For the purpose of this chapter, the following terms have the meanings indicated. Other applicable definitions may be found in COMAR 26.11.01.01. Terms Defined. Actual Emissions. “Actual emissions” means: The actual rate of emissions of a regulated NSR pollutant from an emissions unit as determined in accordance with this subsection; In general, as of a particular date, the average rate in tons per year at which the unit actually emitted the pollutant during a consecutive 24-month period, which precedes the particular date and which is representative of normal source operation, although the Department may allow the use of a different time period upon a determination that it is more representative of normal source operation; and As of a particular date, for any emissions unit which has not begun normal operations on the particular date, the unit's potential to emit on that date. Actual emissions shall be calculated using the emissions unit's actual operating hours, production rates, and types of materials processed, stored, or combusted during the selected time period. The Department may assume that source-specific allowable emissions for the emissions unit are equivalent to the actual emissions of the unit. “Allowable emissions” means the emissions rate calculated using the maximum rated capacity of the source, unless the source is subject to federally enforceable limits which restrict the operating rate, or hours of operation, or both, and the most stringent of the following: Applicable standards as set forth in 40 CFR 60 and 61; Any applicable Maryland State Implementation Plan (SIP) emissions limitation, including those with a future compliance date; or The emissions rate specified as a federally enforceable permit condition including those with a future compliance date. Baseline Actual Emissions. “Baseline actual emissions” means the rate of emissions, in tons per year, of a regulated NSR pollutant. For an existing electric utility steam generating unit, “baseline actual emissions” is determined by the average rate, in tons per year, at which the unit actually emitted the pollutant during any consecutive 24-month period selected by the owner or operator within the 5-year period immediately preceding the date on which a complete application was submitted. The Department may approve a different period upon a demonstration that it is more representative of normal source operations. For an existing emissions unit, other than an electric utility steam generating unit, “baseline actual emissions” is determined by the average rate, in tons per year, at which the emissions unit actually emitted the pollutant during any consecutive 24-month period selected by the owner or operator within the 5-year period immediately preceding the date on which a complete application was submitted. The Department may allow a different 24-month consecutive time period, within the last 10 years, upon a demonstration that it is more representative of normal source operations. For a new emissions unit, the baseline actual emissions for purposes of determining the emissions increase that will result from the initial construction and operation of the unit shall equal zero, and, thereafter, for all other purposes, shall equal the unit's potential to emit. For a PAL for a major stationary source, the baseline actual emissions shall be calculated, for existing electric utility steam generating units, in accordance with the procedures contained in §B(3)(b) of this regulation, for other existing emissions units in accordance with the procedures contained in §B(3)(c) of this regulation, and for a new emissions unit, in accordance with the procedures contained in §B(3)(d) of this regulation. In General. The average rate of emissions shall include fugitive emissions to the extent quantifiable, and emissions associated with start-ups, shutdowns, and malfunctions. The average rate shall be adjusted downward to exclude any noncompliant emissions that occurred while the source was operating above any emissions limitation that was legally enforceable during the consecutive 24-month period. However, if an emission limitation is part of a proposed or promulgated maximum achievable control technology standard under 40 CFR Part 63, the baseline actual emissions need only be adjusted if credit for the emissions reductions was taken in an attainment demonstration or maintenance plan. When a project involves multiple emissions units or different regulated NSR pollutants, only one consecutive 24-month period shall be used to determine the baseline actual emissions for the emissions units being changed. The average rate may not be based on any consecutive 24-month period for which there is inadequate information for determining annual emissions and adjusting the amount if required. “Begin actual construction” means, in general, initiation of physical on-site construction activities on an emissions unit which are of a permanent nature. These activities include installation of building supports and foundations, laying of underground pipework, and construction of permanent storage structures. With respect to a change in method of operation, this definition refers to those on-site activities other than preparatory activities which mark the initiation of the change. Best Available Control Technology. “Best available control technology” means an emissions limitation, including a visible emissions standard, based on the maximum degree of reduction for each regulated NSR pollutant which would be emitted from any proposed major stationary source or major modification which the Department, on a case-by-case basis, taking into account energy, environmental, and economic impacts and other costs, determines is achievable for that source or modification through application of production processes or available methods, systems, and techniques, including fuel cleaning or treatment or innovative fuel combination techniques for control of the pollutant. Application of best available control technology may not result in emissions of any pollutant which would exceed the emissions allowed by an applicable standard under 40 CFR 60 and 61. If the Department determines that technological or economic limitations on the application of measurement methodology to a particular emissions unit would make the imposition of an emissions standard infeasible, a design, equipment, work practice, operational standard, or combination of these, may be prescribed instead to satisfy the requirement for the application of best available control technology. This standard shall, to the degree possible, set forth the emissions reduction achievable by implementation of the design, equipment, work practice, or operation, and shall provide for compliance by means which achieve equivalent results. Building, Structure, Facility, or Installation. “Building, structure, facility, or installation” means all of the pollutant-emitting activities that belong to the same industrial group that are located on one or more contiguous or adjacent properties, and are under the control of the same person, or persons under common control. Pollutant-emitting activities are considered as part of the same industrial group if they belong to the same “Major Group” (that is, have the same two-digit code as described in the Standard Industrial Classification Manual (SIC) prepared by the federal Office of Management and Budget (OMB) and amended in 1987). “Commence”, as applied to construction of a major stationary source or major modification, means that the owner or operator has all necessary preconstruction approvals or permits and either has: Begun, or caused to begin, a continuous program of actual on-site construction of the source to be completed within a reasonable time; or Entered into binding agreements or contractual obligations, which cannot be canceled or modified without substantial loss to the owner or operator, to undertake a program of actual on-site construction of the source to be completed within a reasonable time. “Construction” means any physical change or change in the method of operation, including fabrication, erection, installation, demolition, or modification of an emissions unit, which would result in a change in emissions. “Electric utility steam generating unit” means any steam electric generating unit that is constructed for the purpose of supplying more than 1/3 of its potential electric output capacity and more than 25 megawatts electric output to any utility power distribution system for sale. Any steam supplied to a steam distribution system for the purpose of providing steam to a steam electric generator that would produce electrical energy for sale is also considered in determining the electrical energy output capacity of the affected facility. Emissions Reduction Credit (ERC). “Emissions reduction credit (ERC)” means a permanent, enforceable, quantifiable reduction in actual emissions, occurring on or after January 1, 2003, which is surplus to all applicable State and federally enforceable requirements to be used to offset emission increases. “Emissions reduction credit (ERC)” does not constitute a security or other form of property. “Emissions unit” means any part of a stationary source which emits, or would have the potential to emit, a regulated NSR pollutant. “Existing emissions unit” means an emissions unit that does not meet the requirement in §B(20) of this regulation. “Federally enforceable” means all limitations and conditions which are enforceable by the U.S. Environmental Protection Agency (EPA), including those requirements developed pursuant to 40 CFR 60 and 61, requirements within the SIP, any permit requirements established pursuant to 40 CFR §52.21 or under regulations approved pursuant to 40 CFR Part 51, Subpart I, including operating permits issued under a program that is approved by EPA or that is incorporated into the Maryland SIP and expressly requires adherence to any permit issued under the program. “Fugitive emissions” means those emissions which could not reasonably pass through a stack, chimney, vent, or other functionally equivalent opening. Lowest Achievable Emission Rate. “Lowest achievable emission rate” means, for any emissions unit, the more stringent rate of emissions based on the following: The most stringent emissions limitation which is contained in the implementation plan of any state for the class or category of stationary source, unless the owner or operator of the proposed stationary source demonstrates that these limitations are not achievable; or The most stringent emissions limitation which is achieved in practice by the class or category of stationary sources, with this limitation, when applied to a modification, meaning the lowest achievable emissions rate for the new or modified emissions units within the stationary source. The application of this definition does not permit a proposed new or modified emissions unit to emit any pollutant in excess of the amount allowable under 40 CFR 60. Major Modification. “Major modification” means any physical change in, or change in the method of operation of, a major stationary source that would result in a significant emissions increase and a significant net emissions increase of any regulated NSR pollutant. Any significant emissions increase from any emissions unit or net emissions increase at a major stationary source that is considered significant for volatile organic compounds or NOx is considered significant for ozone. A physical change in or a change in the method of operation does not include: Routine maintenance, repair, and replacement; Use of an alternative fuel or raw material by reason of an order under §2(a) and (b) of the Energy Supply and Environmental Coordination Act of 1974, or any superseding legislation, or by reason of a natural gas curtailment plan pursuant to the federal Power Act; Use of an alternative fuel by reason of an order or rule under §125 of the federal Clean Air Act; Use of an alternative fuel at a steam generating unit to the extent that the fuel is generated from municipal solid waste; Use of an alternative fuel or raw material by a stationary source which the source was capable of accommodating before December 21, 1976, unless the change would be prohibited under any federally enforceable permit condition which was established after December 21, 1976, pursuant to 40 CFR §52.21 or under regulations approved pursuant to 40 CFR Part 51, Subpart I, or 40 CFR §51.166, or the source is approved to use under any federally enforceable permit issued under this subtitle; An increase in the hours of operation or in the production rate, unless such change is prohibited under any federally enforceable permit condition; or Any change in ownership. This definition does not apply with respect to a particular regulated NSR pollutant when the major stationary source is complying with the requirements for a PAL. Major Stationary Source. “Major stationary source” means any stationary source of air pollution which emits or has the potential to emit 100 tons or more of any regulated NSR pollutant, except that lower emissions thresholds apply as follows: 25 tons or more per year of VOC or NOx for sources located in Baltimore City or Anne Arundel, Baltimore, Calvert, Carroll, Cecil, Charles, Frederick, Harford, Howard, Montgomery, or Prince George's counties; 50 tons or more per year of VOC for sources located in Allegany, Caroline, Dorchester, Garrett, Kent, Queen Anne's, St. Mary's, Somerset, Talbot, Washington, Wicomico, or Worcester counties; 50 tons or more per year of carbon monoxide in any serious nonattainment area for carbon monoxide, where stationary sources contribute significantly to carbon monoxide levels in the area; and 70 tons or more per year of PM10 in any serious nonattainment area for PM10. “Major stationary source” also means any physical change that would occur at a stationary source not qualifying under §B(17)(a) of this regulation as a major stationary source, if the change would constitute a major stationary source by itself. A major stationary source that is major for volatile organic compounds or NOx is considered major for ozone. In determining if a source is a major stationary source, fugitive emissions shall be included if the source belongs to one of the categories of stationary sources listed in 40 CFR §51.165(a)(1)(iv)(C). “Necessary preconstruction approvals or permits” means those permits or approvals required under this subtitle. Net Emissions Increase. “Net emissions increase” means, with respect to a regulated NSR pollutant emitted by a major stationary source, the amount by which the sum of the following exceeds zero: Any increase in emissions from a particular physical change or change in the method of operation at a stationary source; and Any other increases and decreases in actual emissions of the particular pollutant that are contemporaneous with the particular change and are otherwise creditable. Baseline actual emissions for calculating increases and decreases under this definition shall be determined as provided in §B(3) of this regulation, except that §B(3)(c) does not apply. An increase or decrease in actual emissions of a particular pollutant is contemporaneous with the increase from the particular change if it occurs within the 5-year period preceding the date on which a complete permit application for the change is submitted and before the date that the increase from the particular change occurs. An increase or decrease in actual emissions is creditable only if the Department has not relied on it in issuing a permit for the source and the permit is in effect when the increase in actual emissions from the particular change occurs. An increase in actual emissions is creditable only to the extent that the new level of actual emissions exceeds the old level. A decrease in actual emissions is creditable only to the extent that: The old level of actual emissions or the old level of allowable emissions, whichever is lower, exceeds the new level of actual emissions; The decrease is enforceable in a practicable manner at and after the time that the actual construction on the particular change begins; The Department has not previously relied on the decrease in issuing any permit under this chapter or in demonstrating attainment or reasonable further progress in the SIP and it is not required by any other State requirement; and It has approximately the same qualitative significance for public health and welfare as that attributed to the increase from the particular change. An increase that results from a physical change occurs when the emissions unit on which construction occurred becomes operational and begins to emit a particular pollutant. Any replacement unit that requires shakedown becomes operational only after a reasonable shakedown period, not to exceed 180 days. “New emissions unit” means an emissions unit which is or will be newly constructed and which has existed for less than 2 years from the date the emissions unit first operated. Potential to Emit. “Potential to emit” means the maximum capacity of a stationary source to emit a pollutant under its physical and operational design. Any physical or operational limitation on the capacity of the source to emit a pollutant, including air pollution control equipment and restrictions on hours of operation or on the type or amount of material combusted, stored, or processed, shall be treated as part of its design only if the limitation or the effect it would have on emissions is federally enforceable. “Project” means a physical change in, or change in the method of operation of, an existing major stationary source. Projected Actual Emissions. “Projected actual emissions” means the maximum annual rate, in tons per year, at which an existing emissions unit is projected to emit a regulated NSR pollutant in any one of the 5 years following the date the unit resumes regular operation after the project, or in any one of the 10 years following that date, if: The project involves increasing the emissions unit's design capacity or its potential to emit the regulated NSR pollutant; and Full utilization of the unit would result in a significant emissions increase or a significant net emissions increase at the major stationary source. In determining the projected actual emissions before beginning actual construction, the owner or operator of the major stationary source shall: Consider all relevant information including historical operational data, the company's own representations, the company's expected business activity, the company's highest projections of business activity, the company's filings with the State or EPA, and compliance plans under the approved plan; Include fugitive emissions to the extent quantifiable and emissions associated with start-ups, shutdowns, and malfunctions; and Exclude, in calculating any increase in emissions that results from the particular project, that portion of the emissions unit's emissions following the project that an existing unit could have accommodated during the consecutive 24-month period used to establish the baseline actual emissions and that are also unrelated to the particular project, including any increased utilization due to product demand growth. In lieu of using the method set out in §B(23)(b) of this definition, a person may elect to use the emissions unit's potential to emit, in tons per year. “Regulated NSR pollutant” means any pollutant for which a national ambient air quality standard has been promulgated and any pollutant that is a constituent or precursor of the pollutant for which there is an ambient air quality standard, provided that the constituent or precursor may only be regulated under this chapter as part of regulation of the pollutant. After January 1, 2011, PM2.5 and PM10 emissions shall include gaseous emissions from a source or activity which condense to form particulate matter at ambient temperature. These emissions shall be accounted for in applicability determinations and in establishing emission limitation in permits. Compliance with PM2.5 and PM10 emission limitations shall be as described in CFR 51.165(a)(1)(xxxvii)(D). Precursors identified for the purpose of NSR in Maryland are: Nitrogen oxides and volatile organic compounds are precursors of ozone in all ozone nonattainment areas. Nitrogen oxides and sulfur dioxide are precursors of PM2.5 in all PM2.5 nonattainment areas. “Replacement unit” means an emissions unit that meets all of the following criteria: No creditable emission reductions are generated by shutting down the existing emissions unit that is replaced; The emissions unit is a reconstructed unit within the meaning of 40 CFR §60.15(b)(1) or the emissions unit completely takes the place of an existing emissions unit; The emissions unit is identical to or functionally equivalent to the replaced emissions unit; The replaced unit does not alter the basic design parameters of the existing emissions unit; and The replaced emissions unit is permanently removed from the major stationary source or otherwise permanently disabled or barred from operation by a permit that is enforceable as a practicable matter. “Significant” means, in reference to a net emissions increase, a significant emissions increase or the potential of a source to emit a regulated NSR pollutant, or a rate of emissions that would equal or exceed any of the following rates: Volatile organic compounds or nitrogen oxides: 25 tons per year (tpy) in Baltimore City or Anne Arundel, Baltimore, Calvert, Carroll, Cecil, Charles, Frederick, Harford, Howard, Montgomery, and Prince George's counties; Volatile organic compounds or nitrogen oxides: 40 tpy in Allegany, Caroline, Dorchester, Garrett, Kent, Queen Anne's, St. Mary's, Somerset, Talbot, Washington, Wicomico, and Worcester counties. PM2.5 emissions: 10 tpy; Sulfur dioxide: 40 tpy; Lead: 0.6 tpy; PM10: 15 tpy; and Carbon monoxide: 100 tpy. “Stationary source” means any building, structure, facility, or installation which emits or may emit any regulated NSR pollutant subject to this chapter.