ARTICLE 6. EMISSIONS FROM EXISTING AND NEW NONPOINT SOURCES

R18-2-601. General For purposes of this Article, any source of air contaminants which due to lack of an identifiable emission point or plume cannot be considered a point source, shall be classified as a nonpoint source. In applying this criteria, such items as air-curtain destructors, heater-planners, and conveyor transfer points shall be considered to have identifiable plumes. Any affected facility subject to regulation under Article 7 of this Chapter or Title 18, Chapter 2, Article 9, shall not be subject to regulation under this Article.

Historical Note

Former Section R9-3-601 repealed, new Section R9-3-601 adopted effective May 14, 1979 (Supp. 79-1). Former Section R9-3-601 renumbered without change as Section R18-2-601 (Supp. 87-3). Amended effective September 26, 1990 (Supp. 90-3). Former Section R18-2-601 renumbered to R18-2- 801, new Section R18-2-601 renumbered from R18-2-401 and amended effective November 15, 1993 (Supp. 93-4). Section updated to reflect corrected citation reference (Supp. 08-1).ARTICLE 4. PERMIT REQUIREMENTS FOR NEW MAJOR SOURCES AND MAJOR

MODIFICATIONS TO EXISTING MAJOR SOURCES

R18

- 2

- 401. Definitions The following definitions apply to this Article:

1. “Adverse impact on visibility” means visibility impairment that interferes with the management, protection, preservation, or enjoyment of the visitor’s visual experience of a Class I area, as determined according to R18

- 2

- 410.
2. “Baseline actual emissions ” means the rate of emissions, in tons per year, of a regulated NSR pollutant, as determined in accordance with subsections (2)(a) through (c). a. For any existing electric utility steam generating unit, baseline actual emissions means 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 five

year period immediately preceding when the owner or operator begins actual construction of the project . The Director shall allow the use of a different time period upon a determination that it is more representative of normal source operation. i. The average rate shall include fugitive emissions to the extent quantifiable, and

emissions associated with sta rtups, shutdowns, and malfunctions. ii. The average rate shall be adjusted downward to exclude any non

- compliant emissions that occurred while the source was operating above any emission limitation that was legally enforceable during the consecutive 24

- mon th period. iii. For a regulated NSR pollutant, when a project involves multiple emissions units, only one consecutive 24

- month period must be used to determine the baseline actual emissions for the emissions units being changed. A different consecutive 24

- month period can be used for each regulated NSR pollutant. iv. The average rate shall not be based on any consecutive 24

- month period for which there is inadequate information for determining annual emissions, in tons per year, and for adjusting this amoun t if required by subsection (2)(a)(ii). b. For any existing emissions unit (other than an electric utility steam generating unit), baseline actual emissions means the average rate, in tons per year, at which the unit actually emitted the pollutant during a ny consecutive 24

- month period selected by the owner or operator within the 10

- year period immediately preceding either the date the owner or operator begins actual construction of the project, or the date a complete permit application is received by the A dministrator for a permit required under 40 CFR 52.21 or by the Director for a permit required under the state implementation plan, whichever is earlier, except that the 10

- year period shall not include any period earlier than November 15, 1990.

i. The ave rage rate shall include fugitive emissions to the extent quantifiable, and emissions associated with startups, shutdowns, and malfunctions. ii. The average rate shall be adjusted downward to exclude any non

- compliant

emissions that occurred while the sourc e was operating above any emission limitation that was legally enforceable during the consecutive 24

- month period. This provision applies to excess emissions associated with a malfunction. iii. The average rate shall be adjusted downward to exclude any emi ssions that would have exceeded an emission limitation with which the major source must currently comply, had such major source been required to comply with such limitations during the consecutive 24

- month period. However, if an emission limitation is partof a maximum achievable control technology standard that the Administrator proposed or promulgated under 40 CFR 63, the baseline actual emissions need only be adjusted if the state of Arizona has taken credit for such emissions reductions in

an attainment demonstration or maintenance plan submitted to the Administrator pursuant to section 110(a)(1) of the Act. iv. For a regulated NSR pollutant, when a project involves multiple emissions units, only one consecutive 24

- month period must be used to determine the baseline actual emissions for all existing emissions units affected by the project. A different

consecutive 24

- month period may be used for each regulated NSR pollutant. v. The average rate shall not be based on any consecutive 24

- month period for whic h there is inadequate information for determining annual emissions, in tons per year, and for adjusting this amount if required by subsection (2)(b)(ii) or (iii). c. For a new emissions unit, the baseline actual emissions for purposes of determining the

em issions increase that will result from the initial construction and operation of such unit shall equal zero; and thereafter, for all other purposes, shall equal the unit’s potential to emit. d. For a PAL for a stationary source, the baseline actual emissio ns shall be calculated for existing electric utility steam generating units in accordance with the procedures in subsection (2)(a), for other existing emissions units in accordance with the procedures contained in subsection (2)(b), and for new emissions u nits in accordance with the procedures contained in subsection (2)(c). 3. “Basic design parameter” means: a. Except as provided in subsection (3)(c), for a process unit at a steam electric generating facility, the owner or operator may select as its basic design parameters either maximum hourly heat input and maximum hourly fuel consumption rate or maximum hourly electric output rate and maximum steam flow rate. When establishing fuel consumption specifications in terms of weight or volume, the minimum fuel quality based on Btu content shall be used for determining the basic design parameters for a

coal

- fired electric utility steam generating unit. b. Except as provided in subsection (3)(c), the basic design parameters for any process unit

that is not at a s team electric generating facility are maximum rate of fuel or heat input, maximum rate of material input, or maximum rate of product output. Combustion process units will typically use maximum rate of fuel input. For sources having multiple end products an d raw materials, the owner or operator should consider the primary product or primary raw material when selecting a basic design parameter. c. If the owner or operator believes the basic design parameters in subsections (3)(a) and (b) are not appropriate f or a specific industry or type of process unit, the owner or operator may propose to the Director an alternative basic design parameters for the source’s process unit. If the Director approves of the use of an alternative basic design parameters, the Direc tor shall issue a permit that is legally enforceable that records such basic design parameters and requires the owner or operator to comply with such
parameters. d. The owner or operator shall use credible information, such as results of historic

maximum c apability tests, design information from the manufacturer, or engineering calculations, in establishing the magnitude of the basic design parameters specified in subsections (3)(a) and (b).e. If design information is not available for a process unit, then the owner or operator shall determine the process unit’s basic design parameters using the maximum value achieved by the process unit in the five

- year period immediately preceding the planned activity. f. Efficiency of a process unit is not a basic design parameter. g. The replacement activity shall not cause the process unit to exceed any emission limitation, or operational limitation that has the effect of constraining emissions, that applies to the process unit and that is legally enforceable. 4. “Compl ete” means, in reference to an application for a permit or permit revision, that the application contains all the information necessary for processing the application. 5. “Dispersion technique” means any technique that attempts to affect the concentration of a pollutant in the ambient air by any of the following: a. Using that portion of a stack that exceeds good engineering practice stack height; b. Varying the rate of emission of a pollutant according to atmospheric conditions or

ambient concentrations of that pollutant; or

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 that

inc reases the exhaust gas plume rise. This shall not include any of the following: i. 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

fro m the facility generating the gas stream. ii. The merging of exhaust gas streams under any of the following conditions: (1) The source owner or operator demonstrates that the facility was originally designed and constructed with the merged gas streams; (2) After July 18, 1985, the 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, applying only to the

emission limitatio n for that pollutant; or (3) Before July 8, 1985, the 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 i ncrease 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 Department shall presume that merging was significan tly motivated by an intent to gain emissions credit for greater dispersion. Absent a demonstration by the source owner or operator that merging was not significantly motivated by such intent, the Department shall deny credit for the effects of the merging in calculating the allowable emissions

for the source. iii. Smoke management in agricultural or silvicultural prescribed burning programs. iv. Episodic restrictions on residential woodburning and open burning. v. Techniques that increase final exhaust gas plume rise if the resulting allowable emissions of sulfur dioxide from the facility do not exceed 5,000 tons per year. 6. “Existing emissions unit” is any emissions unit that is currently in existence and that is not a new emissions unit. A replacement uni t is an existing emissions unit.7. “High terrain” means any area having an elevation of 900 feet or more above the base of the

stack of a source. 8. “Innovative control technology” means any system of air pollution control that has not been adequately dem onstrated in practice but would have a substantial likelihood of achieving greater continuous emissions reduction than any control system in current practice, or of achieving at least comparable reductions at lower cost in terms of energy, economics, or

no nair quality environmental impacts. 9. “Low terrain” means any area other than high terrain. 10. “Lowest achievable emission rate” (LAER) means, for any source, the more stringent rate of emissions based on one of the following: a. The most stringent emis sions limitation that is contained in any implementation plan approved or promulgated under sections 110 or 172 of the Act for the class or category of stationary source, unless the owner or operator of the proposed stationary source

demonstrates that the limitation is not achievable; or b. The most stringent emissions limitation that is achieved in practice by the class or category of stationary source. This limitation, when applied to a modification, means

the lowest achievable emissions rate for the new or modified emissions units within the stationary source. The application of this term shall not permit a proposed new or modified stationary source to emit any pollutant in excess of the amount allowable under applicable standards of performance in Artic les 9 and 11 of this Chapter. 11. “Major source” means: a. Any stationary source located in a nonattainment area that emits, or has the potential to emit, 100 tons per year or more of any regulated NSR pollutant, except that the following thresholds shall apply in areas subject to subpart 2, subpart 3 or subpart 4 of part D, Title I of the Act:

Pollutant

Emitted Nonattainment

Pollutant and

Classification Quantity

Threshold tons/year or

more

Carbon Monoxide (CO) CO, Serious, if stationary sources contribute significantly to CO

levels in the area as determined under rules issued by the

Administrator 50

VOC

VOC

PM 10 NOx

NOx Ozone, Serious

Ozone, Severe

PM 10 , Serious Ozone, Serious Ozone, Severe 50

25

70

50

25
b. Any stationary source located in an attainment or unclassifiable area that emits, or has the potential to emit, 100 tons per year or more of any regulated NSR pollutant if the source is classified as a Categorical Source, or 250 tons per year or more o f any regulated NSR pollutant if the source is not classified as a Categorical Source; c. Any stationary source that emits, or has the potential to emit, five or more tons of lead

per year; d. A major source that is major for VOC or nitrogen oxides shall b e considered major for

ozone; ore. The fugitive emissions of a stationary source shall not be included in determining for any of the purposes of this Section whether it is a major stationary source, unless the source belongs to a section 302(j) category. 12. “New emissions unit” means any emissions unit which is (or will be) newly constructed and which has existed for less than two years from the date such emissions unit first operated. 13. “Plantwide applicability limitation” or “PAL” means an emission li mitation that is based on the baseline actual emissions of all emissions units at the stationary source that emit or have the potential to emit the PAL pollutant, expressed in tons per year, for a pollutant at a major source, that is enforceable as a pract ical matter and established source

- wide in

accordance with this Section.
14. “PAL allowable emissions” means “allowable emissions” as defined in R18

- 2

- 101, except that the allowable emissions for any emissions unit shall be calculated considering any

emiss ion limitations that are enforceable as a practical matter on the emissions unit’s potential to emit. 15. PAL effective date generally means the date of issuance of the PAL permit. However, the PAL effective date for an increased PAL is the date any emissi ons unit that is part of the PAL major modification becomes operational and begins to emit the PAL pollutant. 16. “PAL effective period” means the period beginning with the PAL effective date and ending 10 years later. 17. “PAL major modification” means an y physical change in or change in the method of operation of the PAL source that causes it to emit the PAL pollutant at a level equal to or greater than the PAL. 18. “PAL permit” means the permit issued by the Director that establishes a PAL for a major

so urce. 19. “PAL pollutant” means the pollutant for which a PAL is established at a major source. 20. “Projected actual emissions” means: a. The maximum annual rate, in tons per year, at which an existing emissions unit is projected to emit a regulated NSR p ollutant during any 12

- month period in the 60 calendar months following the date the unit resumes regular operation after the project, or in any 12

- month period in the 120 calendar months following that date if the project involves increasing the design ca pacity or potential to emit of any emissions unit for that 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 source. b. In determining the projecte d actual emissions before beginning actual construction, the owner or operator of the major source: i. Shall consider all relevant information, including but not limited to, historical operational data, the company’s own representations, the company’s expe cted business activity and the company’s highest projections of business activity, the company’s filings with the county, state or federal regulatory authorities, and compliance plans under these regulations; and ii. Shall include fugitive emissions to the extent quantifiable; iii. Shall include emissions associated with startups and shutdowns, except emissions from a shutdown associated with a malfunction; and iv. Shall exclude, only for calculating any increase in emissions that results from the particula r project, that portion of the unit’s emissions following the project that anexisting 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; or c. In lieu of using the method set out subsections (20)(b)(i) through (iv), the owner or operator may elect to use the emissions unit’s potential to emit, in tons per year.

21. “Reconst ruction” of sources located in nonattainment areas shall be presumed to have taken place if the fixed capital cost of the new components exceeds 50% of the fixed capital cost of a comparable entirely new stationary source, as determined in accordance with the provisions of 40 CFR 60.15(f)(1) through (3).

22. “Replacement unit” means an emissions unit for which all the criteria listed in subsections (22)(a) through (d) are met. No creditable emission reductions shall be generated from shutting down the existing emissions unit that is replaced.

a. 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. b. The emissions unit is identical to or functionally equivalent to the replaced emissions

unit.

c. The r eplacement does not alter the basic design parameters of the process unit. d. The replaced emissions unit is permanently removed from the major source, otherwise permanently disabled, or permanently barred from operation by a permit that is

enforceable as a practical matter. If the replaced emissions unit is brought back into operation, it shall constitute a new emissions unit. 23. “Resource recovery project” means any facility at which solid waste is processed for the purpose of extracting, converting to e nergy, or otherwise separating and preparing solid waste for reuse. Only energy conversion facilities that utilize solid waste that provides more than 50% of the heat input shall be considered a resource recovery project under this

Article. 24. “Significan t emissions unit” means an emissions unit that emits or has the potential to emit a PAL pollutant in an amount that is equal to or greater than the significant level for that PAL pollutant, but less than the amount that would qualify the unit as a major em issions

unit. 25. “Significance levels” means the following ambient concentrations for the enumerated pollutants:
Averaging Time

Pollutant Annual 24

- Hour 8

- Hour 3

- Hour 1

- Hour

SO 2 1 μg/m 3 5 μg/m 3 25 μg/m 3

NO 2 1 μg/m 3

CO 0.5 mg/m 3 2 mg/m 3

PM 10 1 μg/m 3 5 μg/m 3

PM2.5

Class I area 0.06 μg/m3 0.07 μg/m3

PM2.5

Class II area 0.3 μg/m3 1.2 μg/m3PM2.5

Class III area 0.3 μg/m3 1.2 μg/m3

Except for the annual pollutant concentrations, the Department shall deem that exceedance of significance levels has occurred when the ambient concentration of the above pollutant is exceeded more than once per year at any one location. If the concentratio n occurs at a specific location and at a time when Arizona ambient air quality standards for the pollutant are not violated, the significance level does not apply.

26. “Small emissions unit” means an emissions unit that emits or has the potential to emit the PAL pollutant in an amount less than the significant level for that PAL pollutant.

Historical Note Adopted effective May 14, 1979 (Supp. 79

- 1). Amended effective October 2, 1979 (Supp.

79

- 5). Former Section R9

- 3

- 401 renumbered without change as Section R18

- 2

- 401 (Supp. 87

- 3). Section R18

- 2

- 401 renumbered to R18

- 2

- 601. New Section R18

- 2

- 401 adopted effec tive November 15, 1993 (Supp. 93

- 4). Amended by final rulemaking at 5 A.A.R. 4074, effective September 22, 1999 (Supp. 99

- 3). Typographical error corrected

in R18

- 2

- 401(9)(a) (Supp. 00

- 4). Amended by final rulemaking at 13 A.A.R. 1134, effective May 5, 200 7 (Supp. 07

- 1). Amended by final rulemaking at 18 A.A.R. 1542,

effective August 7, 2012 (Supp. 12

- 2).