health benefits from the reduction of non-hazardous air pollutants,
primarily PM, which the Agency is required to regulate under other
provisions of the CAA. One

commenter stated that for decades, the EPA set primary ambient air
quality standards that protect public health with an adequate margin of
safety, CAA section 109(b)(1), and set secondary standards that are
[sic] ``requisite to protect the public welfare from any known or
anticipated adverse effects associated with the presence of such air
pollutant in the ambient air,'' CAA 109(b)(2). The commenter notes that
even if EPA now views those past PM standards as inadequate, the EPA
has ongoing regulatory proceedings in which it can address any
perceived health concerns. The commenter concludes that regulation of
EGU HAP emissions under CAA section 112 is an unlawful way to address
those concerns.
    Response: The commenter is incorrect in its assertion that the
Agency has consistently concluded that HAP emissions from EGUs do not
present a hazard to public health. In the 2000 finding, the Agency
concluded that HAP emissions from coal- and oil-fired EGUs do pose a
hazard to public health and determined that it was appropriate and
necessary to regulate such units under CAA section 112. As a result of
that finding, the EPA added coal- and oil-fired EGUs to the CAA section
112(c) list of source categories for which emission standards are to be
established pursuant to CAA section 112(d). Further, in support of the
proposed rule, the EPA conducted additional extensive quantitative and
qualitative analyses, which confirm that it remains appropriate and
necessary to regulate EGUs under CAA section 112. Among other things,
those analyses demonstrate that emissions from coal- and oil-fired EGUs
continue to pose a hazard to public health. The commenter also fails to
note that the EPA found that HAP emissions from EGUs pose a hazard to
the environment as well.
    The commenter seems confused about the basis for the Agency's
appropriate and necessary finding because it maintains that the EPA
made the appropriate and necessary finding based on the health co-
benefits attributable to PM reductions that will be achieved as a
result of the Agency's regulation of HAP emissions from EGUs. Nowhere
in the May 2011 proposal does EPA state that it based the appropriate
and necessary finding on hazards to public health attributable to PM
emissions. The commenter's allegation lacks foundation. The appropriate
and necessary finding unmistakably focuses on the hazards to public
health and hazards to the environment associated with HAP emissions
from EGUs.
    Comment: One commenter stated that CAA section 112 required EPA to
make a risk-based determination in order to regulate HAP. According to
the commenter, the EPA may regulate substances ``reasonably * * *
anticipated to result in an increase in mortality or increase in
serious illness'' to a level that protects public health with an
``ample margin of safety.'' According to the commenter, the EPA has
regulated a number of HAP emitted from industrial source categories
other than EGUs.
    As for EGUs, according to the commenter, the EPA found that the
combustion of fossil fuels produces extremely small emissions of a
broad variety of substances that are present in trace amounts in fuels
and that are removed from the gas stream by control equipment installed
to satisfy other CAA requirements. The commenter stated that the EPA,
in past reviews, found that these HAP emissions did not pose hazards to
public health. See 48 FR 15076, 15085 (1983) (radionuclides). the
commenter further stated that ``[i]n the case of Hg specifically, the
EPA found that ``coal-fired power plants * * * do not emit mercury in
such quantities that they are likely to cause ambient mercury
concentration to exceed'' a level that ``will protect public health
with an ample margin of safety.'' 40 FR 48297-98 (October 19, 1975)
(Hg); 52 FR 8724, 8725 (March. 19, 1987) (reaffirming Hg conclusion).
    According to the commenter, in the late 1980s, the EPA was
concerned that its prior risk assessments of individual HAP emissions
from fossil-fuel-fired power plants may not reflect the total risks
posed by all HAP emitted by those sources. The commenter states that
the EPA modeled the risks posed by all HAP emitted by power plants
(very much like the analyses the Agency would conduct for the Utility
Study ten years later). The commenter asserts that the modeling again
failed to identify threats to public health that warranted regulation
under an ``ample margin of safety'' test.
    Response: The commenter's statements concerning the pre-1990 CAA
are not relevant to the current action. Congress enacted CAA section
112(n)(1) as part of the 1990 amendments to the Act. That provision
requires, among other things, that the Agency evaluate the hazards to
public health posed by HAP emissions from fossil-fuel fired EGUs. Had
Congress concluded, as commenter appears to assert, that HAP emissions
from EGUs did not pose a hazard to public health or the environment, it
defies reason that Congress would have required EPA to conduct the
three studies at issue in CAA section 112(n)(1) (titled ``Electric
utility steam generating units'') and regulate EGUs under section 112
if the Administrator determined in her discretion that it was
appropriate and necessary to do so. The Agency complied with the
statutory mandates in CAA section 112(n)(1) in conducting the studies
and reasonably exercised its discretion in making the appropriate and
necessary finding.
    We acknowledge that Congress treated radionuclide emissions from
EGUs differently. For radionuclides from EGUs (and certain other
sources), Congress included CAA section 112(q)(3), which authorizes but
does not require the Agency to maintain the regulations of
radionuclides in effect prior to the 1990 amendments. The fact that
Congress made an exception for radionuclides and no other HAP from EGUs
further demonstrates that the HAP-related actions EPA took with regard
to EGUs prior to the 1990 amendments to the CAA are not germane.
    As for the commenter's statements about Hg emissions from EGUs, we
find their conclusions wholly inconsistent with CAA section 112(n)(1).
That provision is titled ``Electric utility steam generating units,''
and it directs EPA to conduct two Hg-specific studies. See CAA sections
112(n)(1)(B) and 112(n)(1)(C). The commenter's suggestion that the EPA
could or should rely on assessments of Hg from EGUs conducted prior to
the 1990 amendments is not tenable.
    Finally, the commenter stated that the EPA conducted a risk
assessment of all HAP from EGUs prior to the 1990 amendments and that
the Agency did not identify any HAP that failed the ``ample margin of
safety'' test. The commenter did not cite the study or provide any
information to support the statements so we are unable to respond to
the alleged study directly; however, the risk assessments conducted in
support of the appropriate and necessary finding, as well as the 2000
finding, demonstrate that HAP emissions from EGUs pose hazards to
public health and the environment.
b. Interpretation of ``Appropriate'' and ``Necessary''
    Comment: One commenter stated that in the preamble to the proposed
rule, the EPA sets out its ``interpretation of the critical terms in
CAA section 112(n)(1),'' arguing that this latest interpretation is
``wholly consistent with the CAA'' and with the Agency's earlier ``2000
finding.'' See 76 FR 24976, 24986 (May 3, 2011). The commenter stated
that throughout the proposal EPA tries to suggest that it is returning
to

some earlier, ``correct'' interpretation of CAA section 112(n)(1) set
forth in its 2000 action. See, e.g., 76 FR 24989 (``The Agency's
interpretation of the term `appropriate' * * * is wholly consistent
with the Agency's appropriate finding in 2000''); id. at 24992 (``Our
interpretation of the necessary finding is reasonable and consistent
with the 2000 finding''). According to the commenter, the EPA did not
provide in 2000 any interpretation of what it now characterizes as the
``critical terms'' of section 112(n)(1). See, e.g., 70 FR 15999 n.13
(the ``2000 finding does not provide an interpretation of the phrase
`after imposition of the requirements of the Act' ''); id. at 16000/2
(in 2000, the EPA ``did not provide an interpretation of the term
`appropriate' ''); 76 FR 24992 (the ``Agency did not expressly
interpret the term necessary in the 2000 finding''). The commenter
believes that for that reason alone, it is impossible to credit EPA's
assertion that it ``appropriately concluded that it was appropriate and
necessary to regulate hazardous air pollutants * * * from EGUs'' in
2000, and that it is today merely ``confirm[ing] that finding and
conclud[ing] that it remains appropriate and necessary to regulate
these emissions.* * *'' \53\
---------------------------------------------------------------------------

    \53\ Id. at 24,977/3.
---------------------------------------------------------------------------

    Response: The commenter disagrees with certain statements in the
preamble to the proposed rule that provide that the Agency's
interpretation of CAA section 112(n)(1) is reasonable and consistent
with the 2000 finding. It is difficult to decipher the exact complaint
that the commenter has with EPA's proposed rule in this regard, but the
commenter does assert that ``the Agency did not provide in 2000 any
interpretation of what it now characterizes as the ``critical terms''
of CAA section 112(n)(1).'' The commenter's assertion lacks foundation.
Although the 2000 finding did not provide detailed interpretations of
the regulatory terms at issue, it discussed the types of considerations
relevant to the appropriate and necessary inquiry. For example, it is
clear that in 2000, the Agency was concerned with the then current
hazards to public health and the environment when assessing whether it
was appropriate to regulate EGUs under section 112.\54\ In addition,
when evaluating whether it was necessary to regulate utilities, the
Agency stated that it was necessary to regulate HAP emissions from U.S.
EGUs under section 112 because the implementation of the other
requirements of the Act would not adequately address the serious public
health and environmental hazards arising from HAP emissions from EGUs.
The Agency also specifically noted that ``section 112 is the authority
intended to address'' hazards to public health and the environment
posed by HAP emissions. Id.
---------------------------------------------------------------------------

    \54\ 65 FR 79830.
---------------------------------------------------------------------------

    The detailed interpretation set forth in the preamble to the
proposed rule is consistent with the 2000 finding, but EPA does not
assert that the interpretation is in any way necessary to support the
factual conclusions reached in the 2000 finding. Instead, we noted in
the preamble to the proposed rule that our interpretation is consistent
with the 2000 finding because in 2005 we interpreted the statute in a
manner that was not consistent with the 2000 finding. The commenter has
provided no legal support for its position that the Agency erred in
interpreting the statute in a manner that is consistent with a prior
factual finding.
    Comment: Several commenters assert that in the 1990 amendments to
the Clean Air Act, Congress directed the EPA to base its determination
regarding regulation of fossil-fuel-fired generating units on
consideration of any adverse public health effects identified in the
study mandated by the first sentence of section 112(n)(1)(A) and that
Congress did not dictate in section 112(n)(1)(A) that the EPA must
regulate electric utility steam generating units under section 112.
    According to the commenters the sponsor of the House bill that
became section 112(n)(1)(A) provides an explanation that contradicts
the EPA's approach to regulating EGUs:

    Pursuant to section 112(n), the Administrator may regulate
fossil fuel fired electric utility steam generating units only if
the studies described in section 112(n) clearly establish that
emissions of any pollutant, or aggregate of pollutants, from such
units cause a significant risk of serious adverse effects on the
public health. Thus, * * * he may regulate only those units that he
determines--after taking into account compliance with all provisions
of the act and any other Federal, State, or local regulation and
voluntary emission reductions--have been demonstrated to cause a
significant threat of serious adverse effects on the public health.

136 Cong. Rec. H12,934 (daily ed. Oct. 26, 1990) (statement of Rep.
Michael Oxley).

    The commenters stated that the EPA position is premised on the
assumption that ``regulation under section 112'' necessarily means
``regulation under 112(d)'' and falsely premised on the assumption that
source categories listed by operation of section 112(n)(1)(A) cannot be
regulated differently. The commenters conclude that the language of
section 112(n)(1)(a) reflects Congress' intent that ``regulation of HAP
from EGUs was not intended to operate under section 112(d) but was
instead intended to be tailored to the findings of the utility study
mandated by section 112(n)(1)(A).''
    Response: The commenters maintain that the Agency's interpretation
of CAA section 112(n)(1) is flawed in many respects. The primary
support for one commenter's arguments against EPA's interpretation,
including in the comment above, is legislative history in the form of
statements from one Congressman, Representative Oxley. The Supreme
Court has repeatedly stated that the statements of one legislator alone
should not be given much weight. See Brock v. Pierce County, 476 U.S.
253, 263 (1986) (finding that ``statements by individual legislators
should not be given controlling effect, but when they are consistent
with the statutory language and other legislative history, they provide
evidence of Congress' intent.'') (emphasis added) (citation omitted);
Garcia, et al., v. U.S., 469 U.S. 70, 78 (1984), citing Zuber v. Allen,
396 U.S. 168, 187 (1969) (reiterating its prior findings, the Court
indicated that isolated statements ``are `not impressive legislative
history.' ''); Weinberger, et al., v. Rossi et al., 456 U.S. 25, 35
(declining to make a ruling based on ``one isolated remark by a single
Senator''); Consumer Product Safety Comm., et al. v. GTE Sylvania,
Inc., et al., 447 U.S. 102, 117-118 (1980) (declining to give much
weight to isolated remarks of one Representative); Chrysler Corp. v.
Brown, et al., 441 U.S. 281, 311 (1979) (finding that ``[t]he remarks
of a single legislator, even the sponsor, are not controlling in
analyzing legislative history.''); Zuber, 396 U.S. at 186 (concluding
that ``[f]loor debates reflect at best the understanding of individual
Congressmen.''); and U.S. v. O'Brien, 391 U.S. 367, 384 (1968) (in
evaluating the statements of a handful of Congressmen, the Court
concluded that ``[w]hat motivates one legislator to make a speech about
a statute is not necessarily what motivates scores of others to enact
it. * * *.''). As these cases show, the Supreme Court does not give
weight to the statements of an individual legislator, except when the
statements are supported by other legislative history and the clear
intent of the statute. The commenters cited no case law that would
support reliance on such limited legislative history.
    The commenter has not cited any other legislative history to
support

Representative Oxley's statement, and the lack of additional support
makes the statement of little utility or import under the case law. In
fact, there does not appear to be anything in the House, Senate, or
Committee Reports that supports Oxley's statement. The lack of support
for Oxley's statement in the Committee Report is particularly telling
since, as the commenter notes, the House and Senate bills required
different approaches to regulating EGUs under section 112, with the
Senate bill requiring EGUs be regulated prior to the Utility Study. In
fact, legislative statements from Senator Durenberger, a supporter of
the Senate version, demonstrate that others would almost certainly not
have agreed with Oxley's interpretation. For example, Senator
Durenberger stated, ``It seems to me inequitable to impose a regulatory
regime on every industry in America and then exempt one category,
especially a category like power plants which are a significant part of
the air toxics problem.''
    Senator Durenberger discussed the negotiations with the
Administration and the industry push to avoid regulation, including
industry arguments for not regulating Hg from U.S. EGUs:

    The utility industry continued to adamantly oppose [regulation
under section 112]. First, they argued that mercury isn't much of an
environmental problem. But as the evidence mounted over the summer
and it became clear that mercury is a substantial threat to the
health of our lakes, rivers and estuaries and that power plants are
among the principal culprits, they changed their tactic. Now they
are arguing that mercury is a global problem so severe that just
cleaning up U.S. power plants won't make enough of a difference to
be worth it. They've gone from `we're not a problem' to `you can't
regulate us until you address the whole global problem.' Recasting
an issue that way is not new around here. So, it is not a surprise.
But it does suggest the direction in which this debate will be
heading in the next few years.

136 Cong. Rec. 36062 (October 27, 1990).

    Senator Durenberger also explained why the House version was
adopted:

    Given that a resolution of the difficult issues in the
conference were necessary to conclude work on this bill, the Senate
proposed to recede to the House provision which was taken from the
original administration bill. It provides for a 3-year study of
utility emissions followed by regulation to the extent that the
Administrator finds them necessary.

Id.

    Senator Durenberger's statements indicate that it is unlikely that
he would agree with Oxley's interpretation of CAA section 112(n)(1), a
provision that provides the Agency with considerable discretion, and
nothing indicates that others in the Senate (or for that matter anyone
else in the House) would agree with that interpretation. Given the
Supreme Court's views on the use of such limited legislative history,
the EPA reasonably declined to consider (or even discuss) the
legislative history in the preamble to the proposed rule and we believe
it would be improper to ascribe Representative Oxley's statements to
the entire Congress.
    Moreover, Representative Oxley's statement directly conflicts with
the statutory text. Representative Oxley stated that ``[the
Administrator may regulate only those units that he determines--after
taking into account compliance with all provisions of the act and any
other Federal, State, or local regulation and voluntary emission
reductions--have been demonstrated to cause a significant threat of
serious adverse effects on the public health.'' 136 Cong. Rec. H12934
(daily ed. Oct. 26, 1990), reprinted in 1 1990 Legis. Hist. at 1416-17
(emphasis added). However, the Utility Study required under CAA section
112(n)(1)(A) directs the Agency to consider the hazards to public
health reasonably anticipated to occur after ``imposition of the
requirements of [the Clean Air Act].'' EPA was not required to consider
state or local regulations or voluntary emission reduction programs in
the Utility Study, and that study is the only condition precedent to
making the appropriate and necessary finding.\55\
---------------------------------------------------------------------------

    \55\ In addition, the EPA only considered CAA requirements in
the Utility Study and this was the correct approach because Congress
knew how to require consideration of non-Federal requirements when
directing EPA to conduct a study or assessment. See CAA section
112(n)(5) (Congress required EPA to conduct an assessment of
hydrogen sulfide from oil and gas extraction activities and provided
that the assessment ``shall include review of existing State and
industry control standards, techniques and enforcement.'').
---------------------------------------------------------------------------

    The legislative history the commenters rely on is not controlling.
The Agency believes that it has reasonably interpreted section
112(n)(1)(A), for all the reasons described herein and in the proposal.
The commenters also cite Representative Oxley's statements as support
for alternative interpretations of CAA section 112(n)(1). We believe
that any arguments that rely on such limited legislative history are
without merit.
    Comment: One commenter stated that the EPA does acknowledge that,
in many significant respects, its new interpretation of CAA section
112(n)(1) ``differs from that set forth'' in the Agency's 2005
rulemaking, but argues that its change of position is permissible. See
76 FR 24988/1 (``[T]o the extent our interpretation differs from that
set forth in the 2005 Action, we explain the basis for that difference
and why the interpretation, as set forth in this preamble, is
reasonable.''). In support, commenters note that the EPA cites National
Cable & Telecommunication Ass'n v. Brand X Internet Services, 545 U.S.
967 (2005). The commenters agree that it is true that, in Brand X
Internet Services, the Supreme Court explained that, if an agency
``adequately explains the reasons for a reversal of policy,'' such
change is ``not invalidating,'' since the ``whole point of Chevron is
to leave the discretion provided by the ambiguities of a statute with
the implementing agency.'' 545 U.S. at 981 (internal quotations
omitted). The commenters maintain that all Brand X Internet Services
was saying is that ``[a]gency inconsistency is not a basis for
declining to analyze the agency's interpretation under the Chevron
framework.'' Id.
    According to the commenter, it is not enough that the EPA has
purported to ``explain'' why it has abandoned the interpretation of CAA
section 112(n)(1) adopted in 2005. The commenter states that under the
first step of Chevron, the Agency's latest interpretation must still be
consistent with congressional intent. See Chevron v. NRDC, 467 U.S. at
842-43. The commenters state that under the second step of Chevron, if
there is discretion for EPA to exercise in interpreting the ``critical
terms'' of CAA section 112(n)(1), the Agency must properly define the
range of that discretion and then act reasonably in exercising that
discretion. See Chevron, 467 U.S. at 843; see also Village of
Barrington, Ill. v. Surface Transportation Bd., No. 09-1002 (D.C. Cir.
Mar. 15, 2011).The commenters allege that the EPA failed to properly
define and exercise the scope of its discretion. In each instance, the
commenter maintains that the Agency has departed from the correct
interpretation of CAA section 112(n)(1) that it adopted in 2005,
seizing instead upon a new approach that is contrary to the plain
language of the CAA itself, as interpreted after considering the
statements of Representative Oxley.
    Response: The commenter appears to argue that the EPA's
interpretation of CAA section 112(n)(1) is not consistent with the
plain language of the statute, implying that the statute is clear and
must be evaluated under step one of Chevron. See Chevron v. NRDC, 467
U.S. 837 842-42 (1984) (finding that when the legislative intent is
clear no additional analysis is required).

However, as noted above, much of the commenter's argument that the
plain language of the statute precludes EPA's interpretation is based
on the unpersuasive legislative history discussed above. As explained
in the preamble to the proposed rule, the statute directs the Agency to
determine whether it is appropriate and necessary to regulate EGUs
under section 112. As the D.C. Circuit has held, the terms
``appropriate'' and ``necessary'' are very broad terms. Because these
terms are broad they are susceptible to different interpretations. We
believe we have reasonably interpreted the appropriate and necessary
language in section 112(n)(1)(A). To the extent that interpretation
differs from the one set forth in 2005, we have fully explained the
basis for such changes. See 76 FR 24986-24993 (setting forth the
Agency's interpretation of section 112(n)(1)).
    Furthermore, we properly considered the scope of our discretion in
interpreting the statute as explained in detail in the preamble to the
proposed rule. We believe the interpretation set forth in the preamble
to the proposed rule is consistent with the Act and, therefore, the
Agency should be afforded deference pursuant to National Cable &
Telecommunication Ass'n v. Brand X Internet Services, 545 U.S. 967
(2005).
    Comment: A number of commenters agreed with the Agency's
interpretation of section 112(n)(1) and the terms appropriate and
necessary. The commenters also agreed that the EPA's interpretation of
that provision was reasonable and consistent with the statute.
    Response: We agree with the commenters and appreciate their
support.
    Comment: One commenter asserts that the EPA's ultimate motivation
for rejecting its prior interpretation of CAA section 112(n)(1) and
embracing this flawed new approach is made clear from the very outset
of the proposal. According to the commenter, the EPA touts the fact
that ``one consequence'' of the MACT rule would be that the ``market
for electricity in the U.S. will be more level'' and ``no longer skewed
in favor of the higher polluting units that were exempted from the CAA
at its inception on Congress' assumption that their useful life was
near an end.'' See 76 FR 24979/2. The MACT rule would ``require
companies to make a decision--control HAP emissions from virtually
uncontrolled sources'' or else ``retire these sometimes 60 year old
units and shift their emphasis to more efficient, cleaner modern
methods of generation, including modern coal-fired generation.'' Id.
    The commenter stated that this remarkably forthright statement
establishes that the underlying basis for EPA's proposal to regulate
EGUs under CAA section 112 is not to address any ``hazards to public
health'' that might be attributed to the emission by EGUs of HAP listed
under CAA section 112(b). Rather, according to commenter, the EPA is
utilizing the regulation of EGUs under CAA section 112 as a means to an
entirely different end: To force the imposition of controls that will
also have the result of reducing non-HAP emissions (primarily PM) or
force the shutdown of those units for which the cost of such controls
would be prohibitive. At the same time, according to commenter, the EPA
tacitly acknowledges that it cannot hope to make out a case that the
regulation of EGU HAP emissions is ``appropriate and necessary'' within
the meaning of CAA section 112(n)(1). The commenter asserts that the
only HAP whose health-related benefits EPA quantifies is Hg. Elsewhere,
the commenter stated that the EPA contends there are ``additional
health and environmental effects'' attributable to HAP other than Hg,
but admits that it has ``not quantified'' those risks due supposedly to
``insufficient information.'' See 76 FR 24999/2. With respect to Hg the
commenter stated that the benefits are so questionable and miniscule,
some $4 million to $6 million (given a 3 percent discount rate), that
compared to the total social costs of the rule (i.e., nearly $11
billion) the rule cannot be justified were EPA properly to interpret
CAA section 112(n)(1) and undertake the sort of regulatory analysis
Congress intended. The commenter stated that the reason that the EPA
touts in this rulemaking the health benefits EPA attributes to the
reduction of non-hazardous air pollutants (again, primarily PM), the
regulation of which is authorized under provisions of the CAA apart
from CAA section 112, is to elide the inconvenient truth regarding the
truly trivial nature of the benefits attributable to HAP regulation
itself. The commenter concludes that the EPA distorts CAA section
112(n)(1)(A) ``beyond all recognition.''
    One commenter stated that the EPA is directed by CAA section
112(n)(1)(A) to study the ``hazards to public health anticipated to
occur as a result of emissions'' by EGUs of ``pollutants listed under
subsection (b) of this section''--i.e., HAP and HAP alone. Thereafter,
the EPA is authorized to regulate EGU HAP emissions if, and only if,
they determine that ``such regulation'' of HAP emissions is
``appropriate and necessary'' to address the ``hazards to public
health'' that may be attributable to HAP emissions. According to the
commenter, by contrast, in this rulemaking, the EPA has seized upon the
fact that the control of EGU HAP emissions will also control non-HAP
(such as PM), and then seeks to justify the regulation of HAP emissions
based almost entirely on the health benefits of the reductions in non-
HAP emissions that would be coincidentally achieved. The commenter
believes that this ``regulatory sleight-of-hand'' runs afoul of
congressional intent and is unlawful.
    Response: The commenter alleges that the health-related benefits to
regulating HAP emissions from EGUs are ``questionable and miniscule,''
and that the only real benefits stem from non-HAP emissions, such as
PM. The commenter also implies that regulation of HAP is nothing more
than a straw man and that the Agency's ultimate goal is to regulate
other pollutants, and specifically PM. These allegations are wholly
without merit. The Agency has conducted comprehensive technical
analyses that confirm that HAP emissions from EGUs pose a hazard to
public health. The analyses are discussed at length elsewhere in this
final rule, and a review of the proposed and final rules utterly
refutes commenter's assertion that PM reductions form the basis for the
appropriate and necessary finding. In addition, the commenter appears
to ignore the Agency's findings concerning the hazards to public health
and the environment posed by HAP emissions simply because the Agency is
not able to quantify many of the benefits associated with reductions of
HAP emissions from EGUs or because the estimated HAP benefits that are
quantified are small in relation to the co-benefits achieved through
reductions in non-HAP air pollutants, such as PM and SO2,
which are surrogates for certain HAP. The Agency is regulating EGUs
pursuant to section 112(d) for all of the reasons explained in the
preamble and discussed elsewhere in this response to comments. The
commenter fails to recognize that the statute neither requires a cost-
benefit analysis prior to finding it appropriate and necessary to
regulate EGUs, nor requires such analysis prior to setting emission
standards. Indeed, Congress expressly precluded consideration of costs
when setting MACT floors. As explained below, the EPA does not believe
that it is appropriate to consider costs when

determining whether to regulate EGUs under CAA section 112.
    Comment: One commenter stated that the EPA has ignored the language
and intent of CAA section 112(n)(1)(A), as interpreted based on
Representative Oxley's statements, and that the Agency's interpretation
of this provision violates step one of Chevron. Under Chevron where the
``intent of Congress is clear,'' that is the ``end of the matter,'' for
both the implementing agency and a reviewing court ``must give effect
to the unambiguously expressed intent of Congress.'' Chevron, 467 U.S.
at 842-43. The commenter asserts that the legislative history of CAA
section 112(n)(1)(A) ``sheds considerable light on Congress' unique
approach to regulation of EGUs under CAA Sec.  112.'' According to the
commenter, on April 3, 1990, the Senate passed S. 1630. The Senate bill
would have required EPA to list EGUs under CAA section 112(c) and to
regulate them under the MACT provisions of CAA section 112(d). See S.
1630 section 301, 3 1990 Legis. Hist. at 4407. Thereafter, the House of
Representatives passed a modified version of S. 1630 on May 23, 1990.
This House version substantially changed the provisions of CAA section
112 as they applied to EGUs. See 1 1990 Legis. Hist. at 572-73. The
House version was virtually identical to the current CAA section
112(n)(1)(A), and was ultimately adopted by the conference committee,
enacted by Congress and signed into law. According to the commenter,
Congress expressly rejected the ``list-under-(c)-and-regulate-under-
(d)'' approach that S. 1630 would have applied to EGUs, and that
Congress did choose to apply to other source categories. The commenter
stated that the EPA's interpretation that the Agency is ``required to
establish emission standards for EGUs consistent with the requirements
set forth in section 112(d)'' (Id. at 24,993/3) fails to take the
legislative history into account, and in a footnote, the commenter
states that the Agency erred by not addressing the legislative history
as it did in the 2005 action.
    Response: For the reasons stated above, we believe commenter's
reliance on the single statement of one legislator is flawed. In
addition, in a footnote the commenter stated that the EPA recognized
``that it had to address'' the legislative history in its 2005 action,
and that the EPA erred in this case because we did not address the
legislative history. The commenter cites no case law to support its
contention that an Agency must ``address'' unpersuasive legislative
history. Further, in the 2005 action, the EPA relegated to a footnote
the Oxley statement that commenter relies on so heavily even though the
statement supported the interpretation we provided in that rule. We
recognized then what the commenter fails to recognize now, which is
that the Agency cannot argue that the meaning of CAA section
112(n)(1)(A) is clear based on the statements of one legislator.
    Furthermore, the Agency's interpretation does not violate Chevron
Step 1. The terms ``appropriate'' and ``necessary'' are ambiguous. The
statements of a lone legislator do not transform those ambiguous words
into a Chevron Step 1 situation.
    Moreover, the commenter's assertion that Congress unambiguously
defined the factors to consider in making the appropriate determination
is without merit. We fully explain in the preamble to the proposed rule
the basis for the Agency's interpretation, and we are not revising that
interpretation based on the comments received.
    Finally, the EPA notes that the sentence concerning regulation
under CAA section 112(d) that the commenter quotes from the preamble
states, in full: ``Congress did not exempt EGUs from the other
requirements of section 112 and, once listed, the EPA is required to
establish emission standards for EGUs consistent with the requirements
set forth in section 112(d), as described above.'' 76 FR 24993
(emphasis added). The EPA discusses requirements to regulate section
112(c) listed sources under section 112(d) in response to other
comments.
c. Consideration of Both Environmental Effects and Health Effects From
Other Sources
    Comment: Several commenters stated that the EPA acts contrary to
congressional intent when the Agency considers itself ``thereby
authorized to consider `environmental effects' and the effects of HAP
emissions from non-EGU sources, in making its `appropriate and
necessary' finding under subparagraph (n)(1)(A).''
    Commenters assert that the EPA misreads CAA section 112(n)(1)(B)
and (C) to inject environmental effects in the CAA section 112(n)(1)(A)
determination. According to one commenter the plain language of CAA
section 112(n)(1) establishes that regulation of EGUs is to be
predicated solely on ``hazards to public health'' attributable to HAP
emissions. The legislative history providing that the EPA ``may
regulate [EGUs] only if the studies described in section 112(n) clearly
establish that emissions of any pollutant * * * from such units cause a
significant risk of serious adverse risk to the public health''
confirms that plain language. See Oxley Statement at 1416-17. The
commenter further stated that nothing on the face of CAA section
112(n)(1)(A) indicates that Congress intended that the EPA should (or
must) take into account any additional information that might be
developed through the other studies mentioned in subparagraphs
(n)(1)(B) and (C) (i.e., the Mercury Study \56\ and the NAS Study
\57\), such as HAP emissions from non-EGU sources. The commenter also
identified other provisions of section 112 that specifically require
consideration of environmental effects and states that Congress would
have requires such consideration in CAA section 112(n)(1) if it had
wanted EPA to consider environmental effects.
---------------------------------------------------------------------------

    \56\ U.S. EPA. 1997. Mercury Study Report to Congress. EPA-452/
R-97-003. December.
    \57\ NAS, 2000.
---------------------------------------------------------------------------

    The commenter makes a related assertion that the EPA acts contrary
to congressional intent by assuming authority to assess the ```hazard
to public health or the environment [from] HAP emissions from EGUs
alone' or the `result of HAP emissions from EGUs in conjunction with
HAP emissions from other sources''' (citing 76 FR at 24,988/1).
According to the commenter, the only evident basis for the Agency's
interpretation that, in making its ``appropriate and necessary''
finding, the EPA can (and should) take into account HAP emissions from
sources other than EGUs, is that the Mercury Study authorized by CAA
112(n)(1)(B) references ``mercury emissions from * * * municipal waste
combustion units, and other sources, including area sources,'' in
addition to EGUs. The commenter asserts, however, that subparagraph
(n)(1)(A) identifies the Utility Study as the sole study to inform
EPA's ``appropriate and necessary'' finding. The commenter states that
if Congress had intended that the EPA take into account information
developed through the Mercury Study, Congress ``would not have
specified that the EPA was to predicate its `appropriate and necessary'
finding on the `results of the study required by this subparagraph'
(n)(1)(A).''
    Commenter also cites to a number of other section 112 provisions
that expressly address environmental effects and the commenter states
the only conclusion to draw from the inclusion in those provisions and
the absence of such language in section 112(n)(1)(A) is that Congress
intended public health to be the only basis for the appropriate and
necessary finding.

    Response: The commenter again relies in part on the statements of
one legislator to attack EPA's reasoned interpretation of an ambiguous
statute. To the extent the commenter's arguments rely on this limited
evidence, we refer to the response above. As we stated above, CAA
section 112(n)(1) is an ambiguous statutory provision; thus, the EPA's
interpretation, not commenter's, is entitled to considerable deference
if it is a reasonable reading of the statute. Chevron, 467 U.S. at 843-
44. For the reasons described herein and in the proposal, we believe
that we have reasonably interpreted the statutory terms at issue here.
The Agency directs attention to section III.A. of the proposed rule,
which includes a thorough discussion of the Agency's interpretation of
the relevant statutory terms. To the extent the commenters disagree
with EPA's interpretations, the EPA refers back to its discussion in
the proposal and responds to the comments as follows.
    The commenter appears to maintain that the EPA must interpret the
scope of the appropriate and necessary finding solely in the context of
the CAA section 112(n)(1)(A) Utility Study, such that only hazards to
public health and only EGU HAP emissions may be considered. The
commenter incorrectly conflates the requirements for the Utility Study
with the requirement to regulate EGUs under CAA section 112 if EPA
determines it is appropriate and necessary to do so. The commenter
concedes that the Agency may consider information other than that
contained in the Utility Study, but only to the extent it relates
specifically to hazards to public health directly attributable to HAP
emissions from EGUs. We agree that we may consider additional
information other than that contained in the Utility Study, as we
stated in the preamble to the proposed rule, because courts do not
interpret phrases like ``after considering the results of'' in a manner
that precludes the consideration of other information. See United
States v. United Technologies Corp., 985 F.2d 1148, 1158 (2nd Cir.
1993) (``based upon'' does not mean ``solely); \58\ see also 76 FR
24988. We further explained in the preamble to the proposed rule that
it was reasonable to interpret the scope of the appropriate and
necessary finding in the context of all three studies required under
CAA section 112(n)(1) because the provision is title ``Electric utility
steam generating units.'' \59\ The commenter has provided little more
than unpersuasive legislative history to support its restrictive
interpretation of our authority. Id.
---------------------------------------------------------------------------

    \58\ Several commenters have taken issue with our citation to
United States v. United Technologies Corp. because the language at
issue in that case was ``based upon'' and the language of section
112(n)(1)(A) is ``after considering the results of.'' We believe
that, if anything, ``based upon'' is more prescriptive than ``after
considering the results of'' such that the case supports the
Agency's interpretation that additional information other than the
Utility Study may be considered in making the appropriate and
necessary finding.
    \59\ 76 FR 24986-87.
---------------------------------------------------------------------------

    The commenter also argues that the statute clearly prohibits the
Agency from considering adverse environmental effects or the cumulative
effects of HAP emissions from EGUs and other sources based on its claim
that the statute is clear when one properly considers the legislative
history. Again, the commenter has provided no support for its
contention other than the statements of one Representative and the
improper conflation of the CAA section 112(n)(1)(A) direction on the
conduct of the Utility Study and the appropriate and necessary finding.
Congress left it to the Agency to determine whether it is appropriate
and necessary to regulate EGUs under CAA section 112 and the statute
does not limit the Agency to considering only hazards to public health
and only harms directly and solely attributable to EGUs.
    The commenter stated that Congress specifically told EPA when it
wanted EPA to consider adverse environmental effects in CAA section 112
and cites to several provisions of the Act that require consideration
of adverse environmental effects. The commenter ignores CAA section
112(n)(1)(B), which directs the Agency to consider adverse
environmental effect. In any event, even were we to view section
112(n)(1)(A) in isolation, as the commenter suggests, we still maintain
that we can consider adverse environmental effects under 112(n)(1)(A).
Nothing in section 112(n)(1)(A) precludes consideration of
environmental effects. Congress required the Agency to assess whether
it is appropriate and necessary to regulate EGUs under section 112. We
believe that adverse environmental effects can be considered in the
appropriate analysis. Congress specifically directed the Agency to
consider adverse environmental effects when delisting source categories
pursuant to section 112(c)(9), and thus we believe it is reasonable to
consider such effects when determining whether it is appropriate to
regulate such units under section 112, especially given that Congress
did not limit our appropriate and necessary inquiry to the Utility
Study. See CAA section 112(c)(9)(B)(ii).
    Moreover, the other provisions of CAA section 112 that specifically
discuss environmental effects have purposes that are distinguishable
from CAA section 112(n)(1), and we do not believe one can reasonably
draw the conclusion that the commenter does when comparing those
provisions to CAA section 112(n)(1)(A). The lack of a requirement to
consider environmental effects in CAA section 112(n)(1)(A) does not
equate to a prohibition on the consideration of environmental effects
as the commenter concludes. The EPA maintains that it reasonably
concluded that we should protect against identified or potential
adverse environmental effects absent clear direction to the contrary.
    Concerning the consideration of the cumulative effect of HAP
emissions from EGUs and other sources, we provided a reasonable
interpretation of the statute and noted that our interpretation, unlike
commenters, does not ``ignore the manner in which public health and the
environment are affected by air pollution. An individual that suffers
adverse health effects as the result of the combined HAP emissions from
EGUs and other sources is harmed, irrespective of whether HAP emissions
from EGUs alone would cause the harm.'' \60\
---------------------------------------------------------------------------

    \60\ 76 FR 24988.
---------------------------------------------------------------------------

d. Finding for All HAP To Be Regulated
    Comment: Several commenters stated that for those EGU HAP for which
the Agency makes no CAA section 112(n)(1)(A) determination, their
regulation under CAA section 112 is not authorized. For example, one
commenter maintains that the Agency could regulate HAP emissions from
EGUs under CAA section 112(n). Accordingly, to the extent that the EPA
reads CAA section 112, as construed by National Lime Ass'n, as
compelling it to regulate all HAP emitted by EGUs, should the Agency
make an ``appropriate and necessary'' determination under CAA section
112(n)(1)(A) with respect to a single HAP (e.g., Hg), the EPA stands
poised to commit a fundamental legal error that will condemn the final
rule on review. Cf., e.g., PDK Laboratories, Inc., 362 F.3d at 797-98;
Holland v. Nat'l Mining Ass'n, 309 F.3d at 817 (where an agency applies
a Court of Appeals ``interpretation * * * because it believed that it
had no choice'' and that it ``was effectively `coerced' to do so,''
then the agency ``cannot be deemed to have exercised its reasoned
judgment'').
    Response: We do not agree with the commenter's assertion that
Congress intended EPA to regulate only those EGU HAP emissions for
which an appropriate and necessary finding is

made, and the commenter has cited no provision of the statute that
states a contrary position. The EPA reasonably concluded that we must
find it ``appropriate'' to regulate EGUs under CAA section 112 if we
determine that a single HAP emitted from EGUs poses a hazard to public
health or the environment. If we also find that regulation is
necessary, the Agency is authorized to list EGUs pursuant to CAA
section 112(c) because listing is the logical first step in regulating
source categories that satisfy the statutory criteria for listing under
the statutory framework of CAA section 112. See New Jersey, 517 F.3d at
582 (stating that ``[s]ection 112(n)(1) governs how the Administrator
decides whether to list EGUs. * * *''). As we noted in the preamble to
the proposed rule, D.C. Circuit precedent requires the Agency to
regulate all HAP from major sources of HAP emissions once a source
category is added to the list of categories under CAA section 112(c).
National Lime Ass'n v. EPA, 233 F.3d 625, 633 (D.C. Cir. 2000). 76 FR
24989.
    The commenter does not explain its issues with our interpretation
of how regulation under section 112 works--i.e. making a determination
that a source category should be listed under CAA section 112(c),
listing the source category under CAA section 112(c), regulating the
source category under CAA section 112(d), and conducting the residual
risk review for sources subject to MACT standards pursuant to CAA
section 112(f). Instead, it asserts that our decision is flawed because
the interpretation we provided does not account for all the
alternatives for regulating EGUs under section 112, and that we have
not properly exercised our discretion leading to a fatal flaw in our
rulemaking.
    The commenter also ignores the language of section 112(n)(1)(A). As
explained in the proposed rule, the use of the terms section,
subsection, and subparagraph in section 112(n)(1)(A) demonstrates that
Congress was consciously distinguishing the various provisions of
section 112 in directing EPA's action under section 112(n)(1)(A).
Congress directed the Agency to regulate utilities ``under this
section,'' not ``under this subparagraph,'' and accordingly EGUs should
be regulated under section 112 in the same manner as other categories
for which the statute requires regulation. Furthermore, the D.C.
Circuit Court found that section 112(n)(1) ``governs how the
Administrator decides whether to list EGUs'' and that once listed, EGUs
are subject to the requirements of section 112. New Jersey, 517 F.3d at
583. Indeed, the D.C. Circuit Court expressly noted that ``where
Congress wished to exempt EGUs from specific requirements of section
112, it said so explicitly,'' noting that ``section 112(c)(6) expressly
exempts EGUs from the strict deadlines imposed on other sources of
certain pollutants.'' Id. Congress did not exempt EGUs from the other
requirements of section 112, and once listed, the EPA is reasonably
regulating EGUs pursuant to the standard-setting provisions in section
112(d), as it does for all other listed source categories.
    The commenter provided no alternative theory for regulating EGUs
under CAA section 112, other than to state that the EPA could regulate
under CAA section 112(n)(1). However, even assuming for the sake of
argument, that we could issue standards pursuant to CAA section
112(n)(1), we would decline to do because there is nothing in section
112(n)(1)(A) that provides any guidance as to how such standards should
be developed. Any mechanism we devised, absent explicit statutory
support, would likely receive less deference than a CAA section 112(d)
standard issued in the same manner in which the Agency issues standards
for other listed source categories. We would also decline to establish
standards under section 112(n)(1) because Congress did provide a
mechanism under CAA sections 112(d) and (f) for establishing emission
standards for HAP emissions from stationary sources and it is
reasonable to use that mechanism to regulate HAP emissions from EGUs.
e. Considering Costs in Finding
    Comment: Several commenters assert that the EPA must consider costs
in assessing whether regulation of EGUs is appropriate under CAA
section 112(n)(1)(A). Commenters posit that the EPA's position that
``the term `appropriate' * * * does not allow for the consideration of
costs in assessing whether hazards * * * are reasonably anticipated to
occur based on EGU emissions,'' 76 FR at 24,989/1, does not withstand
scrutiny. According to the commenters, the treatment of ``costs'' under
section 112(c) does not support the Agency's position, and the process
by which sources may be ``delisted'' under section 112(c)(9), including
no consideration of costs, sheds no light on the circumstances under
which it may be ``appropriate'' to regulate EGUs under section
112(n)(1)(A).
    Commenters characterize as ``unintelligible'' the EPA's position
that it is ``reasonable to conclude that costs may not be considered in
determining whether to regulate EGUs'' when ``hazards to public health
and the environmental are at issue (citing 76 FR at 24989). ``Two
commenters stated that a natural reading of the term ``appropriate''
would include the consideration of costs. According to the commenters,
something may be found to be ``appropriate'' where it is ``specially
suitable,'' ``fit,'' or ``proper.'' See Webster's Third New
International Dictionary at 106 (1993). The term ``appropriate''
carries with it the connotation of something that is ``suitable or
proper in the circumstances.'' See New Oxford American Dictionary (2d
Ed. 2005). Considering the costs associated with undertaking a
particular action is inextricably linked with any determination as to
whether that action is ``specially suitable'' or ``proper in the
circumstances.'' One commenter notes that in 2005 (70 FR 15994, 16000;
March 29, 2005) the EPA used the dictionary definition of
``appropriate,'' as being ``especially suitable or compatible'' and
that it would be difficult to fathom how a regulatory program could be
either ``suitable'' or ``compatible'' for a given public health
objective without consideration of cost.
    One commenter asserts that on the face of CAA section 112(n)(1)(A),
it is clear that the EPA is expected to consider costs. According to
the commenter, that Congress intended that the EPA investigate and
consider ``alternative control strategies'' for emissions as part of
the section 112 (n)(1) Utility Study when making the ``appropriate and
necessary'' determination refutes the notion that the Agency can, and
indeed must, disregard the cost of regulation in making that
determination, because the cost of a given emission ``control
strategy'' is a central factor in any evaluation of ``alternative''
controls.
    Further, according to commenters, it is well-settled that CAA
regulatory provisions should be read with a presumption in favor of
considering costs (citing Michigan v. EPA, 213 F.3d 663, 678 (D.C. Cir.
2000)), and the legislative history of section 112(n)(1)(A) confirms
that Congress intended EPA to consider costs (citing Oxley Statement at
1417).
    Commenters also assert that the EPA falsely represents that it
``did not consider costs when making the ``appropriate'' determination
in the EPA's December 2000 notice (76 FR at 24,989/2).
    Response: The commenters first take issue with EPA's explanation of
why the Agency determined that costs should not be considered in making
the appropriate determination. What

commenters do not identify is an express statutory requirement that the
Agency consider costs in making the appropriate determination. Congress
treated the regulation of HAP emissions differently in the 1990 CAA
amendments because the Agency was not acting quickly enough to address
these air pollutants with the potential to adversely affect human
health and the environment. See New Jersey, 517 F.3d at 578.
Specifically, following the 1990 CAA amendments, the CAA required the
Agency to list source categories and nothing in the statute required us
to consider costs in those listing decision, and we have not done so
when listing other source categories. Thus, it is reasonable to make
the listing decision, including the appropriate determination, without
considering costs.
    The commenters next argue that the Agency is compelled by the
statute to consider costs based on a dictionary definition of
``appropriate'' and the CAA section 112(n)(1)(A) direction to consider
alternative control strategies for regulating HAP emissions in the
Utility Study.
    Concerning the definition of ``appropriate'', commenters stated:

    Not only is it ``reasonable'' for EPA to consider costs in
determining whether it is ``appropriate'' to regulate EGU HAP
emissions, a natural reading of the term indicates that excluding
the consideration of costs would be entirely unreasonable. Something
may be found to be ``appropriate'' where it is ``specially
suitable,'' ``fit,'' or ``proper.'' See Webster's Third New
International Dictionary at 106 (1993). The term ``appropriate''
carries with it the connotation of something that is ``suitable or
proper in the circumstances.'' See New Oxford American Dictionary
(2d Ed. 2005) at 76. Considering the costs associated with
undertaking a particular action is inextricably linked with any
determination as to whether that action is ``specially suitable'' or
``proper in the circumstances.''

    The EPA believes the definition of ``appropriate'' that the
commenters provide wholly support its interpretation and nothing about
the definition compels a consideration of costs. It is appropriate to
regulate EGUs under CAA section 112 because EPA has determined that HAP
emissions from EGUs pose hazards to public health and the environment,
and section 112 is ``specially suitable'' for regulating HAP emissions,
and Congress specifically designated CAA section 112 as the ``proper''
authority for regulating HAP emissions from stationary sources,
including EGUs. Section 112 of the CAA is ``suitable [and] proper in
the circumstances'' because EPA has identified a hazard to public
health and the environment from HAP emissions from EGUs and Congress
directed the Agency to regulate HAP emissions from EGUs under that
provision if we make such a finding. Cost does not have to be read into
the definition of ``appropriate'' as commenter suggests. In addition,
as stated elsewhere in response to comments, the Agency does not
consider costs in any listing or delisting determinations, and the EPA
maintains that it is reasonable to assess whether to list EGUs (i.e.
the appropriate and necessary finding) without considering costs.
    The commenters' argument that costs must be considered based on the
CAA section 112(n)(1)(A) requirement to ``develop and describe
alternative control strategies'' in the Utility Study is equally
flawed. The argument is flawed because Congress did not direct the
Agency to consider in the Utility Study the costs of the controls when
evaluating the alternative control strategies. In addition, the EPA did
not consider the costs of the alternative controls in the Utility
Study, as implied by the commenter. Thus, even viewing section
112(n)(1)(A) in isolation, there is nothing in that section that
compels EPA to consider costs. For the reasons described herein, we do
not believe that it is appropriate to consider costs in determining
whether to regulate EGUs under section 112.
    Additionally, one commenter attempts to refute EPA's statement in
the preamble to the proposed rule that the EPA did not consider costs
in the 2000 finding by pointing to the only two mentions of cost in
that notice. However, the EPA did not say that costs were not mentioned
in the 2000 finding and a review of the regulatory finding will show
that costs were not considered in the regulatory finding. 65 FR 79830
(December 20, 2000) (``Section III. What is EPA's Regulatory
Finding?'').
f. Considering Requirements of the CAA in ``Necessary''
    Comment: Several commenters disagree with EPA's position that it
need consider ``only those requirements that Congress directly imposed
on EGUs through the CAA as amended in 1990,'' for which ``EPA could
reasonably predict HAP emission reductions at the time of the Utility
Study.'' According to the commenters, the statutory language of CAA
section 112(n)(1) requires that the EPA consider the scope and effect
of EGU HAP emissions after the imposition of all of the
``requirements'' of the CAA, not just the Acid Rain program. The
commenter maintains that it would have been easy enough for Congress in
subparagraph 112(n)(1)(A) to specify ``after imposition of the
requirements of Title IV of this chapter,'' but Congress did not. The
commenters further add that the legislative history confirms that
Congress meant something much broader than that, providing that the EPA
is authorized to regulate EGUs under CAA section 112 only after
``taking into account compliance with all provisions of the act and any
other Federal, State, or local regulation and voluntary emission
reductions.'' The commenters stated that the CAA's ``requirements''
include the submission by states of ozone and fine PM attainment
demonstrations, as well as SIP provisions needed to reach attainment of
the NAAQS because such provisions could include controls on EGUs to
reduce SO2 and NOX, which controls could also
result in a reduction in Hg emissions.
    Response: The commenter's characterization of the facts is flawed
and its reliance on legislative history that is in direct conflict with
the express terms of the statute is unpersuasive.
    On the facts, the EPA explained in the preamble to the proposed
rule its interpretation of the phrase ``after imposition of the
requirements of [the Act]'' as it related to the conduct of the Utility
Study.\61\ We reasonably concluded that, since Congress only provided 3
years after enactment to conduct the study, the phrase referred to
requirements that were directly imposed on EGUs through the CAA
amendments and for which the Agency could reasonably predict co-benefit
HAP emission reductions. Id. The EPA did not state that the phrase only
applied to the Acid Rain program, as commenter asserts, and the Utility
Study in fact discussed other regulations, including the NSPS for EGUs
and revised NAAQS. With regard to the latter, the EPA ultimately
determined that it could not sufficiently quantify the reductions that
might be attributable to the NAAQS because states are tasked with
implementing those standards. See Utility Study, pages ES-25, 1-3, 2-
32. Conversely, commenter's position is that the EPA must consider
implementation of all the requirements of the CAA, but it does not
indicate how in conducting the Utility Study the Agency could have
possibly considered co-benefit HAP reductions attributable to all
future CAA requirements. The Agency appropriately considered the other
requirements of the Act in the Utility Study and considered those
requirements in determining that it was

necessary to regulate coal- and oil-fired EGUs in December 2000.
---------------------------------------------------------------------------

    \61\ 76 FR 24990.
---------------------------------------------------------------------------

    Although not required, the Agency in the preamble to the proposed
rule conducted further analyses in support of the 2000 finding. In
doing so, we considered a number of requirements that far exceed what
Congress contemplated when enacting CAA section 112(n)(1)(A)), and our
analyses still show that it remains necessary to regulate coal- and
oil-fired EGUs under section 112. 76 FR 24991.
    We maintain that we have reasonably interpreted the requirement to
consider the hazards to public health and the environment reasonably
anticipated to occur after imposition of the requirements of the Act as
explained in the preamble to the proposed rule.\62\ In addition, as
stated above, we also believe it would be reasonable to find it
necessary to regulate HAP emissions from EGUs based on our finding that
such emissions pose a hazard to public health and the environment today
without considering future reductions that we currently project to
occur as the result of imposition of CAA requirements that are not yet
effective (e.g., CSAPR).
---------------------------------------------------------------------------

    \62\ 76 FR 24990.
---------------------------------------------------------------------------

    Moreover, Representative Oxley's statement cited by the commenter
is not consistent with the express terms of CAA section 112(n)(1)(A) on
this issue. Representative Oxley stated that the EPA was to take ``into
account compliance with all the provisions of the act and any other
Federal, State, or local regulation and voluntary emission
reductions,'' but CAA section 112(n)(1)(A) directs the Agency to
consider ``imposition of the requirements of this chapter,'' which
means the CAA. The Agency reasonably focused on the requirements of the
Clean Air Act, which are federally enforceable, and declined to include
potential future reductions that may be attributable to voluntary
emission reduction programs or state and local regulations that have no
basis in the Clean Air Act and are not federally enforceable. In
addition to the statutory direction not to consider such requirements,
the EPA believes it is reasonable not to include potential reductions
attributable to such requirements because the Agency cannot assure that
such requirements and the attendant HAP reductions will remain absent
regulation under section 112. Finally, the commenter implies that EPA's
position is that the Agency will only consider requirements of the Act
that directly regulate HAP emissions. The EPA never stated or suggested
that interpretation and a fair reading of the proposed rule will
demonstrate that EPA considered requirements that achieve co-benefit
HAP emission reductions, for example the Transport Rule (known as
CSAPR).
    Comment: One commenter stated that, under CAA section 112,
regulating EGUs is permissible only insofar as it is focused, targeted,
and predicated on concrete findings by the Agency that such regulation
is indeed ``necessary.'' According to the commenter, the EPA construes
CAA section 112(n)(1)(A) as permitting it to find that it is
``necessary'' to regulate EGUs even where the Agency does not actually
know whether it is ``necessary'' to regulate EGUs. Citing the D.C.
Circuit, the EPA suggests that ```there are many situations in which
the use of the word `necessary,' in context, means something that is
done, regardless of whether it is indispensible,''' in order to
```achieve a particular end.''' 76 FR 24990, quoting Cellular
Telecommunications v. FCC, 330 F.3d 502, 510 (D.C. Cir. 2003). The
commenter stated that in the ``context'' of CAA section 112(n)(1)(A),
as informed by the relevant legislative history from Representative
Oxley, it is clear that regulation of EGU HAP emissions can be
considered ``necessary'' only if EPA were to ``clearly establish'' that
such regulation was effectively ``indispensible'' to address the
identified harm. As EPA concedes that it has made no such determination
here, its proposal is fatally flawed for that reason alone.
    The commenter further asserts that the EPA erred when it concluded
that it may `` `determine it is necessary to regulate under section
112' when the Agency is `uncertain whether imposition of the
requirements of the CAA will address the identified hazards''' (citing
76 FR at 24,991/3). According to the commenter, the EPA ``cannot take
refuge in its own `uncertainty' to support a finding that it is
`necessary' to regulate EGUs under section 112, and the Act precludes
the EPA from ```err[ing] on the side of regulation''' in face of
uncertainty (id.). The commenter also implies that the finding was
based on non-HAP emissions.
    Response: The commenter again relies on the legislative statements
of one Representative and asserts that the statements are controlling.
The EPA disagrees with commenter and maintains that its interpretation
of the term ``necessary'' is reasonable. 76 FR 24990-92 (Section
III.A.2.b of the preamble to the proposed rule contains the EPA's
interpretation of the term ``necessary''.) 76 FR 24990-92 (Section
III.A.2.b of the proposed rule contains EPA's interpretation of the
term ``necessary''.) The commenter also, in a footnote, implies that
EPA based the appropriate and necessary finding on non-HAP air
pollution. The commenter is wrong as explained in more detail above.
    As an initial matter, this comment is only addressing one aspect of
the Agency's interpretation of the term necessary. As EPA stated at
proposal:

    If we determine that the imposition of the requirements of the
CAA will not address the identified hazards, EPA must find it
necessary to regulate EGUs under section 112. Section 112 is the
authority Congress provided to address hazards to public health and
the environment posed by HAP emissions and section 112(n)(1)(A)
requires the Agency to regulate under section 112 if we find
regulation is ``appropriate and necessary.'' If we conclude that HAP
emissions from EGUs pose a hazard today, such that it is
appropriate, and we further conclude based on our scientific and
technical expertise that the identified hazards will not be resolved
through imposition of the requirements of the CAA, we believe there
is no justification in the statute to conclude that it is not
necessary to regulate EGUs under section 112.

76 FR 24991.

    The EPA has determined that the imposition of the requirements of
the CAA will not address the hazards to public health or hazards to the
environment that EPA has identified; therefore, it is necessary to
regulate EGUs under CAA section 112.
    The EPA further interpreted the statute to allow the Agency to find
that it is necessary to regulate EGUs under other circumstances, and it
is with one of our additional interpretations that commenter takes
issue. Specifically, the commenter argues that EPA's interpretation
authorizes the Agency to find it necessary to regulate EGUs when we are
uncertain it is necessary, but that misconstrues our interpretation and
the record. At proposal, the EPA stated:

    In addition, we may determine it is necessary to regulate under
section 112 even if we are uncertain whether the imposition of the
requirements of the CAA will address the identified hazards.
Congress left it to EPA to determine whether regulation of EGUs
under section 112 is necessary. We believe it is reasonable to err
on the side of regulation of such highly toxic pollutants in the
face of uncertainty. Further, if we are unsure whether the other
requirements of the CAA will address an identified hazard, it is
reasonable to exercise our discretion in a manner that assures
adequate protection of public health and the environment. Moreover,
we must be particularly mindful of CAA regulations we include in our
modeled estimates of future emissions if they are not

final or are still subject to judicial review ([e.g.], the Transport
Rule). If such rules are either not finalized or upheld by the
Courts, the level of risk would potentially increase.

Id.
    The CAA requires EPA to exercise its discretion in determining
whether regulation under section 112 is necessary, and the D.C. Circuit
has stated that ``there are many situations in which the use of the
word `necessary,' in context, means something that is done, regardless
of whether it is indispensible, to achieve a particular end.'' See
Cellular Telecommunications & Internet Association, et al. v. FCC, 330
F.3d 502, 510 (D.C. Cir. 2003). The EPA's interpretation of
``necessary'' is reasonable in the context of CAA section 112(n)(1)(A).
    The commenter stated that EPA concedes that the Agency has not
``clearly established'' that regulation of HAP emissions under CAA
section 112 is ``indispensible.'' The EPA has conceded nothing but,
more importantly, the supposed standard that the commenter presents for
evaluating whether it is necessary to regulate HAP emissions from EGUs
is not required by the statute. Even the limited legislative history on
which the commenter incorrectly relies does not espouse such a
standard. The commenter specifically takes issue with EPA's statement
that the Agency may find it is necessary to regulate EGUs under CAA
section 112 if we are ``uncertain whether imposition of the other
requirements of the CAA will sufficiently address the identified
hazards.'' 76 FR at 24990. The commenter has again misinterpreted the
Agency's position by stating that ``EPA construes CAA section
112(n)(1)(A) as permitting it to find that it is ``necessary'' to
regulate EGUs even where the Agency does not actually know whether it
is ``necessary'' to regulate EGUs.'' Instead, the EPA maintains that it
may be necessary to regulate EGUs under CAA section 112 if we identify
a hazard to public health or the environment that is appropriate to
regulate today and our projections into the future do not clearly
establish that the imposition of the requirements of the CAA will
address the identified hazard in the future. Making a prediction about
future emission reductions from a source category is difficult for
statutory provisions that do not mandate direct control of the given
source category or pollutants of concern. We maintain that erring on
the side of caution is appropriate when the protection of public health
and the environment from HAP emissions is not assured based on our
modeling of future emissions.
    Furthermore, as we stated in the preamble to the proposed rule, we
believe it would be reasonable to find it appropriate and necessary to
regulate EGUs under section 112 today based on a determination that HAP
emissions from EGUs pose a hazard to public health and the environment
without considering future HAP emission reductions. 76 FR 24991, n.14.
We maintain this is reasonable because ``Congress could not have
contemplated in 1990 that EPA would have failed in 2011 to have
regulated HAP emissions from EGU's where hazards to public health and
the environment remain.'' Id. The phrase ``after imposition of the
requirements of [the Act]'' as contemplated CAA section 112(n)(1)(A)
could be read to apply only to those requirements clearly and directly
applicable to EGUs under the 1990 CAA amendments, all of which have
been implemented and still hazards to public health and the environment
from HAP emissions from EGUs remain.
g. Listing EGUs Under 112
    Comment: One commenter stated that even if EPA were to establish
under CAA section 112(n)(1)(A) that it is ``appropriate and necessary''
to regulate HAP emissions from EGUs, regulating those emissions in the
form of a MACT standard established pursuant to CAA section 112(d) is
contrary to the plain language of the Act. According to the commenter,
if EPA proceeds to finalize the proposal and adopts such a standard,
the rule will for this reason alone be ``dead-on-arrival''. According
to the commenter, the EPA apparently believes that its only option in
regulating EGU HAP emissions is establishing a MACT standard under CAA
section 112(d). In the preamble to its proposal, the commenter states
that EPA contends that, ``once the appropriate and necessary finding is
made,'' EGUs are then ``subject to section 112 in the same manner as
other sources of HAP emissions''--i.e., by ``listing'' EGUs under CAA
section 112(c) and adopting a MACT standard under CAA section 112(d).
See 76 FR 24993/2 (emphasis added). The commenter further stated that,
given that Congress ``directed the Agency to regulate utilities `under
this section' [i.e., CAA section 112],'' EPA continues, it follows that
``EGUs should be regulated in the same manner as other categories for
which the statute requires regulation.'' Id. (emphasis added). The
commenter asserts that as EPA sees it, because ``Congress did not
exempt EGUs from the other requirements of section 112,'' once EGUs
were ``listed'' under CAA section 112(c), the Agency was ``required to
establish emission standards for EGUs consistent with the requirements
set forth in section 112(d).'' Id. at 24,993/3 (emphasis added).
    The commenter stated that, in support of this reading of the CAA,
the EPA invokes the decision of the U.S. Court of Appeals for the D.C.
Circuit in New Jersey v. EPA, 517 F.3d 574 (D.C. Cir. 2008). The
commenter further alleged that, according to EPA, the D.C. Circuit has
``already held that section 112(n)(1) `governs how the Administrator
decides whether to list EGUs.' '' See 76 FR 24993/2-3, quoting 517 F.3d
at 583. The commenter stated that EPA construes that holding as
indicating that, ``once listed, EGUs are subject to the requirements of
section 112''--including, the EPA presumes, CAA section 112(d). Id. The
commenter stated that elsewhere, the EPA construes CAA section
112(n)(1) (A) as ``govern[ing] how the Administrator decides whether to
list EGUs for regulation under section 112,'' and quotes the D.C.
Circuit's observation in New Jersey that ``Section 112(n)(1) governs
how the Administrator decides whether to list EGUs; it says nothing
about delisting EGUs.'' See 76 FR 24981/2, quoting 517 F.2d at 582.
    The commenter asserts that EPA misinterprets the ``under this
section'' language of CAA section 112(n)(1); overstates the
significance of the New Jersey decision; and, as a consequence,
misapprehends the scope of its own discretion to formulate regulatory
standards for EGUs under CAA section 112. In light of these errors, the
commenter maintains that EPA should withdraw the proposed MACT rule.
    One commenter stated that if Congress had intended that EPA
regulate EGU HAP emissions only through a MACT standard, Congress could
have--and presumably would have--directed the Agency to regulate EGU
emissions ``under CAA section 112(d).'' Thus, the commenter maintained
that EPA's authority to regulate EGU HAP emissions is not derived from
any particular subsection of CAA section 112. Rather, the commenter
stated that EPA is authorized to regulate ``under this section''--i.e.,
CAA section 112 generally--as may be ``appropriate and necessary.'' The
commenter stated that there is nothing on the face of CAA section
112(n)(1)(A) that specifies that regulation of EGUs must occur under
CAA section 112(d). To the contrary, according to the commenter, a
plain reading of CAA section 112(n)(1)(A), as interpreted based on the
Oxley statement, indicates that establishing a

MACT standard for EGUs under CAA section 112(d) is not what Congress
had in mind at all.
    Response: We do not agree with the commenter. The EPA interpreted
CAA section 112(n)(1)(A) in a manner that gives meaning to all the
words used in the provision. See NRDC v. EPA, 489 F.3d 1364, 1373 (D.C.
Cir. 2007) (admonishing EPA for an interpretation of CAA section
112(c)(9) that ignored certain words and the context in which they were
used. The Court stated that ``EPA's interpretation would make the words
redundant and one of them `mere surplusage,' which is inconsistent with
a court's duty to give meaning to each word used by Congress.'')
(citing TRW Inc. v. Andrews, 534 U.S. 19, 31, 122 S. Ct. 441, 151 L.
Ed. 2d 339 (2001)). Specifically, in the preamble to the proposed rule,
we stated:

    The statute directs the Agency to regulate EGUs under section
112 if the Agency finds such regulation is appropriate and
necessary. Once the appropriate and necessary finding is made, EGUs
are subject to section 112 in the same manner as other sources of
HAP emissions. Section 112(n)(1)(A) provision provides, in part,
that: `[t]he Administrator shall perform a study of the hazards to
public health reasonably anticipated to occur as a result of
emissions by electric utility steam generating units of pollutants
listed under subsection (b) of this section after imposition of the
requirements of this chapter. * * * The Administrator shall regulate
electric utility steam generating units under this section, if the
Administrator finds such regulation is appropriate and necessary
after considering the results of the study required by this
subparagraph.'' Emphasis added.

    In the first sentence, Congress described the study and directed
the Agency to evaluate the hazards to public health posed by HAP
emissions listed under subsection (b) (i.e., CAA section 112(b)). The
last sentence requires the Agency to regulate under this section (i.e.,
CAA section 112) if the Agency finds such regulation is appropriate and
necessary after considering the results of the study required by this
subparagraph (i.e., CAA section 112(n)(1)(A)). The use of the terms
``section'', ``subsection'', and ``subparagraph'' demonstrates that
Congress was consciously distinguishing the various provisions of CAA
section 112 in directing the conduct of the study and the manner in
which the Agency must regulate EGUs if the Agency finds it appropriate
and necessary to do so. Congress directed the Agency to regulate
utilities ``under this section,'' and accordingly EGUs should be
regulated in the same manner as other categories for which the statute
requires regulation. See 76 FR 24993.
    We maintain that our interpretation of the statute gives meaning to
all the words, and the commenter's interpretation does not give any
particular meaning to the requirement to ``regulate under this section
[112]''. The commenter is correct that Congress could have in CAA
section 112(n)(1)(A) directed EPA to regulate HAP from EGUs under CAA
section 112(d) after making the appropriate and necessary finding, but
the commenter presumes too much when it stated that Congress would have
directed the Agency to regulate HAP emissions from EGUs in such a
manner if that is what Congress wanted, simply by including the phrase
``regulate under this paragraph'' or ``regulate under this
subparagraph'' instead of directing the Agency to ``regulate under this
section''. It did not do so.
    As we explained in the section II.A. of the proposed rule, CAA
section 112 establishes a mechanism to list and regulate stationary
sources of HAP emissions. 76 FR 24980-81. Regulation under CAA section
112 generally requires listing under CAA section 112(c), regulation
under CAA section 112(d), and, for sources subjected to MACT standards,
residual risk regulations under CAA section 112(f) (as necessary to
protect human health and the environment with an ample margin of
safety). A determination that EGUs should be listed once the
prerequisite appropriate and necessary finding is made is wholly
consistent with the language of section 112(n)(1)(A), and listed
sources must be regulated under CAA section 112(d). See CAA section
112(c)(2); see also New Jersey, 517 F.3d at 583 (112(n)(1)(A) ``governs
how the Administrator decides whether to list EGUs'').
    As noted above, Congress used the terms section, subsection, and
subparagraph in section 112(n)(1)(A). The use of these three terms
demonstrates that Congress was consciously distinguishing between the
various provisions of section 112. Congress directed the Agency to
regulate utilities ``under this section,'' and accordingly EGUs should
be regulated in the same manner as other categories for which the
statute requires regulation.
    Furthermore, the flaws in the commenter's interpretation are
highlighted by other CAA section 112 provisions wherein Congress
provided specific direction as to the manner of regulation. For
example, CAA section 112(m)(6) requires the Administrator to determine
``whether the other provisions of this section [112] are adequate'' and
also indicates that ``[a]ny requirements promulgated pursuant to this
paragraph * * * shall only apply to the coastal waters of the States
which are subject to [section 328 of the CAA].'' (emphasis added).
    In addition, CAA section 112(n)(3) provides that when the Agency is
``promulgating any standard under this section [112] applicable to
publicly owned treatment works, the Administrator may provide for
control measures that include pretreatment of discharges causing
emissions of hazardous air pollutants and process or product
substitutions or limitations that may be effective in reducing such
emissions.'' Finally, CAA section 112(n)(5) directs the Agency to
assess hydrogen sulfide emissions from oil and gas extraction and
``develop and implement a control strategy for emissions of hydrogen
sulfide to protect human health and the environment * * * using
authorities under [the CAA] including [section 111] of this title and
this section [112].'' (emphasis added). We believe these provisions
provide ample evidence that Congress knew how to alter or caveat
regulation under CAA section 112 when that was its intent. For these
reasons, we believe commenter's argument is without merit.
    Comment: Two commenters stated that CAA section 112(n)(1)(A) does
not specify that regulation of EGUs must proceed under CAA section
112(d). According to the commenter, an argument could be made,
therefore, that the CAA accords EPA with the discretion to regulate
EGUs using strategies other than emission standards in CAA section
112(d). The commenters also state that section 112(n)(1)(A) of the CAA
requires that EPA ``develop and describe'' alternative control
strategies for emissions which may warrant regulation under CAA section
112. According to the commenters if Congress meant for EPA to have one
sole regulatory option, i.e., regulation of EGUs only under CAA section
112(d), then the development of alternative control strategies would be
rendered meaningless because under CAA section 112(d)(3), the EPA is
required to determine the level of control that is achieved by the best
performing existing units for which it has data and then to impose that
level of control on all existing units. The commenter further states
that the development of ``alternative control strategies'' has no role
to play in this process. One commenter does note that the consideration
of ``alternative'' controls becomes relevant, if at all, only in those
circumstances where EPA might seek to establish a ``Beyond-the-Floor''
MACT standard pursuant to CAA section 112(d)(2).

    Response: The commenters are correct that CAA section 112(n)(1)(A)
directed the Agency to develop and describe in the Utility Study report
to Congress alternative control strategies for HAP emissions from EGUs
that may warrant regulation in the Utility Study, but the commenters'
interpretation of and conclusion based on that language are both
factually and legally inaccurate.
    The commenters appear to interpret the word ``alternative control
strategies'' to mean something other than the traditional control
technologies and control measures that are used to control HAP
emissions from EGUs. We do not believe that is a reasonable
interpretation of the statute, and the Agency did not interpret the
statute in that manner when it conducted the Utility Study. In Chapter
13 of the Utility Study, the EPA considered a range of control measures
that would reduce the different types of HAP emitted from EGUs. http://www.epa.gov/ttn/atw/combust/utiltox/eurtc1.pdf. The EPA considered pre-
combustion controls such as coal washing, fuel switching, and
gasification; combustion controls such as boiler design; post-
combustion controls such as fabric filters, scrubbers, and carbon
absorption; and alternative controls strategies such as demand-side
management, energy conservation, and use of alternative fuels (e.g.,
biomass) or renewable energy. The options discussed in the Utility
Study for controlling HAP emissions from EGUs are almost universally
available to comply with a CAA section 112(d) standard.
    Given the manner in which the Agency conducted the Utility Study,
the EPA interpreted the statutory direction as a requirement to set
forth the potential alternative control options available to EGUs to
comply with CAA section 112 standards in the event the Agency
determined regulation under section 112 was appropriate and necessary.
The EPA's development and discussion in the Utility Study of
alternative control strategies for complying with the standards would
help prepare EGUs to comply with the standards if promulgated. Thus,
the EPA interpreted the direction to address control strategies in the
Utility Study as a request to identify the controls available to EGUs
for addressing HAP emissions, and such information would, of course, be
relevant if EPA determined that such emissions warranted regulation
under section 112.
    Furthermore, the EPA establishes CAA section 112(d) standards for
stationary sources and it is the responsibility of the sources to
comply with the standards using any mechanism available, including pre-
combustion and post-combustion measures. Also, the establishment of a
MACT standard under CAA section 112(d)(2) and (3) is a two-step
process. In the first step, the Agency establishes a floor based on the
performance of the best controlled unit or units. See CAA section
112(d)(3). In the second step, the Agency must consider additional
measures that may reduce HAP emissions and adopt such measures if
reasonable after considering costs and non-air quality health and
environmental effects. See CAA section 112(d)(2). Under the second
step, the Agency can consider any measure that reduces HAP emissions
even if no source in the category is employing the option under
consideration. So, even under the commenter's flawed interpretation of
``alternative control strategies'', the direction in CAA section
112(n)(1)(A) is not a ``pointless exercise'' for the development of CAA
section 112(d) standards as the Agency considers relevant technologies
and HAP emission reduction approaches in evaluating whether to set a
more stringent beyond the floor standard.
    Comment: One commenter points to CAA section 307(d)(1)(C) and notes
that CAA section 112(n) is listed among the provision for which the
rulemaking requirements of CAA 307(d) apply. Commenter maintains that
this inclusion creates an expectation under the statute that EPA may
establish regulatory standards under CAA 112(n). The commenter points
to CAA sections 112 (n)(1), (n)(3), and (n)(5) and states that those
provisions specifically discuss regulation under CAA section 112 and
that EPA must explain why CAA 307(d)(1)(C) states ``any regulation
under'' CAA 112(n) to defend regulation of utilities under section
112(d). The commenter then implies that EPA erred by not even
mentioning this provision at proposal.
    The commenter also takes issue with EPA's statement in the proposed
rule that ``use of the terms section, subsection, and subparagraph''
``demonstrates that Congress was consciously distinguishing the various
provisions of section 112 in directing the conduct of the study and the
manner in which the Agency must regulate EGUs,'' if EPA determines that
it is appropriate and necessary to regulate EGUs. See 76 FR at 24,993/
2.
    One commenter does not agree with the EPA's finding that the word
``subsection'' in the first sentence of CAA section 112(n)(1)(A)
demonstrates that Congress was consciously distinguishing between the
various provisions of CAA section 112 in directing the conduct of the
study and the manner in which the Agency must regulate EGUs,'' were the
EPA to ``find[ ] it appropriate and necessary to do so.'' See 76 FR
24993/2. According to the commenter, the only evident reason that the
word ``subsection'' is used in the first sentence of CAA section
112(n)(1)(A) is because the reference is made to the ``pollutants''
which the Utility Study is to address--i.e., the ``pollutants'' that
are emitted by EGUs and which are ``listed under subsection (b)'' of
CAA section 112. Similarly, the word ``subparagraph'' is used in the
last sentence of CAA section 112(n)(1)(A) to identify ``the study''
which the EPA is directed to undertake by subparagraph (A) of CAA
section 112(n)(1)--i.e., the Utility Study. That the last sentence of
subparagraph (n)(1)(A) also states that EPA ``shall regulate electric
utility steam generating units under this section'' does not even
imply--much less expressly communicate--that regulation ``under this
section'' must mean ``regulation under section 112(d).'' The commenter
stated that Congress was ``consciously distinguishing'' between the
``various provisions of section 112'' for the sake of clarity in the
drafting of CAA section 112(n).
    The commenter also asserts that the EPA mistakenly relies on
section 112(c)(6) when the EPA states that `` `where Congress wished to
exempt EGUs from specific requirements of section 112, it said so
explicitly. Congress did not exempt EGUs from the other requirements of
section 112,' '' and thus the Agency is `` `required to establish
emission standards for EGUs consistent with the requirements set forth
in section 112(d)' '' (citing 76 FR at 24,993 (internal quotation
omitted)).
    According to the commenter, nothing in section 112(c)(6) indicates
how (or even whether) EGU HAP emissions should be regulated under
section 112; paragraph (c)(6) serves only to reiterate that the
regulation of such emissions is to occur (if at all) as is provided by
section 112(n)(1). The commenter also asserts that the EPA mistakenly
relies on New Jersey. According to the commenter, the D.C. Circuit in
that case did not indicate that the language of section 112(c)(6)
should, or could, be construed to mean that EGUs must be regulated
under a MACT standard adopted pursuant to section 112(d).
    Response: The commenter makes a number of arguments that appear to
take issue with the EPA's determination that EGUs should be regulated
under CAA section 112(d) if the Agency determines that regulation of
HAP emissions from such units is appropriate and necessary.

The commenter implies that the EPA erred because alternative mechanisms
for regulation of EGUs under CAA section 112 might exist. We do not
agree.
    The commenter's argument that the EPA erred because we did not
explain why section CAA section 307(d)(1)(C) contemplates regulations
under CAA section 112(n) is without merit. It is correct that the
Agency believes EGUs should be regulated in the same manner as other
sources if the appropriate and necessary finding is made because of the
structure of CAA section 112. Nothing in CAA section 112(n)(1) requires
or implies that the Agency should or must establish standards for EGUs
under that provision. Furthermore, unlike CAA sections 112(n)(3) and
112(n)(5) that commenter cites, CAA section 112(n)(1)(A) does not
provide any guidance concerning the manner in which EPA is authorized
or required to regulate sources under CAA section 112. See CAA section
112(n)(3) (specifically authorizing identified control measures and
other requirements for consideration in issuing standards under CAA
section 112); see also CAA section 112(n)(5) (directing the Agency to
develop and implement a control strategy for emissions of hydrogen
sulfide using any authority available under the CAA, including sections
112 and 111, if regulation is appropriate). For these reasons, we
disagree that any error occurred because we did not specifically
discuss in this proposed rule whether we could or should regulate EGUs
under CAA section 112(n)(1) instead of CAA section 112(d).\63\ The
Agency validly listed EGUs in 2000 and listed sources must be regulated
pursuant to CAA section 112(d).
---------------------------------------------------------------------------

    \63\ We note that in our January 2004 proposed rule, we
solicited comment on whether section 112(n)(1)(A) provided
independent authority to regulate EGUs. We received several comments
on this issue, and we rejected the concept after reviewing the
comments and further considering the language of section
112(n)(1)(A) and the structure of section 112. As such, we proposed
and are finalizing that once the Agency determines that it is
appropriate and necessary to regulate EGUs under section 112, those
sources are listed pursuant to subsection 112(c), as we did in
December 2000, and the Agency must set standards for those sources
pursuant to section 112(d). See section 112(c) and (d)(1) (requiring
establishment of 112(d) standards for listed source categories).
---------------------------------------------------------------------------

    Even if we agreed that regulation under CAA section 112(n)(1) was a
viable option for EGUs, we would still have listed and regulated EGUs
like other sources because CAA section 112(d) provides a statutory
framework for regulating HAP emissions from sources and CAA section
112(n)(1) does not. We believe that even if CAA section 112(n)(1) were
available to regulate EGUs, there would be sufficient uncertainty about
the legal vulnerability of such an approach to caution against
employing it. This legal uncertainty would be particularly troubling in
light of the fact that we have identified hazards to public health and
the environment from HAP emissions from EGUs that warrant regulation,
and these regulations are long overdue.
    The commenter also takes issue with our statement in the preamble
to the proposed rule that the use of the words ``section'',
``subsection'', and ``subparagraph'' in CAA section 112(n)(1)(A)
``demonstrates that Congress was consciously distinguishing the various
provisions of section 112 in directing the conduct of the study and the
manner in which the Agency must regulate EGUs.'' See 76 FR 24993. The
commenter appears to make much of our use of the word ``must'' in that
sentence and also states that our interpretation of the significance of
the use of the three terms in CAA section 112(n)(1)(A) is flawed
because Congress only used the three terms for purposes of clarity. The
commenter is incorrect on both points. With respect to the commenter's
concern regarding the use of the word ``must'' in the sentence quoted
above, we note that in the next sentence we stated that ``Congress
directed the Agency to regulate utilities `under this section,' and
accordingly EGUs should be regulated in the same manner as other
categories for which the statute requires regulation.'' Id. (emphasis
added). We were not foreclosing the possibility of any alternative
interpretation and our use of the term ``must'' should not detract from
the point we were trying to make. Specifically, we believe that
Congress would have directed us to regulate EGUs under CAA section
112(n)(1)(A) if that was its intent and, absent that mandate, the
better reading of the statute is the one provided in the preamble to
the proposed rule, which is that EGUs should be listed pursuant to CAA
section 112(c) and subject to CAA section 112(d) emission standards.
    The commenter also stated that the EPA relied on CAA section
112(c)(6) to support a conclusion that EGUs must be regulated under CAA
section 112(d). The commenter takes the EPA's statements out of
context. The statement in whole read:

    Furthermore, the D.C. Circuit Court has already held that
section 112(n)(1) ``governs how the Administrator decides whether to
list EGUs'' and that once listed, EGUs are subject to the
requirements of CAA section 112. New Jersey, 517 F.3d at 583.
Indeed, the D.C. Circuit Court expressly noted that ``where Congress
wished to exempt EGUs from specific requirements of section 112, it
said so explicitly,'' noting that ``section 112(c)(6) expressly
exempts EGUs from the strict deadlines imposed on other sources of
certain pollutants.'' Id. Congress did not exempt EGUs from the
other requirements of CAA section 112, and once listed, EPA is
required to establish emission standards for EGUs consistent with
the requirements set forth in CAA section 112(d), as described
below. See 76 FR 24993.

    As can be seen from this passage, the Court cited section 112(c)(6)
as an example of Congress' intent regarding regulating EGUs under CAA
section 112. The commenter cited the last clause of the last sentence
of the paragraph quoted above without including the prefatory clause
``once listed,'' and, without that clause, the statement is not fairly
characterized. The point the EPA was making in that paragraph is that
EGUs are a listed source category and listed sources must be regulated
under CAA section 112(d) unless the EPA delists the source category.
    Comment: One commenter stated that EPA overstates the significance
of the D.C. Circuit's holding in New Jersey by suggesting that the
decision mandates EGU regulation under CAA section 112(d) because EGUs
``remain listed'' under CAA section 112(c), See New Jersey, 517 F.3d at
582. According to the commenter, the court declined to address the
lawfulness of EPA's having ``listed'' EGUs under CAA section 112(c),
leaving that matter to be decided if and when EPA adopted standards for
EGUs under CAA section 112. Nowhere in the decision did the D.C.
Circuit indicate that EPA must regulate EGUs under CAA section 112(d).
    According to the commenter, the EPA must consider both whether the
regulation of EGUs is ``appropriate and necessary'' under section
112(n)(1) and address anew whether the Agency is authorized by section
112 to list EGUs under section 112(c) at all. The commenter asserts
that on the face of the proposal, the EPA has not revisited the
question whether the ``listing'' of EGUs under section 112(c) is
consistent with congressional intent.
    Response: The commenter's arguments are circular and it is
difficult to fully determine exactly what its issue is with EPA's
listing; however, it appears that the commenter believes that EPA
incorrectly relied on the New Jersey decision to justify the listing of
EGUs. The commenter also appears to argue that the Agency has never
explained why it has the authority to list EGUs at all. We disagree.
    As stated in the preamble to the proposed rule, CAA section
112(n)(1)(A)

requires EPA to conduct a study of HAP emissions from EGUs and regulate
EGUs under CAA section 112 if we determine that regulation is
appropriate and necessary, after considering the results of the study.
76 FR 24981, 24986, and 24998. The only condition precedent to
regulating EGUs under CAA section 112 is a finding that such regulation
is appropriate and necessary (after conducting and considering the
Utility Study), and once that finding is made the Agency has the
authority to list EGUs under CAA section 112(c) as the first step in
the process of establishing regulations under section 112. The D.C.
Circuit agrees with that interpretation of the statute as evidenced by
its statement in New Jersey that ``section 112(n)(1)(A) governs how the
Administrator decides whether to list EGUs for regulation under section
112,'' 517 F.3d at 582, and the Court's statement directly contradicts
the commenter's position.
    The EPA did not rely on the New Jersey decision to justify the
appropriate and necessary finding as the commenter suggests. We based
the finding in 2000 on the extensive information available to the
Agency at the time, and we confirmed the finding in the preamble to the
proposed rule based on new information. The commenter had ample
opportunity to comment on the appropriate and necessary finding, and it
may challenge the basis of the listing (i.e. the appropriate and
necessary finding) when EPA issues the final standards.
    Comment: One commenter believes that the D.C. Circuit will condemn
the final rule as a result of EPA's ``misapprehension'' that upon
making an ``appropriate and necessary'' finding, the Agency is
compelled by the CAA to adopt a regulatory standard for EGUs under CAA
section 112(d). According to the commenter, a regulation will be
invalid if the regulation `` `was not based on the [agency's] own
judgment' '' but `` `rather on the unjustified assumption that it was
Congress' judgment that such [a regulation] is desirable' or
required.'' See Transitional Hospitals Corp. v. Shalala, 222 F.3d 1019,
1029 (D.C. Cir. 2000), quoting Prill v. NLRB, 755 F.2d 941, 948 (D.C.
Cir. 1985). The commenter further notes that the D.C. Circuit has held
that, where an agency wrongly construes a judicial decision as
compelling a particular statutory interpretation, and thereby unduly
limits the scope of its own discretion, the agency's action cannot be
sustained. See, e.g., Phillips Petroleum Co. v. FERC, 792 F.2d 1165,
1171 (D.C. Cir. 1986). The commenter believes the rule is bound to be
rejected and that the EPA should ``reconsider the legal interpretations
on which it purports to base its rule.''
    Response: We do not agree that we have improperly interpreted the
statute as limiting our discretion in the manner suggested by the
commenter. The commenter makes only one specific allegation in this
comment and that concerns the Agency's conclusion that it must
establish CAA section 112(d) standards for EGUs in light of the New
Jersey decision. The commenter does not explain why that conclusion is
incorrect. As we state above and in the preamble to the proposed rule,
because EGUs are a CAA section 112(c) listed source category, the
Agency must establish CAA section 112(d) standards or delist EGUs
pursuant to CAA section 112(c)(9). See New Jersey, 517 F.3d at 582-83
(holding that EGUs remain listed under section 112(c)); see also CAA
section 112(c)(2) (requiring the Agency to ``establish emission
standards under subsection [112] (d)'' for listed source categories and
subcategories); 76 FR 24998-99. We concluded in the preamble to the
proposed rule that we could not delist EGUs because our appropriate and
necessary analysis showed that EGUs did not satisfy the CAA section
112(c)(9)(B)(i) delisting criteria. Id. We did not address in the
preamble to the proposed rule whether EGUs satisfied the CAA section
112(c)(9)(B)(ii) criteria because EGUs failed the first prong of the
delisting provisions. Id. We reach the same conclusion in the final
rule and also address the delisting petition submitted by this
commenter. Because we cannot delist EGUs, we must regulate them under
CAA section 112(d). The commenter has provided no legitimate argument
to rebut this conclusion. See also previous responses regarding
regulation under section 112(n)(1)(A).
    Comment: One commenter alleges that EPA impermissibly relied on CAA
section 112(c)(9) to interpret ``hazards to public health'', and argues
that the ``residual risk'' provisions in CAA section 112(f)(2) are more
appropriate for the establishment of standards for EGUs. The commenter
stated that by using CAA section 112(c)(9)(B)(i) in defining ``hazards
to public health'', the Agency has seized on the one interpretation of
the phrase that is surely contrary to congressional intent and, thus,
falls outside the permissible range of its interpretative discretion.
The commenter maintains that the ``delisting'' criteria of CAA section
112(c)(9) are simply irrelevant to the decision whether EGU HAP
emissions will present any ``hazards to public health'' sufficient to
warrant regulation of those emissions under CAA section 112.
    The commenter also argues that Congress intended that EGUs be
treated differently from all other ``major sources'' to which the
``delisting'' provisions of CAA section 112(c)(9), and the standard-
setting provisions of CAA section 112(d) necessarily and automatically
apply. Therefore, according to the commenter, the EPA's proposal to
utilize the criteria of CAA section 112(c)(9) to inform its findings
under CAA section 112(n)(1)(A) treats EGUs exactly the same as all
other major source categories, is contrary to congressional intent, and
thus unlawful. The commenter goes on to state that in exercising its
discretion to define ``hazards to public health'' as the phrase is used
in CAA section 112(n)(1)(A), the EPA would be better served to consider
the ``residual health risk'' provisions of CAA section 112(f)(2). Those
provisions provide a better analogy to the establishment of standards
for EGUs under CAA section 112 than do the ``de-listing'' criteria of
CAA section 112(c)(9).
    The commenter believes the category-specific criteria of paragraph
(c)(9) are a poor fit for an evaluation of ``hazards to public health''
that should reasonably include such factors as the affected population,
the characteristics of exposure, the nature of the health effects, and
the uncertainties associated with the data. The commenter states that,
while CAA section 112(n)(1)(A) does not expressly include any
requirement that EGU emissions be regulated with an ``ample margin of
safety,'' that standard is more appropriate than the ``one-in-a-
million'' cancer risk standard of CAA section 112(c)(9)(B)(i) that EPA
proposes to employ.
    Response: The commenter acknowledges that EPA has broad discretion
to interpret the phrase ``hazard to public health'' but argues that the
one thing we cannot do is use the CAA section 112(c)(9)(B) delisting
provisions as a benchmark in making that interpretation. The commenter
asserts that the use of the delisting standard is clearly contrary to
Congressional intent but it does not provide any substantive rebuttal
to our conclusion that the CAA section 112(c)(9) standards reflects the
level of hazard which Congress concluded warranted continued
regulation. Instead, the commenter reverted to its argument that the
statute treated EGUs differently. The EPA views the disparate treatment
of EGUs in a different light than commenter. While it is true that
Congress established a different

statutory provision governing whether to add EGUs as a regulated source
category under section 112, we do not interpret CAA section
112(n)(1)(A) as providing Congressional license to ignore risks that
Congress determined warranted regulation for all other source
categories. Because CAA section 112(c)(9) defines that level of risk,
it is reasonable to consider it when evaluating whether EGU HAP
emissions pose hazards to public health.
    The commenter also suggests that the ``ample margin of safety
standard'' of CAA section 112(f)(2) is a better fit than the one-in-a-
million standard set forth in CAA section 112(c)(9)(B)(1) for
evaluating hazards to public health. The commenter asserts that an
evaluation of ``hazards to public health'' should include such factors
as the affected population, the characteristics of exposure, the nature
of the health effects, and the uncertainties associated with the data.
However, the EPA did not rely solely on the delisting provisions for
evaluating hazards to public health as commenter suggests. In fact, the
EPA considered all of the factors the commenter suggests in making our
finding.\64\ Thus, we decline to adjust our approach to evaluating
hazards to public health and the environment based on the comments.
---------------------------------------------------------------------------

    \64\ 76 FR 24992.
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h. 2000 Finding (and 2005 Delisting)
    Comment: Several commenters generally support EPA's 2000 finding
that regulating HAP emissions from EGUs under CAA section 112 is
``appropriate and necessary.'' According to the commenters, the 2000
finding was proper under the CAA and within EPA's discretion, well-
supported based on sound science available to the Agency at the time on
the harm from HAP emitted by EGUs, and no additional information makes
the finding invalid. Several commenters cited the conclusions of the
Utility Study \65\ and Mercury Study,\66\ which they assert supported
the finding and satisfied the only prerequisite for the finding. One
commenter specifically asserted that the 2000 finding was well-
supported by the Utility Study's conclusions that (1) there was a link
between anthropogenic Hg emissions and MeHg found in freshwater fish,
(2) Hg emissions from coal-fired utilities were expected to worsen by
2010, and (3) MeHg in fish presents a threat to public health from fish
consumption. One commenter noted that the CAA does not require a
conclusive link between HAP emissions and harm. One commenter stated
that the CAA grants the Administrator discretion in her finding, and
that discretionary decision should not be overly scrutinized, citing
court opinion.\67\ In support of the finding, one commenter stated that
it would not make sense for Congress to limit HAP emissions from small
businesses such as dry cleaners but to exempt U.S. EGUs, which are the
largest sources of many HAP emissions. One commenter agreed that
finding was further supported because numerous control options were
available to reduce HAP emissions. One commenter agreed with the 2000
finding that the Agency lacked sufficient evidence to conclude that
non-Hg HAP from EGUs posed no hazard.
---------------------------------------------------------------------------

    \65\ U.S. EPA 1998. Study of Hazardous Air Pollutant Emissions
from Electric Utility Steam Generating Units--Final Report to
Congress. EPA-453/R-98-004a. February.
    \66\ U.S. EPA, 1997.
    \67\ ``Where a statute is precautionary in nature, the evidence
difficult to come by, uncertain, or conflicting because it is on the
frontiers of scientific knowledge, the regulations designed to
protect the public health, and the decision that of an expert
administrator, [courts] will not demand rigorous step-by-step proof
of cause and effect.'' Ethyl Corp. v. EPA, 541 F.2d 1, 28 (Ct. App.
D.C. Circ. 1978).
---------------------------------------------------------------------------

    The commenters who generally supported the 2000 finding also
commented on specific aspects of the finding. Several commenters
asserted that while the evidence on Hg alone supports the finding, the
potential harm from non-Hg HAP further supported the 2000 finding.
Several commenters noted that new science continues to support the 2000
finding. Several commenters also stated that the ``appropriate''
finding was further supported because numerous control options were
available at the time of the finding that would reduce HAP emissions.
One commenter concurred with EPA that regulating natural gas-fired EGUs
was not appropriate and necessary because the impacts due to HAP
emissions from such units are negligible based on the results of the
Utility Study.
    Several commenters addressed the 2005 reversal of the 2000 finding.
Several commenters specifically supported the vacatur of the 2005
action. Other commenters asserted that the 2005 action was proper, and
that EPA reverted back to the 2000 finding in the proposed rule without
adequate explanation or support. Several commenters cited the 2005
action as invalidating the 2000 finding, specifically noting that EPA
concluded that ``no hazards to public health'' remained after
accounting for emission reductions under CAIR. These commenters assert
that EPA's current position is illegal because EPA took the exact
opposite position on the interpretation of the term ``necessary'' in
its 2005 reversal, and, thus, deserves no judicial deference. One
commenter stated that in 2005 EPA recognized the potential for
excessive regulation created by CAA section 112 and determined that the
2000 finding lacked foundation.
    Several commenters generally disagreed with the 2000 finding, with
two commenters stating that EPA did not have a rational justification
for it and another claiming that it was fraught with misinformation and
overestimating assumptions. One commenter claimed that EPA did not
explain the terms ``appropriate'' and ``necessary'' in the 2000 finding
and that the emission control analysis was inadequate. Two commenters
stated that the 2000 finding was based on data that was more than 10
years old, which causes serious concern regarding the validity of the
findings because technology, the regulatory environment, and the
economic climate have evolved. Furthermore, because the Utility Report
underestimated emissions controls that EGUs would install by 2010 and
additional controls that would be later required by the CSAPR, the
basis for EPA's 2000 finding has changed. Several commenters stated
that a ``plausible link'' between anthropogenic Hg and MeHg in fish is
not an adequate reason for the 2000 finding. Several commenters claim
that EPA only identified health concerns for Hg (and potentially Ni)
but not other HAP from coal-fired EGUs in the 2000 finding, and, thus,
cannot regulate HAP other than Hg because the 2000 finding authorizes
only the regulation of Hg. One commenter questioned the Hg emissions
underlying the 2000 finding, specifically the fraction of total
deposition attributable to U.S. EGUS and the fact that EPA projected an
increase in U.S. EGU emissions from 1990 to 2010 though emissions
actually declined.
    Several commenters raised procedural issues related to the 2000
finding. Several commenters stated that the 2000 finding failed to
provide public notice and comment. According to the commenters, the CAA
requires that any decision made under CAA section 112(n) must go
through public notice and comment. The commenters further stated that
the failure to provide public notice and comment means that this MACT
is outside EPA's statutory authority. One commenter stated that because
the 2000 finding was never ``fully ventilated'' in front of the D.C.
Circuit, the EPA's authority to regulate EGUs under CAA section 112(d)
is directly at issue. The commenters claim that specific issues did not
undergo

public notice and comment, including least-cost regulatory options, the
impact of regulation on electricity reliability, and EPA's
interpretation of the requirements under CAA section 112(n)(1)(A). One
commenter claims that EPA attempted to provide after-the-fact support
for its 2000 finding with new legal analysis and new factual
information, contrary to New Jersey v. EPA that held that EPA may not
revisit its 2000 finding except through delisting under CAA section
112(c)(9). One commenter stated that EPA's 2000 finding should be
reviewed when EPA issues the actual NESHAP.\68\ One commenter stated
that the 2000 finding ignored EO 12866.
---------------------------------------------------------------------------

    \68\ See UARG v. EPA, 2001 WL 936363, No. 01-1074 (D.C. Cir.
July 26, 2001).
---------------------------------------------------------------------------

    Response: EPA agrees with the commenters that the 2000 finding was
reasonable and disagrees with the commenters asserting that the 2000
finding was unreasonable or failed to follow proper procedural
requirements.
    The EPA agrees that reviewing courts defer to the reasoned
scientific and technical decisions of an Agency charged with
implementing complex statutory provisions such as those at issue in
this case. As EPA stated in the preamble to the proposed rule, the EPA
maintains that the 2000 finding was reasonable and based on well-
supported evidence available at the time, including the Utility Study,
the Mercury Study,\69\ and the NAS study,\70\ which all showed the
hazards to public health and the environment from HAP emitted from
EGUs. New technical analyses conducted by EPA confirm that it remains
appropriate and necessary to regulate HAP emissions from EGUs.
Furthermore, the EPA agrees with the commenters on several points
raised, specifically that EGUs were and remain the largest
anthropogenic source of several HAP in the U.S., that risk assessments
supporting the 2000 finding indicated potential concern for several
non-Hg HAP, and that several available control options would
effectively reduce HAP emissions from U.S. EGUs.
---------------------------------------------------------------------------

    \69\ U.S. EPA, 1997.
    \70\ NAS, 2000.
---------------------------------------------------------------------------

    The EPA agrees with the commenters that Congress did not exempt
EGUs from section 112(d) HAP emission limits while simultaneously
limiting emissions at other sources with less HAP emissions. Congress
simply provided EPA with a separate path for listing EGUs by requiring
that the Agency evaluate HAP emissions from EGUs and determine whether
regulation under CAA section 112 was appropriate and necessary. Since
1990, the EPA has promulgated regulations requiring the use of
available control technology and other practices to reduce HAP
emissions for more than 170 source categories. U.S. EGUs are the most
significant source of HAP in the country that remains unaddressed by
Congress's air toxics program. The EPA listed EGUs in 2000 because the
considerable amount of available data supported the conclusion that
regulation of EGUs under CAA section 112 was appropriate and necessary.
That finding was valid at the time, and EPA reasonably added EGUs to
the CAA section 112(c) list of sources that must be regulated under CAA
section 112.
    The EPA acknowledges that we did not expressly define the terms
appropriate and necessary in the 2000 finding, but the finding is
instructive in that it shows that EPA considered whether HAP emissions
from EGUs posed a hazard to public health and the environment and
whether there were control strategies available to reduce HAP emissions
from EGUs when determining whether it was appropriate to regulated
EGUs.\71\ When concluding it was necessary, the Agency stated that
imposition of the requirements of the Act would not address the
identified hazards to public health or environment from HAP emissions
and that section 112 was the proper authority to address HAP
emissions.\72\ The EPA explained in the preamble to the proposed rule
its conclusion that the 2000 finding was fully supported by the
information available at the time,\73\ and EPA stands by the
conclusions in that notice. Furthermore, the EPA provided an
interpretation of the terms appropriate and necessary that is wholly
consistent with the 2000 finding. The EPA does not agree with the
commenters that a quantification of emissions reductions or a specific
identification of the available controls was necessary to support the
2000 finding and listing. The EPA considered the Utility Study when
making the finding, and that study clearly articulated the various
alternative control strategies that EGUs could employ to control HAP
emissions.\74\ As to emission reductions, the EPA cannot estimate the
level of HAP emission reductions until the Agency proposes a CAA
section 112(d) standard after a source category is listed.
---------------------------------------------------------------------------

    \71\ 65 FR 79830.
    \72\ Id.
    \73\ 65 FR 24994-24996.
    \74\ See Chapter 13 of the Utility Study (U.S. EPA, 1998).
---------------------------------------------------------------------------

    The EPA disagrees with commenters that suggest it was not
``rational'' to determine that it was appropriate to regulate HAP
emissions from EGUs due to the cancer risks identified in the Utility
Study or the potential concerns associated with other HAP emissions
from EGUs. Nothing in CAA section 112(n)(1)(A) suggests that EPA must
determine that every HAP emitted by EGUs poses a hazard to public
health or the environment before EPA can find it appropriate to
regulate EGUs under CAA section 112. In fact, the EPA maintains that it
must find it appropriate and necessary to regulate EGUs under CAA
section 112 if it determines that any one HAP emitted from EGUs poses a
hazard to public health or the environment that will not be addressed
through imposition of the requirements of the Act. The EPA disputes the
commenters' conclusion that the 2000 finding was limited to Hg and Ni
emissions, but, even if it were, the EPA reasonably concluded that EGUs
should be listed pursuant to CAA section 112(c) based on the Hg and Ni
finding. As stated in the 2000 finding, cancer risks from some non-Hg
metal HAP (including As, Cr, Ni, and Cd) were not low enough to be to
eliminate as potential concern.\75\ Source categories listed for
regulation under CAA section 112(c) must be regulated under CAA section
112(d), and the D.C. Circuit has stated that EPA has a ``clear
statutory obligation to set emission standards for each listed HAP''.
See Sierra Club v. EPA, 479 F.3d 875, 883 (D.C. Cir. 2007), quoting
National Lime Association v. EPA, 233 F.3d 625, 634 (D.C. Cir. 2000).
Therefore, even if EPA concluded that CAA section 112(n)(1) authorized
a different approach for regulating HAP emissions from EGUs, the chosen
course which is supported by the CAA (i.e., listing under CAA section
112(c)) requires the Agency to regulate under CAA section 112(d)
consistent with the statute and case law interpreting that provision.
---------------------------------------------------------------------------

    \75\ 76 FR 79827.
---------------------------------------------------------------------------

    The EPA disagrees that there is any concern regarding the validity
of the 2000 finding or that the emissions information provided in the
2000 finding makes the finding ``questionable'' as stated by some of
the commenters. The EPA maintains that the 2000 finding was sound and
fully supported by the record available at the time, including the
future year emissions projections. Therefore, the listing of EGUs is
valid based on that finding alone. Even though Hg emissions have
decreased since the 2000 finding instead of increasing as projected,
the new technical analyses confirm that Hg emissions from EGUs continue
to pose hazards to public

health and the environment. The EPA also indicated potential concern
for several non-Hg HAP in the 2000 finding. It is well established that
even small amounts of HAP can cause significant harm to human health
and the environment.
    The EPA agrees with the commenters who assert that the 2005 action
was in error and disagrees with the commenters that the 2005 action
invalidated the 2000 finding. As fully described in the preamble to the
proposal, the EPA erred in the 2005 action by concluding that the 2000
finding lacked foundation. The 2005 action improperly conflated the
``appropriate'' and ``necessary'' analyses by addressing the ``after
imposition of the requirements of the Act'' in the appropriate finding
as well as the necessary finding. The EPA also indicated that it was
not reasonable to interpret the necessary prong of the finding as a
requirement to scour the CAA for alternative authorities to regulate
HAP emissions from stationary sources, including EGUs, when Congress
provided section 112 for that purpose. The EPA asserts that the 2000
finding was sound and fully supported by the record available at the
time for all the reasons stated in this final rule and the proposed
rule. The 2005 action interpreted the statute in a manner inconsistent
with the 2000 finding and attempted to delist EGUs without complying
with the mandates of CAA section 112(c)(9)(B). See New Jersey, 517 F.3d
at 583 (vacating the 2005 ``delisting'' action). In the preamble to the
proposed rule, the EPA set forth a revised interpretation of CAA
section 112(n)(1) that is consistent with the statute and the 2000
finding. The EPA also explained in the preamble to the proposed rule
why the 2005 action was not technically or scientifically sound. The
EPA specifically addressed the errors associated with the 2005 action