[Federal Register Volume 65, Number 102 (Thursday, May 25, 2000)]
[Rules and Regulations]
[Pages 34010-34012]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-13196]



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Part VIII





Environmental Protection Agency





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40 CFR Part 63



National Emission Standards for Hazardous Air Pollutants for Source 
Categories; Final Rules

  Federal Register / Vol. 65, No. 102 / Thursday, May 25, 2000 / Rules 
and Regulations  

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[AD-FRL-6706-1]


National Emission Standards for Hazardous Air Pollutants for 
Source Categories

AGENCY: Environmental Protection Agency (EPA).

ACTION: Interpretative rule.

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SUMMARY: This interpretative rule clarifies the construction by EPA of 
the applicability of sections 112(g) and 112(j) of the Clean Air Act 
(CAA), and of the regulations implementing these provisions for 
stationary combustion turbines in Subpart B--Requirements for Control 
Technology Determinations for Major Sources in Accordance With Clean 
Air Act Sections 112(g) and 112(j).
    Specifically, EPA has determined that case-by-case maximum 
achievable control technology (MACT) determinations under subpart B 
must be made for all new or reconstructed major source stationary 
combustion turbines, regardless of whether they are part of a combined 
cycle system. Waste heat recovery units, including duct burners, which 
are part of a combined cycle system are considered to be steam 
generating units. New or reconstructed waste heat recovery units would 
not be subject to case-by-case MACT determinations under subpart B if 
they are electric utility steam generating units.
    Elsewhere in today's Federal Register, EPA is withdrawing the 
interpretative rule as published on April 21, 2000, at 65 FR 21636. 
This final interpretative rule supersedes the interpretative rule 
erroneously published at 65 FR 21636.

EFFECTIVE DATE: June 26, 2000.

FOR FURTHER INFORMATION CONTACT: For further information, contact Sims 
Roy, Combustion Group, Emission Standards Division (MD-13), U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711, telephone number: (919) 541-5263, facsimile: (919) 541-5450, 
electronic mail address: [email protected].

SUPPLEMENTARY INFORMATION:
    Regulated entities. Stationary combustion turbines which meet the 
criteria for major sources are the regulated entities addressed by this 
interpretative rule.

I. Why Is EPA Issuing This Interpretative Rule?

    The EPA has decided to issue this interpretative rule to resolve an 
ambiguity in the construction of the exclusion for electric utility 
steam generating units set forth in 40 CFR 63.40(c). That provision 
states, ``The requirements of [40 CFR part 63, subpart B] do not apply 
to electric utility steam generating units unless and until such time 
as these units are added to the source category list pursuant to 
section 112(c)(5) of the Act.'' This applicability exclusion was 
intended to limit the need for case-by-case MACT determinations for new 
or reconstructed sources under CAA section 112(g) and 40 CFR 63.40-
63.44, but the same exclusion would also generally apply to case-by-
case MACT determinations for new and existing sources pursuant to CAA 
section 112(j).
    The term ``electric utility steam generating unit'' is defined in 
CAA section 112(a)(8) and at 40 CFR 63.41, as follows:

    The term ``electric utility steam generating unit'' means any 
fossil fuel fired combustion unit of more than 25 megawatts that 
serves a generator that produces electricity for sale. A unit that 
co-generates steam and electricity and supplies more than one-third 
of its potential electric output capacity and more than 25 megawatts 
electric output to any utility power distribution system for sale 
shall be considered an electric utility steam generating unit.

    The EPA explained its reasoning for the electric utility steam 
generating unit exclusion in the preamble to the final rule 
implementing CAA section 112(g) for new and reconstructed major sources 
(61 FR 68387, December 27, 1996). We noted that CAA section 112(n)(1) 
required us to perform a study of the hazards to public health 
associated with hazardous air pollutants (HAP) emissions from electric 
utility steam generating units. After completing the required study and 
considering the results, we are authorized to regulate such units under 
CAA section 112 if we determine such regulation is appropriate and 
necessary. We have not at this time made a determination whether such 
regulation is appropriate and necessary, but we are required by court 
order to make a determination by December 15, 2000. We excluded 
electric utility steam generating units from case-by-case MACT 
determinations under section 112(g) because we concluded that such 
determinations should only be made for sources which would otherwise be 
subject to section 112 MACT standards.
    Stationary combustion turbines were included on the list of source 
categories issued pursuant to CAA section 112(c)(1), and we are, 
therefore, required to issue a MACT standard applicable to this 
category pursuant to CAA section 112(d). Proposal of the MACT standard 
for this source category is anticipated in late 2000, with promulgation 
in early 2002.
    Stationary combustion turbines may be used to generate electricity. 
These stationary combustion turbines are sometimes combined with waste 
heat recovery units which generate steam by extracting heat from the 
exhaust gases (i.e., combined cycle systems). The fact that stationary 
combustion turbines can be used to generate electricity has created 
some ambiguity about whether combustion turbines used in this manner 
are considered electric utilities.
    On the one hand, EPA believes that the most reasonable construction 
of the statutory definition of electric utility steam generating units 
would not include any stationary combustion turbine, regardless of 
whether it is used by an electric utility to generate electricity, and 
regardless of whether it is attached to a waste heat recovery unit 
which generates steam. Accordingly, we are developing a MACT standard 
to regulate emissions from all stationary combustion turbines pursuant 
to CAA section 112(d).
    On the other hand, we also recognize that the first sentence of the 
statutory definition creates ambiguity concerning whether an electric 
utility unit must even generate steam to be included. This ambiguity 
has been compounded by the language in the preamble to the final 
section 112(g) rule, which predicates the exclusion for electric 
utilities based on the study performed pursuant to CAA section 
112(n)(1). That study did, in fact, include some very limited 
consideration of stationary combustion turbines. In light of these 
ambiguities, different permitting authorities have reached differing 
conclusions concerning whether a case-by-case MACT determination under 
section 112(g) is required for new or reconstructed major source 
stationary combustion turbines. At various times, offices within EPA 
have also given differing interpretations concerning whether a case-by-
case MACT determination is required for such facilities.
    This interpretative rule is intended to clearly resolve the 
ambiguity in the construction of 40 CFR 63.40(c) as applied to 
stationary combustion turbines. This interpretative rule will become 
legally effective and binding on June 26, 2000. After that date, all 
EPA offices and permitting authorities must adhere to this 
interpretative rule. Those EPA offices and permitting authorities who 
become aware of this interpretative rule, or the construction of the 
statute set forth herein, prior to the effective

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date should adopt this construction to the full extent it is 
practicable to do so. However, EPA will not seek to revisit the 
legality of, or to otherwise reconsider, any final actions previously 
taken in good faith based on a conclusion that stationary combustion 
turbines used to generate electricity fall within the exclusion.

II. What Is the Agency's Interpretation?

    The EPA construes the term ``electric utility steam generating 
unit,'' as defined by CAA section 112(a)(8) and 40 CFR 63.41, to 
exclude all stationary combustion turbines, regardless of whether or 
not such turbines are utilized to generate electricity or utilized by 
an electric utility, and regardless of whether or not such turbines are 
utilized in conjunction with waste heat recovery units (i.e., combined 
cycle systems). Therefore, a case-by-case MACT determination is 
required for each new or reconstructed stationary combustion turbine 
which is a major source.
    The phrase ``steam generating unit'' in the term ``electric utility 
steam generating unit'' is critical to interpreting which types of 
combustion units are covered by this definition and which types are 
not. The definition clearly covers a conventional fossil fuel fired 
steam generating unit (e.g., coal-fired boiler) which extracts heat 
from the combustion of fuel and generates steam for use in a steam 
turbine, which in turn provides shaft power to spin an electric 
generator and generate electricity.
    However, we do not believe this term was intended to cover a 
stationary combustion turbine which extracts shaft power from the 
combustion of fuel and spins an electric generator to generate 
electricity. Such a combustion turbine does not extract heat to 
generate steam. In fact, there is no steam generated at all in a 
combustion turbine. Hence, we conclude that the term ``electric utility 
steam generating unit'' does not include any stationary combustion 
turbine, and that such turbines must be regulated under a section 
112(d) MACT standard or a section 112(j) determination. Moreover, a 
case-by-case MACT determination under section 112(g) is required for 
any new or reconstructed stationary combustion turbine which is a major 
source.
    This reasoning can be further applied to combined cycle systems. 
For purposes of this discussion, a combined cycle system is a 
combination of a stationary combustion turbine and a waste heat 
recovery unit.
    In a combined cycle system, a combustion turbine extracts shaft 
power from the combustion of fuel and spins an electric generator to 
generate electricity. The hot exhaust gases from the combustion turbine 
are then routed to a separate ``waste heat recovery unit.'' The waste 
heat recovery unit extracts heat from the gases and generates steam for 
use in a steam turbine, which in turn provides shaft power to spin an 
electric generator and generate electricity.
    The combustion turbine in a combined cycle system does not generate 
steam. It is not a ``steam generating unit'' and, therefore, is not an 
``electric utility steam generating unit.''
    However, we also conclude that, because the waste heat recovery 
unit in a combined cycle system does generate steam, it is a steam 
generating unit. Whether a waste heat recovery unit in a new or 
reconstructed combined cycle system is subject to a case-by-case MACT 
is a moot point in many cases because the waste heat recovery unit is 
not an emission source. The emissions from the combustion turbine pass 
through the waste heat recovery unit, but the waste heat recovery unit 
is not a source of additional emissions.
    There is another type of combined cycle system, however, in which 
the waste heat recovery unit does contribute additional emissions. In 
these types of combined cycle systems, fuel is burned in the duct, 
through the use of ``duct burners,'' just before the gases enter the 
waste heat recovery unit.
    These duct burners are analogous to the burners in steam generating 
units (i.e., boilers). Their only purpose is to burn fuel to generate 
more heat for extraction by the waste heat recovery unit in order for 
it to generate more steam. As a result, duct burners (where they are 
used) are considered part of the waste heat recovery unit in a combined 
cycle system--just as the burners in a boiler are considered part of 
the boiler.
    Duct burners in combined cycle systems normally burn natural gas. 
Although it is unlikely that sufficient natural gas would be burned in 
a duct burner in a combined cycle system to result in emissions that 
would themselves exceed the major source threshold, a combined cycle 
system may have aggregate emissions which exceed the major source 
threshold. Therefore, in each instance where a stationary combustion 
turbine in a combined cycle system must meet MACT requirements because 
it is a major source of HAP, an associated duct burner will also be 
subject to MACT requirements unless it is found to be an electric 
utility steam generating unit. It is also possible that there could be 
instances where emissions from a duct burner in a waste heat recovery 
unit which is not an electric utility steam generating unit could cause 
the total emissions from a combined cycle system to exceed the major 
source threshold.
    If the waste heat recovery unit in a combined cycle system operates 
with duct burners, and more than one-third of the potential electrical 
output capacity of the duct burners and more than 25 megawatts of the 
electrical output provided by the duct burners are provided to any 
utility power distribution system for sale, then the waste heat 
recovery unit is an electric utility steam generating unit and is not 
subject to case-by-case MACT determinations unless and until such units 
are added to the source category list pursuant to CAA section 
112(c)(5). However, if the waste heat recovery unit in a combined cycle 
system operates with duct burners and less than one-third of the 
potential electrical output capacity of the duct burners or less than 
25 megawatts of the electrical output provided by the duct burners are 
provided to any utility power distribution system for sale, then the 
waste heat recovery unit must also meet MACT requirements if the 
aggregate HAP emissions from the combined cycle system exceed the major 
source threshold.

III. What Additional Information Is Available?

    As mentioned above, EPA is developing MACT standards for stationary 
combustion turbines. This effort has resulted in collection of 
information regarding the performance, as well as the costs, associated 
with the use of various technologies to reduce emissions of HAP from 
stationary combustion turbines.
    In conjunction with today's interpretative rule, EPA is making 
available two memoranda, the first entitled, ``Hazardous Air Pollutant 
(HAP) Emission Control Technology for New Stationary Combustion 
Turbines,'' and the second entitled, ``Oxidation Catalyst Costs for New 
Stationary Combustion Turbines.'' These two memoranda compile and 
summarize information collected by EPA and may be of assistance in 
making any required case-by-case MACT determinations. These memoranda 
may be obtained by contacting EPA as shown under FOR FURTHER 
INFORMATION CONTACT or downloaded directly by logging on to the 
following EPA website: http://www.epa.gov/ttn/uatw/combust/turbine/turbpg.html.

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IV. Why Is EPA Withdrawing the Interpretative Rule Published on 
April 21, 2000?

    An error by EPA led to publication of a preliminary draft of the 
interpretative rule on April 21, 2000 at 65 FR 36321.

V. What Are the Impacts Associated With This Interpretative Rule?

    As mentioned above, this interpretative rule simply resolves 
current ambiguity concerning the applicability of CAA section 112 to 
new or reconstructed major source stationary combustion turbines. It is 
not intended to subject these entities to any new or additional 
regulatory requirements.

VI. What Is the Applicability of Other Review Requirements?

    Under Executive Order 12866 (58 FR 51736, October 4, 1993), this 
interpretative rule is not a ``significant regulatory action'' and is, 
therefore, not subject to review by the Office of Management and 
Budget.
    Section 553(b)(3)(A) of the Administrative Procedure Act provides 
that interpretative rules are not subject to notice-and-comment 
requirements. Interpretative rules which do not involve the internal 
revenue laws of the United States are not subject to the regulatory 
flexibility provisions of the Regulatory Flexibility Act (5 U.S.C. 601 
et seq.). Because notice-and-comment requirements do not apply to this 
interpretative rule, this rule is also not subject to sections 202 and 
205 of the Unfunded Mandates Reform Act of 1995 (UMRA) (2 U.S.C. 1532 
and 1535).
    In addition, this action does not significantly or uniquely affect 
small governments or impose a significant intergovernmental mandate, as 
described in sections 203 and 204 of UMRA. This interpretative rule 
also does not significantly or uniquely affect the communities of 
tribal governments, as specified by Executive Order 13084 (63 FR 27655, 
May 10, 1998). This interpretative rule will not have significant 
direct effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government, as specified 
in Executive Order 13132 (64 FR 43255, August 10, 1999).
    This interpretative rule is also not subject to Executive Order 
13045 (62 FR 19885, April 23, 1997) because it is not economically 
significant. This action does not involve technical standards; thus, 
the requirements of section 12(d) of the National Technology Transfer 
and Advancement Act of 1995 (15 U.S.C. 272 note) do not apply. This 
interpretative rule also does not involve special consideration of 
environmental justice related issues as required by Executive Order 
12898 (59 FR 7629, February 16, 1994).
    In issuing this interpretative rule, EPA has taken the necessary 
steps to eliminate drafting errors and ambiguity, minimize potential 
litigation, and provide a clear legal standard for affected conduct, as 
required by section 3 of Executive Order 12988 (61 FR 4729, February 7, 
1996). The EPA has complied with Executive Order 12630 (53 FR 8859, 
March 15, 1988) by examining the takings implications of the 
interpretative rule in accordance with the ``Attorney General's 
Supplemental Guidelines for the Evaluation of Risk and Avoidance of 
Unanticipated Takings'' issued under the Executive Order. This 
interpretative rule does not impose an information collection burden 
under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 
3501 et seq.). The EPA's compliance with these statutes and Executive 
Orders for the underlying rule interpreted herein is discussed in the 
March 29, 1996 Federal Register document (61 FR 14029).
    The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the 
Small Business Regulatory Enforcement Fairness Act of 1996, generally 
provides that before a rule may take effect, the agency promulgating 
the rule must submit a rule report, which includes a copy of the rule, 
to each House of the Congress and to the Comptroller General of the 
United States. We have established an effective date of June 26, 2000. 
The EPA will submit a report containing this rule and other required 
information to the U.S. Senate, the U.S. House of Representatives, and 
the Comptroller General of the United States prior to publication of 
the rule in the Federal Register. This rule is not a ``major rule'' as 
defined by 5 U.S.C. 804(2).

List of Subjects in 40 CFR Part 63

    Environmental protection, Air emissions control, Hazardous air 
pollutants, Combustion turbines.

    Dated: May 18, 2000.
Robert Perciasepe,
Assistant Administrator, Office of Air and Radiation.
[FR Doc. 00-13196 Filed 5-24-00; 8:45 am]
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