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###### Environmental Protection Agency

          - 40 CFR Part 63 
          - [AD-FRL-6582-3] 

# AGENCY:

Environmental Protection Agency (EPA). 

# ACTION:

Interpretative rule. 

# SUMMARY:

This action clarifies that all stationary combustion turbines are subject to the provisions of Subpart B—Requirements for Control Technology Determinations for Major Sources in Accordance with Clean Air Act Sections 112(g) and 112(j) (i.e., case-by-case maximum achievable control technology (MACT) determinations). 

# DATES:

 Effective April 21, 2000. 

# FOR FURTHER INFORMATION CONTACT:

 For further information, contact Mr. 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: roy.sims@epa.gov. 

# SUPPLEMENTARY INFORMATION:

*Regulated entities.*                     All new stationary combustion turbines, which meet the criteria for major sources, are the regulated entities addressed by this interpretative rule. However, this interpretative rule does not subject these entities to new or additional rule requirements; it merely resolves confusion which appears to exist in some cases over whether such sources are covered under 40 CFR part 63, Subpart B—Requirements for Control Technology Determinations for Major Sources in Accordance with Clean Air Act Sections 112(g) and 112(j).                 

## I. What Is the Background for This Interpretative Rule 

Subpart B requires “case-by-case” determinations of MACT for major sources constructed after June 29, 1998. It appears that there is confusion regarding the applicability of subpart B to new stationary combustion turbines in some situations. This interpretative rule resolves this confusion by clarifying that all new stationary combustion turbines, regardless of configuration, end use, or location, are subject to subpart B, provided they also meet the definition of a major source. 

Stationary combustion turbines were included on the list of source categories under section 112(c)(5) of the Clean Air Act (CAA) for the development of emission standards, thus, EPA is currently developing national emission standards for hazardous air pollutants (NESHAP) for this source category. Proposal of the NESHAP is anticipated in late 2000, with promulgation in early 2002. 

Electric utility steam generating units, on the other hand, are excluded from subpart B and the development of emission standards under section 112, unless or until such time as they are added to the source category list under section 112(c)(5) of the CAA. Since, among other uses, stationary gas turbines may be used to generate electricity, confusion has arisen whether stationary combustion turbines used to generate electricity are considered “electric utility steam generating units.” 

An “electric utility steam generating unit” is defined in subpart B as follows:

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 phrase “steam generating unit” in the term “electric utility steam generating unit” is critical to understanding which types of combustion units are covered by this definition and which types are not. For example, this 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. 

This definition does not cover a stationary combustion turbine which extracts shaft power from the combustion of fuel and spins an electric generator to generate electricity. The combustion turbine does not extract heat to generate steam; in fact, there is no steam generating unit at all in this example. Hence, the definition “electric utility steam generating unit” does not include stationary combustion turbines, and such turbines are subject to case-by-case MACT determinations. 

The confusion surrounds combined cycle systems. A combined cycle system, consistent with the meaning of the word “combined,” 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 extract heat to generate steam. It is not a “steam generating unit,” and it is not an “electric utility steam generating unit.” New combustion turbines in combined cycle systems, therefore, must undergo case-by-case MACT determinations. 

The waste heat recovery unit in a combined cycle system, however, does generate steam. It is an electric utility steam generating unit. New waste heat recovery units in combined cycle systems, therefore, are excluded from subpart B (i.e., case-by-case MACT determination). 

While new waste heat recovery units in combined cycle systems are excluded from case-by-case MACT, in many cases this is a moot point since they are not an emission source. The sole emission source, in the type of combined cycle system outlined above, is the combustion turbine. 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                           ( print page 21364)                        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. 

As outlined above, the waste heat recovery unit in a combined cycle system is an electric utility steam generating unit. Duct burners in these types of systems, therefore, are also excluded from subpart B (i.e., case-by-case MACT determination). 

## II. What Additional Information Is Available? 

The EPA is developing NESHAP for combustion turbines. This effort has lead to a collection of information regarding the performance, as well as the costs, associated with the use of various technologies to reduce emissions of hazardous air pollutants (HAP) from stationary combustion turbines. 

                    With this clarification that new stationary combustion turbines are subject to subpart B, EPA is making available two memoranda, “Hazardous Air Pollutant (HAP) Emission Control Technology for New Stationary Combustion Turbines” and “Oxidation Catalyst Costs for New Stationary Combustion Turbines,” which compile and summarize the information collected by EPA. These memoranda may be of assistance and as a result, help to expedite the process of 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.                 

## III. What Are the Impacts Associated With This Interpretative Rule? 

Subpart B applies to all new major stationary sources for which emission standards have not been developed except electric utility steam generating units. As a result, subpart B applies to new major source stationary combustion turbines. 

This interpretative rule merely clarifies this point, it does not subject new stationary combustion turbines to any new or additional regulatory requirements. As a result, there are no impacts associated with this interpretative rule. 

## IV. Administrative Requirements 

Section 553 of the Administrative Procedure Act, 5 U.S.C. 553(b)(B), provides that, when an agency for good cause finds that notice and public procedure are impracticable, unnecessary or contrary to the public interest, the agency may issue a rule without providing notice and an opportunity for public comment. We have determined that there is good cause for issuing today's interpretative rule without prior proposal and opportunity for comment because we are merely clarifying the applicability of Subpart B—Requirements for Control Technology Determinations for Major Sources in Accordance With Clean Air Act Sections 112 (g) and 112 (j). Thus, notice and public procedure are unnecessary, and we find that this constitutes good cause under 5 U.S.C. 553(b)(B). 

                    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this action is not a “significant regulatory action” and, therefore, is not subject to review by the Office of Management and Budget. Because we have made a “good cause” finding that this action is not subject to notice-and-comment requirements under the Administrative Procedure Act or any other statute, it is not subject to the regulatory flexibility provisions of the Regulatory Flexibility Act (5 U.S.C. 601*et seq.*), or to sections 202 and 205 of the Unfunded Mandates Reform Act of 1995 (UMRA) (Public Law 104-4).                 

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 substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132 (64 FR 43255, August 10, 1999). 

This interpretative rule also is 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 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. Section 808 allows the issuing agency to make a rule effective sooner than otherwise provided by the Congressional Review Act if the agency makes a good cause finding that notice and public procedure is impracticable, unnecessary or contrary to the public interest. This determination must be supported by a brief statement (5 U.S.C. 808(2)).                 

As stated previously, we have made such a good cause finding, including the reasons therefor, and established an effective date of April 21, 2000. 

                    The EPA will submit a report containing this interpretative 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 interpretative rule in the                     **Federal Register**                    . This action is not a “major rule” as defined by 5 U.S.C. 804(2).                 

      ( print page 21365)    

# List of Subjects in 40 CFR Part 63

      - Environmental protection
      - Air emissions control
      - Hazardous air pollutants
      - Combustion turbines

Dated: April 13, 2000. 

Robert Perciasepe, 

Assistant Administrator, Office of Air and Radiation. 

[FR Doc. 00-9925 Filed 4-20-00; 8:45 am] 

BILLING CODE 6560-50-P