[Federal Register Volume 71, Number 67 (Friday, April 7, 2006)]
[Unknown Section]
[Pages 17729-17738]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-3316]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 63
[EPA-HQ-OAR-2004-0004, FRL-8054-1]
RIN 2060-AK16
National Emission Standards for Hazardous Air Pollutants for
Industrial Process Cooling Towers
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: On September 8, 1994, we promulgated national emission
standards for hazardous air pollutants for industrial process cooling
towers. The rule prohibits the use of chromium-based water treatment
chemicals that are known or suspected to cause cancer or have a serious
health or environmental effect.
Section 112(f)(2) of the Clean Air Act directs us to assess the
risk remaining (residual risk) after the application of national
emission standards for hazardous air pollutants and to promulgate more
stringent standards, if warranted, to provide an ample margin of safety
to protect public health or prevent adverse environmental effect. Also,
section 112(d)(6) of the Clean Air Act requires us to review and revise
the standards, as necessary at least every 8 years, taking into account
developments in practices, processes, and control technologies. On
October 24, 2005, based on the findings from our residual risk and
technology review, we proposed no further action to revise the
standards and requested public comment. Today's final action amends the
applicability section of the rule in response to public comments
received on the proposed action. The final amendment provides that
sources that are operated with chromium-based water treatment chemicals
are subject to this standard; other industrial process cooling towers
are not covered.
DATES: Effective Date: April 7, 2006.
ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OAR-2004-0004. All documents in the docket are listed on the
http://www.regulations.gov Web site. Although listed in the index, some
information is not publicly available, i.e., confidential business
information or other information whose disclosure is restricted by
statute. Certain other material, such as copyrighted material, is not
placed on the Internet and will be publicly available only in hard copy
form. Publicly available docket materials are available either
electronically through http://www.regulations.gov or in hard copy at
the national emission standards for hazardous air pollutants (NESHAP)
for Industrial Process Cooling Towers (IPCT)Docket, EPA/DC, Docket ID
No. EPA-HQ-OAR-2004-0004, EPA West, Room B102, 1301 Constitution Ave.,
NW., Washington, DC. The Public Reading Room is open from 8:30 a.m. to
4:30 p.m., Monday through Friday, excluding legal holidays. The
telephone number for the Public Reading Room is (202) 566-1744, and the
telephone number for the Air Docket Center is (202) 566-1742.
FOR FURTHER INFORMATION CONTACT: For questions about the final action,
contact Mr. Phil Mulrine, U.S. EPA, Office of Air Quality Planning and
Standards, Sector Policies and Programs Division, Metals and Minerals
Group (D243-02), Research Triangle Park, North Carolina 27711;
telephone number: (919) 541-5289; fax number: (919) 541-5450; e-mail
address: [email protected]. For questions on the residual risk
analysis, contact Mr. Scott Jenkins, U.S. EPA, Office of Air Quality
Planning and Standards, Health and Environmental Impacts Division,
Sector Based Assessment Group (C539-02), Research Triangle Park, North
Carolina 27711, telephone number: (919) 541-1167, fax number: (919)
541-0840, e-mail address: [email protected].
SUPPLEMENTARY INFORMATION: Regulated Entities. The regulated categories
and entities affected by the NESHAP include:
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Examples of regulated
Category NAICS code \1\
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Industry....................... 324110 IPCT located at major
325181 sources, including
325120 petroleum refineries,
325131 chemical manufacturing
325188 plants, primary metals
325191 processing plants,
325311 glass manufacturing
plants, tobacco
products manufacturing
plants, rubber
products manufacturing
plants, and textile
finishing plants.
325312
325314
325320
325520
325920
325910
325182
325998
331111
331411
331419
327211
327213
327212
312221
[[Page 17730]]
312229
312229
326211
313311
313311
313312
Federal Government............. .............. Not affected.
State, local, tribal government .............. Not affected.
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\1\ North American Industry Classification System.
This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by the
NESHAP. To determine whether your facility would be affected by the
NESHAP, you should examine the applicability criteria in 40 CFR
63.400(a) of subpart Q (IPCT NESHAP). If you have any questions
regarding the applicability of the NESHAP 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).
World Wide Web (WWW). In addition to being available in the docket,
an electronic copy of today's final action will also be available on
the WWW through the Technology Transfer Network (TTN). Following the
Administrator's signature, a copy of the final action will be posted on
the TTN's policy and guidance page for newly proposed or promulgated
rules at: http://www.epa.gov/ttn/oarpg. The TTN provides information
and technology exchange in various areas of air pollution control.
Judicial Review. Under section 307(b)(1) of the Clean Air Act
(CAA), judicial review of the final action is available only by filing
a petition for review in the U.S. Court of Appeals for the District of
Columbia Circuit by June 6, 2006. Under section 307(d)(7)(B) of the
CAA, only an objection to the final action amendment that was raised
with reasonable specificity during the period for public comment can be
raised during judicial review. Moreover, under section 307(b)(2) of the
CAA, the requirements established by the final action may not be
challenged separately in any civil or criminal proceedings brought by
EPA to enforce the requirements.
Outline. The information presented in this preamble is organized as
follows:
I. Background
A. What Is the Statutory Authority for This Action?
B. What Did the IPCT NESHAP Accomplish?
C. What Were the Conclusions of the Residual Risk Assessment?
D. What Were the Conclusions of the Technology Review?
E. What Was the Proposed Action?
II. Today's Action
A. What Is Today's Final Action?
B. What Comments Were Received on the Proposed Action?
III. 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 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. Congressional Review Act
I. Background
A. What Is the Statutory Authority for This Action?
Section 112 of the CAA establishes a comprehensive regulatory
process to address hazardous air pollutants (HAP) from stationary
sources. In implementing this process, we have identified categories of
sources emitting one or more of the HAP listed in the CAA, and
industrial process cooling towers are identified as one such source
category. Section 112(d) requires us to promulgate national technology-
based emission standards for sources within those categories 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 (known as major sources), as well as for certain area sources
emitting less than those amounts. These technology-based NESHAP must
reflect the maximum reductions of HAP achievable (after considering
cost, energy requirements, and non-air health and environmental
impacts) and are commonly referred to as maximum achievable control
technology (MACT) standards.
In what is referred to as the technology review, we are required
under section 112(d)(6) of the CAA to review these technology-based
standards no less frequently than every 8 years. Further, if we
conclude that a revision is necessary, we have the authority to revise
these standards, taking into account ``developments in practices,
processes, and control technologies.''
The residual risk review is described in section 112(f) of the CAA.
Section 112(f)(2) requires us to determine for each section 112(d)
source category, except area source categories for which we issued a
generally available control technology standard, whether the NESHAP
protects public health with an ample margin of safety. If the NESHAP
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 one in one million,'' we must decide whether additional
reductions are necessary to provide an ample margin of safety. As part
of this decision, we may consider costs, technological feasibility,
uncertainties, or other relevant factors. We must determine whether
more stringent standards are necessary to prevent adverse environmental
effect (defined in CAA section 112(a)(7) as ``any significant and
widespread adverse effect, which may reasonably be anticipated to
wildlife, aquatic life, or other natural resources, including adverse
impacts on populations of endangered or threatened species or
significant degradation of environmental quality over broad areas.''),
but in making this decision we must consider cost, energy, safety, and
other relevant factors.
B. What Did the IPCT NESHAP Accomplish?
On September 8, 1994 (59 FR 46350), we promulgated the IPCT NESHAP
and required existing sources to comply with the rule requirements by
March 8, 1996.
Cooling towers are devices that are used to remove heat from a
cooling fluid, typically water, by contacting the
[[Page 17731]]
fluid with ambient air. The IPCT source category includes cooling
towers that are used to remove heat that is produced as an input or
output of chemical or industrial processes. The IPCT source category
also includes cooling towers that cool industrial processes in
combination with heating, ventilation, and air conditioning (HVAC)
systems. The IPCT NESHAP applies specifically to IPCT that use
chromium-based water treatment chemicals and are located at major
sources of HAP emissions. Standards to control chromium emissions from
cooling towers that cool HVAC systems exclusively (comfort cooling
towers) were promulgated under section 6 of the Toxic Substances
Control Act (55 FR 222, January 3, 1990).
The primary industries that use IPCT include petroleum refineries,
chemical manufacturing plants, primary metals processing plants, glass
manufacturing plants, rubber products manufacturing plants, tobacco
products manufacturing plants, and textile manufacturing plants. When
the IPCT NESHAP were promulgated, we estimated that there were
approximately 6,945 IPCT located at these plants nationwide, and that
approximately 260 of these IPCT used chromium-based water treatment
chemicals. We estimated that the IPCT NESHAP would reduce emissions of
chromium compounds from these facilities by 22.7 megagrams per year
(Mg/yr) (25 tons per year (tpy)) by prohibiting the use of chromium-
based water treatment chemicals in IPCT. In addition, we estimated that
the NESHAP would prevent emissions of 1.6 Mg/yr (1.8 tpy) of chromium
compounds from the 870 new IPCT projected by the 5th year of the
standards (1998).
When the NESHAP were promulgated, we had no information that
indicated that HAP other than chromium compounds were emitted from
IPCT. Consequently, we did not address emissions of other HAP in the
IPCT NESHAP.
C. What Were the Conclusions of the Residual Risk Assessment?
As required by section 112(f)(2) of the CAA, we prepared a risk
assessment to determine the residual risk posed by IPCT after
implementation of the NESHAP. To evaluate the residual risk for the
IPCT source category, we identified the HAP emitted from IPCT and, as a
discretionary matter in this instance, estimated worst-case emission
rates for each of those HAP. These worst-case emission rates were used,
along with facility parameters representing an actual facility, to
perform the risk assessment.
Because the IPCT NESHAP prohibits the use of chromium-based water
treatment chemicals in IPCT, we believe that chromium compound
emissions from IPCT have been eliminated by the NESHAP. In assessing
the residual risk for the source category, however, we also considered
emissions of other HAP from IPCT.
In the absence of process leaks or malfunctions, the chemical
species that are emitted from IPCT consist of the naturally-occurring
constituents of the cooling water and any substances that are added to
the cooling water. To determine what other HAP may be emitted from
IPCT, we first contacted suppliers of cooling water treatment chemicals
for information on cooling water additives that either contain HAP or
form HAP, which could be emitted from IPCT. Then, we conducted a
literature search for information on emissions from cooling towers. The
information collected from the water treatment chemical suppliers and
through the literature search indicated that some biocides used to
treat industrial cooling water either contain HAP or form HAP that can
be emitted from IPCT. These HAP include chloroform, methanol, and
ethylene thiourea.
Industrial process cooling towers typically use one and not all of
the biocides that release the three listed HAP at any given time.
Therefore, IPCT emit no more than one of the three listed HAP. We
estimated worst-case emission rates for chloroform, methanol, and
ethylene thiourea based on the range of concentrations of these
constituents in cooling water and the model plants developed for the
IPCT NESHAP. We used these emission rates to model exposure
concentrations surrounding those sources, calculated the risk of
possible chronic cancer and noncancer health effects, evaluated whether
acute exposures might exceed relevant health thresholds, and
investigated human health multipathway and ecological risks.
Consistent with the tiered modeling approach described in the
``Residual Risk Report to Congress'' (EPA-453/R-99-001), the risk
assessment for this source category started with a simple assessment
which used conservative assumptions in lieu of site-specific data. The
results demonstrated negligible risks for potential chronic cancer,
chronic noncancer, and acute noncancer health endpoints. Also, no
significant human health multipathway or ecological risks were
identified. Had the resulting risks been determined to be non-
negligible, a more refined analysis with site-specific data would have
been necessary. The assessment is described in detail in the memorandum
``Residual Risk Assessment for the Industrial Process Cooling Source
Category,'' which is available in the docket.
Since our assessment shows that sources subject to the IPCT NESHAP
pose maximum lifetime excess cancer risks which are significantly less
than 1 in 1 million, EPA concluded that public health is protected with
an ample margin of safety, and since noncancer health risks and
ecological risks were also found to be insignificant for this source
category, EPA is not obligated to adopt standards under section 112(f)
of the CAA.
D. What Were the Conclusions of the Technology Review?
Section 112(d)(6) of the CAA requires EPA to review, and revise as
necessary (taking into account developments in practices, processes,
and control technologies), emission standards promulgated under section
112 no less often than every 8 years. As we stated in the preamble to
the Coke Ovens residual risk rule (70 FR 20009, April 15, 2005), and as
discussed below, the facts underlying a section 112(f) determination
should be key factors in making any subsequent section 112(d)(6)
determinations. For this and several other source categories, we were
under consent decree deadlines to complete both the section 112(d)(6)
technology review and the section 112(f)(2) residual risk analysis by
the same date. As a result, we conducted the two reviews concurrently
and did not have the results of the section 112(f)(2) analysis before
we began the section 112(d)(6) technology review.
For the IPCT source category, the emission standards imposed an
absolute prohibition on the use of chromium-based water treatment
chemicals in IPCT. As the emission standards imposed for this
particular source are already at the most stringent level, no more
stringent standards could be imposed. Nor has EPA received any evidence
which would justify a downward revision of the standards. In the
residual risk analysis discussed above, EPA has considered risks for
HAP emissions that are not currently subject to emission standards but
are attributable to the source category or subcategory. Since the risk
from other HAP emitted from IPCT due to the addition of water treatment
chemicals was determined to be very low and the emission standards
already preclude the use of chromium-based water treatment
[[Page 17732]]
chemicals, we concluded that no further controls are necessary under
112(d)(6).
E. What Was the Proposed Action?
On October 24, 2005 (70 FR 61411), based on the findings from our
residual risk and technology review, we proposed no further action to
revise the NESHAP and requested public comment.
II. Today's Action
A. What Is Today's Final Action?
Today's final action responds to public comments received on the
proposed action and announces our final decision to amend the
applicability section of the rule.
B. What Comments Were Received on the Proposed Action?
In the proposed action, we requested public comment on our residual
risk review and our technology review and on issues of delisting the
source category and conducting future technology reviews. By the end of
the public comment period, comments from nine entities had been
received. A summary of the major comments and EPA's responses are
provided below in sections II.B.1 through II.B.7 of this preamble.
1. Residual Risk Approach
Comment: Two commenters urged EPA to carefully lay out the context
and framework of the Residual Risk Program to ensure that the public
understands the program and can adequately evaluate EPA's decisions
regarding residual risk. The commenters identified several specific
aspects of the program, which they believe need to be conveyed to the
public. Among those, they included: the success of the MACT program in
controlling HAP emissions; further regulatory steps are not required if
EPA determines that existing MACT standards have provided an ample
margin of safety; and the public can be assured that residual risk
rules will provide such a margin of safety in those cases where the
standard has not achieved an ample margin of safety. The commenters
also stated that it is important for EPA to put the risks associated
with major stationary sources in the proper context. The commenters
stated that major stationary sources account for only a small
percentage of the estimated cancer risk from HAP nationwide. In
addition, they urged EPA to present risk from air toxics in context
with the risks from other forms of air pollution. Specifically, they
pointed out that the unit risk factors assigned to air toxics are much
more conservative than the factors assigned to criteria pollutants. As
a result, risk estimates for criteria pollutants should not be compared
to estimates of risk based on HAP emissions from stationary sources
subject to NESHAP.
Response: We agree that it is important to provide context for any
residual risk rule. In this preamble, we describe the MACT program and
its impact on the IPCT source category. We also describe our statutory
authority and our obligations to assess risks to human health and the
environment under section 112(f) of the CAA, as well as the requirement
to further regulate categories of sources if any of the estimated
individual cancer risks exceed the statutory trigger level of 1 in 1
million.
The risks posed by any individual major stationary source depend
upon a number of factors, including emission rates at the source,
proximity of exposed populations to the emission source, the specific
HAP emitted, local meteorological conditions, and terrain conditions
surrounding the source. Therefore, the relative contribution of a
particular major stationary source to individual risk levels in its
vicinity will vary dramatically depending on the local conditions at
and around that specific source. This variability is not captured by
the national average contribution of major sources to population risk
levels mentioned by the commenter, whereas the risk assessments we
perform for the purposes of evaluating residual risk are designed
specifically to capture localized individual risks associated with
individual sources.
We agree that our screening risk assessment for the IPCT source
category appropriately contains a number of health-protective
assumptions and uses health-protective inhalation risk values. The
overall result is a screening assessment that is designed to
overestimate, rather than underestimate, risks. The commenters make the
seemingly contradictory arguments that we should both present risks
from air toxics in the context of those from criteria pollutants and
that it is inappropriate to make direct comparisons between assessments
of risk for air toxics and criteria pollutants. Given the different
goals of the residual risk program and the criteria pollutant program,
we agree with their second point that estimates of risk generated for
air toxics are not directly comparable to those generated for criteria
pollutants.
Comment: Four commenters expressed support for EPA's tiered
approach to evaluating residual risk by first performing a screening
assessment, followed by a refined assessment. One commenter commented
that, if a screening risk assessment based on conservative assumptions
showed that risks are negligible, no further assessments or actions
should be taken. All four commenters stated that EPA must proceed with
the refined approach unless, as was the case for IPCT, the worst-case
screening assessment indicates that the risk is less than 1 in 1
million. One commenter stated that in evaluating the residual risk for
IPCT, EPA correctly used the same approach used for the 1989 Benzene
NESHAP (40 CFR part 61, subpart Y).
Response: We acknowledge the commenters' support of our general
approach to risk assessment and agree that, had risks from the IPCT
exceeded the statutory trigger of 1 in 1 million cancer risk or
exceeded a similar level of protection for threshold effects, we would
have conducted a more refined assessment.
Comment: Three commenters stated that, when presenting the results
of the initial screening assessment, it is important for EPA to explain
the conservative nature of the assumptions and the limitations of this
approach to avoid any misperceptions by the public. Two of the
commenters added that otherwise, the public may mistakenly believe that
the contribution to risk from major stationary sources is much greater.
The commenters also encouraged EPA to use the most accurate emission
data and models to ensure accurate risk assessments and to avoid
mischaracterizing the risk from the regulated sources. One commenter
added that site-specific data should be used in residual risk
assessments when possible.
Response: We agree that our risk assessment for IPCT contains a
number of health-protective assumptions resulting in a screening
assessment that is designed to overestimate, rather than underestimate,
risks. However, the health-protective assumptions incorporated into
this screening risk assessment are appropriate because we are
generalizing the results from a single model facility to all cooling
towers in the source category. We designed this approach to ensure that
the model facility presents at least as much risk as the worst-case
actual facility. Then, by demonstrating that risks from our worst-case
model facility are low, we can easily conclude that risks from IPCT at
any actual facility will also be low.
The details of our risk assessment can be found in the memorandum
titled, ``Residual Risk Assessment for the Industrial Process Cooling
Towers Source Category,'' which is available in the docket. As
indicated above, a
[[Page 17733]]
number of health-protective assumptions are incorporated into the
assessment. For example, we based the configuration of our model
facility on one of the largest and highest-emitting actual facilities
in the IPCT source category. We estimated worst-case emission rates for
this facility by assuming that it emitted methanol, ethylene thiourea,
and chloroform from its cooling towers even though it is unlikely that
any actual towers would emit more than one of these HAP. We assumed
that individuals are exposed to IPCT emissions for 24 hours per day and
365 days per year for 70 years although the activity patterns of actual
individuals would decrease exposure. Finally, we assumed that people
lived at locations very close to the cooling towers. Often, these
locations would actually be within the facility's fenceline, where no
one actually resides. This combination of health-protective assumptions
is appropriate for the IPCT assessment because it allows us to
generalize the low-risk finding from a single model source to all
sources in the category. If we had not been able to use this approach
to make the low-risk finding, we would indeed have collected more
refined, site-specific data to develop a more precise risk assessment,
but, in this situation, that step was not necessary.
2. Co-Located Sources
Comment: Four commenters agreed with EPA's approach of considering
the risk associated with the specific sources regulated by the NESHAP
and not considering co-located sources. Two of the commenters noted
that the risk attributed to co-located sources will be evaluated when
the appropriate source category is reviewed under section 112(f) of the
CAA. The commenters stated that section 112(f) clearly indicates that
Congress intended the residual risk assessment for a specific source
category to focus on the source category, as defined in the rulemaking
under section 112(d), and not to encompass other source categories.
Response: We agree with commenters that the risks attributable to
sources collocated with IPCT will be evaluated when the appropriate
category is reviewed under section 112(f). We do not agree that our
section 112(f) residual risk analyses must always focus only on the
source category as defined in the rulemaking under section 112(d) or
that Congress intended to limit all residual risk analyses to the
individual source categories in question. As we stated in the preamble
to the Coke Ovens residual risk rule (70 FR 19998, April 15, 2005),
``EPA disagrees that section 112(f) precludes EPA from considering
emissions other than those from the source category or subcategory
entirely.'' Rather, we have concluded that, when the statutory risk
trigger is exceeded, the two-step approach set forth in the preamble to
the Benzene NESHAP (54 FR 38044, September 14, 1989) remains the
approach that we should follow in determinations under section 112(f).
At the first step, when determining ``acceptable risk,'' we will
consider risks that result from emissions from the source category
only. However, during the second step, we must determine whether
additional reductions should be required to protect public health with
``an ample margin of safety.'' EPA believes that one of the ``other
relevant factors'' that may be considered in this second step is co-
location of other emission sources that augment the identified risks
from the source category. In the case of coke ovens, this included the
consideration of co-located source categories that are integral parts
of the same industrial activity. Additional information regarding co-
located sources and 112(f) requirements is provided in the preamble to
the coke oven residual risk rule (70 FR 19996).
3. Approach When No Pre-Existing NESHAP Level of Control Exists
Comment: Three commenters responded to our request for comment on
the approach to evaluating residual risk when no pre-existing NESHAP
requirement exists for the HAP emissions. For example, in the case of
IPCT, the residual risk assessment considered three HAP that were not
regulated under the NESHAP. The commenters agreed with EPA's approach,
stating that it is appropriate to evaluate and control emissions of
other HAP if those HAP pose an unacceptable level of risk.
Response: We acknowledge the commenters' support of our approach to
evaluating residual risk by considering all HAP emitted by the
regulated source category. Section 112(f) requires EPA to determine if
an ample margin of safety has been provided for the source category and
as part of that determination we identified other HAP that are emitted
from the source category.
4. Subcategorizing Source Categories to Satisfy CAA Section 112(f)(2)
Comment: Five commenters responded to our request for comment on
the possibility of subcategorizing source categories for the purpose of
satisfying the residual risk requirements specified in section
112(f)(2) of the CAA. All five commenters supported the concept of
subcategorizing source categories characterized by a broad range of
risk levels. Four of the commenters noted that section 112(c) gives EPA
broad discretion in creating and modifying categories and subcategories
of sources. By subcategorizing, EPA can distinguish between lower risk
subcategories and those categories for which additional control is
warranted. One of the commenters pointed out that emission
characteristics, which vary by subcategory, define the risk of adverse
health and environmental impacts. Therefore, establishing separate
subcategories on the basis of risk would be consistent with, and would
best achieve, the overall statutory mandate of section 112 of the CAA.
The same commenter stated that Congress provided a mechanism and
criteria for subcategorizing with respect to risk in sections
112(c)(9)(B)(i) and (ii) to preclude overregulating sources that can
meet consistent low-risk criteria. Four of the commenters believed that
subcategorizing with respect to residual risk would encourage sources
to develop site-specific approaches for reducing risk in order to avoid
additional regulatory control, work practices, and associated
permitting costs. One commenter stated that the intent of Congress was
that EPA should focus MACT standards and residual risk requirements on
those sources that present a risk of concern. Two of the commenters
cited the ``Residual Risk Report to Congress'' (EPA-453/R-99-001),
which supports the concept of regulating only those sources within a
source category associated with unacceptable risk. Three of the
commenters commented that sources within a lower risk subcategory would
still be subject to the NESHAP and would have to continue complying
with the standard in order to maintain its low-risk status. The
commenters further explained that, even if EPA decides not to
subcategorize based on risk, residual risk standards should focus only
on the subset of sources that poses unacceptable risk.
Response: We acknowledge the commenters' support for
subcategorizing based on risk in order to satisfy section 112(f)(2) of
the CAA. For the IPCT source category, our risk assessment indicated
that all sources in the category are low-risk. Therefore, there is no
need, in the present case, to subcategorize based on risk or any other
criteria.
[[Page 17734]]
5. Emissions From IPCT
Comment: One commenter commented on our conclusion that emissions
of chlorine from IPCT are unlikely under normal operating conditions.
We based this conclusion on discussions with water treatment chemical
suppliers and information presented in several technical publications
on water treatment, all of which clearly stated that chlorine emissions
occur only under acidic conditions (i.e., pH of 3.0 or less), and IPCT
water treatment programs are designed to maintain alkaline conditions
(i.e., pH of 7.5 to 9.0) in the cooling water. The commenter stated
that IPCT that are treated with chlorine gas (Cl2)
experience significant flash-off of molecular chlorine. He noted that
one facility estimated that chlorine emissions from flash-off amounted
to 18 percent of the chlorine gas used to treat the cooling water in an
IPCT, and that annual emissions of chlorine from the IPCT were
estimated to be 18.2 tons. The commenter did not provide documentation
for that estimate. However, he did cite a report prepared by the
University of Texas for the Texas Natural Resource Conservation
Commission (TNRCC), ``Emission Inventory for Atomic Chlorine Precursors
in Southeast Texas,'' which supports his comments regarding chlorine
emissions due to flash-off from IPCT. The TNRCC Report also states that
the greater the pH, the greater the flash-off rate, which may appear to
contradict our conclusion regarding the relationship between pH and
Cl2 emissions from IPCT.
Response: As noted above, the commenter did not provide
documentation for the estimate of 18.2 tpy of chlorine emissions from a
single IPCT. We assume that the basis for that estimate was the TNRCC
Report. We reviewed the TNRCC Report, as well as the primary references
used as the basis for the chlorine emission estimates presented in the
report. Based on our review, we maintain our conclusion that emissions
of Cl2 from IPCT are not likely to occur under normal
operating conditions.
With respect to the discrepancy between our conclusions regarding
emissions of chlorine from IPCT, the statement by the commenter, and
the information presented in the TNRC Report, there are two issues that
must be resolved: (1) Which chlorine species are emitted from IPCT, and
(2) what is the relationship between those emissions and the pH of the
cooling water.
When gaseous chlorine is added to cooling water, it dissociates to
form hypochlorous acid (HClO), hydrogen (H+), and chloride
(Cl-) ions. The HClO further dissociates to form
hypochlorite (ClO-) and H+ ions. With respect to
the chlorine species emitted, the TNRCC Report presents estimates
assuming that chlorine emissions are entirely in the form of
Cl2. The Report does not provide the basis for this
assumption, but does note that ``* * * chlorine may be released as
HClO, Cl2, or in other chemical forms * * *'' The Report
later states that emissions ``* * * may be in the form of HOCl rather
than Cl2.'' Apparently, because the focus of the TNRCC
Report was the magnitude of the emissions rather than the form of the
chlorine emitted, the researchers did not attempt to determine which
chlorine species would be emitted. The primary references cited in the
TNRCC Report regarding chlorine emissions from IPCT are two journal
articles from 1984 by Holzwarth, et al. The introduction to the first
of those articles explains that chlorine gas added to cooling water ``*
* * immediately reacts with water to form HOCl and HCl.'' All of the
subsequent discussion and calculations in both papers regarding flash-
off are in terms of HOCl and other non-Cl2 chlorine
compounds. In fact, Cl2 is not mentioned again in either
article. In other words, the Holzwarth articles support our conclusion
that chlorine is not emitted from IPCT in the form of Cl2.
With respect to the relationship between pH and emissions of
chlorine species, we do not argue that emissions from flash-off may
increase with increasing pH. However, our assessment concluded that
these emissions would be entirely in the form of HOCl and not as
Cl2. The studies by Holzwarth, et al. also support this
conclusion, that emissions of HOCl increase with increasing pH, while
emissions of Cl2 decrease with increasing pH.
In summary, we believe our conclusions regarding emissions of
Cl2 from IPCT are correct. Neither the commenter, nor the
references cited by the commenter provide any basis for concluding
otherwise.
6. Delisting the IPCT Source Category
Comment: Six commenters responded to our request for comment on the
issue of delisting the IPCT source category in light of the results of
the residual risk assessment. Two of the commenters opposed delisting
the source category; one of the commenters supported delisting; and the
other commenters, although not opposed to delisting, found no
compelling reason to do so. One of the commenters who opposed delisting
stated that delisting the source category would not be appropriate
because such action would allow owners and operators of IPCT to revert
back to using chromium water treatment chemicals. The commenter also
noted that delisting the source category would require State and local
agencies to amend their rules accordingly. Because there would not be a
NESHAP to adopt by reference, State and local agencies would be
required to develop and adopt their own regulations on IPCT. In
addition, the commenter pointed out that some regulatory agencies are
prevented from adopting rules that are more stringent than Federal
requirements. In those cases, States and local agencies would have no
legal means of preventing IPCT owners and operators from resuming the
use of chromium water treatment chemicals in IPCT.
The other commenter who opposed delisting stated that, if the
source category were delisted, there would be nothing to prevent
sources from increasing their HAP emissions substantially or changing
their processes to emit new HAP, either of which could result in HAP
levels that are unacceptable to public health and the environment. He
noted that such action would disregard the possibility that HAP
emissions have been reduced to an acceptable level because of the
NESHAP.
Three of the commenters were not opposed to delisting the IPCT
source category, but remarked that there was no compelling reason to do
so. The commenters noted that, even though the IPCT NESHAP does not
apply to any existing sources, it is possible for the rule to apply to
sources in the future. The commenters gave the example of an area
source, which operated an IPCT using chromium water treatment chemicals
and later became a major source. Once the facility became a major
source, it would be subject to the NESHAP and would have to discontinue
the use of chromium water treatment chemicals. The commenters stated
that, on the other hand, delisting a source category does not affect
the applicability of an existing NESHAP. The commenters explained that
the applicability of the Asbestos NESHAP (40 CFR part 61, subpart M)
was unchanged after the source category was delisted. Finally, the
commenters pointed out that none of the applicability requirements of
40 CFR part 63 standards (i.e., NESHAP) depend on source category
listing.
One of the commenters supported delisting the IPCT source category.
The commenter stated that our request for comment on this issue implied
that we
[[Page 17735]]
interpreted section 112(c)(9) of the CAA to apply only before a MACT
standard has been promulgated. According to the commenter, section
112(c)(9) grants EPA the authority to delist a source category whenever
the Administrator determines that the risks meet the established
criteria. The commenter noted that delisting source categories based on
risk prior to establishing standards under section 112(d) actually
would conflict with the sequence of EPA's duties under section 112,
which requires EPA to evaluate residual risk 8 years after
promulgation. In addition, the commenter pointed out that EPA would
likely not have sufficient data to fully assess the risk until several
years after a standard had been in place. Finally, if EPA were to
delist the source category, section 112(c)(9) could still be used to
establish requirements to ensure that the risk remains within
acceptable levels if EPA were to conclude that the risk associated with
the source category could become unacceptable in the future.
Response: Based on our risk assessment of the IPCT source category,
we have concluded that these sources are low-risk and, therefore, that
no further standards are required to protect public health with an
ample margin of safety or to protect the environment. However, we agree
with the commenter who argues that this conclusion is based, at least
in part, on the fact that the MACT requirements for these sources
prevent IPCT from using chromium-based water treatment strategies.
Further, we disagree with the comment that delisting would not affect
the existing NESHAP. The commenter cited the delisting action following
the Asbestos NESHAP as support for their argument, noting that the
applicability of that rule was not affected by delisting. However, the
Asbestos NESHAP was established under 40 CFR part 61, which is not
directly relevant in this situation since the IPCT NESHAP is a 40 CFR
part 63 rule. If we delist this source category, it is our opinion that
existing facilities with IPCT would no longer be subject to the NESHAP
and would not be banned from using chromium. If any sources reverted to
using chromium, risks could increase, and the basis for our finding
that the source category is low-risk would be compromised. Thus, since
compliance with the MACT standard is part of the basis for our low-risk
determination, we believe our policy objectives are best served if we
do not delist the IPCT source category. However, as long as the NESHAP
exists and prohibits the use of chromium-based water treatment
chemicals, we agree with the commenters who suggest that IPCT sources
no longer using these chemicals should not be subject to this NESHAP.
Therefore, we are amending the applicability section of the rule to
clarify that sources no longer using chromium-based water treatment
chemicals are not subject to this NESHAP. The NESHAP remains in effect,
and any source that uses chromium-based water treatment chemicals will
be subject to the rule and in violation.
Contrary to one commenter's contention, we do not interpret section
112(c)(9) of the CAA to apply only before a MACT standard has been
promulgated, although that is expected to be the situation in which it
is most likely exercised. We agree that section 112(c)(9) grants EPA
the authority to delist a source category when the Administrator
determines that risks meet the established criteria, including after
promulgation of a MACT standard.
The Agency would like to remove the burden of the repetitive review
of Section 112 standards for low risk source categories. At the same
time, we think it is appropriate to maintain the MACT controls in this
case. We plan to further investigate approaches for removing low-risk
source categories from the Section 112 universe while maintaining MACT-
level controls. An example of a similar approach is found in the
Plywood and Composite Wood Products MACT where we allow a subcategory
of facilities to reduce emissions to acceptable risk levels through
Title 5 permits and remove them from the MACT universe.
7. Technology Reviews Under CAA Section 112(d)(6)
Comment: One commenter remarked that EPA should not have conducted
an initial technology review of the IPCT source category. The commenter
explained that once a residual risk determination indicates the risk is
acceptable, EPA must find that revising the standard under CAA section
112(d)(6) is not necessary. The commenter stated that the legislative
history of the CAA demonstrates that Congress rejected imposing
controls beyond levels considered to be safe and protective of public
health because those controls would impose regulatory costs without any
public health benefit. The commenter stated that, if Congress had
intended EPA to conduct technology reviews regardless of the outcome of
the residual risk assessment, there would be no need for CAA section
112(f). The commenter believes that technology reviews under section
112(d)(6) were meant to be regulatory backstop authority for residual
risk reviews, similar to the MACT hammer provision in section 112(j) of
the CAA. That is, if EPA failed to address the residual risk for a
source category, section 112(d)(6) authority could be used to ensure
that advances in technology could still be applied to the source
category.
Response: We disagree with the comment that we should not have
conducted an initial technology review under CAA section 112(d)(6) for
the IPCT source category. The timing requirements for the initial
analysis under section 112(d)(6) coincide with those for the residual
risk analysis. Thus, it is appropriate for us to conduct both analyses
at the same time. Although the results of the risk analysis may impact
future section 112(d)(6) technology reviews, these results do not
negate the need to perform the initial review. Additional information
regarding the relationship between residual risk standards and
112(d)(6) review requirements is provided in the preamble to the Coke
Oven residual risk rule (70 FR 20008, April 15, 2005).
Comment: Seven commenters responded to our request for comment on
continuing technology reviews every 8 years for source categories
subject to NESHAP, as required by section 112(d)(6) of the CAA. Four
commenters stated that EPA should not use a ``bright line approach'' in
determining the need for technology reviews under section 112(d)(6) of
the CAA. For example, the decision of whether or not to perform a
technology review should not be based on a 1-in-1-million risk level,
as is the case for residual risk. One of those commenters stated that
discontinuing technology reviews would be contrary to the requirements
of the CAA. The commenter noted that the phrase ``* * * every 8 years''
implies a continuum rather than a single action, and if Congress had
intended the technology review to be a one-time requirement, it would
have used other language in the CAA. As an example of a one-time
requirement, the commenter cited CAA section 112(n)(1), which states
that ``The Administrator shall conduct, and transmit to Congress not
later than 4 years after the date of enactment * * *'' The other
commenter who opposed discontinuing technology reviews remarked that,
without future reviews, it is unlikely that EPA would know what new
technologies have been developed or know of any unforeseeable
circumstances that might substantially change the source category or
its emissions.
[[Page 17736]]
Three of the commenters stated that, by implementing residual risk
requirements under section 112(f) or determining that residual risk
requirements are not warranted, EPA completes its obligation to conduct
technology reviews under section 112(d)(6) of the CAA. Thus, once the
residual risk has been evaluated and the appropriate action taken,
technology reviews are no longer required. However, the commenters also
stated that later technology reviews may be appropriate if the ample
margin of safety established by the residual risk process is based
largely on cost or technical feasibility, and feasible, cost-effective
controls are identified in the future. Four of the commenters stated
that technology reviews under section 112(d)(6) should not provide for
a continuing technology ratchet based on the availability of new
technology. Instead, technology reviews should be conducted in the
context of providing an ample margin of safety under section 112(f) of
the CAA.
Response: We agree that a technology review is required every 8
years for emission standards under 112(d) or if new standards are
issued pursuant to 112(f). However, if the ample margin of safety
analysis for a section 112(f) standard shows that remaining risk for
non-threshold pollutants falls below 1 in 1 million and for threshold
pollutants falls below a similar threshold of safety, then further
revision would not be needed because an ample margin of safety has
already been assured. Additional information regarding the relationship
between residual risk standards and 112(d)(6) review requirements is
provided in the preamble to the Coke Oven residual risk rule (70 FR
20008, April 15, 2005).
Comment: Four commenters commented that technology reviews under
section 112(d)(6) should be limited to emission standards already
established under section 112(d). Three of the commenters stated that,
although it is appropriate to evaluate and control emissions of other
HAP not regulated by the NESHAP under section 112(f), such HAP should
not be considered under the section 112(d)(6) technology review.
Response: The emission standards imposed a prohibition on the use
of chromium-based water treatment chemicals in IPCT. Since the risk
from other HAP emitted from IPCT due to the addition of water treatment
chemicals was determined to be very low and the emission standards
already preclude the use of chromium-based water treatment chemicals,
we concluded that no further controls are necessary under either 112(f)
or 112(d)(6). As stated previously, section 112(d)(6) requires that the
emission standard be reviewed and revised as necessary no less often
than every 8 years. Additional information regarding the relationship
between residual risk standards and 112(d)(6) review requirements is
provided in the preamble to the residual risk for coke ovens (70 FR
20008, April 15, 2005).
III. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review
Under Executive Order 12866 (58 FR 51735, October 4, 1993), EPA
must determine whether a regulatory action is ``significant'' and,
therefore, subject to Office of Management and Budget (OMB) review and
the requirements of the Executive Order. The Executive Order defines
``significant regulatory action'' as one that is likely to result in a
rule that may:
(1) Have an annual effect on the economy of $100 million or more,
or adversely affect in a material way the economy, a sector of the
economy, productivity, competition, jobs, the environment, public
health or safety, or State, local, or tribal governments or
communities;
(2) Create a serious inconsistency or otherwise interfere with an
action taken or planned by another agency;
(3) Materially alter the budgetary impact of entitlements, grants,
user fees, or loan programs, or the rights and obligations of
recipients thereof; or
(4) Raise novel legal or policy issues arising out of legal
mandates, the President's priorities, or the principles set forth in
the Executive Order.
Pursuant to the terms of Executive Order 12866, OMB has notified
EPA that it considers this a ``significant regulatory action'' within
the meaning of the Executive Order. EPA has submitted this action to
OMB for review. Changes made in response to OMB suggestions or
recommendations will be documented in the public record.
B. Paperwork Reduction Act
The final rule amendment does not impose any information collection
burden. It will not change the burden estimates from those previously
developed and approved for the existing NESHAP. OMB has previously
approved the information collection requirements contained in the
existing regulation (40 CFR part 63, subpart Q) under the provisions of
the Paperwork Reduction Act, 44 U.S.C. 3501, et seq. (OMB control
number 2060-0268). However, this information collection request has
been discontinued because the information requested in the original
regulation is no longer needed.
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
EPA has determined that it is not necessary to prepare a regulatory
flexibility analysis in connection with this final rule amendment.
For purposes of assessing the impacts of today's final rule
amendment on small entities, small entity is defined as: (1) A small
business as defined by the Small Business Administration at 13 CFR
121.201; (2) a small governmental jurisdiction that is a government of
a city, county, town, school district, or special district with a
population of less than 50,000; and (3) a small organization that is
any not-for-profit enterprise which is independently owned and operated
and is not dominant in its field.
After considering the economic impacts of today's final rule
amendment on small entities, EPA has concluded that this final action
will not have a significant economic impact on a substantial number of
small entities. The final rule amendment does not impose any
requirements on small entities.
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
[[Page 17737]]
statement, including a cost-benefit analysis, for proposed and final
rules with ``Federal mandates'' that may result in expenditures to
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 final rule amendment does not
contain a Federal mandate (under the regulatory provisions of Title II
of the UMRA) for State, local, or tribal governments or the private
sector because it imposes no enforceable duty on any State, local, or
tribal governments or the private sector. Thus, today's final amendment
is not subject to the requirements of sections 202 and 205 of the UMRA.
In addition, EPA has determined that the final amendment contains no
regulatory requirements that might significantly or uniquely affect
small governments, because it contains no requirements that apply to
such governments or impose obligations upon them.
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.''
Today's final amendment does not have federalism implications. It
will 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. Thus, Executive
Order 13132 does not apply to the final amendment.
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 final amendment does not
have tribal implications as specified in Executive Order 13175. It will
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.
Thus, Executive Order 13175 does not apply to today's final amendment.
G. Executive Order 13045: Protection of Children From Environmental
Health and Safety Risks
Executive Order 13045 (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 EPA.
The final amendment is not subject to the Executive Order because
it is not economically significant as defined in Executive Order 12866
and because EPA does not have reason to believe the environmental
health or safety risks addressed by this action present a significant
disproportionate risk to children.
H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
The final amendment is not subject to Executive Order 13211 (66 FR
28355, May 22, 2001) because it is not an economically significant
regulatory action under Executive Order 12866.
I. National Technology Transfer Advancement Act
As noted in the proposed rule, section 12(d) of the National
Technology Transfer and Advancement Act of 1995 (NTTAA), Public Law
104-113, (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. The 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 does not use available and
applicable VCS. The final amendment does not involve technical
standards. Therefore, EPA is not considering the use of any VCS.
J. Congressional Review Act
The Congressional Review Act, 5 U.S.C. 801, et seq., as added by
the Small Business Regulatory Enforcement Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. EPA will submit a report containing the final rule and
other required information to the United States Senate, the United
States House of Representatives, and the Comptroller General of the
United States prior to publication of the final rule in the Federal
Register. A major rule cannot take effect until 60 days after it is
published in the Federal Register.This action is not a ``major rule''
as defined by 5 U.S.C. 804(2). The final amendment is effective on
April 7, 2006.
List of Subjects in 40 CFR Part 63
Environmental protection, Air pollution control, Hazardous
substances, Reporting and recordkeeping requirements.
[[Page 17738]]
Dated: March 31, 2006.
Stephen L. Johnson,
Administrator.
0
For the reasons stated in the preamble, title 40, chapter I, part 63 of
the Code of Federal Regulations is amended as follows:
PART 63--[AMENDED]
0
1. The authority citation for part 63 continues to read as follows:
Authority: 42 U.S.C. 7401, et seq.
Subpart Q--[Amended]
0
2. Section 63.400 is amended by revising paragraph (a) to read as
follows:
Sec. 63.400 Applicability.
(a) The provisions of this subpart apply to all new and existing
industrial process cooling towers that are operated with chromium-based
water treatment chemicals and are either major sources or are integral
parts of facilities that are major sources as defined in Sec. 63.401.
* * * * *
[FR Doc. 06-3316 Filed 4-6-06; 8:45 am]
BILLING CODE 6560-50-P