National Emission Standards for Hazardous Air Pollutants for Industrial Process Cooling Towers, 17729-17738 [06-3316]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 71, Number 67 (Friday, April 7, 2006)]
[Unknown Section]
[Pages 17729-17738]
From the Federal Register Online via the Government Printing 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 
https://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 https://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: mulrine.phil@epa.gov. 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: jenkins.scott@epa.gov.

SUPPLEMENTARY INFORMATION: Regulated Entities. The regulated categories 
and entities affected by the NESHAP include:

------------------------------------------------------------------------
                                                  Examples of regulated
            Category                  NAICS              code \1\
------------------------------------------------------------------------
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.
------------------------------------------------------------------------
\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: https://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 operat