[Federal Register: September 4, 2007 (Volume 72, Number 170)]
[Proposed Rules]
[Page 50715-50742]
[DOCID:fr04se07-9]

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Part II

Environmental Protection Agency

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40 CFR Part 63

 National Emission Standards for Hazardous Air Pollutants From
Petroleum Refineries; Proposed Rule

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2003-0146; FRL-8461-3]
RIN 2060-AO55

National Emission Standards for Hazardous Air Pollutants From
Petroleum Refineries

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This action proposes amendments to the national emission
standards for petroleum refineries to address the risk remaining after
application of the 1995 standards. This action also provides the
results of EPA's 8-year review of developments in practices, processes,
and control technologies that have occurred since the time EPA adopted
the emissions standards. Based on the results of the residual risk and
technology review, this action proposes two options for both wastewater
treatment systems and storage vessels. For wastewater treatment
systems, the first option would not require any additional controls as
necessary to address residual risk or under the technology review. The
second option would require refineries to apply new or additional
requirements for wastewater treatment systems. For storage vessels, the
first option would also not require any additional controls as
necessary to address residual risk or under the technology review and
the second option would require refineries to apply new or additional
requirements for storage vessels. Finally, we are also proposing two
options for amendments to add emissions standards for cooling towers.

DATES: Comments must be received on or before November 5, 2007.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2003-0146 (for petroleum refineries), 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: U.S. Postal Service, send comments to: National
Emission Standards for Hazardous Air Pollutants from Petroleum
Refineries: Residual Risk Standards Docket, Environmental Protection
Agency, Air and Radiation Docket and Information Center, Mailcode:
2822T, 1200 Pennsylvania Avenue, NW., Washington, DC 20460. Please
include a total of two copies. We request that a separate copy also be
sent to the contact person identified below (see FOR FURTHER
INFORMATION CONTACT).
     Hand Delivery: In person or by courier, deliver comments
to: EPA Docket and Information Center, Public Reading Room, EPA West
Building, Room 3334, 1301 Constitution Avenue, NW., Washington, DC
20004. Such deliveries are accepted only 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-
2003-0146. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
http://www.regulations.gov, including any personal information

provided, unless the comment includes information claimed to be
confidential business information (CBI) or other information whose
disclosure is restricted by statute. Do not submit information that you
consider to be CBI or otherwise protected through http://www.regulations.gov

or 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.
    Docket: All documents in the docket are listed in the
http://www.regulations.gov index. Although listed in the index, some

information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in http://www.regulations.gov or in hard copy at the National Emission

Standards for Hazardous Air Pollutants from Petroleum Refineries:
Residual Risk Standards Docket, Environmental Protection Agency, EPA
West Building, Room 3334, 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 and Radiation Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Mr. Robert Lucas, Office of Air
Quality Planning and Standards, Sector Policies and Programs Division,
Coatings and Chemicals Group (E143-01), Environmental Protection
Agency, Research Triangle Park, North Carolina 27711, telephone number
(919) 541-0884; fax number<PHONE_NUMBER>; e-mail address:
<EMAIL_ADDRESS>

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does this action apply to me?

    The regulated category and entities affected by this proposed
action include:

------------------------------------------------------------------------
                                    NAICS \1\    Examples of regulated
             Category                  code             entities
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Industry..........................      32411  Petroleum refineries
                                                located at a major
                                                source that are subject
                                                to 40 CFR part 63,
                                                subpart CC.
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\1\ North American Industrial Classification System.

    This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be regulated by the
proposed rule. To determine whether your facility would be regulated by
the proposed amendments, you should carefully examine the applicability
criteria in 40 CFR 63.100 of subpart CC (National

Emission Standards for Hazardous Air Pollutants From Petroleum
Refineries). If you have any questions regarding the applicability of
this action to a particular entity, contact either the air permit
authority for the entity or your EPA regional representative as listed
in 40 CFR 63.13 of subpart A (General Provisions).

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

    Do not submit information containing CBI to EPA through
http://www.regulations.gov or e-mail. Send or deliver information as CBI only

to the following address: Roberto Morales, OAQPS Document Control
Officer (C404-02), Office of Air Quality Planning and Standards,
Environmental Protection Agency, Research Triangle Park, NC 27711,
Attention Docket ID EPA-HQ-OAR-2003-0146 (for petroleum refineries).
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.

C. Where can I get a copy of this document?

    In addition to being available in the docket, an electronic copy of
this proposed action will also be available on the Worldwide Web
through the Technology Transfer Network (TTN). Following signature, a
copy of this proposed action will be posted on the TTN(s policy and
guidance page for newly proposed or promulgated rules at the following
address: http://www.epa.gov/ttn/oarpg/. The TTN provides information

and technology exchange in various areas of air pollution control.

D. When would a public hearing occur?

    If anyone contacts EPA requesting to speak at a public hearing
concerning the proposed amendments by September 17, 2007, we will hold
a public hearing on October 1, 2007. If you are interested in attending
the public hearing, contact Bob Lucas at<PHONE_NUMBER> to verify that
a hearing will be held. If a public hearing is held, it will be held at
10 a.m. at the EPA's Environmental Research Center Auditorium, Research
Triangle Park, NC, or an alternate site nearby.

E. How is this document organized?

I. General Information
    A. Does this action apply to me?
    B. What should I consider as I prepare my comments to EPA?
    C. Where can I get a copy of this document?
    D. When would a public hearing occur?
    E. How is this document organized?
II. Background Information
    A. What is the statutory authority for regulating hazardous air
pollutants?
    B. What source category is affected by this action?
    C. What are the emissions sources at petroleum refineries?
    D. What hazardous air pollutants are emitted from petroleum
refineries?
    E. What does the NESHAP require?
III. Summary of Proposed Amendments to NESHAP for Petroleum
Refineries
    A. What options are we proposing?
    B. What are the proposed requirements to meet CAA sections
112(f)(2) and (d)(6) for storage vessels?
    C. What are the proposed requirements to meet CAA sections 112
(f)(2) and (d)(6) for EBU used to treat Group 1 wastewater streams?
    D. What are the proposed requirements for cooling towers under
CAA sections 112(d)(2) and (f)(2)?
    E. What other revisions are we proposing?
    F. What is the compliance schedule for the proposed amendments?
IV. Rationale for Proposed Amendments
    A. What actions are we proposing under CAA section 112(d)(2)?
    B. How did we estimate residual risk?
    C. What are the residual risks from petroleum refineries?
    D. What are the uncertainties in risk assessments?
    E. What is our proposed decision under CAA section 112(f)?
    F. What is EPA proposing pursuant to CAA section 112(d)(6)?
V. Request for Comments
VI. 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
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions 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

II. Background Information

A. What is the statutory authority for regulating hazardous air
pollutants?

    Section 112 of the Clean Air Act (CAA) establishes a two-stage
regulatory process to address emissions of hazardous air pollutants
(HAP) from stationary sources. In the first stage, after EPA has
identified categories of sources emitting one or more of the HAP listed
in section 112(b) of the CAA, section 112(d) calls for us to promulgate
national emission standards for hazardous air pollutants (NESHAP) for
those sources. For ``major sources'' that emit or have the potential to
emit any single HAP at a rate of 10 tons or more per year or any
combination of HAP at a rate of 25 tons or more per year, these
technology-based standards must reflect the maximum reductions of HAP
achievable (after considering cost, energy requirements, and non-air
quality health and environmental impacts) and are commonly referred to
as maximum achievable control technology (MACT) standards.
    The MACT floor is the minimum control level allowed for NESHAP and
is defined under section 112(d)(3) of the CAA. For new sources, the
MACT floor cannot be less stringent than the emission control that is
achieved in practice by the best-controlled similar source. The MACT
standards for existing sources can be less stringent than standards for
new sources, but they cannot be less stringent than the average
emission limitation achieved by the best-performing 12 percent of
existing sources in the category or subcategory (or the best-performing
five sources for categories or subcategories with fewer than 30
sources). In developing MACT, we must also consider control options
that are more stringent than the floor. We may establish standards more
stringent than the floor based on the consideration of the cost of
achieving the emissions reductions, any non-air quality health and
environmental impacts, and energy requirements. We published the final
MACT standards for petroleum refineries (40 CFR part 63, subpart CC) on
August 18, 1995 (60 FR 43620).
    The EPA is then required to review these technology-based standards
and to revise them ``as necessary (taking into account developments in
practices, processes, and control technologies)'' no less frequently
than every 8 years, under CAA section 112(d)(6). In this proposal, we
are publishing the results of our 8-year review for the petroleum
refineries source category. We are required by a consent decree to
propose the results of our CAA section 112(d)(6) review by

August 21, 2007. The consent decree also requires EPA to consider and
address the application of the NESHAP general provisions in 40 CFR part
63, subpart A to the existing rule.
    The second stage in standard-setting focuses on reducing any
remaining ``residual'' risk according to CAA section 112(f). This
provision requires, first, that EPA prepare a Report to Congress
discussing (among other things) methods of calculating risk posed (or
potentially posed) by sources after implementation of the MACT
standards, the public health significance of those risks, the means and
costs of controlling them, actual health effects to persons in
proximity of emitting sources, and recommendations as to legislation
regarding such remaining risk. EPA prepared and submitted this report
(Residual Risk Report to Congress, EPA-453/R-99-001) in March 1999.
Congress did not act in response to the report, thereby triggering
EPA's obligation under CAA section 112(f)(2) to analyze and address
residual risk.
    CAA Section 112(f)(2) requires us to determine for source
categories subject to certain section 112(d) standards whether the
emissions limitations protect public health with an ample margin of
safety. If the MACT standards for HAP ``classified as a known,
probable, or possible human carcinogen do not reduce lifetime excess
cancer risks to the individual most exposed to emissions from a source
in the category or subcategory to less than 1-in-1 million,'' EPA must
promulgate residual risk standards for the source category (or
subcategory) as necessary to provide an ample margin of safety to
protect public health. The EPA must also adopt more stringent standards
if necessary to prevent an adverse environmental effect (defined in CAA
section 112(a)(7) as any significant and widespread adverse effect * *
* to wildlife, aquatic life, or natural resources * * *), but must
consider cost, energy, safety, and other relevant factors in doing so.
Section 112(f)(2) of the CAA expressly preserves our use of a two-step
process for developing standards to address any residual risk and our
interpretation of ``ample margin of safety'' developed in the National
Emission Standards for Hazardous Air Pollutants: Benzene Emissions from
Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, Benzene Storage
Vessels, Benzene Equipment Leaks, and Coke By-Product Recovery Plants
(Benzene NESHAP) (54 FR 38044, September 14, 1989).
    The first step in this process is the determination of acceptable
risk. The second step provides for an ample margin of safety to protect
public health, which is the level at which the standards are set
(unless a more stringent standard is required to prevent an adverse
environmental effect after the consideration of costs, energy, safety,
and other relevant factors).
    The terms ``individual most exposed,'' ``acceptable level,'' and
``ample margin of safety'' are not specifically defined in the CAA.
However, CAA section 112(f)(2)(B) directs us to use the interpretation
set out in the Benzene NESHAP. See also, A Legislative History of the
Clean Air Act Amendments of 1990, volume 1, p. 877 (Senate debate on
Conference Report). We notified Congress in the Residual Risk Report to
Congress that we intended to use the Benzene NESHAP approach in making
CAA section 112(f) residual risk determinations (EPA-453/R-99-001, p.
ES-11).
    In the Benzene NESHAP, we stated as an overall objective:

    * * * in protecting public health with an ample margin of
safety, we strive to provide maximum feasible protection against
risks to health from hazardous air pollutants by (1) Protecting the
greatest number of persons possible to an individual lifetime risk
level no higher than approximately 1-in-1 million; and (2) limiting
to no higher than approximately 1-in-10 thousand [i.e., 100-in-1
million] the estimated risk that a person living near a facility
would have if he or she were exposed to the maximum pollutant
concentrations for 70 years.

    The Agency also stated that, ``The EPA also considers incidence
(the number of persons estimated to suffer cancer or other serious
health effects as a result of exposure to a pollutant) to be an
important measure of the health risk to the exposed population.
Incidence measures the extent of health risk to the exposed population
as a whole, by providing an estimate of the occurrence of cancer or
other serious health effects in the exposed population.'' The Agency
went on to conclude that ``estimated incidence would be weighed along
with other health risk information in judging acceptability.'' \1\ As
explained more fully in our Residual Risk Report to Congress, EPA does
not define ``rigid line[s] of acceptability,'' but considers rather
broad objectives to be weighed with a series of other health measures
and factors (EPA-453/R-99-001, p. ES-11).
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    \1\ In the Benzene NESHAP decision, the Agency considered the
same risk measures in the ``acceptability'' analysis as in the
``margin of safety'' analysis, stating: ``In the ample margin
decision, the Agency again considers all of the health risk and
other health information considered in the first step. Beyond that
information, additional factors relating to the appropriate level of
control will also be considered, including costs and economic
impacts of controls, technological feasibility, uncertainties, and
any other relevant factors. Considering all of these factors, the
Agency will establish the standard at a level that provides an ample
margin of safety to protect the public health, as required by
section 112.''
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    The determination of what represents an ``acceptable'' risk is
based on a judgment of ``what risks are acceptable in the world in
which we live'' (54 FR 38045, quoting the Vinyl Chloride decision at
824 F.2d 1165) recognizing that our world is not risk-free.
    In the Benzene NESHAP, we stated that ``EPA will generally presume
that if the risk to [the maximum exposed] individual is no higher than
approximately 1-in-10 thousand, that risk level is considered
acceptable.'' We discussed the maximum individual lifetime cancer risk
as being ``the estimated risk that a person living near a plant would
have if he or she were exposed to the maximum pollutant concentrations
for 70 years.'' We explained that this measure of risk ``is an estimate
of the upper bound of risk based on conservative assumptions, such as
continuous exposure for 24 hours per day for 70 years.'' We acknowledge
that maximum individual lifetime cancer risk ``does not necessarily
reflect the true risk, but displays a conservative risk level which is
an upper bound that is unlikely to be exceeded.''
    Understanding that there are both benefits and limitations to using
maximum individual lifetime cancer risk as a metric for determining
acceptability, we acknowledged in the 1989 Benzene NESHAP that
``consideration of maximum individual risk * * * must take into account
the strengths and weaknesses of this measure of risk.'' Consequently,
the presumptive risk level of 100-in-1 million (1-in-10 thousand)
provides a benchmark for judging the acceptability of maximum
individual lifetime cancer risk, but does not constitute a rigid line
for making that determination.
    The Agency also explained in the 1989 Benzene NESHAP the following:
``In establishing a presumption for MIR, rather than rigid line for
acceptability, the Agency intends to weigh it with a series of other
health measures and factors. These include the overall incidence of
cancer or other serious health effects within the exposed population,
the numbers of persons exposed within each individual lifetime risk
range and associated incidence within, typically, a 50 km exposure
radius around facilities, the science policy assumptions and estimation
uncertainties associated with the risk measures, weight of the
scientific evidence for human health effects, other quantified or
unquantified health

effects, effects due to co-location of facilities, and co-emission of
pollutants.''
    In some cases, these health measures and factors taken together may
provide a more realistic description of the magnitude of risk in the
exposed population than that provided by maximum individual lifetime
cancer risk alone.

B. What source category is affected by this action?

    Petroleum refineries are facilities engaged in refining and
producing products made from crude oil or unfinished petroleum
derivatives. Based on the Energy Information Administration's Refinery
Capacity Report 2006, there are 150 operable petroleum refineries in
the United States (U.S.) and the U.S. territories. A few of these 150
refineries have integrated operations between two nearby, but non-
contiguous, locations. Therefore, we have identified and have data on
153 distinct petroleum refinery facilities (according to the definition
of facility in the CAA), all of which are major sources of HAP
emissions. Petroleum refineries are located in 35 States, as well as
Puerto Rico and the U.S. Virgin Islands. Texas, Louisiana, and
California are the States with the most petroleum refining capacity.
The permitting process has begun for construction of a new refinery in
Arizona; this is the only newly constructed refinery anticipated over
the next 5 years. However, a few additional refineries have announced
significant expansion or modification projects that will essentially
double their refining capacity.
    EPA listed two separate Petroleum Refinery source categories for
regulation under CAA section 112(d), both of which include any facility
engaged in producing gasoline, naphtha, kerosene, jet fuels, distillate
fuel oils, residual fuel oils, lubricants, or other products from crude
oil or unfinished petroleum derivatives. The first and primary source
category for which regulations were developed, Petroleum Refineries--
Other Sources Not Distinctly Listed (Refinery MACT 1), includes all
emission sources from petroleum refinery process units except those
that were expected to be regulated elsewhere, such as the NESHAP for
Boilers and Process Heaters (40 CFR part 63 subpart DDDDD). Refinery
process units include, but are not limited to: Crude distillation,
vacuum distillation, thermal cracking, catalytic cracking, catalytic
reforming, hydrotreating, hydrorefining, isomerization, polymerization,
lube oil processing, and hydrogen production. The Refinery MACT 1 rule
specifically excludes three types of process vents: Catalytic cracking
unit catalyst regeneration vents, catalytic reforming unit catalyst
regeneration vents, and sulfur plant vents. These specific vents are
regulated by the NESHAP for Petroleum Refineries: Catalytic Cracking
Units, Catalytic Reforming Units, and Sulfur Recovery Units (Refinery
MACT 2) in 40 CFR part 63, subpart UUU. It is important to note that
equipment leaks and wastewater produced from catalytic cracking units,
catalytic reforming units, and sulfur recovery units are subject to
Refinery MACT 1; only the process vent emissions associated with these
units are subject to Refinery MACT 2.

C. What are the emissions sources at petroleum refineries?

    The emissions sources subject to the Refinery MACT 1 rule include
miscellaneous process vents, storage vessels, wastewater streams, and
equipment leaks associated with petroleum refining process units, as
well as gasoline loading racks and marine tank vessel loading
operations located at a petroleum refinery. Storage vessels and
equipment leaks associated with a bulk gasoline terminal or pipeline
breakout station located at a petroleum refinery and under common
control of the refinery are also subject to Refinery MACT 1. Cooling
towers associated with petroleum refining process units are part of the
MACT 1 source category although no specific emission limitations were
established for cooling towers in the original Refinery MACT 1 rule.
Thus, there are seven general types of emission sources under Refinery
MACT 1: Miscellaneous process vents, storage vessels, wastewater
streams, equipment leaks, gasoline loading racks, marine tank vessel
loading operations, and cooling towers. Each of these emission sources
are described briefly in sections II.C.1 through II.C.7 of this
preamble.
1. Miscellaneous Process Vents
    Many unit operations at petroleum refineries generate gaseous
streams that contain HAP. These streams may be routed to other unit
operations for additional processing (i.e., a gas stream from a reactor
that is routed to a distillation unit for separation) or they may be
sent to a blowdown system or vented to the atmosphere. Miscellaneous
process vents emit gases to the atmosphere, either directly or after
passing through recovery and/or control devices.
2. Storage Vessels
    Storage vessels contain crude oil, intermediate products, and
finished products. Different types of vessels are used to store various
types of products. Gases are stored in pressurized vessels that are not
vented to the atmosphere during normal operations while liquids are
stored in horizontal, fixed roof, or floating roof tanks, depending on
properties and volumes to be stored. Liquids with vapor pressures
greater than 11 pounds per square inch of air (psia) are typically
stored in fixed roof tanks that are vented to a control device.
Volatile liquids with vapor pressures up to 11 psia are usually stored
in floating roof tanks because such vessels have lower emission rates
than fixed roof tanks within this vapor pressure range. Emissions from
storage vessels typically occur as working losses. As a storage vessel
is filled, HAP-laden vapors inside the tank become displaced and can be
emitted to the atmosphere. Also, diurnal temperature changes result in
breathing losses of organic HAP-laden vapors from storage vessels.
3. Wastewater Streams
    Many refinery process units generate wastewater streams that
contain HAP. Significant wastewater sources include the crude desalting
unit, process waters, steam stripper blowdown, and storage tank draws.
Organic HAP compounds in the wastewater can volatilize and be emitted
to the atmosphere from wastewater collection and treatment units if
these units are open or vented to the atmosphere. Potential sources of
HAP emissions associated with wastewater collection and treatment
systems include drains, manholes, trenches, surface impoundments, oil/
water separators, storage and treatment tanks, junction boxes, sumps,
basins, and biological treatment systems.
4. Equipment Leaks
    Equipment leaks are releases of process fluid or vapor from
processing equipment, including pump and compressor seals, process
valves, pressure relief devices, open-ended lines, flanges and other
connectors, agitators, and instrumentation systems. These releases
occur primarily at the interface between connected components of
equipment or in sealing mechanisms.
5. Gasoline Loading Racks
    Loading racks are the collection of equipment, including loading
arms, pumps, meters, shutoff valves, relief valves, and other piping
and valves used to fill gasoline cargo tanks. Emissions from loading
racks may be

released when gasoline loaded into cargo tanks displaces vapors inside
these containers.
6. Marine Vessel Loading Operations
    Marine vessel loading operations load and unload liquid commodities
in bulk, such as crude oil, gasoline and other fuels, and naphtha. The
cargo is pumped from the terminal's large, above-ground storage tanks
through a network of pipes and into a storage compartment (tank) on the
vessel. The HAP emission result from the displaced vapors during the
filling operation.
7. Cooling Towers
    Cooling tower systems include closed loop recirculation systems and
once through systems that receive non-contact process water from a heat
exchanger for the purposes of cooling the process water prior to
returning the water to the heat exchanger or discharging the water to
another process unit, waste management unit, or to a receiving water
body. Cooling towers typically use force draft air ventilation of the
process water to cool the process water. Heat exchangers occasionally
develop leaks which result in process fluids entering the cooling tower
process water. The HAP and other organics in these process fluids are
then emitted to the atmosphere due to stripping in the cooling tower.
Cooling tower emissions arising from the addition of chemicals to the
cooling water to prevent fouling or to decontaminate the water are not
covered by this standard, but are instead covered under the Industrial
Process Cooling Tower NESHAP.
D. What hazardous air pollutants are emitted from petroleum refineries?
    The specific HAP emitted by petroleum refineries varies by facility
and process operations but can include a variety of organic and
inorganic compounds and metals. Emissions originate from various
process vents, storage vessels, wastewater streams, loading racks,
marine tank vessel loading operations, and equipment leaks associated
with refining facilities. Process vents, wastewater streams, and
storage vessels generally emit organic HAP. Organic compounds account
for the majority of the total mass of HAP emitted by petroleum refinery
sources, with toluene, hexane, mixed and individual isomers of xylenes,
benzene, methanol, methyl tert-butyl ether, and ethyl benzene
accounting for about 90 percent of the HAP mass emitted. Other HAP
emissions may include biphenyl, 1,3-butadiene, cumene, carbon
disulfide, carbonyl sulfide, cresols, ethylene dibromide, 1,2
dichloroethane, diethanolamine, ethylene glycol, methyl isobutyl
ketone, 2,2,4-trimethylpentane, naphthalene, and phenol.
    The HAP emitted from emissions sources subject to the Refinery MACT
1 rule are associated with a variety of health effects, depending on
the specific pollutants involved and the degree and duration of
exposure. The range of adverse health effects include cancer and a
number of other chronic health disorders (e.g., aplastic anemia,
panctopenia, pernicious anemia, lung structural changes) and a number
of acute health disorders (difficulty in breathing, upper respiratory
tract irritation, conjunctivitis, tremors, delirium, coma,
convulsions). More details on the health effects of individual HAP may
be found in numerous sources, including http://www.epa.gov/iris.html,

http://www.atsdr.cdc.govlmrls.html, and http://www.oehha.ca.gov/air/acute_rels/index
.html.

E. What does the NESHAP require?

    The Refinery MACT 1 rule (40 CFR part 63, subpart CC) applies to
petroleum refining process units and their collocated emissions points
that are part of a plant site that is a major source and that emit or
have equipment containing or contacting one or more of the 28 HAP
listed in Table 1 in the appendix to the rule. Section 63.640(c) of the
rule specifies that emissions points subject to the rule include an
individual miscellaneous process vent, storage vessel, wastewater
stream, or equipment leak associated with a petroleum refining process
unit; an individual storage vessel or equipment leak associated with a
bulk gasoline terminal or pipeline breakout station classified under
Standard Industrial Classification (SIC) code 2911 located at a
petroleum refinery; a gasoline loading rack classified under SIC code
2911 located at a petroleum refinery and under common control with the
refinery; or a marine tank vessel loading operation located at a
petroleum refinery. The rule establishes applicability criteria to
distinguish between Group 1 emissions points and Group 2 emissions
points. Controls are required only for emissions points meeting the
Group 1 criteria. Group 2 emissions points are subject to recordkeeping
requirements only. We estimate that the 1995 rule reduces HAP emissions
by 53,000 tons per year (tpy)--a 59-percent reduction (60 FR 43248,
August 18, 1995).
    Section 63.641 of the rule defines Group 1 miscellaneous process
vents as those with volatile organic compound (VOC) emissions equal to
or greater than 33 kilograms per day (kg/day) (72 pounds per day (lb/
day)) for existing sources and 6.8 kg/day (15 lb/day) for new sources.
Under Sec.  63.643, the owner or operator of a Group 1 miscellaneous
process vent must reduce organic HAP using a flare that meets the
equipment specifications in 40 CFR 63.11 of the general provisions
(subpart A) or use a control device to reduce organic HAP emissions by
98 weight-percent or to a concentration of 20 parts per million by
volume (ppmv dry basis, corrected to 3 percent oxygen).
    Section 63.646(a) of the Refinery MACT 1 rule requires each Group 1
storage vessel to comply with 40 CFR 63.119 through 63.121 of subpart G
(National Emission Standards for Organic Hazardous Air Pollutants From
the Synthetic Organic Chemical Manufacturing Industry for Process
Vents, Storage Vessels, Transfer Operations, and Wastewater). A Group 1
storage vessel at an existing refinery has a design storage capacity
and maximum true vapor pressure greater than the values specified in
the existing rule. Under 40 CFR 63.119, a Group 1 storage vessel must
be equipped with an internal floating roof with proper seals, an
external floating roof with proper seals, an external floating roof
converted to an internal floating roof with proper seals, or a closed
vent system to a control device that reduces HAP emissions by 95
percent or to 20 ppmv. Storage vessels at existing sources are not
subject to certain equipment specifications and inspection requirements
for automatic bleeder vents, gaskets, slotted membranes, and sleeve
seals. See 40 CFR 63.640(c). The requirements for a Group 1 storage
vessel at a new refinery apply to tanks with a smaller design capacity
and lower vapor pressures and HAP liquid concentration. These tanks
also must comply with the storage vessel requirements in 40 CFR part
63, subpart G.
    Each Group 1 wastewater stream at a new or existing refinery must
comply with 40 CFR 61.340 through 61.355 of the National Emission
Standard for Benzene Waste Operations (BWON) in 40 CFR part 61, subpart
FF. Group 1 wastewater streams are those wastewater streams (at a
petroleum refinery that has a total annual benzene loading of 10
megagrams per year (Mg/yr) or greater) that have a flow rate greater
than 0.02 liters per minute, a benzene concentration of 10 parts per
million by weight (ppmw) or greater, and are not exempt from control
requirements under the BWON. The BWON requires affected waste streams

to comply with one of several options for controlling benzene emissions
from waste management units and treating the benzene containing wastes.
    The Refinery MACT 1 rule requires the owner or operator of an
existing refinery to comply with the equipment leak provisions in 40
CFR part 60, subpart VV (Standards of Performance for Equipment Leaks
of VOC in the Synthetic Organic Chemicals Manufacturing Industry) for
all equipment in organic HAP service. The term ``in organic HAP
service'' means that a piece of equipment either contains or contacts a
fluid (liquid or gas) that is at least 5 percent by weight of total
organic HAP. The owner or operator of a new facility must comply with a
modified version of 40 CFR part 63, subpart H (National Emission
Standards for Organic Hazardous Air Pollutants for Equipment Leaks).
Both subpart VV of part 60 and modified subpart H of part 63 require
inspection and repair of leaking equipment. The leak definition under
subpart VV that triggers repair requirements is an instrument reading
of 10,000 ppmv. In the modified version of subpart H, the leak
definition for pumps and valves begins at 10,000 ppmv but drops to
2,000 ppmv or 1,000 ppmv, respectively, in subsequent years.
    Group 1 gasoline loading racks at refineries must comply with the
requirements of the National Emission Standards for Gasoline
Distribution Facilities (Bulk Gasoline Terminals and Pipeline Breakout
Stations) in 40 CFR part 63, subpart R. Marine tank vessel loading
operations at refineries must comply with the requirements in 40 CFR
part 63, subpart Y (National Emission Standards for Marine Tank Vessel
Loading Operations).

III. Summary of Proposed Amendments to NESHAP for Petroleum Refineries

A. What options are we proposing?

    We are proposing regulatory options for storage vessels with
external floating roofs and regulatory options for an enhanced
biodegradation unit (EBU) to meet the requirements of CAA sections
112(f)(2) and (d)(6). We are also proposing options to require a leak
detection and repair program for cooling towers under section 112(d)(2)
and (f)(2).
    A detailed summary of the proposed amendments under the
requirements of CAA section 112(f)(2) and (d)(6) is provided below.
This section also includes our discussion of the proposal to regulate
cooling towers under CAA section 112(d)(2) and (f)(2). Our rationale
for the proposed amendments is provided in section IV of this preamble.

B. What are the proposed requirements to meet CAA sections 112(f)(2)
and (d)(6) for storage vessels?

    Currently, the Refinery MACT 1 rule requires Group 1 storage
vessels at an existing source to comply with the requirements in 40 CFR
63.119 through 63.121 of 40 CFR part 63, subpart G, except where
specifically noted. Under 40 CFR 63.640(c) of the rule, storage vessels
at existing sources are not subject to the requirements in 40 CFR
63.119(b)(5), (b)(6), (c)(2), and (d)(2) of subpart G. The requirements
in 40 CFR 63.119(c)(2) contain equipment specifications for storage
tanks with external floating roofs.
    EPA is proposing two regulatory options for storage vessels. We
believe that either of these options might achieve an ample margin of
safety as described in the Benzene NESHAP. The Agency's basis for
selecting one of these options in the final rule would reflect our
consideration of the relative risk reduction and cost of the options,
as well as consideration of other relevant factors as identified in the
Benzene NESHAP. For existing storage vessels, Option 1 requires no
revisions to the Refinery MACT 1 rule to meet the requirements of CAA
section 112(d)(6) and (f)(2). Option 2 would remove the current
exemption for the requirements in 40 CFR 63.119(c)(2)(ix) and (x) for
slotted guide poles. Removal of this exemption would require the owner
or operator of a Group 1 storage vessel at an existing source that is
equipped with an external floating roof to equip each slotted guide
pole with a gasketed sliding cover or flexible fabric sleeve seal and a
gasketed cover or other device which closes off the liquid surface from
the atmosphere. The proposed amendments also revise related inspection
requirements in 40 CFR 63.646(e) and reporting requirements in 40 CFR
63.654(f)(1)(A)(1), (g)(1), and (g)(3)(iii)(A) to account for the
requirements for slotted guide poles.

C. What are the proposed requirements to meet CAA sections 112(f)(2)
and (d)(6) for EBU used to treat Group 1 wastewater streams?

    EPA is proposing two regulatory options for EBU. We believe that
either of these options might achieve an ample margin of safety as
described in the Benzene NESHAP. The Agency's basis for selecting one
of these options in the final rule would reflect our consideration of
the relative risk reduction and cost of the options, as well as
consideration of other relevant factors as identified in the Benzene
NESHAP.
    Option 1 requires no revisions to the Refinery MACT 1 rule to meet
the requirements of CAA sections 112(f)(2) and (d)(6). Option 2 for EBU
proposes to revise the wastewater provisions in the Refinery MACT 1
rule to add a specific performance standard and monitoring requirement
for EBU. The proposed amendments require owners or operators to operate
and maintain EBU to achieve a minimum treatment efficiency for benzene
of 90 percent. The owner or operator would be required to conduct an
initial performance demonstration using the procedures in 40 CFR part
63, appendix C (Determination of the Fraction Biodegraded (Fbio) in a
Biological Treatment Unit). Based on the demonstration results,
facilities would establish operating limits for the mixed liquor
volatile suspended solids (MLVSS) concentration and the food-to-
microorganism ratio according to the rule requirements. The operating
parameters would be monitored at least once a week. Exceedance of an
operating limit would be a deviation that must be reported in the
periodic (semiannual) report required by 40 CFR 63.654.

D. What are the proposed requirements for cooling towers under CAA
sections 112(d)(2) and (f)(2)?

    Because the Refinery MACT 1 rule does not address HAP emissions
from cooling towers, we are proposing to regulate cooling towers under
CAA section 112(d)(2) and (d)(3) in this action. As we are proposing
later in the preamble, once cooling towers have been regulated pursuant
to CAA section (d)(2) and (d)(3), no additional controls are needed to
provide an adequate margin of safety under CAA section (f)(2).
    We are proposing work practice standards for cooling towers which
would require the owner or operator of a new or existing source to
monitor for leaks in the cooling tower return lines from heat
exchangers in organic HAP service (i.e., lines that contain or contact
fluids with 5 weight percent or greater of total organic HAP listed in
Table 1 of the rule) and, where leaks are detected, to repair such
leaks within a specified period of time. The two options that are being
co-proposed differ in the detection methods used to identify leaks for
existing sources, and in the frequency of monitoring for new sources.
The first option reflects our MACT floor analysis and would reject
imposing controls beyond the MACT

floor. Under this option, the owner or operator of existing source
cooling towers receiving cooling water from heat exchangers in organic
HAP service would be required to monitor chemical addition rates or
other surrogate indicators of leaks. If the surrogate indicators
suggest a leak, the owner or operator would conduct sampling and
analyses to determine if the indicated leak is an organic HAP leak. For
existing sources, an organic HAP leak is defined as an organic HAP
concentration in the cooling tower water of 1 ppmw or greater. Owner
and operators of new source cooling towers receiving cooling water from
heat exchangers in organic HAP service would be required to conduct
quarterly sampling and analyses to identify any organic HAP leaks into
the cooling tower water and to take appropriate corrective action to
fix the leaks.
    Under the second option, we would select a control option based on
our beyond the floor analysis and would require the owner or operator
of new and existing sources to conduct monthly sampling and analyses to
identify any organic HAP leaks into the cooling tower water.
    Under both options, a leak into the cooling tower water would be
defined as either a mass leak rate of 100 pounds of total organic HAP
per day or greater or a mass leak rate of 10 pounds of any single
organic HAP per day or greater. Under both options, if a leak is
detected, the owner or operator would be required to identify the
source of the leak as soon as practicable but not later than 30 days
after receiving the sampling results. Unless a delay in repair is
allowed under the proposed requirements, the owner or operator would be
required to repair the leak no later than 30 days after identifying the
source of the leak. The proposed rule would allow a delay in repair of
the leak if repair of the leak would require the process unit served by
the leaking heat exchanger to be shut down, and the shutdown would
result in greater emissions than the potential emissions from the
cooling tower leak from the time the leaking heat exchanger was first
identified and the next planned shutdown. The owner or operator would
be required to continue monthly monitoring and repair the heat
exchanger within 30 days if sampling results show that the projected
emissions from the cooling tower exceed the startup and shutdown
emissions estimates. The proposed rule would also allow a delay in
repair if the necessary parts are not reasonably available. In this
case, the owner or operator would be required to complete the repair as
soon as practicable upon receiving the necessary parts, but no later
than 120 days after identifying the leaking heat exchanger. All new or
existing refineries with a cooling tower system also would be required
to prepare and follow a monitoring plan for cooling towers. The plan is
necessary to document emissions potential for employing the delay of
repair provisions.

E. What other revisions are we proposing?

    We are also proposing clarifications to the requirements in the
Refinery MACT 1 rule. The proposed amendments clarify that the control
requirements for gasoline loading racks apply to Group 1 gasoline
loading racks. ``Group 1 gasoline loading rack'' is the term used to
define the affected emissions source subject to emissions control
requirements. This clarification would amend 40 CFR 63.640 of subpart
CC.

F. What is the compliance schedule for the proposed amendments?

    The proposed amendments to the Refinery MACT 1 rule would become
effective on the date of publication of the final amendments in the
Federal Register. Under section 112 (i)(1) of the CAA, any new facility
would be required to comply upon startup. For existing sources, CAA
section 112(i)(3)(A) requires compliance no later than 3 years after
the effective date of the standard. The proposed 3-year compliance date
is appropriate because it will allow facilities time to perform
monitoring and install required controls. For cooling towers, we are
allowing 3 years to identify which towers are affected, to identify the
ability to repair these cooling towers without a process unit
turnaround, to determine the HAP emissions that would occur if a
shutdown is required to control a heat exchanger leak, and to establish
an appropriate monitoring program that meets the requirements of the
proposed rule. For EBU, 3 years is necessary to perform tests of
benzene destruction efficiency, to calculate the overall effectiveness
of the EBU using the procedures in Appendix C, to establish appropriate
monitoring provisions and install and test necessary equipment, and to
make modifications to the EBU if necessary to increase the efficiency
of the system to meet the proposed requirements. For storage tanks, 3
years are being proposed to allow flexibility in the addition of the
guidepole controls for safety and operational concerns. In promulgating
similar requirements for storage tanks, we have extended the compliance
time until the next scheduled turnaround requiring emptying and
degassing of the tank or 10 years, whichever is sooner. This is because
the emissions that occur during emptying and degassing exceed the HAP
emission reductions that would occur as a result of applying the
controls. We are requesting comments on whether it is necessary to
empty and degas tanks for retrofitting the proposed controls.

IV. Rationale for Proposed Amendments

A. What actions are we proposing under CAA section 112(d)(2)?

    We did not establish standards for cooling towers in the Refinery
MACT 1 rule. Industry emissions information and data demonstrate that
organic HAP emissions from cooling towers at petroleum refineries are
significant, and we are proposing to add emissions standards for
organic HAP from cooling towers at petroleum refineries under the
authority of CAA section 112(d)(2). Because the emissions from cooling
towers are not emitted through a stack and are not practically
measurable, we have established work practice standards as provided for
under CAA section 112(h)(2) to address these emissions.
    In evaluating the MACT floor, we must determine the average
emissions limitations achieved by the top 12 percent of the affected
sources. We have often interpreted the average of the top 12 percent as
the performance of the 6th percentile unit. Of the 150 refineries, the
6th percentile is represented by the 9th ranked top-performing unit.
Based on available information, we have determined that the top 12
percent of the industry currently implements cooling tower monitoring
programs to detect and repair leaks of process fluids into cooling
water using chemical usage rates or other surrogate indicators of heat
exchanger leaks. Therefore, we have determined that the MACT floor for
existing cooling towers is monitoring of surrogate indicators of heat
exchanger leaks in cooling water and to repair leaks. The nationwide
total annual cost (TAC) to conduct cooling tower monitoring of
surrogate indicators and repairs is estimated to be $750,000. This cost
includes a product recovery credit of $1.2 million, and includes no
costs for repair of heat exchangers under that assumption that refiners
would repair leaking heat exchangers when they are made aware of the
leak as part of their routine operations. For large leaks, reasons for
repairing leaks immediately could be safety concerns or the recovery of
large product losses. For smaller leaks, these concerns might not be
valid

and therefore refiners might incur additional costs beyond routine
operations. EPA requests comment on the extent to which immediate
repairs would be based on these concerns, and on typical costs of
repair. The HAP emissions reduction for the MACT floor is estimated to
be 373 tpy total HAP and 28.3 tpy of benzene. The HAP baseline for
cooling towers was estimated to be 3,024 tpy.
    The MACT floor for new sources is represented by the best-
performing similar unit. Based on all of the information available, the
best performance standard currently being implemented is direct organic
chemical concentration monitoring of their Refinery MACT 1 cooling
towers on a quarterly basis. Based on emissions data for the facility
implementing this program, we have determined that the performance of
this cooling tower monitoring program would limit leaks into the
cooling water to less than 10 lbs/day of a single organic HAP and less
than 100 lbs/day of total organic HAP. Therefore, we have determined
that the MACT floor for new cooling towers is quarterly organic
chemical-specific monitoring with an action level of 10 lbs/day or
greater of a single organic HAP and 100 lbs/day or greater of total
organic HAP.
    EPA has concluded, based on available data, that existing industry
monitoring of surrogate parameters will only detect large leaks, which
would miss leaks that would generate significant organic HAP emissions
(see memorandum to docket: Cooling towers: Control Options and Impact
Estimates). EPA analyzed the amount of HAP that could be emitted from
cooling water based on HAP concentration data and flow rates for
cooling towers at several petroleum refinery facilities and decided to
structure regulatory options to account for variable cooling water flow
and minimum detection limit capabilities of 10 parts per billion by
weight (ppbw) for the concentrations of individual HAP in water. For
example, at a petroleum refinery with total organic HAP concentration
of 30 ppbw and a cooling water flow rate of 40,000 gallons per minute
(gal/min), the potential organic HAP emissions from the cooling tower
are 14 lbs/day or over 2.5 tons if the leak lasted for a year.
    As part of our beyond the floor analysis, we considered
alternatives more stringent than the MACT floor option for existing and
new sources. For existing and new sources, we identified two
alternatives that would require monitoring by collecting a cooling
water sample and analyzing for speciated HAP. In both alternatives, the
cost of the monitoring is likely less than the value of the product
that would no longer be lost to the atmosphere. Additionally, we have
not included repair costs in any of the options as we considered these
costs to be routine operational costs. The costs discussed also apply
to new as well as existing sources, since there are no retrofit issues
associated with the proposed monitoring program.
    One alternative more stringent than the MACT floor includes
quarterly monitoring of cooling water by water sampling and a leak
definition of greater than or equal to 10 pounds of any single organic
HAP or greater than or equal to 100 pounds organic HAP per day and
results in a total annualized cost saving of $2.1 million. This savings
includes a product recovery credit of $4.4 million. The organic HAP
emissions reduction for this alternative regulatory option 1 is 1,330
tpy and the cost-effectiveness is -$1,600/ton.
    Another alternative more stringent than the MACT floor includes
monthly monitoring of cooling water by water sampling and a leak
definition of greater than or equal to 10 pounds of any single organic
HAP or greater than or equal to 100 pounds organic HAP per day. The
nationwide TAC is a savings of $1.6 million, including a recovery
credit of $5.7 million. The organic HAP emissions reduction for this
alternative is 1,720 tpy. The cost-effectiveness of this alternative is
-$920/ton.
    EPA is co-proposing two options for finalizing MACT standards for
new and existing cooling towers. Option 1 represents the MACT floor for
new and existing units, as discussed above. Option 2 is more stringent
than the MACT floor and is described above as requiring monthly (as
opposed to quarterly) monitoring of individual (speciated) organic HAP.
Table 1 of this preamble summarizes nationwide impacts of the proposed
options.

                                                 Table 1.--Nationwide Impacts for Cooling Tower Options
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Product                                       Cost-effectiveness  ($/ton)
                                                            Monitoring       recovery      Total annual   HAP  emissions -------------------------------
                         Option                           cost  ($1,000)      credit      cost  ($1,000/   (tons/yr HAP)
                                                                            ($1,000/yr)         yr)                           Overall       Incremental
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline................................................               0               0               0           3,024               0               0
1 (MACT Floor)..........................................           1,990          -1,240             750           2,647           1,980           1,980
2 (Beyond the floor)....................................           4,100          -5,680          -1,590           1,304            -920         -1,750
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: The monthly monitoring alternative is projected to result in a positive incremental cost-effectiveness of $1,400 per ton (as compared to the
  quarterly alternative).

    This analysis indicates that Option 2 will result in an overall
cost savings. Further, the incremental cost-effectiveness of Option 2
monitoring compared to Option 1 is a negative $1,750/ton of HAP
emissions controlled, which indicates a cost savings above the MACT
floor option and is reasonable given these assumptions. However, there
are some fundamental assumptions that may affect this analysis, for
example, the amount of recovery credit generated by each program is
uncertain and we did not consider repair costs or production downtime
costs in our analysis. Therefore, we are co-proposing Option 1, the
MACT floor option, and Option 2 in the event that the costs and
feasibility of going beyond the floor are not reasonable. We are
requesting comments on this analysis and on these options.
    Additionally, under both options, a delay in repair is allowed
under the proposed requirements if repair of the leak would require the
process unit served by the leaking heat exchanger to be shut down, and
the shutdown would result in greater HAP emissions than the projected
HAP emissions from the cooling tower leak or if the necessary parts are
not reasonably available. We request comments on other possible
criteria for delay of repair in addition to these. In addition, we are
requesting comments on another option for heat exchanger systems that
cannot be repaired without a shutdown that would allow delay of repair
until the next unit shutdown. This allowance could be contingent on
factors such as the level of HAP emissions from the cooling tower or
the duration to the next scheduled shutdown. Finally, we

request comments on tracking the HAP emissions that occur during the
delayed repair and relationship between this monitoring and emission
measurement and the reportable quantity requirements under CERCLA.

B. How did we estimate residual risk?

    EPA modeled available data on the emissions from petroleum
refineries to assess the risks associated with petroleum refinery HAP
emissions after compliance with the Refinery MACT 1 standard but prior
to the proposed MACT amendments for cooling towers. Consistent with
previous residual risk assessments, standard air toxics risk assessment
practices and principles were used to conduct assessments of potential
chronic and acute exposures and risks for both inhalation and non-
inhalation pathways. In addition, the potential for an adverse
environmental effect arising from these sources was also evaluated.
Complete documentation for the methods used and results from the risk
assessment is available in a report entitled, draft Residual Risk
Assessment for MACT 1 Petroleum Refining Sources, which is available in
the docket.
    Emissions data for 153 petroleum refineries nationwide were
developed starting from the EPA's 2002 National Emissions Inventory
(NEI), incorporating site-specific emissions and source information
which were provided by the American Petroleum Institute (API) for 22
facilities. The emissions database was published for public comment
through an Advanced Notice of Proposed Rulemaking (ANPRM). Comments and
corrections to the database received during the public comment period
were evaluated by technical reviewers for quality and consistency with
engineering data; valid corrections to the database were incorporated
for an additional 50 facilities (beyond the 22). No comments or
corrections were received on the emissions or source data for 81
facilities.\2\ The 153 refineries included in the database are believed
to be all of the sources in the category.
---------------------------------------------------------------------------

    \2\ For an explanation of the corrections we accepted and the
corrections we did not accept, see docket.
---------------------------------------------------------------------------

C. What are the residual risks from petroleum refineries?

    Table 2 of this preamble summarizes the results of the inhalation
risk assessment. These estimates characterize the lifetime risk of
developing cancer or noncancer health effects for individuals living
within 50 kilometers (km) of any petroleum refinery.

 Table 2.--Risk Estimates Due to HAP Exposure Based on 70-Year Exposure
                                Duration
------------------------------------------------------------------------
                                                            Results for
                                                           refinery MACT
                        Parameter                            1 source
                                                             category
------------------------------------------------------------------------
Maximum individual lifetime cancer risk (in 1 million)..              70
Maximum hazard index \1\ (chronic respiratory effects)..             0.3
Estimated size of population at risk....................      90,000,000
    greater than 1-in-1 million.........................         460,000
    greater than 10-in-1 million........................           6,000
    greater than 100-in-1 million.......................               0
Annual cancer incidence (number of cases per year)......       0.04-0.09
------------------------------------------------------------------------
\1\ If the hazard index (HI) is calculated to be less than or equal to
  1, then no adverse heath effects are expected as a result of the
  exposure.

    We estimate that approximately 90 million people live within 50 km
of a refinery. Results from the risk assessment indicate that none of
the facilities posed a cancer risk greater than 100-in-1 million.
Approximately 60 percent of the refineries have a maximum individual
lifetime cancer risk (MIR) of greater than 1-in-1 million, and about 14
percent are associated with a MIR greater than 10-in-1 million. The
highest MIR value at any facility is 70-in-1 million. The cumulative
cancer incidence from all MACT 1 refinery emission sources is estimated
to be between 0.04 and 0.09 cases per year, or 1 case every 11 to 25
years. Benzene, naphthalene, polycyclic organic matter, and ethylene
dibromide emissions are responsible for most of the estimated cancer
incidence. Since the benzene cancer unit risk estimate (URE) is
reported as a range of values, each end of which is considered to be
equally plausible, the range of incidence reflects calculated risks
using either end of the range, as well as different methods for
extrapolating the risks from subsets of facility emission estimates.
Additionally, the maximum noncancer hazard index (HI) associated with
emissions from any refinery is estimated to be less than 1. This allows
us to conclude that human inhalation exposures to pollution from
Refinery MACT 1 sources are without appreciable risk of chronic
noncancer health effects, and that direct atmospheric exposures of
these pollutants to ecological receptors should not result in any
potential environmental impact.
    We performed acute screening-level assessments of potential acute
impacts of concern on each facility and refined those assessments by
analyzing aerial photographs of facilities with potential exceedances
of acute benchmarks to determine which potential exceedances were truly
outside facility boundaries. The results indicated that 12 facilities
show a potential to exceed 1-hour California acute Reference Exposure
Levels (REL) for 3 pollutants (benzene, acrolein, and arsenic). The
acute 1-hour REL is defined as the concentration level at or below
which no adverse health effects are anticipated for a 1-hour exposure.
Acute REL values are designed to protect the most sensitive individuals
in a population by including margins of safety. The highest potential
exceedance of any REL was for acrolein, and the REL was exceeded by a
factor of 70. Other pollutants showing potential exceedances of the REL
value are benzene (exceeded by a factor of 40), and arsenic (exceeded
by a factor of 30). In spite of the fact that potential exceedances of
these 3 acute REL values are shown by this analysis, none of the
facilities investigated showed any potential to exceed available mild
1-hour Acute Exposure Guideline Levels (AEGL-1) for any of the modeled
pollutants. The AEGL-1 is the airborne concentration of a substance
above which it is predicted that the general population, including
susceptible individuals, could experience notable discomfort,
irritation, or certain asymptomatic nonsensory effects.
    Given the definitions of the acute REL and the AEGL-1, it is
reasonable to conclude that (1) Health effects in humans could occur as
exposures increase above the AEGL-1, and (2) exposures below the REL
are very unlikely to result in adverse health effects. Potential
exposures in between these values (which is what this analysis shows)
are more difficult to interpret in terms of health risk. That is, these
potential exposures are in the ``gray area'' of uncertainty where the
true threshold for adverse effects lies, and thus it is not clear if
adverse effects could actually occur at the levels determined by this
analysis. Further, we did not refine these results by incorporating
actual site-specific short-term emission variability into the analysis,
so these results are believed to be very conservative and should be
interpreted with care.
    We also performed a screening-level multipathway risk assessment on
the

emissions of mercury, cadmium, lead, and polycyclic aromatic
hydrocarbons (PAH), all compounds which are considered to be persistent
and bioaccumulative HAP. Based on the results of this screening,
noncancer human health risks due to the ingestion of these pollutants
were all below levels considered to be without appreciable risk of
adverse health effect. One of these pollutants, PAH, showed a potential
to cause individual cancer risks as high as 40-in-1 million, exceeding
1-in-1 million, but less than 100-in-1 million. However, because of our
inability to accurately speciate and estimate risks for individual
compounds within the PAH class, we believe that this result is highly
conservative, and that the true risks associated with these PAH are
likely to be less than 1-in-1 million.
    For the ecological assessment, two exceedances (cadmium and PAH) of
ecological toxicity benchmarks were observed when examining the
predicted TRIM.FaTE media concentrations (see Draft Residual Risk
Assessment for MACT I Petroleum Refining Sources document). Given the
conservative nature of the screening scenario, the results of the
comparisons and a review of additional information available on the
ecological toxicity of cadmium and PAH, we concluded that it is highly
unlikely that these two exceedances are of concern. Overall, the
potential for emissions from petroleum refinery sources to result in an
adverse environmental impact is likely to be very low for all
persistent bioaccumulative HAP emitted.

D. What are the uncertainties in risk assessments?

    Uncertainty and the potential for bias are inherent in all risk
assessments, including those performed for the petroleum refineries
source categories affected by this proposal. A full discussion of
uncertainties is found in the Draft Residual Risk Assessment for
Petroleum Refining Sources (August 2007), available in the docket.
    Although the development of the risk and technology review (RTR)
database involved quality assurance/quality control processes, the
accuracy of emissions values will vary depending on the source of the
data present, incomplete or missing data, errors in estimating
emissions values, and other factors. Our review of the data indicates
that there may be a low bias in reported emissions for many facilities.
It appears that data from several processes and operations are not
included in the reported emissions from many facilities. These include
exclusion of upset, malfunction, startup, and shutdown events as well
as omission of emissions sources that are unexpected, not measured, or
not considered in inventories, such as leaks in heat exchanger systems;
emissions from process sewers and wastewater systems; fugitive
emissions from delayed coking units; and emissions from tank roof
landings. Further, the emissions values considered in this analysis are
annual totals for a single calendar year (2002) and do not reflect
actual fluctuations during the course of the year, as well as
variations from year to year. Finally, although we have performed a
significant amount of quality control on the data set, for many
facilities the physical characteristics (i.e., stack height, physical
location) of the reported sources may be inaccurate for detailed risk
characterization purposes.
    We recently discovered that certain area source location attributes
may have been incorrectly incorporated into our atmospheric dispersion
simulations, resulting in a positional translation error which may
locate certain emission points closer to or farther from potentially-
exposed populations. While the impact of this error has not been fully
evaluated, we believe that it will not dramatically alter the MIR value
for the source category, and that it will have very little impact on
the total cancer incidence. Nonetheless, we will investigate and
correct this error between proposal and promulgation of the final
petroleum refineries MACT 1 residual risk decision and will consider
any impact of this error in our final decision.
    The uncertainties in our risk assessment can be generally divided
into uncertainties in our ability to characterize exposures and
uncertainties in our ability to characterize dose-response. We believe
that the primary source of uncertainty in our exposure assessment is
the uncertainty in the underlying emissions data, which are generally
thought to be biased low, based on recent studies indicating that
emission points such as cooling towers and wastewater treatment units
are historically underestimated or even omitted from petroleum refinery
emission inventories. Elsewhere in this notice, we request comment on
methods that might reduce these emission uncertainties through moderate
efforts to conduct ambient monitoring. The assessment uses
toxicological dose-response values typically extrapolated from high-
dose animal exposure or occupational exposures, to estimate risk.
Consistent with EPA guidance, RfCs are developed by using order-of-
magnitude factors to account for uncertainties in developing values
protective of sensitive subpopulations. Most of the URE in this
assessment were developed using linearized low-dose extrapolation.
Risks could be overestimated if the true dose-response relationship
(which is usually unknown) is sublinear. Impacts have been extrapolated
from short-duration, high-dose animal or occupational exposures to
longer durations and lower doses, using uncertain interspecies scaling
methods. In general, EPA considers these URE's to be upper-bound
estimates based on the method of extrapolation, meaning they represent
a plausible upper limit to the true value. (Note that this is usually
not a true statistical confidence limit.) The true risk is therefore
likely to be less, could be as low as zero, but also could be greater.
As previously noted, benzene cancer risks were estimated from the
reported URE range, which is considered to be based on maximum
likelihood exposure and risk estimates.

E. What is our proposed decision under CAA Section 112(f)?

    Based on the emissions data we have, we estimate that the MIR
associated with exposures to HAP emissions from the sources covered by
the Refinery MACT 1 rule is 70-in-1 million. Because the MIR is less
than 100-in-1 million, the risk is acceptable. However, since the MIR
is greater than 1-in-1 million, we must consider whether to require
additional controls to protect public health with an ample margin of
safety.
    In making the ample margin of safety determination, we consider the
estimate of health risk and other health-related information (such as
the weight of evidence for carcinogenicity or the severity of the
noncancer health effect) along with additional factors relating to the
appropriate level of control, including costs and economic impacts of
controls, technological feasibility, uncertainties, and other relevant
factors, consistent with the approach of the 1989 Benzene NESHAP, as
summarized earlier.
    In developing our proposed options under CAA section 112(f)(2), we
considered control options for each of the Refinery MACT 1 emissions
sources. In developing the control options, we wanted to target further
emission reductions to the extent possible to reduce public health
risks. The following provides a discussion of the control options that
we evaluated for each of the Refinery MACT 1 emission sources.

1. Control Options Considered
a. Miscellaneous Process Vents, Gasoline Loading Racks, and Marine
Vessel Loading Control Measures
    Group 1 miscellaneous process vents and transfer loading operations
(gasoline loading racks and marine vessel loading) are regulated by
performance standards based on the use of technologies such as thermal
oxidizers and carbon. We did not identify any other technically
feasible control technologies that would reduce HAP emissions beyond
these levels. Therefore, the only way to reduce residual risk would be
to change the applicability (i.e., certain Group 2 emission points
under the original rule would become Group 1 emission points under a
revised rule). We could not identify any cost-effective control
options; the control option based on lowering the Group 1 thresholds
exceeds $40,000 per ton of HAP reduced and $400,000 per ton of benzene
reduced.
b. Equipment Leak Control Measures
    For equipment leaks, we evaluated reducing the leak definition and
requiring monitoring of open-ended lines. The cost-effectiveness of
this option is approximately $20,000 per ton of HAP reduced and
approximately $300,000 per ton of benzene reduced. We rejected these
options due to their unreasonable cost-effectiveness.
c. Storage Vessel Control Measures
    For storage vessels, we evaluated two control alternatives for
Group 1 external floating roof storage vessels. First, we considered
requiring a gasketed sliding cover or a flexible fabric sleeve and
requiring a gasketed float or other device which closes off the liquid
surface from the atmosphere for slotted guide poles. Next, we
considered requiring geodesic domes. The slotted guide pole sleeve
control option would reduce HAP by 1,046 tpy and benzene emissions by
105 tpy. The annualized cost of this control option would be completely
offset by the value of the organic products that would not be emitted
by the addition of controls. The geodesic dome control option is not
cost-effective when added to the proposed requirement for slotted guide
pole sleeves.
d. Wastewater Control Measures
    For refinery wastewater systems, the refinery MACT standard is
based on the BWON requirements (55 FR 8346, 58 FR 3095). The BWON was
developed under the two-step Benzene NESHAP approach and at that time
we concluded that the controls provided an ample margin of safety.
Because the BWON was incorporated by reference into the Petroleum
Refineries MACT standard, we must now determine whether the BWON
protects public health with an ample margin of safety. We believe that
additional controls may be necessary to ensure an ample margin of
safety.
    We worked with industry to improve the emissions data used in the
risk assessment. As part of this effort, refinery trade organizations
provided EPA with detailed benzene emissions data from 22 petroleum
refineries expected to be representative of the industry (see docket).
Most refineries reported zero or minimal emissions from wastewater
systems. For systems with EBU operating at 92 percent benzene reduction
efficiency (the benzene reduction we estimated would be achieved in the
BWON), we would expect benzene emissions on the order of 3 to 10 tpy,
depending on the load into the system. The wastewater emissions
reported the 22 refineries are much less than this amount,
approximately 20 tpy, which leads us to believe that the emission
estimates exclude or significantly under-report benzene emissions from
the EBU.
    For well-operated EBU, the benzene emissions are expected to be
small; however, there are no requirements in the Refinery MACT 1 rule
or the BWON to demonstrate the proper performance of EBU. Since the
BWON was promulgated, we have developed procedures and test methods to
verify the performance of EBU.
    Analysis of the potential emissions and associated risks from EBU
when the biological treatment efficiency is less than 90 percent
indicates that these sources could contribute significantly to risk.
Therefore, we are evaluating a control option that the EBU demonstrate
a fraction biodegraded of 90 percent or greater for benzene through an
initial performance demonstration. This would be coupled with weekly
monitoring of process parameters.
e. Cooling Tower Control Measures
    The Refinery MACT 1 rule does not include provisions for cooling
towers; we are proposing MACT requirements for cooling towers to
address total organic HAP emissions under CAA section 112(d)(2). Those
requirements are described in section IV.A of this preamble. In that
section, we discuss our floor and beyond the floor analysis pursuant to
CAA section 112(d)(2) and (d)(3). We could not identify any additional
control requirements that could cost-effectively reduce emissions from
cooling towers beyond the options described above in our beyond-the-
floor analysis.
    More information of our evaluation of the control options
considered for the Refinery MACT 1 emission sources is contained in
memoranda in the docket.
f. Fenceline Monitoring
    Numerous commenters on the ANPR for Phase II risk and technology
review, including the Residual Risk Coalition representing the American
Petroleum Institute, expressed concern about the quality and accuracy
of emissions data available to conduct refined risk assessments. Based
on our review of these data, we agree that there appears to be
significant uncertainty, not only in identifying and characterizing
emissions sources within facilities, but also in the amount and types
of HAP emitted. In addition to inherent uncertainty in the development
and use of emission factors, our review of the data indicates that
there may be a low bias in reported emissions, as discussed earlier.
Additional discussion of the potential low bias in emission estimates
is available in the docket.
    Our concerns regarding the potential low bias in the emission
estimates leads us to request public comment on requiring fenceline
monitoring of ambient benzene. A fenceline monitoring program may
provide an effective method to assess the general magnitude of
uncertainty in facility emissions estimates for benzene. Additional
information on fenceline monitoring may be found in a technical
memorandum in the docket.
2. Regulatory Decisions Under CAA Section 112(f)(2)
a. Regulatory Decision for Storage Vessels
    We are proposing two options for our rulemaking on whether to
establish additional emission standards to protect public health with
an ample margin of safety. Option 1 is to maintain the current level of
control in the Refinery MACT 1 rule with no further modifications.
Option 2 includes controls for storage vessels.
    Impacts of the proposed control option requiring existing storage
vessels with external floating roofs to install and operate a gasketed
sliding cover or a flexible fabric sleeve and a gasketed float or other
device which closes off the liquid surface from the atmosphere for
slotted guide poles were evaluated and are presented in Table 3 of this
preamble along with the associated costs and emissions reductions.
These controls prevent the loss of products from storage vessels.
Therefore, the

control costs are offset by the increased product sales that are
available by this pollution prevention. The VOC credit was calculated
to be $480 per ton of VOC reduced, resulting in a net cost savings
presented below. Table 4 of this preamble presents the risk reduction
associated with the control option for storage vessels.

                      Table 3.--Cost and Emissions Impacts of Option 2 for Storage Vessels
----------------------------------------------------------------------------------------------------------------
                                                  Total
                                    Total      annualized      Product        Total         HAP        Average
      Control requirement          capital    cost without    recovery     annualized    emissions     cost per
                                 investment   recovery  ($   credit  ($     cost  ($       (tpy)      ton of HAP
                                 ($ million)    million)      million)      million)                   ($/ton)
----------------------------------------------------------------------------------------------------------------
Option 1 (Baseline)...........          0              0             0             0          1,867            0
Option 2 Storage Vessel                 2.76           1.1          -4.6          -3.5          821       -3,340
 Controls.....................
----------------------------------------------------------------------------------------------------------------

  Table 4.--Risk Impacts of Regulatory Alternative for Storage Vessels
------------------------------------------------------------------------
                                                             Option 2
                Parameter                    Option 1     storage vessel
                                             baseline         control
------------------------------------------------------------------------
Risk to Most Exposed Individual:
    Cancer (in 1 million)...............              70              70
    Noncancer (HI)......................             0.3             0.3
Size of Population at Cancer Risk :\1\
    > 100-in-1 million..................               0               0
    > 10-in-1 million...................           6,000           5,100
    > 1-in-1 million....................         460,000         393,000
Number of Plants at Cancer Risk Level
 :\1\
    > 100-in-1 million..................               0               0
    > 10-in-1 million...................              21              15
    > 1-in-1 million....................              96              91
Population with HI > 1 \2\..............               0               0
No. of Plants with HI > 1...............               0               0
Cancer Incidence........................        0.04-.09        0.03-.08
Cancer Incidence Reduction (Percent)....              NA           10-25
HAP Emission Reduction (Percent)........              NA             15
------------------------------------------------------------------------
\1\ Population risks and plant risk bin estimates are based on utilizing
  the high end of the reported cancer URE range for benzene. These
  estimates may be as much as 30 percent lower when estimated using the
  lower end of the benzene URE range.
\2\ If the Hazard Index (HI) is calculated to be less than or equal to
  1, then no adverse health effects are expected as a result of the
  exposure.

    Under option 1, we are proposing to make no changes to the current
Refinery MACT rule, instead proposing to find that the current level of
control called for by the existing MACT standard represents both an
acceptable level of risk (the cancer risk to the most exposed
individual is approximately 70-in-1 million) and provides public health
protection with an ample margin of safety. This proposed finding is
based on considering the uncertainty of the cost impacts of further
control for individual refineries and the relatively small reductions
in health risks that are achieved by further control.
    The Agency would conclude under proposed option 1 that the $3.5
million per year nationwide cost savings is uncertain and that some
refineries may have positive net costs under Option 2, and that these
costs would be unreasonable given the minor associated risk reductions.
Baseline cancer incidence under the current Refinery MACT 1 rule is
estimated at 0.04 to .09, or 0.07 cases per year, on average. Proposed
Option 2 would reduce incidence by about 0.01 cases per year.
Statistically, this level of risk reduction means that Option 2 would
prevent 1 cancer case every 100 years. Accordingly, if we were to
conclude that there were not cost savings, the cost of this option
could be considered to be disproportionate to the level of incidence
reduction achieved. In addition, the Agency proposes to conclude that
there are no changes in the distribution of risks reflected in Table 4
of this preamble (i.e., the MIR is not reduced from 70-in-1 million by
additional control), and there are no noncancer HI values above 1.
Consequently, under Option 1, we are proposing that it is not necessary
to impose any additional controls on the industry to provide an ample
margin of safety to protect public health.
    Alternatively, we are also proposing that Option 2 provides an
ample margin of safety to protect public health. This option reduces
HAP emissions and risks beyond the current MACT standard using controls
that are technically and economically feasible and that pose no adverse
environmental impacts. We estimate that these changes would reduce the
number of people at cancer risk greater than one in a million by 67,000
individuals and the cancer incidence by 0.01 cases per year (i.e.,
prevent one cancer case every 100 years). Option 2 would reduce
emissions of VOC by 9,500 tpy. Reducing VOC provides the added benefit
of reducing ambient concentrations of ozone and may reduce fine
particulate matter. The annualized cost impacts of Option 2 are
estimated to be a cost savings of $3.5 million. Our economic analysis
(summarized later in this preamble) indicates that this cost will have
little impact on the price and output of petroleum products.
b. Regulatory Decision for EBU
    We are proposing two options for our rulemaking on whether to
establish additional emission standards to protect public health with
an ample margin of safety. Option 1 maintains the current level of
control in the Refinery MACT 1 rule with no further modifications.

Option 2 requires refinery owners and operators of EBU to demonstrate
and ensure a fraction biodegraded of 90 percent or greater for benzene
through an initial performance demonstration coupled with weekly
monitoring of process parameters to ensure the EBU are achieving the
ample margin of safety as intended by the BWON rule. Impacts of the
proposed Option 2 are presented in Table 5.

                            Table 5.--Cost and Emissions Impacts of Option 2 for EBU
----------------------------------------------------------------------------------------------------------------
                                                                Total
                                                              installed       Total         HAP        Average
                    Control requirement                        capital     annualized    emissions     cost per
                                                               cost  ($     cost  ($       (tpy)      ton of HAP
                                                               million)     million)                   ($/ton)
----------------------------------------------------------------------------------------------------------------
Option 1 (Baseline)........................................            0           0          5,000            0
Option 2 EBU Performance Demonstration and Monitoring......            0           1.1        3,200          600
----------------------------------------------------------------------------------------------------------------

    Impacts presented in Table 5 assume that 50 percent of EBU may
degrade benzene at an efficiency of 80 percent. In the development of
the BWON, we estimated that EBU would achieve between 88 to 93 percent
control efficiency (Final NESHAP Standards for Waste Operations: Basis
for Impact Calculations, Feb. 1990), on average, and made the finding
that the reductions achieved from EBU would result in acceptable risk,
and we did not require further reductions as part of our ample margin
of safety decision. At that time, we had no consistent method of
characterizing the performance of these treatment systems. Since the
promulgation of the Refinery MACT 1 rule, we have promulgated
procedures in appendix C of 40 CFR Part 63 to estimate the performance
of biological treatment systems and have required the use of appendix C
to demonstrate treatment efficiencies on other industries that use
biological treatment systems. Our experience with other industries
suggest that, while high biological treatment efficiencies can be
achieved for low volatility, oxygenated compounds, achievement of high
control efficiencies for benzene and other aromatic compounds is more
difficult. As noted previously, many refineries who provided data to
the Agency reported zero or minimal emissions from wastewater treatment
systems, many of which employ EBU for treatment. For EBU operating at
92 percent benzene reduction efficiency, we would expect benzene
emissions ranging from 3 to 10 tons/year. The emissions reported by the
22 refineries are much less than this amount, which leads us to believe
that the emission estimates exclude or significantly under-report
benzene emissions from EBU. We specifically request comments on
additional data that would address these concerns. Further, the use of
appendix C by refineries at the present time is very limited, and,
therefore, there is no data to either confirm or refute the validity of
the original assumption of 92 percent made under the BWON.
    The costs are based on the initial performance demonstration
averaged over 5 years, so that the annual cost of the performance
evaluation was $5,000/year. Once the performance evaluation is
completed, refineries are expected to develop operating limits for the
minimum MLVSS concentration and the maximum food to microorganism
ratio, which must be determined on a weekly basis. Although owners and
operators of EBU are expected to routinely conduct these analyses, we
estimated that an additional cost of $5,000/year would be incurred for
these analyses and the associated recordkeeping and reporting
requirements. Additionally, we assumed that by altering the operating
characteristics of the unit (e.g., increasing system mixing
characteristics, increasing biomass or submerged aeration), we assumed
that all of the units not originally achieving 90 percent treatment
efficiency could achieve 90 percent treatment efficiency at no cost.
EPA understands that significant material and/or labor costs actually
might be incurred by owners/operators who implement treatment process
changes such as adding or modifying aerators, or implementing other
process improvements, and specifically requests comment on this
assumption. Nevertheless, we currently estimate that refineries using
EBU for treatment of affected wastewater streams would incur, on
average, a cost of $10,000/year over the first 5 years.
    Table 6 presents the estimated risk reductions for the EBU control
Option. Table 6 also presents the risk impacts assuming a hypothetical
baseline based on the addition of emissions from cooling towers and
wastewater operations to the RTR dataset. It is important to note that
the risk impacts resulting from a higher HAP baseline estimated
assuming that 50 percent of EBU are achieving an average of 80 percent,
rather than 92 percent control, and that this is an assumption (an
estimate of hypothetical emissions) based on our judgment of what could
be occurring in the industry, and is not based on actual emissions
estimates or modeling. EPA specifically requests comment and data
related to the validity of this assumption. The baseline benzene
emissions were assumed to increase from 136 tpy benzene (in the RTR
database) to 388 tpy benzene, and the reductions achieved as a result
of imposing demonstration requirements leading to better EBU process
controls were calculated to be 138 tpy benzene. Finally, based on a
ratio of 7.7 percent benzene to HAP for wastewater, we calculated
reductions of 1,800 tpy HAP from this option. Additionally, we also
increased the adjusted baseline to account for unreported cooling tower
emissions of 285 tpy benzene. Accordingly, risk impacts for the
baseline were scaled linearly, and the EBU controls were estimated to
reduce cancer incidence from the hypothetical baseline by .01 to .02.
It should be noted that this is not a rigorous risk analysis, but a
rough estimate of risk impacts based on projected wastewater emissions.

                            Table 6.--Risk Impacts of Regulatory Alternative for EBU
----------------------------------------------------------------------------------------------------------------
                                                                                Option 1
                                                                                adjusted      Option 2 EBU
                            Parameter                              RTR baseline   (hypothetical)     controls
                                                                                baseline     (hypothetical)
----------------------------------------------------------------------------------------------------------------
Risk to Most Exposed Individual:
    Cancer (in 1 million).......................................              70              70              70
    Noncancer (HI)..............................................             0.3             0.3             0.3
Size of Population at Cancer Risk: \1\
    > 100-in-1 million..........................................               0               0               0
    > 10-in-1 million...........................................           6,000          10,500           9,300
    > 1-in-1 million............................................         460,000         805,000         716,000
Number of Plants at Cancer Risk Level: \1\
    > 100-in-1 million..........................................               0               0               0
    > 10-in-1 million...........................................              21              41              36
    > 1-in-1 million............................................              96             108             104
Population with HI > 1 \2\......................................               0               0               0
No. of Plants with HI > 1.......................................               0               0               0
Cancer Incidence................................................       0.04-0.09        0.07-.16        0.06-.14
Cancer Incidence Reduction (Percent)............................  ..............              NA              15
HAP Emission Reduction (Percent)................................  ..............              NA              11
----------------------------------------------------------------------------------------------------------------
\1\ Population risks and plant risk estimates are based on utilizing the high end of the reported cancer URE
  range for benzene. These estimates may be as much as 30 percent lower when estimated using the lower end of
  the benzene URE range.
\2\ If the Hazard Index (HI) is calculated to be less or equal to 1, then no adverse health effects are expected
  as a result of the exposure.

    Under Option 1, we are proposing to make no changes to the current
Refinery MACT rule, and are proposing that the current level of control
under the existing MACT standard represents both an acceptable level of
risk (the cancer risk to the most exposed individual is approximately
70-in-1 million) and provides public health protection with an ample
margin of safety. This proposed finding is based on the existing data
(emissions estimates from 22 refineries, the NEI, and from public
review of the NEI data) that indicate that risks posed to wastewater
treatment systems are low and that further reduction of such low risk
is not warranted and is not necessary to achieve an ample margin of
safety.
    We are also proposing that Option 2 provides an ample margin of
safety to protect public health. This option may reduce HAP emissions
and risks beyond the current MACT standard using controls that are
technically and economically feasible and that pose no adverse
environmental impacts. Further, the option addresses the uncertainty in
emissions estimates by requiring that owners and operators of EBU
demonstrate their systems are effective as reflected by the low
reported emissions estimates for wastewater treatment systems. We
believe this option addresses the consideration of uncertainty in the
ample margin of safety decision.
    We estimate that these changes could reduce the number of people at
cancer risk greater than one in a million by 89,000 individuals. In
addition, Option 2 could reduce the cancer incidence by between 0.01
and 0.02 cases per year (i.e., prevent one cancer case every 100 to 50
years), depending on the accuracy of our assumptions, and resulting in
a cost of $110 to $55 million per cancer case avoided. The annualized
cost impacts of Option 2 are estimated at 1.1 million. Our economic
analysis (summarized later in this preamble) indicates that this cost
will have little impact on the price and output of petroleum products.
c. Regulatory Decision for Cooling Towers
    Section 112(f)(2) of the CAA requires that we evaluate residual
risk and set standards as necessary to protect human health with an
ample margin of safety within 8 years of promulgation of a MACT
standard. We are performing the CAA section 112(f)(2) review for all
petroleum refinery MACT 1 sources, including cooling towers, in this
proposal.
    As stated previously, the petroleum refinery risks are now
acceptable. We believe that with the controls proposed as meeting CAA
sections (d)(2) and (d)(3), no additional controls for cooling towers
are needed to provide an ample margin of safety under CAA section
(f)(2). In the final rule we will select MACT as one of these two
options or other options that are a logical outgrowth of public
comments. We will then assess the risk that remains and also perform
the ample margin of safety analysis in the manner described above.

F. What is EPA proposing pursuant to CAA section 112(d)(6)?

    Section 112(d)(6) of the CAA requires us to review and revise MACT
standards, as necessary, every 8 years, taking into account
developments in practices, processes, and control technologies that
have occurred during that time. This authority provides us with broad
discretion to revise the MACT standards as we determine necessary, and
to account for a wide range of relevant factors.
    We do not interpret CAA section 112(d)(6) as requiring another
analysis of MACT floors for existing and new sources. Rather, we
interpret the provision as essentially requiring us to consider
developments in pollution control in the industry (``taking into
account developments in practices, processes, and control
technologies''), and assessing the costs of potentially stricter
standards reflecting those developments (69 FR 48351). As the U.S.
Court of Appeals for the District of Columbia Circuit has found
regarding similar statutory provisions directing EPA to reach
conclusions after considering various enumerated factors, we read this
provision as providing EPA with substantial latitude in weighing these
factors and arriving at an appropriate balance in revising our
standards. This discretion also provides us with substantial
flexibility in choosing how to apply modified standards, if necessary,
to the affected industry.
    In an earlier rulemaking, we elaborated on how we expect we would
address the need for future reviews under certain circumstances and our
position regarding when revisions may be likely under CAA section
112(d)(6). For more information on this subject, see Nation Emission
Standards for

Hazardous Air Pollutants for Organic Hazardous Air Pollutants from the
Synthetic Organic Chemical Manufacturing Industry (71 FR 34437-34438,
June 14, 2006).
    We could not identify any other developments in practices,
processes, and control technologies for Refinery MACT 1 sources.
Therefore, as a result of this CAA section 112(d)(6) review, we are
proposing the same two options as we proposed to meet section
112(f)(2). Based on the uncertainty of the cost of control for
individual refineries and the relatively small reductions in health
risks that are achieved by these controls, we are proposing that these
controls are not necessary under 112(d)(6). Alternately, if we conclude
in the final rule that there are cost savings associated with requiring
slotted guidepole controls for storage vessels, we are proposing to
require those controls pursuant to CAA section 112(d)(6).
    The consent decree also requires us to consider and address the
application of subpart A to subpart CC of part 63, as appropriate. The
requirements of 40 CFR part 63, subpart A are contained in Table 6 of
40 CFR part 63, subpart CC. As a result of our review, no changes are
currently proposed to Table 6 of the rule. However, as discussed in
section V of this preamble, we are requesting comments on entries to
the table that may be confusing to owners and operators.

V. Request for Comments

    We request comment on all aspects of the proposed rule. All
significant comments received during the comment period will be
considered in the development and selection of the final rule. In
addition to general comments on the proposed options, we particularly
request comments and data on the following issues. Comments must
provide supporting documentation in sufficient detail to allow
characterization of the quality and representativeness of the data or
information.

1. Fenceline Monitoring

    Based on the residual risk results, one of the primary risk drivers
from the Refinery MACT 1 emission sources is benzene. The primary
releases of benzene are fugitive emissions from process equipment,
wastewater treatment, storage tanks, and loading operations and
generally occur near ground level. Thus, the highest benzene
concentrations outside the facility will likely occur near ground level
at the property boundaries. Consequently, monitoring at the property
boundary (fenceline) would provide a measure of the annual average
benzene concentrations immediately surrounding the refinery, which
might be useful in efforts to eliminate uncertainties in emissions
estimates.
    As noted in section IV.H of this preamble, we are requesting
comment on: the need for a fenceline monitoring program, potential
monitoring methods (e.g., diffusive sampling or alternative active
sampling methods, alternative sorbents for measuring HAP other than
benzene), monitor siting, monitoring frequency, feasibility of various
monitoring approaches/methods, sampling and analytical precision and
accuracy, reliability of monitoring methods and devices, consideration
of non-facility related emissions, and sampling and analytical costs.

2. Test Methods for Wastewater

    We are also requesting comment on the applicability and feasibility
of Method 5220 for the measurement of chemical oxygen demand (COD) in
wastewater treated by EBU and alternative COD methods.

3. Applicability of Subpart A to Subpart CC

    In addition, we request comments on Table 11 of the Appendix to
subpart CC of 40 CFR part 63. The Appendix to subpart CC addresses the
application of the 40 CFR part 63 General Provisions in subpart A to
subpart CC of 40 CFR part 63. We have tried to make the Appendix to
subpart CC consistent with the Appendix A in subpart UUU, the other 40
CFR part 63 MACT standard affecting petroleum refineries.

VI. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this
action is a ``significant regulatory action'' because it may raise
novel legal or policy issues. 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 the proposed amendments
to the NESHAP for Petroleum Refining (40 CFR part 63, subpart CC) will
be submitted for approval to OMB under the Paperwork Reduction Act, 44
U.S.C. 3501, et seq. A separate notice seeking public comment on these
information collection requirements will be published in the Federal
Register.
    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 part 63 are listed in 40 CFR part 9.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act generally requires an agency to
prepare a regulatory flexibility analysis of any rule subject to notice
and comment rulemaking requirements under the Administrative Procedure
Act or any other statute unless the agency certifies that the rule
would not have a significant economic impact on a substantial number of
small entities. Small entities include small businesses, small not-for-
profit enterprises, and small governmental jurisdictions.
    For the purposes of assessing the impacts of this proposed rule on
small entities, small entity is defined as: (1) A small business that
meets the Small Business Administration size standards for small
businesses at 13 CFR 121.201 (a firm having no more than 1,500
employees and no more than 125,000 barrels per day of capacity of
petroleum-based inputs, \3\ including crude oil or bona fide feedstocks
for NAICS code 32411); (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.
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    \3\ Capacity includes owned or leased facilities as well as
facilities under a processing agreement or an agreement such as an
exchange agreement or a throughput. The total product to be
delivered under the contract must be at least 90 percent refined by
the successful bidder from either crude oil or bona fide feedstocks.
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    After considering the economic impacts of this proposed rule on
small entities, I certify that this action will not have a significant
economic impact on a substantial number of small entities. Based on our
analyses of both options, the amendments would either result in a
nationwide net cost of about $1.0 million or achieve a nationwide net
savings (i.e., a return) of about $4.0 million per year due to
reductions in product losses. Only one affected small firm would incur
net costs as a result of the proposed amendments; all other small or
large firms owning affected refineries would have net savings. Net
costs for the affected small firm are well below 0.01 percent of its
revenue; therefore, no adverse economic impacts are expected for any
small entity. Thus, the costs associated with the proposal would not
result in any ``significant'' adverse economic impact for any small
entity.
    Although the proposed rule will not have a significant economic
impact on a substantial number of small entities, we nonetheless tried
to reduce the impact of the proposed rule on small entities. We held
meetings with industry trade associations and company representatives
to discuss the proposed rule and have included provisions for small
facilities that address their concerns. We continue to be interested in
the potential impacts of the proposed action on small entities and
welcome comments on issues related to such impacts.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public
Law 104-4, establishes requirements for Federal agencies to assess the
effects of their regulatory actions on State, local, and tribal
governments and the private sector. Under section 202 of the UMRA, EPA
generally must prepare a written statement, including a cost-benefit
analysis, for proposed and final rules with ``Federal mandates'' that
may result in expenditures by State, local, and tribal governments, in
the aggregate, or to the private sector, of $100 million or more in any
1 year. Before promulgating an EPA rule for which a written statement
is needed, section 205 of the UMRA generally requires EPA to identify
and consider a reasonable number of regulatory alternatives and adopt
the least costly, most cost-effective, or least burdensome alternative
that achieves the objectives of the rule. The provisions of section 205
do not apply when they are inconsistent with applicable law. Moreover,
section 205 allows EPA to adopt an alternative other than the least
costly, most cost-effective, or least burdensome alternative if the
Administrator publishes with the final rule an explanation why that
alternative was not adopted. Before EPA establishes any regulatory
requirements that may significantly or uniquely affect small
governments, including tribal governments, it must have developed under
section 203 of the UMRA a small government agency plan. The plan must
provide for notifying potentially affected small governments, enabling
officials of affected small governments to have meaningful and timely
input in the development of EPA regulatory proposals with significant
Federal intergovernmental mandates, and informing, educating, and
advising small governments on compliance with the regulatory
requirements.
    The EPA has determined that the proposed amendments do not contain
a Federal mandate that may result in expenditures of $100 million or
more for State, local, and tribal governments, in the aggregate, or to
the private sector in any 1 year. As discussed earlier in this
preamble, these amendments result in nationwide net savings to the
private sector. Thus, the proposed rule is not subject to the
requirements of sections 202 and 205 of the UMRA. In addition, the
proposed amendments do not significantly or uniquely affect small
governments. The proposed amendments contain no requirements that apply
to such governments, and impose no obligations upon them. The proposed
rule is not subject to section 203 of the UMRA.

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled Federalism (64 FR 43255, August 10,
1999), requires EPA to develop an accountable process to ensure
``meaningful and timely input by State and local officials in the
development of regulatory policies that have federalism implications.''
``Policies that have federalism implications'' is defined in the
Executive Order to include regulations that have ``substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government.''
    The proposed amendments do not have federalism implications. They
would not have substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government, as specified in Executive Order 13132. These proposed
amendments add control and performance demonstration requirements. They
do not modify existing responsibilities or create new responsibilities
among EPA Regional offices, States, or local enforcement agencies.
Thus, Executive Order 13132 does not apply to the proposed amendments.
    In the spirit of Executive Order 13132, and consistent with EPA
policy to promote communications between EPA and State and local
governments, EPA specifically solicits comments on these proposed
amendments from State and local officials.

F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

    Executive Order 13175, entitled Consultation and Coordination with
Indian Tribal Governments (65 FR 67249, November 9, 2000), requires EPA
to develop an accountable process to ensure ``meaningful and timely
input by tribal officials in the development of regulatory policies
that have tribal implications.'' The proposed amendments do not have
tribal implications, as specified in Executive Order 13175. They would
not have substantial direct effects on tribal governments, on the
relationship between the Federal government and Indian tribes, or on
the distribution of power and responsibilities between the Federal
government and Indian tribes, as specified in Executive Order 13175.
The proposed amendments impose no requirements on tribal governments.
Thus, Executive Order 13175 does not apply to the proposed amendments.
    EPA specifically solicits additional comment on these proposed
amendments from tribal officials.

G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks

    Executive Order 13045, Protection of Children from Environmental
Health Risks and Safety Risks (62 FR 19885, April 23, 1997), applies to
any rule that: (1) Is determined to be ``economically significant,'' as
defined under Executive Order 12866, and (2) concerns an environmental
health or safety risk that EPA has reason to believe may have a
disproportionate effect on children. If the regulatory action meets
both criteria, EPA must evaluate the environmental health or safety
effects of the planned rule on children, and explain why the planned
regulation is preferable to other potentially effective and reasonably

feasible alternatives considered by the Agency.
    The proposed rule is not subject to the Executive Order because
they are not economically significant as defined in Executive Order
12866, and because the Agency does not have reason to believe the
environmental health or safety risks addressed by this action present a
disproportionate risk to children.

H. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use

    The proposed amendments are not a ``significant energy action'' as
defined in Executive Order 13211, Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use (66 FR 28355,
May 22, 2001) because they are not likely to have a significant adverse
effect on the supply, distribution, or use of energy. Further, we have
concluded that the proposed amendments are not likely to have any
adverse energy effects because they result in overall savings due to
product recovery.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement
Act of 1995 (NTTAA) (Public Law No. 104-113, 12(d) (15 U.S.C. 272 note)
directs EPA to use voluntary consensus standards (VCS) in its
regulatory activities, unless to do so would be inconsistent with
applicable law or otherwise impractical. VCS are technical standards
(e.g., materials specifications, test methods, sampling procedures, and
business practices) that are developed or adopted by VCS bodies. The
NTTAA directs EPA to provide Congress, through OMB, explanations when
the Agency decides not to use available and applicable VCS.
    This proposed rule involves technical standards. EPA cites the
following methods in this rule: EPA Method 8260B, Volatile Organic
Compounds by Gas Chromatography/Mass Spectrometry (GC/MS), in Test
Methods for Evaluating Solid Waste, Physical/Chemical Methods
(incorporated by reference--see 40 CFR 63.14), for analysis of water
samples taken from cooling tower return lines; 40 CFR 61.355(c)(3) of
the National Emission Standards for Benzene Waste Operations for water
sample collection; and 40 CFR part 63, appendix C, for the fraction
biodegradation of benzene in EBU. This proposed rule also cites the
following VCS: Method 5210, Biochemical Oxygen Demand (BOD), for
measuring BOD5 (for 5-day BOD), Method 5220, Chemical Oxygen
Demand (COD), for measuring COD, and Method 2540E, Fixed and Volatile
Solids Ignited at 500 degrees C, for measuring MLVSS concentration, all
in Standard Methods for the Examination of Water and Wastewater
(incorporated by reference--see 40 CFR 63.14).
    Consistent with the NTTAA, EPA conducted searches to identify VCS
in addition to the methods cited in this proposed rule. One VCS was
found that could potentially be applicable to this rule in lieu of
Standard Method 5220, Chemical Oxygen Demand (COD), for measuring COD.
This potential standard is ASTM D1252-06, Standard Test Methods for
Chemical Oxygen Demand (Dichromate Oxygen Demand) of Water. The EPA
requests comments on whether this standard should be reviewed for
relevancy to today's proposed rule. Based on the comments received, the
EPA will review this method for inclusion in the final rule. No VCS
were found for the other methods cited in this rule.
    For the methods required or referenced by these proposed
amendments, a source may apply to EPA for permission to use alternative
test methods or alternative monitoring requirements in place of any
required testing methods, performance specifications, or procedures
under 40 CFR 63.7(f) and 40 CFR 63.8(f) of subpart A of the General
Provisions. In general, EPA welcomes comments on this aspect of the
proposed amendments and, specifically, invites the public to identify
other potentially-applicable VCS and to explain why such standards
should be used in this regulation.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629, February 16, 1994) establishes
Federal executive policy on environmental justice. Its main provision
directs Federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
    EPA has determined that these proposed amendments will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because they increase the
level of environmental protection for all affected populations without
having any disproportionately high and adverse human health or
environmental effects on any population, including any minority or low-
income population. These proposed amendments add new control
requirements to established national standards for petroleum
refineries.

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Hazardous
substances, Incorporation by reference, Reporting and recordkeeping
requirements.

    Dated: August 21, 2007.
Stephen L. Johnson,
Administrator.
    For the reasons stated in the preamble, title 40, chapter I, part
63 of the Code of Federal Regulations is proposed to be amended as
follows:

PART 63--[AMENDED]

    1. The authority citation for part 63 continues to read as follows:

    Authority: 42 U.S.C. 7401, et seq.

Subpart A--[Amended]

Option 1 for Sec.  63.14

    2. Section 63.14 is amended by adding paragraph (k)(1)(iv) to read
as follows:

Sec.  63.14  Incorporations by reference.

* * * * *
    (k) * * *
    (1) * * *
    (iv) Method 8260B, Volatile Organic Compounds by Gas
Chromatography/Mass Spectrometry (GC/MS), Revision 2 (and subsequent
revisions), dated December 1996 and in Update III, IBR approved for
Sec.  63.654(a)(1) and (b) of Subpart CC of this part.
* * * * *

Option 2 for Sec.  63.14

    3. Section 63.14 is amended by adding paragraphs (k)(1)(iv) and (l)
to read as follows:

Sec.  63.14  Incorporations by reference.

* * * * *
    (k) * * *
    (1) * * *
    (iv) Method 8260B, Volatile Organic Compounds by Gas
Chromatography/Mass Spectrometry (GC/MS), Revision 2 (and subsequent
revisions), dated December 1996 and in Update III, IBR approved for
Sec.  63.654(a)(1) and (b) of Subpart CC of this part.
* * * * *
    (l) The following material is available from the American Public
Health Association, 1015 15th Street, NW.,

Washington, DC 20005 or at http://www.standardmethods.org:
    (1) The following methods as published in Standard Methods for the

Examination of Water and Wastewater, A.D. Eaton (ed.), et al., 21st
Edition (and subsequent editions), dated 2005:
    (i) Method 2540E, Solids, dated 1997, IBR approved for Sec.
63.647(d)(5) of Subpart CC of this part.
    (ii) Method 5210, Biochemical Oxygen Demand (BOD), dated 2001, IBR
approved for Sec.  63.647(d)(6) of Subpart CC of this part.
    (iii) Method 5220, Chemical Oxygen Demand (COD), dated 1997, IBR
approved for Sec.  63.647(d)(6) of Subpart CC of this part.
    (2) [Reserved]

Subpart CC--[Amended]

Option 1 for Sec.  63.640

    4. Section 63.640 is amended by:
    a. Revising paragraph (a) introductory text;
    b. Revising paragraph (c) introductory text;
    c. Revising paragraphs (c)(6) and (7);
    d. Adding paragraph (c)(8);
    e. Revising paragraph (h) introductory text;
    f. Adding paragraph (h)(6);
    g. Revising the first sentence in paragraph (l) introductory text
and the first sentence in paragraph (l)(3) introductory text; and
    h. Adding paragraph (s).

Sec.  63.640  Applicability and designation of affected source.

    (a) This subpart applies to petroleum refining process units and to
related emissions points that are specified in paragraphs (c)(5)
through (8) of this section that are located at a plant site and that
meet the criteria in paragraphs (a)(1) and (2) of this section:
* * * * *
    (c) For the purposes of this subpart, the affected source shall
comprise all emissions points, in combination, listed in paragraphs
(c)(1) through (8) of this section that are located at a single
refinery plant site.
* * * * *
    (6) All marine vessel loading operations located at a refinery
meeting the criteria in paragraph (a) of this section and the
applicability criteria of subpart Y, Sec.  63.560;
    (7) All storage vessels and equipment leaks associated with a bulk
gasoline terminal or pipeline classified under Standard Industrial
Classification code 2911 located within a contiguous area and under
common control with a refinery meeting the criteria in paragraph (a) of
this section; and
    (8) All cooling tower systems associated with petroleum refining
process units meeting the criteria in paragraph (a) of this section and
which meets the criteria in either paragraph (a)(8)(i) or (a)(8)(ii) of
this section:
    (i) The cooling tower system provides non-contact cooling water to
any heat exchanger in Table 1 HAP service.
    (ii) The cooling tower system receives cooling water from multiple
heat exchangers which serve different petroleum refinery process units
and any of the heat exchangers are in Table 1 HAP service.
* * * * *