Current through Register Vol. XLI, No. 50, December 13, 2024
Section 45-20-2 - Definitions2.1. "Stack" means any point in a source designed to emit solids, liquids, or gases into the air, including a pipe or duct but not including flares.2.2. "Stack in Existence" means that the owner or operator had: 2.2.a. begun, or caused to begin, a continuous program of physical onsite construction of the stack; or2.2.b. entered into binding agreements or contractual obligations, which could not be canceled or modified without substantial loss to the owner or operator, to undertake a program of construction of the stack to be completed in a reasonable time.2.3. "Dispersion Technique" means any technique which attempts to affect the concentration of a pollutant in the ambient air by:2.3.a. using that portion of a stack which exceeds good engineering practice stack height; or2.3.b. varying the rate of emission of a pollutant according to atmospheric conditions or ambient concentrations of that pollutant; or2.3.c. increasing final exhaust gas plume rise by manipulating source process parameters, exhaust gas parameters, stack parameters, or combining exhaust gases from several existing stacks into one stack; or other selective handling of exhaust gas streams so as to increase the exhaust gas plume rise.2.3.d. Such techniques do not include: d.1. the reheating of a gas stream, following use of a pollution control system, for the purpose of returning the gas to the temperature at which it was originally discharged from the facility generating the gas stream; ord.2. the merging of exhaust gas streams where: 2.A. the source owner or operator demonstrates that the facility was originally designed and constructed with such merged gas streams; or 2.B. after July 8, 1985, such merging is part of a change in operation at the facility that includes the installation of pollution controls and is accompanied by a net reduction in the allowable emissions of a pollutant. This exclusion from the definition of "dispersion techniques" applies only to the emission limitation for the pollutant affected by such change in operation; or 2.C. before July 8, 1985, such merging was part of a change in operation at the facility that included the installation of emissions control equipment or was carried out for sound economic or engineering reasons. Where there was an increase in the emission limitation or, in the event that no emission limitation was in existence prior to the merging, an increase in the quantity of pollutants actually emitted prior to the merging, the Director shall presume that merging was significantly motivated by an intent to gain emissions credit for greater dispersion. If such a demonstration cannot be made by the source owner or operator that such merging was not significantly motivated by such intent, the Director shall deny credit for the effects of such merging in calculating the allowable emissions for the source; or d.3. smoke management in agricultural or silvicultural prescribed burning programs; or d.4. episodic restrictions on residential woodburning and open burning; or d.5. techniques which increase final exhaust gas plume rise where the resulting allowable emissions of sulfur dioxide from the facility do not exceed 5,000 tons per year. 2.4. "Good Engineering Practice" (GEP) stack height means the greater of:2.4.a. 65 meters, measured from a ground-level elevation at the base of the stack; or2.4.b.b.1. for stacks in existence on January 12, 1979, and for which the owner or operator had obtained all applicable permits or approvals required, Hg = 2.5H, provided the owner or operator produces evidence that this equation was actually relied on in establishing an emission limitation; or b.2. for all other stacks, Hg = H + 1.5L, where Hg = good engineering practice stack height, measured from the ground-level elevation at the base of the stack,
H = height of nearby structure(s) measured from the ground-level elevation at the base of the stack,
L = lesser dimension, height or projected width, of nearby structure(s)
provided that the Director may require the use of a field study or fluid model to verify GEP stack height for the source; or
2.4.c. the height demonstrated by a fluid model or a field study approved by the Director, which ensures that the emissions from a stack do not result in excessive concentrations of any air pollutant as a result of atmospheric downwash, wakes, or eddy effects created by the source itself, nearby structures or nearby terrain features.2.5. "Nearby" as used in Subsection 2.4 of this rule is defined for a specific structure or terrain feature; and2.5.a. for purposes of applying the formulae provided in Subsection 2.4.b of this rule means that distance up to five (5) times the lesser of the height or the width dimension of a structure, but not greater than 0.8 km (2 mile), and2.5.b. for conducting demonstrations under Subsection 2.4.c. means not greater than 0.8 km (2 mile), except that the portion of a terrain feature may be considered to be nearby which falls within a distance of up to 10 times the maximum height (H) of the feature, not to exceed two (2) miles if such feature achieves a height (H), 0.8 km from the stack that is at least 40 percent of the GEP stack height determined by the formulae provided in Subsection 2.4.b.B of this rule or twenty-six (26) meters, whichever is greater, as measured from the ground-level elevation at the base of the stack. The height of the structure or terrain feature is measured from the ground-level elevation at the base of the stack.2.6. "Excessive Concentration" means for the purpose of determining good engineering practice stack height under Subsection 2.4.c and means:2.6.a. for sources seeking credit for stack height exceeding that established under Subsection 2.4.b. of this rule, a maximum ground-level concentration due to emissions from a stack due in whole or part to downwash, wakes, and eddy effects produced by nearby structures or nearby terrain features which individually is at least forty (40) percent in excess of the maximum concentration experienced in the absence of such downwash, wakes, or eddy effects and which contributes to a total concentration due to emissions from all sources that is greater than an ambient air quality standard. For sources subject to 45CSR14 the (Prevention of Significant Deterioration) an excessive concentration alternatively means a maximum ground-level concentration due to emissions from a stack due in whole or part to downwash, wakes, or eddy effects produced by nearby structures or nearby terrain features which individually is at least forty (40) percent in excess of the maximum concentration experienced in the absence of the maximum concentration experienced in the absence of such downwash, wakes, or eddy effects and greater than a prevention of significant deterioration increment. The allowable emission rate to be used in making demonstrations under this part shall be prescribed by 45CSR16 (Standards of Performance for New Stationary Sources) that is applicable to the source category unless the owner or operator demonstrates that this emission rate is infeasible. Where such demonstrations are approved by the Director, an alternative emission rate shall be established in consultation with the source owner or operator;2.6.b. for sources seeking credit after October 11, 1983, for increases in existing stack heights up to the heights established under Subsection 2.4.b of this rule, either: b.1. a maximum ground-level concentra- tion due in whole or part to downwash, wakes, or eddy effects as provided in Subsection 2.6.a of this rule except that the emission rate specified by any rule of the Director (or, in the absence of such a limit, the actual emission rate) shall be used; or b.2. the actual presence of a local nuisance caused by the existing stack, as determined by the Director, and 2.6.c. for sources seeking credit after January 12, 1979 for a stack height determined under Subsection 2.4.b of this rule where the Director requires the use of a field study or fluid model to verify GEP stack height, for sources seeking stack height credit after November 9, 1984, based on the aerodynamic influence of cooling towers, and for sources seeking stack height credit after December 31, 1970, based on the aerodynamic influence of structures not adequately represented by the equations in Subsection 2.4.b of this rule, a maximum ground-level concentration due in whole or part to downwash, wakes or eddy effects that is at least forty (40) percent in excess of the maximum concentration experienced in the absence of such downwash, wakes, or eddy effects.2.7. "Allowable Emissions" means the emission rate of a stationary source calculated using the maximum rated capacity of the source (unless the source is subject to federally enforceable limits or limits enforceable by the Director which restrict the operating rate, or hours of operation, or both) and the most stringent of the following: 2.7.a. all other applicable standards as set forth in 45CSR15 (Emission Standards for Hazardous Air Pollutants) and 45CSR16 (Standards of Performance for New Stationary Sources);2.7.b. all other applicable emissions limitations or permit conditions, including those with a future compliance date; or2.7.c. The applicable federally enforceable emissions limitations or permit conditions, including those with a future compliance date.2.8. "Director" means the Director of the Division of Environmental Protection..2.9. "Air Pollutants" means solids, liquids, or gases which, if discharged into the air, may result in a statutory air pollution. 2.10. "Emission" means the release, escape, or emission of air pollutants into the air.2.11. "Air Pollution", 'statutory air pollution', shall have the meaning ascribed to it in W. Va. Code '22-5-2. as amended.2.13. "Ambient Air Quality Standard" means the numerical expression of a specified concentration level for a particular air pollutant in the ambient air and the time-averaging interval over which that concentration level is measured.2.14. "Stationary Source" means any building, structure, facility, or installation which emits or may emit any air pollutant. Other words and phrases used in this rule, unless otherwise indicated, shall have the meaning ascribed to them in W. Va. Code '22-5-1 et seq..