be
used to generate income for a facility, for example, to supply power to
an electric grid or otherwise supply power as part of a financial
arrangement with another entity.
    Owners and operators of existing stationary RICE located at area
sources, that are subject to management practices as shown in Table 2,
are required to keep records that show that management practices that
are required are being met. Such records are to be kept on-site by
owners and operators. These records must include, but may not be
limited to: oil and filter change dates, oil amounts added and
corresponding hour on the hour meter, fuel consumption rates, air
filter change dates, records of repairs and other maintenance
performed.
    In terms of reporting requirements, owners and operators of
existing stationary RICE, except stationary RICE that are less than 100
HP, existing emergency stationary RICE, and existing stationary RICE
that are not subject to numerical emission standards, must submit all
of the applicable notifications as listed in the NESHAP General
Provisions (40 CFR part 63, subpart A), including an initial
notification, notification of performance test, and a notification of
compliance for each stationary RICE which must comply with the
specified emission limitations.

IV. Rationale for Proposed Rule

A. Which control technologies apply to stationary RICE?

    EPA reviewed various control technologies applicable to stationary
engines. For detailed information on the control technology review that
EPA conducted, refer to information in the docket for this proposed
rule. The following sections provide general descriptions of currently
available controls that can be used to reduce emissions from stationary
engines.
    Non-selective catalytic reduction has been commercially available
for many years and has been widely used on stationary engines. This
technology utilizes catalytic material to reduce some pollutants like
NOX , while also oxidizing other pollutants like CO, HAP and
VOC. The technology can be applied to rich burn stationary engines and
is capable of significantly reducing HAP emissions from stationary
RICE. Based on available information, NSCR appears to be technically
feasible for rich burn engines down to 25 HP. The NESHAP for stationary
rich burn RICE greater than 500 HP located at major sources that were
promulgated in 2004 were based upon applying NSCR to meet the emission
standards. In order to meet the emission standards promulgated on
January 18, 2008 (73 FR 3568), new stationary rich burn engines are
also expected to use NSCR.
    Oxidation catalysts are another type of aftertreatment that can be
applied to stationary engines and are typically used with lean burn
engines. The technology can be applied to either diesel or natural gas
fired lean burn engines. Significant reductions in HAP and CO are
achieved with oxidation catalysts and applying the technology to diesel
fired engines also yields PM mass emissions reductions. Oxidation
catalyst control has been widely used and has been available for
decades for use with lean burn stationary engines. While oxidation
catalysts are very effective at reducing HAP and CO emissions, there is
some concern about increasing NO2 emissions as a result of
using highly catalyzed devices. Thus, EPA requests comments and
information on the potential increase in NO2 emissions and
any strategies to help reduce their formation.
    Catalyzed diesel particulate filters are applicable to CI engines
using diesel fuel and are primarily used to reduce PM emissions.
Applying CDPF can significantly reduce PM emissions, while also
significantly reducing emissions of HAP and CO. Catalyzed diesel
particulate filters are the basis for EPA's current on-highway diesel
PM standards (40 CFR Part 86), the Tier 4 emission standards for PM for
most nonroad CI engines regulated by 40 CFR part 1039, the most recent
locomotive and marine engine standards and also for most new non-
emergency stationary CI engines regulated under 40 CFR part 60, subpart
IIII. Recently finalized standards for stationary CI engines in
California are also based on the use of particulate filters in some
cases.

B. How did EPA determine the basis and level of the proposed standards?

1. Stationary RICE at Major Sources
    Section 112 of the CAA requires that EPA establish NESHAP for the
control of HAP from new and existing sources in regulated source
categories. The CAA requires the NESHAP for major sources to reflect
the maximum degree of reduction in emissions of HAP that is achievable.
This level of control is commonly referred to as the maximum achievable
control technology, or MACT.
    In promulgating a MACT standard, EPA must first calculate the
minimum stringency levels for new and existing sources in a category or
subcategory. The minimum level of stringency is called the MACT
``floor,'' and CAA section 112(d)(3) sets forth differing levels of
minimum stringency that EPA's standards must achieve, based on whether
they regulate new and reconstructed sources, or existing sources. For
new and reconstructed sources, CAA section 112(d)(3) provides that the
``degree of reduction in emissions that is deemed achievable [* * *]
shall not be less stringent than the emissions control that is achieved
in practice by the best controlled similar source, as determined by the
Administrator.'' Emissions standards for existing units may be less
stringent than standards for new units, but ``shall not be less
stringent * * * than the average emissions limitation achieved by the
best performing 12 percent of the existing sources (for which the
Administrator has emissions information),'' (or the best performing 5
sources for categories or subcategories with fewer than 30 sources).
CAA section 112(d)(3). The MACT standard must be no less stringent than
the MACT floor.
    In developing MACT, EPA must also determine whether to control
emissions ``beyond-the-floor,'' after considering the costs, nonair
quality health and environmental impacts, and energy requirements of
such more stringent control. Section 112 of the CAA allows EPA to
establish subcategories among a group of sources, based on criteria
that differentiate such sources. The subcategories that have been
developed for stationary RICE were previously listed and are necessary
in order to capture the distinct differences, which could affect the
emissions of HAP from these engines. The complete rationale explaining
the development of these subcategories is provided in the memorandum
titled ``Subcategorization and MACT Floor Determination for Stationary
Reciprocating Internal Combustion Engines <=500 HP at Major Sources''
and is available from the docket.
    For the MACT floor determination, EPA reviewed the data in its
Office of Air Quality Planning and Standards' RICE Population Database
(hereafter referred to as the ``Population Database'') and RICE
Emissions

Database (hereafter referred to as the ``Emissions Database''). The
Population and Emissions Databases represent the best information
available to EPA. Information in the Population and Emissions Database
was obtained from several sources and is further described in the
notice of proposed rulemaking for the RICE NESHAP for engines greater
than 500 HP at major sources (67 FR 77830, December 19, 2002) and in
the docket for the RICE NESHAP rulemaking (EPA-HQ-OAR-2002-0059). In
order to establish the emission standard for each subcategory of
stationary existing RICE, EPA referred to the Emissions Database. The
following sections describe the MACT floor review and proposed MACT
determinations for each subcategory of existing stationary RICE.
    a. Stationary RICE <50 HP. According to the Population Database
there are no existing stationary RICE less than 50 HP using catalyst
type controls. In assessing the average of the top twelve percent best
performing engines, EPA determined that the MACT floor is 2 ppmvd
formaldehyde. EPA is not expecting any stationary CI engines less than
50 HP since such engines are typically considered nonroad mobile
engines and regulated under EPA's mobile source requirements. Also, EPA
does not expect any lean burn engines in this subcategory as lean burn
engines tend to be found in larger engine size segments. Therefore, EPA
believes that engines less than 50 HP would be 4SRB engines.
Subsequently, EPA reviewed formaldehyde emissions from 4SRB engines and
averaged the emissions associated with the best performing 12 percent
of sources. As a result, the MACT floor for engines below 50 HP is 2
parts per million by volume, dry basis (ppmvd) of formaldehyde at 15
percent oxygen (O2).
    EPA considered regulatory options more stringent than the MACT
floor, in particular, emission standards based on the use of NSCR. The
cost per ton of HAP reduced for stationary engines less than 50 HP
equipped with NSCR is substantial, particularly when considering the
potential HAP reductions that would be expected. Therefore, MACT is
equivalent to the MACT floor. For details on the cost per ton analysis,
refer to the memorandum entitled ``Above-the-Floor Determination for
Stationary RICE,'' included in the docket.
    b. Stationary Landfill/Digester Gas =50 HP. According to
the Population Database there are no existing landfill or digester gas
engines using catalyst type controls. EPA consulted several sources,
including the Emissions Database, in order to determine the level being
achieved by the best performing 12 percent of landfill and digester gas
engines.
    Based on reviewing recently obtained test reports for landfill and
digester gas engines, EPA concluded that the latest information
obtained on the current levels being achieved by landfill gas engines
is the most appropriate and representative information and therefore
was used to determine the MACT floor limit. EPA analyzed the CO
emissions from landfill and digester gas test reports. EPA has
previously discussed the appropriateness of using CO emissions as a
surrogate for HAP emissions and therefore reviewed CO emissions from
landfill and digester gas engines. EPA selected the best performing 12
percent and averaged those 12 percent to determine the MACT floor. As a
result, the MACT floor for landfill and digester gas stationary RICE
greater than or equal to 50 HP is 177 ppmvd of CO at 15 percent
O2.
    Currently, there are no viable beyond-the-floor options for engines
that combust landfill or digester gas. Aftertreatment controls could
theoretically be applied to engines burning waste gas; however,
numerous studies have shown that a family of silicon-based compounds
named siloxanes present in landfill gas can foul add-on catalyst
controls. Such fouling can render the catalyst inoperable within short
periods of time. Pre-treatment systems could be applied to clean the
fuel prior to combustion theoretically allowing catalysts to be used,
but has not shown to be a reliable technology at this time. Therefore,
MACT is equivalent to the MACT floor.
    c. Stationary Emergency CI 50= HP <=500. EPA reviewed CO
emissions from CI engines and selected the best performing 12 percent.
As a result, the MACT floor for CI emergency stationary RICE greater
than or equal to 50 HP and less than or equal to 500 HP is 40 ppmvd of
CO at 15 percent O2.
    As part of our analysis for the possibility of going beyond the
MACT floor, EPA considered requiring add-on controls for emergency
engines. However, due to the limited operation of emergency engines
(about 50 hours per year on average), the cost per ton of HAP removed
by such controls is high. The estimated cost of oxidation catalyst per
ton of HAP reduced ranges from $1 million to $2.8 million for emergency
CI engines in this size range. For CDPF, the estimated cost per ton of
HAP reduced for emergency CI engines between 50 and 500 HP ranges from
$3.7 million to $8.7 million. In addition, the total HAP reductions
achieved by applying aftertreatment controls would be minimal since
stationary emergency engines are operated only an average of about 50
hours per year. Therefore, MACT is equivalent to the MACT floor. A
fuller discussion of EPA's analysis of regulatory alternatives above-
the-floor is presented in the memorandum entitled ``Above-the-Floor
Determination for Stationary RICE.''
    d. Stationary Non-Emergency CI 50= HP <=500. As a result
of our review of the Emissions Database, the MACT floor for CI non-
emergency stationary RICE greater than or equal to 50 HP and less than
or equal to 500 HP is 40 ppmvd of CO at 15 percent O2.
    As part of our analysis of going beyond the MACT floor, EPA
considered the use of add-on controls for this subcategory of engines.
The applicable add-on controls that yield significant HAP reductions
are oxidation catalyst and CDPF. Diesel oxidation catalysts are capable
of reducing HAP emissions by significant amounts in excess of 90
percent in some cases. Diesel oxidation catalysts also reduce emissions
of CO as well as PM. Achievable mass reductions of PM are on the order
of 30 percent for oxidation catalysts. Catalyzed diesel particulate
filters are capable of reducing HAP and CO emissions by similar if not
greater amounts, and are more efficient in reducing PM than oxidation
catalysts. Achievable PM reductions are on the order of 90 percent or
more with CDPF. However, CDPFs are considerably more expensive than
diesel oxidation catalysts.
    EPA estimated the cost per ton of HAP removal by potentially
applying oxidation catalysts and CDPFs to existing non-emergency CI
engines. The specific costs associated with add-on controls can be
found in memoranda available from the rulemaking docket. The cost per
ton of HAP removed for CDPFs is in general significantly higher than
the cost per ton of HAP removed for oxidation catalysts, and the cost
per ton for both options drastically increases as the size of the
engine decreases and is more favorable towards larger size engines. EPA
requests data and other information on the ability of oxidation
catalysts to remove HAP compared to CDPF. In addition, we request
comment on the performance capability of these control devices to
remove metallic HAP.
    Considering the HAP emission reductions capable from oxidation
catalysts, the cost of oxidation catalyst control compared to CDPF, and
the low capital costs associated with oxidation catalyst makes
oxidation catalysts a

favorable option for reduction of HAP emissions from larger existing
non-emergency stationary diesel engines. However, going above-the-floor
and requiring oxidation catalysts on all non-emergency stationary CI
engines would require significant total capital investment and total
annual control costs. As stated, the cost per ton significantly
decreases with increasing HP. For the greater than 300 HP segment the
cost per ton of HAP removed, which includes a mixture of organic and
metallic HAP, is estimated to be $51,973. This cost is almost a third
less than the estimated cost per ton of $140,395 for stationary engines
50 to 100 HP.
    Stationary existing diesel engines were largely uncontrolled at the
Federal level prior to the promulgation of EPA's emission standards for
stationary diesel engines in 2004, which affected engines constructed
beginning in 2002. Non-emergency diesel engines are estimated to emit
90 percent of total combined PM and NOX emissions from all
existing stationary diesel engines, with emergency engines emitting the
remaining 10 percent. Of the non-emergency diesel engines, about 50,000
non-emergency engines rated 300 HP or higher were built prior to 2002,
which is about 29 percent of the existing population of non-emergency
stationary diesel engines. These 50,000 non-emergency diesel engines
emit approximately 72 percent of the total HAP emissions, 66 percent of
the total PM emissions, and 62 percent of the total NOX
emissions from existing non-emergency stationary diesel engines. This
information is based on data from the Power Systems Research Database
that was presented in Tables 1-4 of EPA's January 24, 2008 ANPRM for
stationary diesel engines emission standards (73 FR 4136).
    For these reasons, EPA concluded that it can achieve the highest
level of HAP emission reduction relative to cost, while requiring
controls where appropriate, by requiring more stringent emission
standards on non-emergency stationary diesel engines with a power
rating greater than 300 HP. For these reasons and considering the
higher level of HAP reductions achieved from engines greater than 300
HP and the reduced annual cost of control, EPA believes that requiring
above-the-floor levels that rely on oxidation catalyst control is
appropriate for engines greater than 300 HP. EPA solicits comments and
data on whether 300 HP is the appropriate size division for setting
beyond-the-floor MACT standards requiring the use of add-on controls.
Specifically, EPA is seeking comment on whether it would be appropriate
to extend the more stringent standards to engines that are less than
300 HP.
    Of further consideration are the co-benefits that would be achieved
by the use of oxidation catalyst as it will reduce other pollutants
such as CO and PM. Taking into account the reductions in CO and PM
associated with applying oxidation catalyst to non-emergency CI
engines, the cost per ton of pollutants reduced decreases. The total
co-benefits of this proposed regulation are presented in a separate
memorandum titled ``Impacts Associated with NESHAP for Existing
Stationary RICE,'' which provides the costs and emissions impacts of
this regulation. These emission estimates are also summarized in
Chapter 4 of the RIA.
    EPA believes that the emission reductions associated with use of
oxidation catalysts, taking into account the costs of such controls,
are justified under section 112(d). Therefore, EPA is proposing MACT to
be the level that is achieved by applying oxidation catalyst to non-
emergency CI engines greater than 300 HP, which is 4 ppmvd of CO at 15
percent O2, or 90 percent CO efficiency. A fuller discussion
of EPA's analysis of regulatory alternatives above-the-floor is
presented in the memorandum entitled ``Above-the-Floor Determination
for Stationary RICE.''
    While these proposed HAP emission standards would not require the
use of CDPFs, EPA notes that when compared to oxidation catalysts,
CDPFs provide significantly greater reductions in levels of PM from
diesel engines, which are a significant health concern. PM emissions
from these engines contain several constituents, including black carbon
and trace amounts of metallic HAP. EPA estimates that the range of
PM2.5 emission reductions would increase from 2,600 tons to
7,600 tons if CDPFs are used rather than oxidation catalysts.
    The contribution of black carbon emissions to global climate is
being evaluated in a number of scientific forums.3 4 EPA is
interested in comments and information on other regulatory and non-
regulatory approaches that could help address black carbon emissions
from existing stationary diesel engines.
---------------------------------------------------------------------------

    \3\ Intergovernmental Panel on Climate Change (IPCC). 2007.
Changes in Atmospheric Constituents and in Radiative Forcing, in
Climate Change 2007, Cambridge University Press, New York, Cambridge
University Press.
    \4\ Atmospheric Aerosol Properties and Climate Impacts. 2009.
U.S. Climate Change Science Program Synthesis and Assessment Product
2.3, January 2009.
---------------------------------------------------------------------------

    Sources may wish to review whether it is appropriate for some
existing CI engines to use CDPFs to meet the requirements of this rule,
given the considerable co-benefits of using CDPF. For example, the cost
effectiveness associated with reducing PM2.5 with oxidation
catalysts on a 300 HP diesel engine is $27,000 per ton, while using a
CDPF improves the cost effectiveness to about $9,000 per ton. These
cost effectiveness numbers include any potential reductions of metallic
HAP which would be emitted in the particle phase. EPA notes, however,
that some have suggested that the use of CDPF on older uncontrolled
engines may be more problematic than for newer engines that already
have some level of engine control.
    One of the potential problems raised by industry are the
difficulties with retrofitting CDPFs on mechanically-controlled engines
versus those that use electronic controls. Furthermore, the diesel PM
levels from older engines are, according to some, too high for
efficient operation of a CDPF. EPA is requesting comment on the use of
CDPF to meet the HAP standards for this rule and on the benefits
generally of using CDPFs on older stationary CI engines. EPA also asks
for comment on technical feasibility issues that might preclude the use
of such devices on older diesel engines.
    Stationary diesel engines also emit trace amounts of metallic HAP.
EPA believes that formaldehyde and CO are reasonable surrogates for
total HAP, including these very small trace emissions of metals.
Nonetheless, EPA is taking comment on whether there are more
appropriate surrogates for metallic HAP from stationary diesel engines.
EPA does not have data regarding the use of other surrogates for these
emissions from stationary diesel engines, so EPA is soliciting data on
any other such surrogates.
    The proposed rule requires the use of ULSD for existing non-
emergency stationary diesel engines greater than 300 HP with a
displacement of less than 30 liters per cylinder. The use of ULSD is
necessary due to concerns about oxidation catalysts simultaneously
oxidizing SO2 to form sulfate particulate. A limit on the
diesel fuel sulfur level of 15 ppm will reduce the potential for
increased sulfate emissions from diesel engines equipped with oxidation
catalysts. The limit on fuel sulfur will also improve the efficiency of
the oxidation catalyst. The use of ULSD will also enable stationary
diesel engines to utilize CDPF if desired. EPA has already promulgated
similar diesel fuel sulfur standards for highway and

nonroad diesel engines and for new stationary diesel engines.
    e. Stationary Non-Emergency CI 500 HP. A regulation
covering existing stationary diesel engines greater than 500 HP at
major sources was promulgated in 2004. However, based on the MACT floor
analysis conducted at that time, the regulation subjected existing
diesel engines greater than 500 HP at major sources to emission
standards of no further emission control.
    However, due to the availability of technically feasible and
reasonably cost-effective technologies to control emissions from these
existing large stationary CI engines, and the potential of reducing
exhaust HAP (as well as PM), EPA is proposing to address HAP emissions
from these existing diesel engines >500 HP pursuant to its authority
under CAA section 112(d).
    As a result of our review of the Emissions Database, the MACT floor
for CI non-emergency stationary RICE greater than or equal to 50 HP and
less than or equal to 500 HP is 40 ppmvd of CO at 15 percent
O2.
    As part of our analysis of going beyond the MACT floor, EPA
considered the emissions associated with the use of oxidation
catalysts. Similar to EPA's analysis of the emission reductions and
costs associated with the use of oxidation catalysts for diesel engines
from 300-500 HP, EPA believes the HAP emission reductions associated
with use of oxidation catalysts, taking into account the costs of such
controls, are justified under section 112(d). A fuller discussion of
EPA's analysis of regulatory alternatives above-the-floor is presented
in the memorandum entitled ``Above-the-Floor Determination for
Stationary RICE.''
    EPA is proposing to address emissions from existing non-emergency
CI engines greater than 500 HP located at major sources by limiting the
CO to 4 ppmvd at 15 percent O2 or by reducing CO by 90
percent or more. The proposed standards are based on what is achieved
by applying oxidation catalyst controls. Oxidation catalyst controls
reduce HAP, CO, and PM from diesel engines. The proposed emission
standard is in terms of CO, which has been shown to be an appropriate
surrogate for HAP. Stationary diesel engines also emit trace amounts of
metallic HAP. EPA believes that formaldehyde and CO are reasonable
surrogates for total HAP, including these very small trace emissions of
metals. Nonetheless, EPA is taking comment on whether there are more
appropriate surrogates for metallic HAP from stationary diesel engines.
EPA does not have data regarding the use of other surrogates for these
emissions from stationary diesel engines, so EPA is soliciting data on
any other such surrogates.
    For the same reasons provided above for non-emergency diesel
engines between 300-500 HP, EPA is requiring the use of ULSD for non-
emergency diesel engines above 500 HP.
    f. Stationary Emergency SI 50=HP=500. As a
result of our review of the Emissions Database and industry estimates,
EPA determined the MACT floor for SI emergency stationary RICE greater
than or equal to 50 HP and less than or equal to 500 HP is 2 ppmvd of
formaldehyde at 15 percent O2.
    As part of EPA's beyond-the-floor MACT analysis, EPA considered
add-on controls for this subcategory. However, the same issues apply to
emergency SI engines as to emergency CI engines; in particular, the
cost-effectiveness of such controls for HAP reduction on emergency
engines and questions about the feasibility of such controls on
emergency engines. According to the Population Database there are no SI
emergency stationary RICE greater than or equal to 50 HP and less than
or equal to 500 HP using catalyst type controls. Therefore, it is not
appropriate to require add-on controls on emergency SI engines. EPA
also found no other techniques appropriate to go beyond the MACT floor.
MACT is therefore equivalent to the MACT floor.
    g. Stationary Non-Emergency 2SLB 50=HP<=500. EPA
selected the best performing 12 percent of engines for formaldehyde,
identified the corresponding CO tests, and averaged the CO emissions
from the corresponding tests. As a result, the MACT floor for non-
emergency 2SLB stationary RICE greater than or equal to 50 HP and less
than or equal to 500 HP is 85 ppmvd of CO at 15 percent O2.
    As part of EPA's beyond-the-floor MACT analysis, EPA considered
applying oxidation catalyst controls to this subcategory and estimated
the cost per ton of HAP removed. EPA believes the costs to be
reasonable for engines 250 HP and above equipped with oxidation
catalyst and can be justified in light of the significant reductions of
HAP that would be achieved. For example, the cost effectiveness of
reducing HAP from 2SLB engines in the 300 to 500 HP size range is about
$2,900 per ton. Oxidation catalysts can reduce HAP and CO from
stationary spark-ignition engines by approximately 90 percent. The
Emissions Database did not indicate any other proven and cost-effective
control technologies or other methods that can reduce HAP emissions
from 2SLB engines to levels lower than those achieved by oxidation
catalysts. The proposed emission limit is in terms of CO, which has
been shown to be an appropriate surrogate for HAP. EPA believes the HAP
emission reductions associated with use of oxidation catalysts, taking
into account the costs of such controls, are justified. Therefore, MACT
for engines 250 HP and above is the level that is achievable by
applying oxidation catalyst and is 8 ppmvd of CO at 15 percent
O2 or 90 percent CO efficiency. MACT for engines below 250
HP is equivalent to the MACT floor.
    h. Non-Emergency 4SLB 50=HP<=249. According to the
Population Database, there are no non-emergency 4SLB stationary RICE
greater than or equal to 50 HP and less than or equal to 249 HP using
catalyst type controls.
    EPA reviewed formaldehyde emissions tests from 4SLB engines. EPA
selected the best performing 12 percent of engines for formaldehyde and
identified the corresponding CO values from the top 12 tests for
formaldehyde. The corresponding CO values were then averaged. As a
result, the MACT floor for 4SLB stationary RICE greater than or equal
to 50 HP and less than or equal to 249 HP is 95 ppmvd of CO at 15
percent O2.
    As part of EPA's beyond-the-floor MACT analysis, EPA considered
applying oxidation catalyst controls to this subcategory. However the
cost per ton of HAP removed was determined to be too significant and to
outweigh the expected HAP reductions from these stationary engines.
Therefore, MACT is equivalent to the MACT floor.
    i. Non-Emergency 4SLB 250=HP<=500. For non-emergency
4SLB engines between 250 and 500 HP, EPA found that 5.7 percent of the
population is controlled with aftertreatment that yields HAP
reductions, particularly oxidation catalysts.
    As part of EPA's beyond-the-floor MACT analysis, EPA considered
applying oxidation catalyst and estimated the cost per ton of HAP
removed. The use of oxidation catalysts on these engines can achieve 90
percent HAP reductions. EPA concluded that the control costs associated
with installing oxidation catalysts are reasonable for this type of
stationary engine, and thus can be justified considering the
significant reductions of HAP that would be achieved by using oxidation
catalysts. Oxidation catalysts can reduce HAP and CO from stationary
spark-ignition engines. The proposed emission limit is in terms of CO,
which has been shown to be an appropriate surrogate for HAP. EPA
believes the

HAP emission reductions associated with use of oxidation catalysts,
taking into account the costs of such controls, are justified. The
Emissions Database did not indicate any other proven and cost-effective
control technologies or other methods that can reduce HAP emissions
from 4SLB engines to levels lower than those achieved by oxidation
catalysts.
    EPA determined that the appropriate numerical MACT level could be
determined by analyzing uncontrolled levels of HAP and reducing the
levels by the expected reductions from oxidation catalysts. EPA
analyzed formaldehyde emissions from 4SLB tests for engines without
add-on controls. EPA took the average of the best performing 12 percent
of engines for formaldehyde and identified the corresponding CO values
from the best performing 12 percent of tests. The corresponding CO
values were then averaged. The result for 4SLB stationary RICE greater
than or equal to 250 HP and less than or equal to 500 HP is 95 ppmvd of
CO at 15 percent O2.
    Given an expected 90 percent reduction from the use of oxidation
catalysts, MACT is 9 ppmvd of CO at 15 percent O2 or 90
percent CO efficiency. A fuller discussion of EPA's analysis of
regulatory alternatives above-the-floor is presented in the memorandum
entitled ``Above-the-Floor Determination for Stationary RICE.''
    j. Non-Emergency 4SRB 50>=HP<=500. For SI non-emergency stationary
4SRB engines greater than or equal to 50 HP and less than or equal to
500 HP, EPA found that 5.6 percent of the population are using catalyst
type controls, according to the Population Database. The add-on control
that typically applies to this subcategory of engines is NSCR.
    As part of EPA's beyond-the-floor MACT analysis, EPA considered the
application of NSCR to such engines. The Emissions Database provided no
other proven and cost effective emission control methods currently
available which can reduce HAP emissions from 4SRB engines to levels
lower than that achieved through NSCR control.
    The technology is proven, has been applied to thousands of rich
burn engines, and is efficient at reducing HAP emissions. EPA
considered applying NSCR and estimated the cost per ton of HAP removed.
EPA believes the costs are reasonable and appropriate and can be
justified considering the significant reductions of HAP that would be
achieved by using NSCR on this subcategory of engines. For example, the
cost effectiveness of reducing HAP from stationary 4SRB engines in the
300 to 500 HP size range is about $5,000 per ton.
    Other pollutants are also reduced through the use of NSCR including
significant reductions in NOX and CO emissions. Taking into
consideration the emission reductions achieved by applying NSCR to 4SRB
engines greater than 50 HP, the cost per ton of emissions reduced is
favorable for this type of stationary engines. A fuller discussion of
EPA's analysis of regulatory alternatives above-the-floor is presented
in the memorandum entitled ``Above-the-Floor Determination for
Stationary RICE.''
    EPA determined that the appropriate numerical MACT level could be
determined by analyzing uncontrolled levels of HAP and reducing the
levels by the expected reductions from NSCR. EPA analyzed formaldehyde
emissions from 4SRB engines without add-on controls and averaged the
emissions from the best performing 12 percent of engines. The result
for 4SRB stationary RICE greater than or equal to 50 HP and less than
or equal to 500 HP is 2 ppmvd of formaldehyde at 15 percent
O2.
    Therefore, MACT is the level that is achievable by applying NSCR
and is 200 ppbvd of formaldehyde at 15 percent O2 or 90
percent formaldehyde efficiency.
2. Engines at Area Sources
    Under section 112(k) of the CAA, EPA developed a national strategy
to address air toxic pollution from area sources. The strategy is part
of EPA's overall national effort to reduce toxics, but focuses on the
particular needs of urban areas. Section 112(k) requires EPA to list
area source categories and to ensure 90 percent of the emissions from
area sources are subject to standards pursuant to section 112(d) of the
CAA. Under section 112(k), the CAA specifically mandated that EPA
develop a strategy to address public health risks posed by air toxics
from area sources in urban areas. Section 112(k) also mandates that the
strategy achieve a 75 percent reduction in cancer incidence
attributable to HAP emitted by stationary sources. As mentioned,
stationary RICE are listed as a source category under the Urban Air
Toxics Strategy developed under the authority of sections 112(k) and
112(c)(3) of the CAA. These area sources are subject to standards under
section 112(d).
    Section 112(d)(5) of the CAA indicates that EPA may elect to
promulgate standards or requirements to area sources ``which provide
for the use of generally available control technologies or management
practices by such sources to reduce emissions of hazardous air
pollutants.'' For determining emission limitations, GACT standards can
be more flexible requirements than MACT standards. For example, the CAA
provisions for setting GACT do not require setting control baseline or
``floor'' that is equal to the average emission levels achieved by the
best performing 12 percent of a type of facility, for existing sources,
or the emission control achieved in practice by the best controlled
similar source, for new sources. EPA is permitted to consider costs and
other factors during the GACT analysis. Control technology options
available to stationary RICE located at area sources are the same as
those discussed for engines located at major sources.
    The requirements being proposed in this action are applicable to
stationary RICE located at area sources of HAP emissions. EPA has
chosen to propose national requirements, which not only focus on urban
areas, but address emissions from area sources in all areas (urban and
rural).
    For stationary RICE, it would not be practical or appropriate to
limit the applicability to urban areas and EPA has determined that
national standards are appropriate. Stationary RICE are located in both
urban and rural areas. In fact, there are some rural areas with high
concentrations of stationary RICE. Stationary RICE are employed in
various industries used for both the private and public sector for a
wide range of applications such as generator sets, irrigation sets, air
and gas compressors, pumps, welders, and hydro power units. Stationary
RICE may be used by private entities for agricultural purposes and be
located in a rural area, or it may be used as a standby generator for
an office building located in an urban area. Other stationary RICE may
operate at large sources for electric power generation, transmission,
or distribution purposes.
    In previous rulemakings, EPA had determined that stationary RICE
are located all over the U.S., and EPA cannot say that these sources
are more prevalent in certain areas of the country. Therefore, for the
source category of stationary RICE, EPA is proposing national
requirements without a distinction between urban and non-urban areas.
EPA requests comment on this approach and its appropriateness for
today's population of stationary RICE.
    For subcategories of larger engines, particularly those above 500
HP and those for which EPA has based MACT on the use of add-on
controls, the control technologies that create the basis for the
emission standards for engines located at major sources are readily
available and feasible for all engines.

Further, for those cases where EPA is basing the MACT emission
standards on add-on controls, the MACT standards is in all cases beyond
the MACT floor. In these cases, EPA determined that costs associated
with implementing HAP-reducing technologies are reasonable and
justified. Hence, there is no reason why GACT should be any different
than MACT for larger engines located at area sources. Consequently, EPA
has determined that for area sources that are non-emergency 2SLB
engines greater than or equal to 250 HP, non-emergency 4SLB engines
greater than or equal to 250 HP, non-emergency 4SRB greater than or
equal to 50 HP, emergency CI engines greater than 500 HP, non-emergency
CI engines greater than 300 HP, landfill and digester gas engines
greater than 500 HP, and emergency SI engines greater than 500 HP, GACT
is based on the same emission controls as are discussed above for major
sources.
    As discussed, GACT provides EPA more flexibility in setting
requirements than MACT and can include available control technologies
or management practices to reduce HAP emissions. EPA has determined
that for area sources that are non-emergency 2SLB engines greater than
or equal to 50 HP and less than 250 HP, non-emergency 4SLB engines
greater than or equal to 50 HP and less than 250 HP, emergency CI
engines greater than or equal to 50 HP and less than or equal to 500
HP, non-emergency CI engines greater than or equal to 50 HP and less
than or equal to 300 HP, engines less than 50 HP, landfill and digester
gas engines greater than or equal to 50 HP and less than or equal to
500 HP, and emergency SI engines greater than or equal to 50 HP and
less than or equal to 500 HP, EPA proposes that GACT is management
practices.
    Management practices include several specific maintenance
requirements that will help ensure that the exhaust emissions from
these engines are minimized. Some of the management practices include
changing oil and filter, changing spark plugs and replacement of air
cleaners. EPA specifically requests comments on these management
practices and asks commenters to provide information on any additional
management practices that may be appropriate for these engines. A
maintenance plan is required in order to help keep records that the
management practices are being followed.
    Although add-on controls are technically feasible for some engines
located at area sources, control costs are high and EPA believes that
it is possible to achieve reasonable controls using management
practices. For example, capital costs associated with installing an
oxidation catalyst on a 200 HP diesel engine are about $2,100 with
annual costs of $700. Such costs are significant particularly when one
considers that the cost per ton of this option is on the order of
$72,000 per ton of HAP reduced. Considering the high cost per ton of
HAP reduced, it is difficult to justify requiring add-on controls on
these engines.
    Furthermore, EPA is attempting to minimize the burden of the
proposed rule, specifically on small businesses and individual owners
and operators. EPA does not believe that management practices would be
a substantial burden on owners and operators such as private owners and
small entities.
3. Startup, Shutdown, and Malfunction Limits
    With respect to the exemption from emission standards during
periods of Startup, Shutdown and Malfunction in the General Provisions
(see, e.g., 40 CFR 63.6(f)(1) (exemption from non-opacity emission
standards) and (h)(1) (exemption from opacity and visible emission
standards)), we note that on December 19, 2008, in a decision
addressing a challenge to the 2002, 2004 and 2006 amendments to those
provisions, the Court of Appeals for the District of Columbia Circuit
vacated the SSM exemption. Sierra Club v. EPA 2008 U.S. App. LEXIS
25578 (D.C. Cir. Dec. 19, 2008). We are still evaluating the recent
court decision, and the time for appeal of that decision has not yet
run. However, in light of the court decision, EPA is proposing not to
apply the SSM exemption for non-opacity standards set forth in 40 CFR
63.6(f)(1) to this NESHAP. The SSM exemption for opacity and visible
emissions standards in 40 CFR 63.6(h)(1) is not relevant here because
the standards proposed in this action do not constitute opacity or
visible emission standards.
    EPA recognizes that there are different modes of operation for any
stationary source, and those modes generally include start-up, normal
operations, shut-down, and malfunctions. EPA does not believe that
emissions should be different during periods of shutdown compared to
normal operations, but EPA does believe that emissions will likely be
different during periods of startup and malfunction, particularly for
engines relying on catalytic controls.
    EPA is proposing two options in this action for subcategories where
the proposed emission standard is based on the use of catalytic
controls. The first option is to have the same standards apply during
both normal operation and periods of startup and malfunctions. While
EPA is aware of the general properties of engine catalytic controls,
our Emissions Database has no specific data showing that emissions
during periods of startup and malfunction are different than during
normal operation. Furthermore, EPA does not have substantial
information regarding the specific parameters (e.g. timing,
temperature) of such differences in emissions.
    Although we lack specific data on emissions during start-up and
malfunction, EPA recognizes that emissions are likely to differ during
these periods for engines relying on catalytic controls. Accordingly,
for subcategories where the proposed emission standard is based on the
use of catalytic controls, EPA is also co-proposing emission
limitations that would apply to stationary RICE during periods of
startup and malfunction in order to account for the different emissions
characteristics of stationary internal combustion engines during
startup and malfunction periods, compared to other periods of
operation. In particular, engines using catalytic controls like OC and
NSCR to reduce emissions cannot rely on the operation of such devices
during periods of startup, because the engine exhaust temperatures need
to increase up to a certain level for such controls to work
effectively. In addition, add-on controls cannot be presumed to work
reliably during periods of malfunction. Malfunctions may include
failure of engine control systems that are essential for the proper
performance and emissions of the engine. Engine malfunctions may affect
the exhaust gas temperatures and composition of the exhaust gases in
ways that could decrease the effectiveness or even damage permanently
the emission control device.
    During startup operation with an OC, engine exhaust temperatures
must reach about 250 to 300 degrees C in order to work effectively. In
the case of NSCR, exhaust gas temperatures must reach between 425 to
650 degrees C in order to work effectively. It can take about 15 to 30
minutes of operation--depending on engine size--for exhaust
temperatures to reach those temperature levels. Thus, for the
subcategories of stationary RICE discussed above where the proposed
emission standard is based on the use of catalytic controls, EPA is co-
proposing that the standards during periods of startup and malfunction
will be based on emissions expected from the best controlled sources
prior to the full warm-up of the catalytic control. The standard is
based on the emissions levels from the best controlled engines that do
not include catalytic controls,

because prior to warm-up, the engine conditions do not allow for
effective catalytic control.
    Under either co-proposal, for the subcategories of stationary RICE
discussed above where the proposed emission limitations during normal
operation are not based on the use of oxidation catalyst or NSCR, we
are proposing the same emission limitations during startup and
malfunction as during periods of normal operation.
    EPA requests comment on these proposed approaches to addressing
emissions during start-up, shutdown and malfunction and the proposed
standards that would apply during these periods. See Tables 1, 2 and 3
of this preamble, setting forth proposed standards using the approach
of differentiating between periods of start-up and malfunction and
normal operations. EPA requests comment on other approaches to setting
MACT standards during periods of start-up, shutdown or malfunction, and
notes that an approach that sets a single MACT standard that applies at
all times, including SSM periods, may result in a higher overall MACT
standard, based on the need to account for variation of operations in
setting MACT standards. Sierra Club v. EPA, 439 F.3d 875 (D.C. Cir.
2007) (holding that EPA may legitimately account for variability
because ``each [source] must meet the [specified] standard every day
and under all operating conditions.'' (quoting Mossville Environmental
Action Network v. EPA, 370 F.3d 1232 (D.C. Cir. 2004). EPA also asks
for comment on the level of specificity needed to define the periods of
startup and malfunction to assure clarity regarding when standards for
those periods apply, including whether it should be based on the time
necessary for an engine to warm to temperatures needed for effective
catalytic control and whether maximum time limits should be included.

C. How did EPA determine the compliance requirements?

    EPA discussed the specific compliance requirements that are being
proposed in section III of the preamble. In general, EPA has attempted
to reduce the burden on affected owners and operators. The following
presents the rationale for the proposed compliance requirements.
    Stationary non-emergency RICE located at major sources that are
less than 100 HP, stationary RICE located at area sources that are not
subject to numerical emission standards, and all stationary emergency
RICE are only subject to compliance requirements in the form of
management practices to minimize emissions. EPA does not believe that
the proposed management practices are a burdensome requirement, and it
is expected that most owners and operators are already using such
practices. It is in the owner's best interest to operate and maintain
the engine and aftertreatment device (if one is installed) properly.
The proposed requirements minimize the burden on individual owners and
operators and small entities, while ensuring that the engine and
aftertreatment device is operated and maintained correctly. Further,
EPA does not believe that it is reasonable to subject small stationary
RICE and stationary emergency RICE to performance testing. Subjecting
the engines to maintenance requirements will assist in minimizing and
maintaining emissions below the emission standards. The cost of
requiring performance testing on these engines would be too significant
when compared to the cost of the unit itself and to the benefits of
such testing. In addition, subjecting stationary RICE located at area
sources that are not subject to numerical emission standards to
performance testing would serve little purpose, given that the purpose
of testing is to determine whether the engine is meeting numerical
limits, which is unnecessary where no such limits apply.
    For stationary non-emergency RICE located at major sources that are
greater than or equal to 100 HP and stationary RICE located at area
sources that are subject to numerical emission standards, EPA
determined that performance testing is necessary to confirm that the
emission standards are being met. Again, EPA has attempted to reduce
compliance requirements and is proposing a level of performance testing
commensurate with ensuring that the emission standards are being met.
Therefore, for non-emergency stationary RICE located at major sources
that are greater than or equal to 100 HP and less than or equal to 500
HP and stationary RICE located at area sources that are subject to
numerical emission standards, EPA chose to require an initial
performance test only. However, if the engine is rebuilt or overhauled,
the engine must be re-tested to demonstrate that it meets the emission
standards.
    For existing non-emergency stationary RICE greater than 500 HP,
testing every 8,760 hours of operation of 3 years, whichever comes
first, is also required. EPA believes such a requirement is appropriate
for these size engines, but does not believe that further testing is
necessary for smaller engines, i.e., those less than or equal to 500
HP. Subsequent performance testing is appropriate for engines greater
than 500 HP due to their size and frequency of operation. Plus, many
States mandate more stringent compliance requirements for large
engines. Finally, the RICE NESHAP for engines greater than 500 HP
located at major sources also required further performance testing
following the initial compliance demonstration.
    Owners and operators of stationary non-emergency 2SLB, 4SLB, 4SRB,
and CI RICE that are greater than 500 HP and are located at an area
source, and stationary non-emergency CI RICE that are greater than 500
HP and are located at a major source must continuously monitor pressure
drop across the catalyst and catalyst inlet temperature if the engine
is equipped with oxidation catalyst or NSCR. These parameters serve as
surrogates of the catalyst performance. The pressure drop across the
catalyst can indicate if the catalyst is damaged or fouled, in which
case, catalyst performance would decrease. If the pressure drop across
the catalyst deviates by more than two inches of water from the
pressure drop across the catalyst measured during the initial
performance test, the catalyst might be damaged or plugged. If the
catalyst is changed, the pressure drop across the catalyst must be
reestablished. The catalyst inlet temperature is a requirement for
proper performance of the catalyst. In general, the catalyst
performance will decrease as the catalyst inlet temperature decreases.
In addition, if the catalyst inlet temperature is too high, it might be
an indication of ignition misfiring, poisoning, or fouling, which would
decrease catalyst performance. In addition, the catalyst requires inlet
temperatures to be greater than or equal to the specified temperature
for the reduction of HAP emissions.
    EPA is proposing to remove the proposed EPA Method 323 from 40 CFR
part 63, subpart ZZZZ, as an acceptable method for determining
compliance with the formaldehyde emission limitation. The method is
currently included as an optional test method for measuring
formaldehyde in addition to EPA Method 320 and ASTM D6348-03 for
stationary engines. EPA Method 323 was first proposed as part of the
NESHAP for Stationary Combustion Turbines published January 14, 2003
(68 FR 1888) for measuring formaldehyde emissions from natural gas-
fired sources. However, the method was not included in the final rule
due to reliability concerns and EPA never promulgated EPA Method 323 as
a final

standard in 40 CFR part 63, appendix A. Due to unresolved technical
issues associated with the method affecting engine test results, EPA
has no plans to finalize EPA Method 323. Therefore, EPA finds it
appropriate to propose to remove the method from subpart ZZZZ.

D. How did EPA determine the reporting and recordkeeping requirements?

    EPA discussed the specific reporting and recordkeeping requirements
that are being proposed in section III of the preamble. In general, EPA
has attempted to reduce the reporting and recordkeeping burden on
affected owners and operators. The following presents the rationale for
the proposed reporting and recordkeeping requirements.
    Owners and operators of emergency engines are required to keep
records of their hours of operation (emergency and non-emergency).
Owners and operators must install a non-resettable hour meter on their
engines to record the necessary information. The owner and operators
are required to record the time of operation and the reason the engine
was in operation during that time. EPA believes these requirements are
appropriate for emergency engines. The requirement to maintain records
documenting why the engine was operating will ensure that regulatory
agencies have the necessary information to determine if the engine was
in compliance with the maintenance and testing hour limitation of 100
hours per year.
    EPA does not believe the recordkeeping requirements being placed
upon owners and operators of stationary emergency engines are onerous.
Emergency engines are often equipped with the equipment necessary to
record hours of operation and operators may already be recording the
information. Even as a brand new requirement, recording the time and
reason of operation should take minimal time and effort. Further,
recording the hours and reason for operation is necessary to assure
that the engine is in compliance. Finally, these requirements are
consistent with previously promulgated requirements affecting the same
or similar engines, namely under the CI and SI NSPS.
    The reporting requirements being proposed in this rule are
consistent with those required for engines subject to the 2004 rule,
i.e., stationary RICE greater than 500 HP located at major sources, and
are based on the General Provisions. Owners and operators of existing
emergency stationary RICE, existing stationary RICE that are less than
100 HP and existing stationary RICE that are not subject to any
numerical emission standards, do not have to submit the notifications
listed in the NESHAP General Provisions (40 CFR part 63, subpart A).
Owners and operators of all other engines must submit an initial
notification, notification of performance test, and a notification of
compliance for each stationary RICE which must comply with the
specified emission limitations.

V. Summary of Environmental, Energy and Economic Impacts

A. What are the air quality impacts?

    The proposed rule is expected to reduce total HAP emissions from
stationary RICE by 13,000 tons per year (tpy) beginning in the year
2013 or the first year the rule will become effective. EPA estimates
that approximately 290,000 stationary SI engines will be subject to the
rule and nearly 1 million stationary CI engines will be subject to the
rule. These estimates include stationary engines located at major and
area sources; however, not all stationary engines are subject to
numerical emission standards. Further information regarding the
estimated reductions of the proposed rule can be found in the
memorandum entitled ``Impacts Associated with NESHAP for Existing
Stationary RICE,'' which is available in the docket.
    In addition to HAP emissions reductions, the proposed rule will
reduce other pollutants such as CO, NOX , and PM. The
proposed rule is expected to reduce emissions of CO by more than
510,000 tpy in the year 2013. Emissions of NOX are expected
to be reduced by 79,000 tpy in the year 2013. Reductions of PM are
estimated at close to 2,600 tpy in the year 2013, and SOX
reductions are expected to be more than 4,000 tpy in the year 2013.
Emissions of volatile organic compounds (VOC) are estimated to be
reduced by 90,000 tpy in the year 2013.

B. What are the cost impacts?

    The total national capital cost for the final rule for existing
stationary RICE is estimated to be $528 million, with a total national
annual cost of $345 million in year 2013 (the first year the rule is
implemented). Further information regarding the estimated cost impacts
of this proposed rule can be found in the memorandum entitled ``Impacts
Associated with NESHAP for Existing Stationary RICE,'' which is
available in the docket.

C. What are the benefits?

    We estimate the monetized benefits of this proposed NESHAP to be
$930 million to $2.0 billion (2007$, 3% discount rate) in the year of
full implementation (2013); higher or lower estimates are plausible
according to alternate models identified by experts describing the
relationship between PM2.5 and premature mortality.\5\ The
benefits at a 7% discount rate are $850 million to $1.8 billion
(2007$). We base the estimate of human health benefits derived from the
PM2.5 and PM2.5 precursor emission reductions on
the approach and methodology laid out in the Technical Support Document
that accompanied the Regulatory Impact Analysis (RIA) for the revision
to the National Ambient Air Quality Standard for Ground-level Ozone
(NAAQS), March 2008. We generated estimates that represent the total
monetized human health benefits (the sum of premature mortality and
morbidity) of reducing PM2.5 and PM2.5 precursor
emissions. A summary of the range of the monetized benefits estimates
at discount rates of 3% and 7% is in Table 4 of this preamble.
---------------------------------------------------------------------------

    \5\ 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 4--Summary of the Range of Monetized Benefits Estimates for the Proposed RICE NESHAP
----------------------------------------------------------------------------------------------------------------
                                       Emission      Total monetized  benefits       Total monetized  benefits
             Pollutant                reductions    (millions  of 2007 dollars,     (millions  of 2007 dollars,
                                        (tons)           3% discount) \1\                7% discount) \1\
----------------------------------------------------------------------------------------------------------------
Direct PM2.5.......................        2,561  $550 to $1,200................  $500 to $1,100.
PM2.5 precursors...................      184,536  $380 to $820..................  $350 to $740.
                                    ----------------------------------------------------------------------------

    Grand total....................  ...........  $930 to $2,000................  $850 to $1,800.
----------------------------------------------------------------------------------------------------------------
\1\ All estimates are for the analysis year (full implementation, 2013), and are rounded to two significant
  figures so numbers may not sum across rows. We assume that 40% of emissions reductions are from major point
  sources and 60% are from area sources. PM2.5 precursors reflect emission reductions of NOX, SOX, and VOCs. All
  fine particles are assumed to have equivalent health effects, and the monetized benefits incorporate the
  conversion from precursor emissions to ambient fine particles. Monetized benefits from HAP reductions are not
  included in these estimates.

    The specific estimates of benefits per ton of pollutant reductions
included in this analysis are largely driven by the concentration
response function for premature mortality. Experts have advised 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. For
this proposed NESHAP we cite two key empirical studies, one based on
the American Cancer Society cohort study \6\ and the extended Six
Cities cohort study.\7\ Alternate models identified by experts
describing the relationship between PM2.5 and premature
mortality would yield higher and lower estimates (Roman et al. 2008).
---------------------------------------------------------------------------

    \6\ 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.
    \7\ Laden et al., 2006. ``Reduction in Fine Particulate Air
Pollution and Mortality.'' American Journal of Respiratory and
Critical Care Medicine. 173: 667-672.
---------------------------------------------------------------------------

    EPA is exploring updates to the benefit-per-ton estimates,
including two technical updates, as well as addressing the assumption
regarding thresholds in the health impact function. For more
information, please consult the RIA for this proposed rule that is
available in the docket.
    To generate the benefit-per-ton estimates, we used a model to
convert emissions of direct PM2.5 and PM2.5
precursors into changes in PM2.5 air quality and another
model to estimate the changes in human health based on that change in
air quality. Finally, the monetized health benefits were divided by the
emission reductions to create the benefit-per-ton estimates. Even
though all fine particles are assumed to have equivalent health
effects, the benefit-per-ton estimates vary between precursors because
each ton of precursor reduced has a different propensity to form
PM2.5. For example, NOX 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.
    This analysis does not include the type of detailed uncertainty
assessment found in the 2006 PM2.5 NAAQS RIA because we lack
the necessary air quality input and monitoring data to run the benefits
model. However, the 2006 PM2.5 NAAQS benefits analysis
provides an indication of the sensitivity of our results to the use of
alternative concentration response functions, including those derived
from the PM expert elicitation study.
    The annualized costs of this rulemaking are estimated at $345
million (2007 dollars) in the year of full implementation, and the
benefits are estimated at $930 million to $2.0 billion (2007 dollars,
3% discount rate) for that same year. Thus, net benefits of this
rulemaking are estimated at $590 million to $1.6 billion (2007 dollars,
3% discount rate); higher or lower estimates are plausible according to
alternate models identified by experts describing the relationship
between PM2.5 and premature mortality. The net benefits at a
7% discount rate are $500 million to $1.5 billion (2007$). EPA believes
that the benefits are likely to exceed the costs by a significant
margin even when taking into account the uncertainties in the cost and
benefit estimates. It should be noted that the range of benefits
estimates provided above does not include ozone-related benefits from
the reductions in VOC and NOX emissions expected to occur as
a result of this final rule, nor does this range include benefits from
the portion of total PM emissions reduction that is not
PM2.5 or other hazardous air pollutants. We do not have
sufficient information or modeling available to provide such estimates
for this rulemaking. For more information, please refer to the RIA for
this proposed rule that is available in the docket.

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

    EPA does not anticipate any adverse non-air health, environmental
or energy impacts as a result of this proposed rule.

VI. Solicitation of Public Comments and Participation

    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 EPA
to make maximum use of the comments. The Agency invites all parties to
coordinate their data collection activities with EPA to facilitate
mutually beneficial and cost-effective data submissions.
    EPA is requesting specific comment on the proposed emission
standards for existing non-emergency 4SLB engines greater than or equal
to 250 HP and existing non-emergency 4SRB engines greater than or equal
to 50 HP. Specifically, EPA is seeking comment on the appropriateness
of setting more stringent emission standards for certain existing rich
burn engines than what is currently required for other rich burn
engines already regulated. For example, the proposed emission standards
for existing non-emergency 4SRB engines greater than or equal to 50 HP
is 200 ppbvd of formaldehyde or 90 percent formaldehyde reduction,
whereas the current emission standards for existing and new non-
emergency 4SRB engines greater than 500 HP at major sources is 350
ppbvd and 75 percent formaldehyde reduction.
    EPA is also requesting comment on the proposed formaldehyde
emission standards that apply to rich burn engines. EPA is particularly
interested in determining whether it would be appropriate to include a
VOC emission standard in place of or as an alternative to the
formaldehyde emission standards. If so, EPA is requesting information
on what an appropriate VOC emission standard should be. Commenters are

encouraged to submit stationary engine test data containing VOC
emissions pre- and post-catalyst as well as any engine test data that
includes both formaldehyde and VOC emissions from the same engine. In
addition, we ask for comments and data on whether there are other more
appropriate surrogates than formaldehyde and CO for the metallic HAP
that are emitted by stationary diesel engines.
    EPA is proposing emission standards for existing stationary non-
emergency CI engines that are greater than 300 HP that are based on the
use of oxidation catalyst. EPA solicits comments on whether 300 HP is
the appropriate size division for setting beyond-the-floor MACT
standards requiring the use of add-on controls. Specifically, EPA is
seeking comment on whether it is feasible or appropriate to extend the
more stringent standards to engines that are less than 300 HP. EPA also
requests comments on the possibility of requiring CDPFs for existing
diesel engines, rather than oxidation catalysts, and, if so, which
subcategory or subcategories of stationary diesel engines would be most
appropriate for control using CDPFs. The use of CDPFs would help
achieve the same level of HAP reduction as oxidation catalysts, with a
higher level of control of diesel PM. EPA is also interested in
comments and information on other regulatory and non-regulatory
approaches for addressing black carbon emissions from existing
stationary diesel engines.
    EPA also requests comments on other proven technologies that may be
able to achieve significant HAP reductions. For example, we request
comment on the possible requirement of using closed crankcase
ventilation systems on engines affected by this proposed rule. Closed
crankcase ventilation systems have been used in mobile engine
applications for many years.
    In addition, EPA is requesting comment on the fuel requirements.
EPA is proposing that existing stationary non-emergency CI engines
greater than 300 HP with a displacement of less than 30 liters per
cylinder must meet the ULSD fuel requirement of 40 CFR 80.510(b). These
engines would be required to be operated with fuel having a sulfur
content of less than or equal to 15 ppm. EPA is specifically interested
in whether it would be appropriate to require all existing stationary
CI engines (except those with a displacement of greater than or equal
to 30 liters per cylinder) to use 15 ppm sulfur fuel. EPA is interested
in determining if smaller engines, i.e., those less than 300 HP, and
emergency engines should be subject to fuel requirements also and is
requesting comment on this issue. Furthermore, EPA is also interested
in receiving comments and information about the option of adding a
requirement to the regulations that would prohibit the burning of
crankcase oil or mixing crankcase oil with fuel in engines equipped
with exhaust aftertreatment technologies. EPA is interested in
information on whether such practice has the potential for increasing
HAP emissions or damaging exhaust aftertreatment technologies that
would be used to meet the proposed emission limits.
    Finally, EPA is requesting comment on the management practices
being proposed for some subcategories of engines located at area
sources. EPA is interested to receive information on any additional
management practices that could be required.

VII. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and 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, EPA submitted this
action to the Office of Management and Budget (OMB) for review under
Executive Order 12866, and any changes made in response to OMB
recommendations have been documented in the docket for this action.

B. Paperwork Reduction Act

    The information collection requirements in this proposed rule have
been submitted for approval to OMB under the Paperwork Reduction Act,
44 U.S.C. 3501 et seq. The Information Collection Request (ICR)
document prepared by EPA has been assigned EPA ICR number 1975.06.
    The information requirements are based on notification,
recordkeeping, and reporting requirements in the NESHAP General
Provisions (40 CFR part 63, subpart A), which are mandatory for all
operators subject to national emission standards. These recordkeeping
and reporting requirements are specifically authorized by section 114
of the CAA (42 U.S.C. 7414). All information submitted to EPA pursuant
to the recordkeeping and reporting requirements for which a claim of
confidentiality is made is safeguarded according to Agency policies set
forth in 40 CFR part 2, subpart B.
    This proposed rule will not require any notifications or reports
beyond those required by the General Provisions. The recordkeeping
requirements require only the specific information needed to determine
compliance.
    The annual monitoring, reporting, and recordkeeping burden for this
collection (averaged over the first 3 years after sources must comply)
is estimated to be 3,422,879 labor hours per year at a total annual
cost of $15,554,937. This estimate includes notifications of compliance
and performance tests, engine performance testing, semiannual
compliance reports, continuous monitoring, and recordkeeping. The total
capital costs associated with the requirements over the 3-year period
of the ICR is estimated to be $30,772,678 per year. There are no
additional operation and maintenance costs for the requirements over
the 3-year period of the ICR.
    Burden means the total time, effort, or financial resources
expended by persons to generate, maintain, retain, or disclose or
provide information to or for a Federal agency. This includes the time
needed to review instructions; develop, acquire, install, and utilize
technology and systems for the purposes of collecting, validating, and
verifying information, processing and maintaining information, and
disclosing and providing information; adjust the existing ways to
comply with any previously applicable instructions and requirements;
train personnel to be able to respond to a collection of information;
search data sources; complete and review the collection of information;
and transmit or otherwise disclose the information.
    An Agency may not conduct or sponsor, and a person is not required
to respond to a collection of information unless it displays a
currently valid OMB control number. The OMB control numbers for EPA's
regulations in 40 CFR are listed in 40 CFR part 9.
    To comment on the Agency's need for this information, the accuracy
of the provided burden estimates, and any suggested methods for
minimizing respondent burden, including the use of automated collection
techniques, EPA has established a public docket for this rule, which
includes this ICR, under Docket ID number EPA-HQ-OAR-2008-0708. Submit
any comments related to the ICR for this proposed rule to EPA and OMB.
See ADDRESSES section at the beginning of this action for where to
submit comments to EPA. Send comments to OMB at the Office of
Information and Regulatory Affairs, Office of Management and Budget,
725

17th Street, NW., Washington, DC 20503, Attention: Desk Officer for
EPA. Since OMB is required to make a decision concerning the ICR
between 30 and 60 days after March 5, 2009, a comment to OMB is best
assured of having its full effect if OMB receives it by April 6, 2009.
The final rule will respond to any OMB or public comments on the
information collection requirements contained in this proposal.

C. Regulatory Flexibility Act

    For purposes of assessing the impacts of this proposed rule on
small entities, small entity is defined as: (1) A small as defined by
the Small Business Administration's (SBA) regulations at 13 CFR
121.201; (2) a small governmental jurisdiction that is a government of
a city, county, town, school district or special district with a
population of less than 50,000; and (3) a small organization that is
any not-for-profit enterprise which is independently owned and operated
and is not dominant in its field.
    The companies owning facilities with affected RICE can be grouped
into small and large categories using Small Business Administration
(SBA) general size standard definitions. Size standards are based on
industry classification codes (i.e., North American Industrial
Classification System, or NAICS) that each company uses to identify the
industry or industries in which they operate in. The SBA defines a
small business in terms of the maximum employment, annual sales, or
annual energy-generating capacity (for electricity generating units--
EGUs) of the owning entity. These thresholds vary by industry and are
evaluated based on the primary industry classification of the affected
companies. In cases where companies are classified by multiple NAICS