EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 1 of 112

51.160 Legally Enforceable Procedures Where included in AZ NSR Rules

(a) (a) Each plan must set forth legally enforceable procedures that enable the State or local 

agency to determine whether the construction or modification of a facility, building, 

structure or installation, or combination of these will result in—

See Section 5.2.1 of the TSD for more discussion on 

approval issues related to the definition for 

"proposed final permit" in R18-2-101(114).

(1) A violation of applicable portions of the control strategy; or Program requires registrations, Class II permits, and 

Class I permits to include all "applicable 

requirements" as defined R18-2-101. This would 

include all applicable portions of the SIP (control 

strategy). See R18-2-302.01(E), R18-2-306(A)(2), R18-

2-316, R18-2-403(I), and R18-2-406(G).

(2) Interference with attainment or maintenance of a national standard in the State in 

which the proposed source (or modification) is located or in a neighboring State.

R18-2-302.01(C),R18-2-316, R18-2-334(C)(2) and (E), 

R18-2-406(A)(5). See Section 5.2.1 of the TSD. 

ADEQ's program generally reference the State's air 

standards in Article 2 or generally references to 

"state ambient air quality standards." It is not clear 

that ADEQ's rules would evaluate impacts on areas 

outside of ADEQ's jurisdiction. R18-2-334 does not 

fully ensure this requirement is met because 

implementation of RACT can be used to avoid this 

analysis. R18-2-334(G) still allows the Director to 

require an analysis, but this provides too great of 

director's discretion. 

(b) (b) Such procedures must include means by which the State or local agency responsible for 

final decision-making on an application for approval to construct or modify will prevent such 

construction or modification if—

See Section 5.2.1 of the TSD for more discussion on 

approval issues related to the definition for 

"proposed final permit" in R18-2-101(114).

(1) It will result in a violation of applicable portions of the control strategy; or Program requires registrations, Class II permits, and 

Class I permits to include all "applicable 

requirements" as defined R18-2-101. This would 

include all applicable portions of the SIP (control 

strategy). See R18-2-302.01(E), R18-2-306(A)(2), R18-

2-406(A)(4). However, R18-2-302.01(E) does not 

meet this requirement and should include "ensure 

compliance" with all applicable requirements, like 

Class I and II permits. 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 2 of 112

(2) It will interfere with the attainment or maintenance of a national standard. R18-2-302.01(C)(4), R18-2-334(F), R18-2-306(A)(2), 

R18-2-403, R18-2-406(A)(5). Section Section 5.2.1 of 

the TSD. Analysis of impacts is not required in all 

instances, so this requirement is not fully met for the 

registration program. R18-2-302.01(C)(4) should 

include "or maintenance" of a standard. Further, 

these analyses may not apply to impacts beyond 

state boundaries/jurisdictions, as only state 

standards are reviewed. For NA-NSR, compliance 

with SIP will ensure not interfering with attainment 

plan, and program requires offsets of emissions 

beyond the existing attainment plan or 

demonstration of reasonable further progress.

(c ) (c) The procedures must provide for the submission, by the owner or operator of the 

building, facility, structure, or installation to be constructed or modified, of such information 

on—

(c)(1) (1) The nature and amounts of emissions to be emitted by it or emitted by associated 

mobile sources;

R18-2-302.01(A), R18-2-304 . (1) R18-2-304(E)(9) 

allows emissions information to be excluded from an 

application if it is an insignificant activity, as defined 

in R18-2-101. Definition is typically associated with 

the title V program. (2) R18-2-302.01(A)(3) contains 

a reference to R18-2-327(C) for calculating potential 

emissions. However, R18-2-237 is not in the SIP, or 

submitted for SIP approval, and it identifies the 

methods for determining actual emissions for 

purposes of ADEQ’s annual emissions inventory. 

There is a typo in R18-2-304(E) - there are two 7s and 

no 8.

(c)(2) (2) The location, design, construction, and operation of such facility, building, structure, or 

installation as may be necessary to permit the State or local agency to make the 

determination referred to in paragraph (a) of this section.

R18-2-302.01(A), R18-2-304, and Appendix 1 (already 

in SIP). Recommend submitting current Appendix 1 

to replace 1980's version.

(d) (d) The procedures must provide that approval of any construction or modification must not 

affect the responsibility to the owner or operator to comply with applicable portions of the 

control strategy.

R18-2-334(K), R18-2-403(I), R18-2-406(G) - However, 

not found in R18-2-302.01
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 3 of 112

(e) (e) The procedures must identify types and sizes of facilities, buildings, structures, or 

installations which will be subject to review under this section. The plan must discuss the 

basis for determining which facilities will be subject to review.

R18-2-101(99) - permitting exemption threshold. R18-

2-302(B). Provided basis in submittal. See page 1547-

1549 of ADEQ's NFRM. However, there are 

disapproval issues, see Section 5.2.2.

(f) (f) The procedures must discuss the air quality data and the dispersion or other air quality 

modeling used to meet the requirements of this subpart.

R18-2-302.01(C), R18-2-334(C)(2) and (I), R18-2-

403(I), and R18-2-406(G). Also, R18-2-410, but not 

included in submittal.

(f)(1) (1) All applications of air quality modeling involved in this subpart shall be based on the 

applicable models, data bases, and other requirements specified in appendix W of this part 

(Guideline on Air Quality Models).

R18-2-334(I). Also, R18-2-406(A)(6) and 409(A). R18-

2-302.01 does not contain a reference to Appendix 

W - only SCREEN modeling. It is not clear that the 

SCREEN modeling would follow Appendix W.

(f)(2) (2) Where an air quality model specified in appendix W of this part (Guideline on Air Quality 

Models) is inappropriate, the model may be modified or another model substituted. Such a 

modification or substitution of a model may be made on a case-by-case basis or, where 

appropriate, on a generic basis for a specific State program. Written approval of the 

Administrator must be obtained for any modification or substitution. In addition, use of a 

modified or substituted model must be subject to notice and opportunity for public 

comment under procedures set forth in §51.102.

R18-2-409. Recommend ADEQ revised R18-2-302.01 

and R18-2-334 to refer to R18-2-409 - Air Quality 

Models

[51 FR 40669, Nov. 7, 1986, as amended at 58 FR 38822, July 20, 1993; 60 FR 40468, Aug. 9, 

1995; 61 FR 41840, Aug. 12, 1996]
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 4 of 112

51.161 §51.161 Public availability of information. Where included in AZ NSR Rules

(a) (a) The legally enforceable procedures in §51.160 must also require the State or local agency 

to provide opportunity for public comment on information submitted by owners and 

operators. The public information must include the agency's analysis of the effect of 

construction or modification on ambient air quality, including the agency's proposed 

approval or disapproval.

R18-2-302.01(B)(3),R18-2-330, R18-2-334(H). However, 

exempts some sources subject to minor NSR from public 

notice - R18-2-334(G), R18-2-319(A)(7) and (B)(1)(a), R18-

2-320(B)(3). R18-2-330(A) - does not include 

registrations, so it unclear what requirements apply. 

Program must also include public notice of disappprovals. 

Sources seeking "elective limits" do not fully meet the 

public notice requirement as the particular limit is not in 

the rule nor would be public noticed at a later date. See 

Section 5.3 of the TSD.

(b) (b) For purposes of paragraph (a) of this section, opportunity for public comment shall 

include, as a minimum—

(1) Availability for public inspection in at least one location in the area affected of the 

information submitted by the owner or operator and of the State or local agency's analysis 

of the effect on air quality;

R18-2-330(D)(11), R18-2-330(F), R18-2-304(I)(4). Not clear 

that the agency's analysis would be included with notice 

materials. Also, Department only has two offices. 

Depending on location of the source a place for public 

inspection in the affected area is not met. Remedy could 

include (1) identifying materials will be available at a 

public location in the same county (e.g. library) (2) 

Identify in the notice a specific web address where all 

materials are accessible electronically and in the 

information for a local library - then presumably the 

public could go to their local library to view the 

documents. 

(2) A 30-day period for submittal of public comment; and R18-2-330(G), R18-2-330 applies to public notice for 

major and minor sources. 

(3) A notice by prominent advertisement in the area affected of the location of the source 

information and analysis specified in paragraph (b)(1) of this section.

R18-2-330(C), (D)(11) and (F)

( c) (c) Where the 30-day comment period required in paragraph (b) of this section would 

conflict with existing requirements for acting on requests for permission to construct or 

modify, the State may submit for approval a comment period which is consistent with such 

existing requirements.

Not applicable
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 5 of 112

(d) (d) A copy of the notice required by paragraph (b) of this section must also be sent to the 

Administrator through the appropriate Regional Office, and to all other State and local air 

pollution control agencies having jurisdiction in the region in which such new or modified 

installation will be located. The notice also must be sent to any other agency in the region 

having responsibility for implementing the procedures required under this subpart. For lead, 

a copy of the notice is required for all point sources. The definition of point for lead is given 

in §51.100(k)(2) - For lead or lead compounds measured as elemental lead, any stationary 

source that actually emits a total of 4.5 metric tons (5 tons) per year or more..

R18-2-334(H) and R18-2-402(I)(2). Rules generally meets 

the 5 tpy lead point source requirements - R18-2-

402(G)(8), R18-2-401(11) - all 5 tpy or greater lead sources 

are considered major sources. Registrations under R18-2-

302.01 subject to public notice do not meet this 

requirement.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 6 of 112

51.162 Identification of responsible agency. Where included in AZ NSR Rules

Each plan must identify the State or local agency which will be responsible for meeting the 

requirements of this subpart in each area of the State. Where such responsibility rests with 

an agency other than an air pollution control agency, such agency will consult with the 

appropriate State or local air pollution control agency in carrying out the provisions of this 

subpart.

ARS 49-402 and 49-107. See Section 5.4 of the TSD.

51.163 Administrative Procedures Where included in AZ NSR Rules

The plan must include the administrative procedures, which will be followed in making the 

determination specified in paragraph (a) of §51.160.

R18-2-301, R18-2-302, R18-2-302.01, R18-2-304, R18-

2-334, R18-2-402, Appendix 1. However, procedures 

reference R18-2-317 and R18-2-317.02 which were 

not included in the SIP submittal. See Section 5.5 of 

the TSD.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 7 of 112

51.164 Requirements of 40 CFR 51.164 Related to Stack Heights Where included in AZ NSR 

Rules

§51.164 Stack height procedures.

Such procedures must provide that the degree of emission limitation required of any source for control of any air 

pollutant must not be affected by so much of any source's stack height that exceeds good engineering practice or by 

any other dispersion technique, except as provided in §51.118(b) [see below]. Such procedures must provide that 

before a State issues a permit to a source based on a good engineering practice stack height that exceeds the height 

allowed by §51.100(ii) (1) or (2) [see below], the State must notify the public of the availability of the demonstration 

study and must provide opportunity for public hearing on it. This section does not require such procedures to 

restrict in any manner the actual stack height of any source.

R18-2-332(C and E). R18-2-332(E) 

contains a reference to R18-1-402, 

which is not in the SIP or submitted 

for SIP approval. R18-2-332(D) 

contains additional provisions which 

may allow for stack heights in excess 

of GEP. Recommend changing 

reference to R18-2-330 or submit R18-

1-402. 

(a) The plan must provide that the degree of emission limitation required of any source for control of any air 

pollutant must not be affected by so much of any source's stack height that exceeds good engineering practice or by 

any other dispersion technique, except as provided in §51.118(b). The plan must provide that before a State submits 

to EPA a new or revised emission limitation that is based on a good engineering practice stack height that exceeds 

the height allowed by §51.100(ii) (1) or (2), the State must notify the public of the availability of the demonstration 

study and must provide opportunity for a public hearing on it. This section does not require the plan to restrict, in 

any manner, the actual stack height of any source.

R18-2-332(C and E). R18-2-332(E) 

contains a reference to R18-1-402, 

which is not in the SIP or submitted 

for SIP approval. Recommend 

changing reference to R18-2-330 or 

submit R18-1-402. 

(b) The provisions of §51.118(a) shall not apply to (1) stack heights in existence, or dispersion techniques 

implemented on or before December 31, 1970, except where pollutants are being emitted from such stacks or using 

such dispersion techniques by sources, as defined in section 111(a)(3) of the Clean Air Act, which were constructed, 

or reconstructed, or for which major modifications, as defined in §§51.165(a)(1)(v)(A), 51.166(b)(2)(i) and 

52.21(b)(2)(i), were carried out after December 31, 1970; or (2) coal-fired steam electric generating units subject to 

the provisions of section 118 of the Clean Air Act, which commenced operation before July 1, 1957, and whose 

stacks were constructed under a construction contract awarded before February 8, 1974.

R18-2-332(A). However, R18-2-332(A) 

does not include "except where 

pollutants are ....were constructed, or 

reconstructed, or for which major 

modifications, as defined in 

§§51.165(a)(1)(v)(A), 51.166(b)(2)(i) 

and 52.21(b)(2)(i)." In addition, while 

likely a typo - R18-2-332(A)(3) 

references 1975 instead of 1957. 

(hh)(1) Dispersion technique means any technique which attempts to affect the concentration of a pollutant in the 

ambient air by:

R18-2-401(5) and R18-2-301(6). Note: 

Below only R18-2-301(6) is reviewed 

in detail. The same definition for 

dispersion technique also appears in 

R18-2-401(5). Both definitions are 

approvable, except as noted 

otherwise.

§51.118 Stack height provisions. (General requirement for a Control Strategy - not a specific NSR program requirement)

§51.100(hh) through (kk)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 8 of 112

(i) Using that portion of a stack which exceeds good engineering practice stack height: R18-2-301(6)(a)

(ii) Varying the rate of emission of a pollutant according to atmospheric conditions or ambient concentrations of 

that pollutant; or

R18-2-301(6)(b)

(iii) 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.

R18-2-301(6)(c )

(2) The preceding sentence does not include:

(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 from the facility generating the gas stream;

R18-2-301(6)(c)(i)

(ii) The merging of exhaust gas streams where: R18-2-301(6)(c)(ii)

(A) The source owner or operator demonstrates that the facility was originally designed and constructed with such 

merged gas streams;

R18-2-301(6)(c)(ii)(1)

(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 shall apply only to the emission limitation for the pollutant affected by 

such change in operation; or

R18-2-301(6)(c)(ii)(2) There is a typo in 

R18-2-401(5)(ii)(2) - references July 18 

instead of July 8.

(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 reviewing agency shall presume 

that merging was significantly 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 

reviewing agency shall deny credit for the effects of such merging in calculating the allowable emissions for the 

source;

R18-2-301(6)(c)(ii)

(iii) Smoke management in agricultural or silvicultural prescribed burning programs; R18-2-301(6)(c)(iii)

(iv) Episodic restrictions on residential woodburning and open burning; or R18-2-301(6)(c)(iv)

(v) Techniques under §51.100(hh)(1)(iii) 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.

R18-2-301(6)(c)(v). 

(ii) Good engineering practice (GEP) stack height means the greater of:

R18-2-332(B). R18-2-332(D) contains 

provisions that appear to allow for the 

use of stack heights in excess of GEP.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 9 of 112

(1) 65 meters, measured from the ground-level elevation at the base of the stack: R18-2-332(B)(1) - does not include 

"measured from the ground level....." 

However, this is defined in R18-2-

332(B)(3). Approvable, but 

recommend revising for clarity

(2)(i) For stacks in existence on January 12, 1979, and for which the owner or operator had obtained all applicable 

permits or approvals required under 40 CFR parts 51 and 52.

Hg = 2.5H,

provided the owner or operator produces evidence that this equation was actually relied on in establishing an 

emission limitation:

Not included - R18-2-332(B)(2)

(ii) 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 EPA, State or local control agency may require the use of a field study or fluid model to verify GEP 

stack height for the source; or

(3) The height demonstrated by a fluid model or a field study approved by the EPA State or local control agency, 

which ensures that the emissions from a stack do not result in excessive concentrations [see below] of any air 

pollutant as a result of atmospheric downwash, wakes, or eddy effects created by the source itself, nearby 

structures or nearby [see below] terrain features.

R18-2-332(B)(4) - Recommend revising 

"terrain obstacles" to "terrain 

features, which is used in the federal 

regulation and in R18-2-332(B)(5)

(jj) Nearby 

as used in §51.100(ii) of this part is defined for a specific structure or terrain feature and R18-2-332(B)(5)

(1) For purposes of applying the formulae provided in §51.100(ii)(2) means that distance up to five times the lesser 

of the height or the width dimension of a structure, but not greater than 0.8 km ( 1⁄2 mile), and

R18-2-332(B)(5)(a)

(2) For conducting demonstrations under §51.100(ii)(3) means not greater than 0.8 km ( 1⁄2 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 (Ht) of the feature, not to exceed 2 miles if such feature achieves a height (Ht) 0.8 km from the 

stack that is at least 40 percent of the GEP stack height determined by the formulae provided in §51.100(ii)(2)(ii) of 

this part or 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.

R18-2-332(B)(5)(b)

(kk) Excessive concentration

R18-2-332(B)(2) - also includes 

reference to R18-2-403 

(Nonattainment NSR). This reference 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 10 of 112

is defined for the purpose of determining good engineering practice stack height under §51.100(ii)(3) and means: R18-2-332(B)(6)

(1) For sources seeking credit for stack height exceeding that established under §51.100(ii)(2) a maximum groundlevel 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 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 the prevention of significant deterioration program (40 CFR 51.166 and 52.21), 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 40 percent in excess 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 the new source 

performance standard 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 authority administering the State 

implementation plan, an alternative emission rate shall be established in consultation with the source owner or 

operator.

R18-2-332(B)(6)(a) - Recommend 

revising reference to Article 4 to R18-2-

406

(2) For sources seeking credit after October 11, 1983, for increases in existing stack heights up to the heights 

established under §51.100(ii)(2), either (i) a maximum ground-level concentration due in whole or part to 

downwash, wakes or eddy effects as provided in paragraph (kk)(1) of this section, except that the emission rate 

specified by any applicable State implementation plan (or, in the absence of such a limit, the actual emission rate) 

shall be used, or (ii) the actual presence of a local nuisance caused by the existing stack, as determined by the 

authority administering the State implementation plan; and

R18-2-332(B)(6)(b) - missing "(or, in 

the absence of such a limit, the actual 

emission rate)" - Recommend adding 

this statement to the rule.

(3) For sources seeking credit after January 12, 1979 for a stack height determined under §51.100(ii)(2) where the 

authority administering the State implementation plan 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 §51.100(ii)(2), a maximum ground-level 

concentration due in whole or part to downwash, wakes or eddy effects that is at least 40 percent in excess of the 

maximum concentration experienced in the absence of such downwash, wakes, or eddy effects.

R18-2-332(B)(6)( c)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 11 of 112

51.165 Requirements of 40 CFR 51.165 for Nonattainment NSR Programs Where included 

in AZ NSR Rules

§51.165 Permit requirements.

(a) (a) State Implementation Plan and Tribal Implementation Plan provisions satisfying sections 

172(c)(5) and 173 of the Act shall meet the following conditions:

(a)(1) (1) All such plans shall use the specific definitions. Deviations from the following wording will be 

approved only if the State specifically demonstrates that the submitted definition is more stringent, 

or at least as stringent, in all respects as the corresponding definition below:

(a)(1)(i) Stationary source (i) Stationary source means any building, structure, facility, or installation which emits or may emit 

a regulated NSR pollutant.

R18-2-101(139). 

Definition references 

"any air pollutant" 

instead of "regulated 

NSR pollutant." This is 

generally okay, but 

should probably use a 

defined term. Possibly - 

air pollution. In 

addition, contains a 

reference to ADEQ 

permitting statute -49-

426(A). It is unclear 

whether this reference 

limits a stationary 

source to only those 

sources requiring 

permits instead of those 

emitting regulated NSR 

permits. See Section 

5.7.2 of the TSD.

(a)(1)(ii) Building, structure, 

facility or 

installation

(ii) Building, structure, facility, or installation means all of the pollutant-emitting activities which 

belong to the same industrial grouping, are located on one or more contiguous or adjacent 

properties, and are under the control of the same person (or persons under common control) 

except the activities of any vessel. Pollutant-emitting activities shall be considered as part of the 

same industrial grouping if they belong to the same Major Group (i.e., which have the same twodigit code) as described in the Standard Industrial Classification Manual, 1972, as amended by the 

1977 Supplement (U.S. Government Printing Office stock numbers 4101-0065 and 003-005-00176-

0, respectively).

R18-2-101(139). 

References the 1987 

Manual - which is the 

current version. 

Acceptable.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 12 of 112

(a)(1)(iii) Potential to emit (iii) 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. Secondary emissions do not count in determining the potential to emit of a stationary 

source.

R18-2-101(109) - - 

Consistent with 

guidance. See 

http://www.epa.gov/reg

ion07/air/title5/t5memo

s/pottoemi.pdf

(a)(1)(iv) Major stationary 

source

(iv)(A) Major stationary source means: R18-2-401(11) - uses 

the term "major source" 

but seems to 

inadvertently refer to 

"major stationary 

source" within the 

definition at (e)

(1) Any stationary source of air pollutants that emits, or has the potential to emit, 100 tons per 

year or more of any regulated NSR pollutant, except that lower emissions thresholds shall apply 

in areas subject to subpart 2, subpart 3, or subpart 4 of part D, title I of the Act, according to 

paragraphs (a)(1)(iv)(A)(1)(i) through (vi) of this section.

(i ) 50 tons per year of volatile organic compounds in any serious ozone nonattainment area.

(ii ) 50 tons per year of volatile organic compounds in an area within an ozone transport region, 

except for any severe or extreme ozone nonattainment area.

(iii ) 25 tons per year of volatile organic compounds in any severe ozone nonattainment area.

(iv ) 10 tons per year of volatile organic compounds in any extreme ozone nonattainment area.

(v ) 50 tons 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 (as determined under rules issued by the Administrator).

(vi ) 70 tons per year of PM-10 in any serious nonattainment area for PM-10;

(2) For the purposes of applying the requirements of paragraph (a)(8) of this section to 

stationary sources of nitrogen oxides located in an ozone nonattainment area or in an ozone 

transport region, any stationary source which emits, or has the potential to emit, 100 tons per 

year or more of nitrogen oxides emissions, except that the emission thresholds in paragraphs 

(a)(1)(iv)(A)(2)(i) through (vi) of this section shall apply in areas subject to subpart 2 of part D, 

title I of the Act.

(i ) 100 tons per year or more of nitrogen oxides in any ozone nonattainment area classified as 

marginal or moderate.

(ii ) 100 tons per year or more of nitrogen oxides in any ozone nonattainment area classified as 

a transitional, submarginal, or incomplete or no data area, when such area is located in an 

ozone transport region.

(iii ) 100 tons per year or more of nitrogen oxides in any area designated under section 107(d) 

of the Act as attainment or unclassifiable for ozone that is located in an ozone transport region.

R18-2-401(11). Didn't 

include (ii) and (iv), but 

don't currently have 

these areas. Acceptable.

R18-2-401(11) Didn't 

include (vi), but don't 

have these areas. 

Acceptable.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 13 of 112

(iv ) 50 tons per year or more of nitrogen oxides in any serious nonattainment area for ozone.

(v ) 25 tons per year or more of nitrogen oxides in any severe nonattainment area for ozone.

(vi ) 10 tons per year or more of nitrogen oxides in any extreme nonattainment area for ozone; 

or

(3) Any physical change that would occur at a stationary source not qualifying under paragraphs 

(a)(1)(iv)(A)(1) or (2) of this section as a major stationary source, if the change would constitute 

a major stationary source by itself.

Not included.

(B) A major stationary source that is major for volatile organic compounds shall be considered 

major for ozone

R18-2-401(11)

(C) The fugitive emissions of a stationary source shall not be included in determining for any of the 

purposes of this paragraph whether it is a major stationary source, unless the source belongs to 

one of the following categories of stationary sources:

(1) Coal cleaning plants (with thermal dryers);

(2) Kraft pulp mills;

(3) Portland cement plants;

(4) Primary zinc smelters;

(5) Iron and steel mills;

(6) Primary aluminum ore reduction plants;

(7) Primary copper smelters;

(8) Municipal incinerators capable of charging more than 250 tons of refuse per day;

(9) Hydrofluoric, sulfuric, or nitric acid plants;

(10) Petroleum refineries;

(11) Lime plants;

(12) Phosphate rock processing plants;

(14) Sulfur recovery plants;

(15) Carbon black plants (furnace process);

(17) Fuel conversion plants;

(18) Sintering plants;

(19) Secondary metal production plants;

(20) Chemical process plants—The term chemical processing plant shall not include ethanol 

production facilities that produce ethanol by natural fermentation included in NAICS codes 

325193 or 312140;

(22) Petroleum storage and transfer units with a total storage capacity exceeding 300,000 

barrels;

(23) Taconite ore processing plants;

(24) Glass fiber processing plants;

(25) Charcoal production plants;

R18-2-401(11)(e) - list 

of source categories is 

in R18-2-101(128). 

Likely contains a typo - 

refers to "this section" 

when it should be all of 

Article 4. Also, 

recommend adding a 

cross reference to 

definition for "Section 

302(j) category" as it is 

not obvious this is a 

term defined in Article 

1.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 14 of 112

(26) Fossil fuel-fired steam electric plants of more than 250 million British thermal units per hour 

heat input; and

(27) Any other stationary source category which, as of August 7, 1980, is being regulated under 

section 111 or 112 of the Act.

(a)(1)(v) Major modification (v)(A) Major modification means any physical change in or change in the method of operation of a 

major stationary source that would result in:

(1) A significant emissions increase of a regulated NSR pollutant (as defined in paragraph 

(a)(1)(xxxvii) of this section); and

(2) A significant net emissions increase of that pollutant from the major stationary source.

(B) Any significant emissions increase (as defined in paragraph (a)(1)(xxvii) of this section) from 

any emissions units or net emissions increase (as defined in paragraph (a)(1)(vi) of this section) at 

a major stationary source that is significant for volatile organic compounds shall be considered 

significant for ozone.

(C) A physical change or change in the method of operation shall not include:

(1) Routine maintenance, repair and replacement. Routine maintenance, repair and replacement 

shall include, but not be limited to, any activity(s) that meets the requirements of the equipment 

replacement provisions contained in paragraph (h) of this section;

Note to paragraph (a)(1)(v)(C)(1): On December 24, 2003, the second sentence of this 

paragraph (a)(1)(v)(C)(1) is stayed indefinitely by court order. The stayed provisions will become 

effective immediately if the court terminates the stay. At that time, EPA will publish a document 

in the Federal Register advising the public of the termination of the stay.

(2) Use of an alternative fuel or raw material by reason of an order under sections 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;

R18-2-101(74)(c)(ii)

(3) Use of an alternative fuel by reason of an order or rule section 125 of the Act; R18-2-101(74)(c)(iii)

(4) Use of an alternative fuel at a steam generating unit to the extent that the fuel is generated 

from municipal solid waste;

R18-2-101(74)(c)(iv)

(5) Use of an alternative fuel or raw material by a stationary source which;

(i ) The source was capable of accommodating before December 21, 1976, unless such change 

would be prohibited under any federally enforceable permit condition which was established 

after December 12, 1976 pursuant to 40 CFR 52.21 or under regulations approved pursuant to 

40 CFR subpart I or §51.166, or

(ii ) The source is approved to use under any permit issued under regulations approved 

pursuant to this section;

(6) An increase in the hours of operation or in the production rate, unless such change is 

prohibited under any federally enforceable permit condition which was established after 

December 21, 1976 pursuant to 40 CFR 52.21 or regulations approved pursuant to 40 CFR part 

51 subpart I or 40 CFR 51.166.

R18-2-101(74)(c)(vi)

(7) Any change in ownership at a stationary source. R18-2-101(74)(c)(vii)

(8) [Reserved]

(9) The installation, operation, cessation, or removal of a temporary clean coal technology 

demonstration project, provided that the project complies with:

R18-2-101(74)(c)(i) - 

consistent with the stay, 

only adopted first 

sentence.

R18-2-101(74)(c)(v)

R18-2-101(74)(c)(ix)

R18-2-101(74)(a)

R18-2-101(74)(b)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 15 of 112

(i ) The State Implementation Plan for the State in which the project is located, and

(ii ) Other requirements necessary to attain and maintain the national ambient air quality 

standard during the project and after it is terminated.

(D) This definition shall not apply with respect to a particular regulated NSR pollutant when the 

major stationary source is complying with the requirements under paragraph (f) of this section for 

a PAL for that pollutant. Instead, the definition at paragraph (f)(2)(viii) of this section shall apply.

R18-2-101(74)(d)

(E) For the purpose of applying the requirements of (a)(8) of this section to modifications at major 

stationary sources of nitrogen oxides located in ozone nonattainment areas or in ozone transport 

regions, whether or not subject to subpart 2, part D, title I of the Act, any significant net emissions 

increase of nitrogen oxides is considered significant for ozone.

R18-2-101(74)(b)

(F) Any physical change in, or change in the method of operation of, a major stationary source of 

volatile organic compounds that results in any increase in emissions of volatile organic compounds 

from any discrete operation, emissions unit, or other pollutant emitting activity at the source shall 

be considered a significant net emissions increase and a major modification for ozone, if the major 

stationary source is located in an extreme ozone nonattainment area that is subject to subpart 2, 

part D, title I of the Act.

Does not include, but no 

extreme ozone 

nonattainment areas.

(G) Fugitive emissions shall not be included in determining for any of the purposes of this section 

whether a physical change in or change in the method of operation of a major stationary source is 

a major modification, unless the source belongs to one of the source categories listed in paragraph 

(a)(1)(iv)(C) of this section. NOTE: By court order, this provision has been stayed indefinitely

Not included in 

definition, consistent 

with stay.

(a)(1)(vi) Net emissions 

increase

(vi)(A) Net emissions increase means, with respect to any regulated NSR pollutant emitted by a 

major stationary source, the amount by which the sum of the following exceeds zero:

R18-2-101(87)(a)

(1) The increase in emissions from a particular physical change or change in the method of 

operation at a stationary source as calculated pursuant to paragraph (a)(2)(ii) of this section; and

R18-2-101(87)(a)(i)

(2) Any other increases and decreases in actual emissions at the major stationary source that are 

contemporaneous with the particular change and are otherwise creditable. Baseline actual 

emissions for calculating increases and decreases under this paragraph (a)(1)(vi)(A)(2) shall be 

determined as provided in paragraph (a)(1)(xxxv) of this section, except that paragraphs 

(a)(1)(xxxv)(A)(3) and (a)(1)(xxxv)(B)(4) of this section shall not apply.

R18-2-101(87)(a)(ii and 

iii)

(B) An increase or decrease in actual emissions is contemporaneous with the increase from the 

particular change only if it occurs before the date that the increase from the particular change 

occurs;

(C) An increase or decrease in actual emissions is creditable only if:

(1) It occurs within a reasonable period to be specified by the reviewing authority; and

(2) The reviewing authority has not relied on it in issuing a permit for the source under 

regulations approved pursuant to this section, which permit is in effect when the increase in 

actual emissions from the particular change occurs; and

R18-2-101(87)(b) and 

(c')
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 16 of 112

(3) As it pertains to an increase or decrease in fugitive emissions (to the extent quantifiable), it 

occurs at an emissions unit that is part of one of the source categories listed in paragraph 

(a)(1)(iv)(C) of this section or it occurs at an emissions unit that is located at a major stationary 

source that belongs to one of the listed source categories. Fugitive emission increases or 

decreases are not creditable for those emissions units located at a facility whose primary activity 

is not represented by one of the source categories listed in paragraph (a)(1)(iv)(C) of this section 

and that are not, by themselves, part of a listed source category. NOTE: This paragraph has 

been stayed by court order indefinitely.

Did not adopt - 

consistent with stay

(D) An increase in actual emissions is creditable only to the extent that the new level of actual 

emissions exceeds the old level.

R18-2-101(87)(e)

(E) A decrease in actual emissions is creditable only to the extent that:

(1) The old level of actual emission or the old level of allowable emissions whichever is lower, 

exceeds the new level of actual emissions;

(2) It is enforceable as a practical matter at and after the time that actual construction on the 

particular change begins; and

(3) The reviewing authority has not relied on it in issuing any permit under regulations approved 

pursuant to 40 CFR part 51 subpart I or the State has not relied on it in demonstrating 

attainment or reasonable further progress;

(4) It has approximately the same qualitative significance for public health and welfare as that 

attributed to the increase from the particular change; and

(F) An increase that results from a physical change at a source 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.

R18-2-101(87)(g)

(G) Paragraph (a)(1)(xii)(B) of this section shall not apply for determining creditable increases and 

decreases or after a change.

Not included.

(a)(1)(vii) Emissions unit (vii) Emissions unit means any part of a stationary source that emits or would have the potential to 

emit any regulated NSR pollutant and includes an electric steam generating unit as defined in 

paragraph (a)(1)(xx) of this section. For purposes of this section, there are two types of emissions 

units as described in paragraphs (a)(1)(vii)(A) and (B) of this section.

R18-2-101(48)

(A) A new emissions unit is any emissions unit which is (or will be) newly constructed and which 

has existed for less than 2 years from the date such emissions unit first operated.

R18-2-401(12)

(B) An existing emissions unit is any emissions unit that does not meet the requirements in 

paragraph (a)(1)(vii)(A) of this section. A replacement unit, as defined in paragraph (a)(1)(xxi) of 

this section, is an existing emissions unit.

R18-2-401(6)

(a)(1)(viii) Secondary 

emissions

(viii) Secondary emissions means emissions which would occur as a result of the construction or 

operation of a major stationary source or major modification, but do not come from the major 

stationary source or major modification itself. For the purpose of this section, secondary emissions 

must be specific, well defined, quantifiable, and impact the same general area as the stationary 

source or modification which causes the secondary emissions. Secondary emissions include 

emissions from any offsite support facility which would not be constructed or increase its emissions 

except as a result of the construction of operation of the major stationary source of major 

modification. Secondary emissions do not include any emissions which come directly from a mobile 

source such as emissions from the tailpipe of a motor vehicle, from a train, or from a vessel.

R18-2-101(127). 

Missing the word 

"except" in the third 

sentence.

R18-2-101(87)(f). 

Needs to identify R18-2-

302.01 in R18-2-

101(87)(f)(v) because it 

would be a program 

approved under Subpart 

I.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 17 of 112

(a)(1)(ix) Fugitive emissions (ix) Fugitive emissions means those emissions which could not reasonably pass through a stack, 

chimney, vent or other functionally equivalent opening.

R18-2-101(59)

(a)(1)(x) Significant (x)(A) Significant means, in reference to a net emissions increase or the potential of a source to 

emit any of the following pollutants, a rate of emissions that would equal or exceed any of the 

following rates:

Pollutant Emission Rate

Carbon monoxide: 100 tons per year (tpy)

Nitrogen oxides: 40 tpy

Sulfur dioxide: 40 tpy

Ozone: 40 tpy of volatile organic compounds or nitrogen oxides

Lead: 0.6 tpy

PM10: 15 tpy

PM2.5: 10 tpy of direct PM2.5 emissions; 40 tpy of sulfur dioxide emissions; 40 tpy of nitrogen 

oxide emissions unless demonstrated not to be a PM2.5 precursor under paragraph (a)(1)(xxxvii) 

of this section

(B) Notwithstanding the significant emissions rate for ozone in paragraph (a)(1)(x)(A) of this 

section, significant means, in reference to an emissions increase or a net emissions increase, any 

increase in actual emissions of volatile organic compounds that would result from any physical 

change in, or change in the method of operation of, a major stationary source locating in a serious 

or severe ozone nonattainment area that is subject to subpart 2, part D, title I of the Act, if such 

emissions increase of volatile organic compounds exceeds 25 tons per year.

R18-2-405(B) and R18-

2-101(130)(b). Does 

not refer to the 

regulatory term "net 

emissions increase." 

R18-2-405(B) can be 

revised such that it 

relies soley on the 

definition for net 

emissions increase. 

(C) For the purposes of applying the requirements of paragraph (a)(8) of this section to 

modifications at major stationary sources of nitrogen oxides located in an ozone nonattainment 

area or in an ozone transport region, the significant emission rates and other requirements for 

volatile organic compounds in paragraphs (a)(1)(x)(A), (B), and (E) of this section shall apply to 

nitrogen oxides emissions.

R18-2-101(130)(a),(b), 

and R18-2-405(B) - 

same SER applied to 

NOX and VOC

(D) Notwithstanding the significant emissions rate for carbon monoxide under paragraph 

(a)(1)(x)(A) of this section, significant means, in reference to an emissions increase or a net 

emissions increase, any increase in actual emissions of carbon monoxide that would result from any 

physical change in, or change in the method of operation of, a major stationary source in a serious 

nonattainment area for carbon monoxide if such increase equals or exceeds 50 tons per year, 

provided the Administrator has determined that stationary sources contribute significantly to carbon 

monoxide levels in that area.

R18-2-101(130)(c )

(E) Notwithstanding the significant emissions rates for ozone under paragraphs (a)(1)(x)(A) and (B) 

of this section, any increase in actual emissions of volatile organic compounds from any emissions 

unit at a major stationary source of volatile organic compounds located in an extreme ozone 

nonattainment area that is subject to subpart 2, part D, title I of the Act shall be considered a 

significant net emissions increase.

Did not include, but no 

extreme ozone 

nonattainment areas

R18-2-101(130)(a). 

References R18-2-405 

for serious and severe 

areas. R18-2-405(B) 

does not use the term 

"net emissions increase" 

as required by federal 

definition. 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 18 of 112

(a)(1)(xi) Allowable emissions (xi) Allowable emissions means the emissions rate of a stationary source 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:

R18-2-101(13)

(A) The applicable standards set forth in 40 CFR part 60 or 61; R18-2-101(13)(a). 

Recommend revising to 

use "and" instead of 

"or" for consistency with 

federal reg.

(B) Any applicable State Implementation Plan emissions limitation including those with a future 

compliance date; or

R18-2-101(13)(b) - 

does not include "future 

compliance date" 

language.

(C) The emissions rate specified as a federally enforceable permit condition, including those with 

a future compliance date.

R18-2-101(13)(c) does 

not include "future 

compliance date" 

language

(a)(1)(xii) Actual emissions (xii)(A) Actual emissions means the actual rate of emissions of a regulated NSR pollutant from an 

emissions unit, as determined in accordance with paragraphs (a)(1)(xii)(B) through (D) of this 

section, except that this definition shall not apply for calculating whether a significant emissions 

increase has occurred, or for establishing a PAL under paragraph (f) of this section. Instead, 

paragraphs (a)(1)(xxviii) and (xxxv) of this section shall apply for those purposes.

R18-2-101(2)(a) and 

(e)

(B) In general, actual emissions as of a particular date shall equal 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. The reviewing 

authority shall allow the use of a different time period upon a determination that it is more 

representative of normal source operation. Actual emissions shall be calculated using the unit's 

actual operating hours, production rates, and types of materials processed, stored, or combusted 

during the selected time period.

R18-2-101(2)(a)

(C) The reviewing authority may presume that source-specific allowable emissions for the unit are 

equivalent to the actual emissions of the unit.

R18-2-101(2)(b)

(D) For any emissions unit that has not begun normal operations on the particular date, actual 

emissions shall equal the potential to emit of the unit on that date.

R18-2-101(2)(c) and ( 

d) - references to Class 

I and Class II sources, 

no definition for Class I 

or Class II source. 

Could revise to 

reference "source with a 

Class I or Class II 

permit".

(a)(1)(xiii) LAER (xiii) Lowest achievable emission rate (LAER) means, for any source, the more stringent rate of 

emissions based on the following:
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 19 of 112

(A) The most stringent emissions limitation which is contained in the implementation plan of any 

State for such class or category of stationary source, unless the owner or operator of the proposed 

stationary source demonstrates that such limitations are not achievable; or

R18-2-401(10)(b)

(B) The most stringent emissions limitation which is achieved in practice by such class or category 

of stationary sources. This limitation, when applied to a modification, means the lowest achievable 

emissions rate for the new or modified emissions units within or stationary source. In no event shall 

the application of the term permit a proposed new or modified stationary source to emit any 

pollutant in excess of the amount allowable under an applicable new source standard of 

performance.

R18-2-401(10)(b). 

Contains reference to 

Articles 9 and 11, see 

discussion in Section 

5.7.2 of the TSD.

(a)(1)(xiv) Federally 

enforceable

(xiv) Federally enforceable means all limitations and conditions which are enforceable by the 

Administrator, including those requirements developed pursuant to 40 CFR parts 60 and 61, 

requirements within any applicable State implementation plan, 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 an EPA-approved program that is incorporated into the 

State implementation plan and expressly requires adherence to any permit issued under such 

program.

R18-2-101(53) - 

(53)(d) contains 

clarifications for 

requirements pursuant 

to R18-2-306.01 or R18-

2-306.02. See 

disapproval issue 

discussed in Section 

5.7.2 of the TSD.

(a)(1)(xv) Begin actual 

construction

(xv) Begin actual construction means in general, initiation of physical on-site construction activities 

on an emissions unit which are of a permanent nature. Such activities include, but are not limited 

to, installation of building supports and foundations, laying of underground pipework, and 

construction of permanent storage structures. With respect to a change in method of operating this 

term refers to those on-site activities other than preparatory activities which mark the initiation of 

the change.

R9-3-101(20).

(a)(1)(xvi) Commence (xvi) 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:

(A) Begun, or caused to begin, a continuous program of actual on-site construction of the source, 

to be completed within a reasonable time; or

(B) 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 

construction of the source to be completed within a reasonable time.

(a)(1)(xvii) Necessary 

preconstruction 

approvals or 

permits

(xvii) Necessary preconstruction approvals or permits means those Federal air quality control laws 

and regulations and those air quality control laws and regulations which are part of the applicable 

State Implementation Plan.

R18-2-101(86)

(a)(1)(xviii) Construction (xviii) Construction means any physical change or change in the method of operation (including 

fabrication, erection, installation, demolition, or modification of an emissions unit) that would result 

in a change in emissions.

R18-2-101(32). Uses 

the term "actual 

emissions" instead of 

"emissions." Actual 

emissions is a defined 

term, its use in this 

context is unclear. 

R18-2-101(31)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 20 of 112

(a)(1)(xix) VOC (xix)Volatile organic compounds (VOC) is as defined in §51.100(s) of this part. R18-2-101(152) - a few 

exemptions from 

definition are missing, 

but does not make less 

stringent

(a)(1)(xx) Electric utility 

steam generating 

unit

(xx) Electric utility steam generating unit means any steam electric generating unit that is 

constructed for the purpose of supplying more than one-third of its potential electric output 

capacity and more than 25 MW electrical 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 steamelectric generator that would produce electrical energy for sale is also considered in determining 

the electrical energy output capacity of the affected facility.

R18-2-101(45)

(a)(1)(xxi) Replacement unit (xxi) Replacement unit means an emissions unit for which all the criteria listed in paragraphs 

(a)(1)(xxi)(A) through (D) of this section 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 §60.15(b)(1) of this chapter, 

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 replacement does not alter the basic design parameters (as discussed in paragraph (h)(2) 

of this section) of the process unit.

(D) The replaced emissions unit is permanently removed from the major stationary 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.

(a)(1)(xxii) Temporary clean 

coal technology 

demonstration 

project

(xxii) Temporary clean coal technology demonstration project means a clean coal technology 

demonstration project that is operated for a period of 5 years or less, and which complies with the 

State Implementation Plan for the State in which the project is located and other requirements 

necessary to attain and maintain the national ambient air quality standards during the project and 

after it is terminated.

R18-2-101(141)

(a)(1)(xxiii) Clean coal 

technology

(xxiii) Clean coal technology means any technology, including technologies applied at the 

precombustion, combustion, or post combustion stage, at a new or existing facility which will 

achieve significant reductions in air emissions of sulfur dioxide or oxides of nitrogen associated with 

the utilization of coal in the generation of electricity, or process steam which was not in widespread 

use as of November 15, 1990.

R18-2-101(27)

(a)(1)(xxiv) Clean coal 

technology 

demonstration 

project

(xxiv) Clean coal technology demonstration project means a project using funds appropriated 

under the heading “Department of Energy-Clean Coal Technology,” up to a total amount of 

$2,500,000,000 for commercial demonstration of clean coal technology, or similar projects funded 

through appropriations for the Environmental Protection Agency. The Federal contribution for a 

qualifying project shall be at least 20 percent of the total cost of the demonstration project.

R18-2-101(28)

(a)(1)(xxv) (xxv) [Reserved]

R18-2-401(22)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 21 of 112

(a)(1)(xxvi) Pollution prevention (xxvi) Pollution prevention means any activity that through process changes, product reformulation 

or redesign, or substitution of less polluting raw materials, eliminates or reduces the release of air 

pollutants (including fugitive emissions) and other pollutants to the environment prior to recycling, 

treatment, or disposal; it does not mean recycling (other than certain “in-process recycling” 

practices), energy recovery, treatment, or disposal.

Not included, but phrase 

no longer applicable to 

the rest of 51.165. 

Phrase was used for 

pollution control 

projects (PCPs) rule 

revisions, which were 

vacated in 2006.

(a)(1)(xxvii) Significant 

emissions increase

(xxvii) Significant emissions increase means, for a regulated NSR pollutant, an increase in 

emissions that is significant (as defined in paragraph (a)(1)(x) of this section) for that pollutant.

R18-2-101(131)

(a)(1)(xxviii) Projected actual 

emissions

(xxviii)(A) 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 

(12-month period) 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 of 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 

stationary source.

R18-2-401(20)(a)

(B) In determining the projected actual emissions under paragraph (a)(1)(xxviii)(A) of this section 

before beginning actual construction, the owner or operator of the major stationary source:

R18-2-401(20)(b)

(1) Shall consider all relevant information, including but not limited to, historical operational data, 

the company's own representations, the company's expected business activity and the company's 

highest projections of business activity, the company's filings with the State or Federal regulatory 

authorities, and compliance plans under the approved plan; and

R18-2-401(20)(b)(i)

(2) Shall include fugitive emissions to the extent quantifiable, and emissions associated with 

startups, shutdowns, and malfunctions; and

R18-2-401(20)(b)(ii) 

and (iii). Does not 

include malfunctions. 

(3) Shall exclude, in calculating any increase in emissions that results from the particular project, 

that portion of the 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 under paragraph (a)(1)(xxxv) of this section and that are also unrelated to the 

particular project, including any increased utilization due to product demand growth; or,

R18-2-401(20)(b)(iv)

(4) In lieu of using the method set out in paragraphs (a)(1)(xxviii)(B)(1) through (3) of this 

section, may elect to use the emissions unit's potential to emit, in tons per year, as defined under 

paragraph (a)(1)(iii) of this section.

R18-2-401(20)(c)

(a)(1)(xxix) (xxix) [Reserved]
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 22 of 112

(a)(1)(xxx) Nonattainment NSR 

program

(xxx) Nonattainment major new source review (NSR) program means a major source 

preconstruction permit program that has been approved by the Administrator and incorporated into 

the plan to implement the requirements of this section, or a program that implements part 51, 

appendix S, Sections I through VI of this chapter. Any permit issued under such a program is a 

major NSR permit.

Not included. See 

review of 40 CFR 

51.165(f)(1)(iii)(B), f(9) 

and f(11). If issues 

corrected for these 

requirements, then 

approvable. 

(a)(1)(xxxi) CEMS (xxxi) Continuous emissions monitoring system (CEMS) means all of the equipment that may be 

required to meet the data acquisition and availability requirements of this section, to sample, 

condition (if applicable), analyze, and provide a record of emissions on a continuous basis.

R18-2-101(34)

(a)(1)(xxxii) PEMS (xxxii) Predictive emissions monitoring system (PEMS) means all of the equipment necessary to 

monitor process and control device operational parameters (for example, control device secondary 

voltages and electric currents) and other information (for example, gas flow rate, O2 or CO2 

concentrations), and calculate and record the mass emissions rate (for example, lb/hr) on a 

continuous basis.

R18-2-101(102). Does 

not include examples 

provided in federal 

regulation. Definition is 

less clear. 

(a)(1)(xxxiii) CPMS (xxxiii) Continuous parameter monitoring system (CPMS) means all of the equipment necessary to 

meet the data acquisition and availability requirements of this section, to monitor process and 

control device operational parameters (for example, control device secondary voltages and electric 

currents) and other information (for example, gas flow rate, O2 or CO2 concentrations), and to 

record average operational parameter value(s) on a continuous basis.

R18-2-101(36). Does 

not include examples 

provided in federal 

regulation. Definition is 

less clear. 

(a)(1)(xxxiv) CERMS (xxxiv) Continuous emissions rate monitoring system (CERMS) means the total equipment required 

for the determination and recording of the pollutant mass emissions rate (in terms of mass per unit 

of time).

R18-2-101(35)

(a)(1)(xxxv) Baseline actual 

emissions

(xxxv) Baseline actual emissions means the rate of emissions, in tons per year, of a regulated NSR 

pollutant, as determined in accordance with paragraphs (a)(1)(xxxv)(A) through (D) of this section.

R18-2-401(2)

(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 5-year period 

immediately preceding when the owner or operator begins actual construction of the project. The 

reviewing authority shall allow the use of a different time period upon a determination that it is 

more representative of normal source operation.

R18-2-401(2)(a)

(1) The average rate shall include fugitive emissions to the extent quantifiable, and emissions 

associated with startups, shutdowns, and malfunctions.

R18-2-401(2)(a)(i)

(2) 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-month period.

R18-2-401(2)(a)(ii)

(3) 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.

R18-2-401(2)(a)(iii)

(4) 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 amount if required by paragraph (a)(1)(xxxv)(A)(2) of this section.

R18-2-401(2)(a)(iv)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 23 of 112

(B) For an 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 emissions unit actually 

emitted the pollutant during any 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 

reviewing authority for a permit required either under this section or under a plan approved by 

the Administrator, whichever is earlier, except that the 10-year period shall not include any 

period earlier than November 15, 1990.

R18-2-401(2)(b)

(1) The average rate shall include fugitive emissions to the extent quantifiable, and emissions 

associated with startups, shutdowns, and malfunctions.

R18-2-401(2)(b)(i)

(2) The average rate shall be adjusted downward to exclude any non-compliant emissions that 

occurred while the source was operating above an emission limitation that was legally 

enforceable during the consecutive 24-month period.

R18-2-401(2)(b)(ii)

(3) The average rate shall be adjusted downward to exclude any emissions that would have 

exceeded an emission limitation with which the major stationary source must currently comply, 

had such major stationary source been required to comply with such limitations during the 

consecutive 24-month period. However, if an emission limitation is part of a maximum 

achievable control technology standard that the Administrator proposed or promulgated under 

part 63 of this chapter, the baseline actual emissions need only be adjusted if the State has 

taken credit for such emissions reductions in an attainment demonstration or maintenance plan 

consistent with the requirements of paragraph (a)(3)(ii)(G) of this section.

R18-2-401(2)(b)(iii) - 

references section 

110(a)(l) instead of 

51.165(a)(3). 

Approvable.

(4) 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.

R18-2-401(2)(b)(iv)

(5) 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 amount if required by paragraphs (a)(1)(xxxv)(B)(2) and (3) of this section.

R18-2-401(2)(b)(v)

(C) 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 such unit shall 

equal zero; and thereafter, for all other purposes, shall equal the unit's potential to emit.

R18-2-401(2)(c)

(D) 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 

paragraph (a)(1)(xxxv)(A) of this section, for other existing emissions units in accordance with 

the procedures contained in paragraph (a)(1)(xxxv)(B) of this section, and for a new emissions 

unit in accordance with the procedures contained in paragraph (a)(1)(xxxv)(C) of this section.

R18-2-401(2)(d)

(xxxvi) [Reserved]

(a)(1)(xxxvii) Regulated NSR 

pollutant

(xxxvii) Regulated NSR pollutant, for purposes of this section, means the following: R18-2-101(122)

(A) Nitrogen oxides or any volatile organic compounds; Not included.

(B) Any pollutant for which a national ambient air quality standard has been promulgated; R18-2-101(122)(a))
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 24 of 112

(C) Any pollutant that is identified under this paragraph (a)(1)(xxxvii)(C) as a constituent or 

precursor of a general pollutant listed under paragraph (a)(1)(xxxvii)(A) or (B) of this section, 

provided that such constituent or precursor pollutant may only be regulated under NSR as part of 

regulation of the general pollutant. Precursors identified by the Administrator for purposes of NSR 

are the following:

R18-2-101(122)(a). 

Missing language 

specifying that 

"provided that such 

constituent or precursor 

pollutant may only be 

regulated under NSR as 

part of a regulation of 

the general pollutant."

(1) Volatile organic compounds and nitrogen oxides are precursors to ozone in all ozone 

nonattainment areas.

R18-2-101(122)(a)(i)

(2) Sulfur dioxide is a precursor to PM2.5 in all PM2.5 nonattainment areas. R18-2-101(122)(a)(ii)

(3) Nitrogen oxides are presumed to be precursors to PM2.5 in all PM2.5 nonattainment areas, 

unless the State demonstrates to the Administrator's satisfaction or EPA demonstrates that 

emissions of nitrogen oxides from sources in a specific area are not a significant contributor to 

that area's ambient PM2.5 concentrations.

R18-2-101(122)(a)(iii), 

presumed precursor

(4) Volatile organic compounds and ammonia are presumed not to be precursors to PM2.5 in 

any PM2.5 nonattainment area, unless the State demonstrates to the Administrator's 

satisfaction or EPA demonstrates that emissions of volatile organic compounds or ammonia 

from sources in a specific area are a significant contributor to that area's ambient PM2.5 

concentrations; or

No determination to 

include VOC and 

ammonia as precursors. 

However, see Section 

5.7.3 of the TSD 

regarding recent federal 

Court decision related to 

PM2.5.

(D) PM2.5 emissions and PM10 emissions shall include gaseous emissions from a source or 

activity which condense to form particulate matter at ambient temperatures. On or after January 

1, 2011 (or any earlier date established in the upcoming rulemaking codifying test methods), 

such condensable particulate matter shall be accounted for in applicability determinations and in 

establishing emissions limitations for PM2.5 and PM10 in nonattainment major NSR permits. 

Compliance with emissions limitations for PM2.5 and PM10 issued prior to this date shall not be 

based on condensable particulate matter unless required by the terms and conditions of the 

permit or the applicable implementation plan. Applicability determinations made prior to this date 

without accounting for condensable particulate matter shall not be considered in violation of this 

section unless the applicable implementation plan required condensable particulate matter to be 

included.

R18-2-101(122)(f) 

Contains references to 

particulate matter that 

have recently been 

removed from 51.166. 

See discussion in 

Section 5.7.4 of the 

TSD.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 25 of 112

(a)(1)(xxxviii) Reviewing authority (xxxviii) Reviewing authority means the State air pollution control agency, local agency, other 

State agency, Indian tribe, or other agency authorized by the Administrator to carry out a permit 

program under this section and §51.166, or the Administrator in the case of EPA-implemented 

permit programs under §52.21.

Uses the term Director 

or Department - which 

carry out the SIP. Also 

have a definition for 

permitting authority at 

R18-2-101(98).

(a)(1)(xxxix) Project (xxxix) Project means a physical change in, or change in the method of operation of, an existing 

major stationary source.

R18-2-101(112)

(a)(1)(xl) Best available 

control technology

(xl) Best available control technology (BACT) 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 reviewing authority, on a case-by-case basis, taking into account energy, environmental, and 

economic impacts and other costs, determines is achievable for such source or modification through 

application of production processes or available methods, systems, and techniques, including fuel 

cleaning or treatment or innovative fuel combustion techniques for control of such pollutant. In no 

event shall application of best available control technology result in emissions of any pollutant 

which would exceed the emissions allowed by any applicable standard under 40 CFR part 60 or 61. 

If the reviewing authority 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 thereof, may be prescribed instead to satisfy the requirement for the application of 

BACT. Such standard shall, to the degree possible, set forth the emissions reduction achievable by 

implementation of such design, equipment, work practice or operation, and shall provide for 

compliance by means which achieve equivalent results.

R18-2-101(21). See 

also R18-2-406(A)(4) 

which is referenced in 

(21). Contains a typo -

"air" where the federal 

regulation has "a". The 

"a" in the federal reg is 

a typo - "air" should be 

deleted. ADEQ 

references Articles 9 

and 11, instead of parts 

60 and 61, which 

contain NSPS and 

NESHAP requirements. 

These Articles are not in 

the SIP and do not 

necessarily include all of 

the subparts in 60 and 

61.

(a)(1)(xli) PSD permit (xli) Prevention of Significant Deterioration (PSD) permit means any permit that is issued under a 

major source preconstruction permit program that has been approved by the Administrator and 

incorporated into the plan to implement the requirements of §51.166 of this chapter, or under the 

program in §52.21 of this chapter.

Not included, but not 

otherwise used by 

51.165

(a)(1)(xlii) Federal Land 

Manager

(xlii) Federal Land Manager means, with respect to any lands in the United States, the Secretary of 

the department with authority over such lands.

R18-2-101(52)

(a)(1)(xliii) Process unit (xliii)(A) In general, process unit means any collection of structures and/or equipment that 

processes, assembles, applies, blends, or otherwise uses material inputs to produce or store an 

intermediate or a completed product. A single stationary source may contain more than one 

process unit, and a process unit may contain more than one emissions unit.

(B) Pollution control equipment is not part of the process unit, unless it serves a dual function as 

both process and control equipment. Administrative and warehousing facilities are not part of the 

process unit.

(C) For replacement cost purposes, components shared between two or more process units are 

proportionately allocated based on capacity.

Not included. These 

provisions were stayed 

indefinitely by the DC 

Circuit Court on 

December 24, 2003 and 

are not needed for a 

PSD program.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 26 of 112

(D) The following list identifies the process units at specific categories of stationary sources.

(1) For a steam electric generating facility, the process unit consists of those portions of the 

plant that contribute directly to the production of electricity. For example, at a pulverized coalfired facility, the process unit would generally be the combination of those systems from the 

coal receiving equipment through the emission stack (excluding post-combustion pollution 

controls), including the coal handling equipment, pulverizes or coal crushers, feedwater heaters, 

ash handling, boiler, burners, turbine-generator set, condenser, cooling tower, water treatment 

system, air preheaters, and operating control systems. Each separate generating unit is a 

separate process unit.

(2) For a petroleum refinery, there are several categories of process units: those that separate 

and/or distill petroleum feedstocks; those that change molecular structures; petroleum treating 

processes; auxiliary facilities, such as steam generators and hydrogen production units; and 

those that load, unload, blend or store intermediate or completed products.

(3) For an incinerator, the process unit would consist of components from the feed pit or refuse 

pit to the stack, including conveyors, combustion devices, heat exchangers and steam 

generators, quench tanks, and fans.

Note to paragraph (a)(1)(xliii): By a court order on December 24, 2003, this paragraph 

(a)(1)(xliii) is stayed indefinitely. The stayed provisions will become effective immediately if the 

court terminates the stay. At that time, EPA will publish a document in the Federal Register 

advising the public of the termination of the stay.

(a)(1)(xliv) Functionally 

equivalent 

component

(xliv) Functionally equivalent component means a component that serves the same purpose as the 

replaced component.

Note to paragraph (a)(1)(xliv): By a court order on December 24, 2003, this paragraph 

(a)(1)(xliv) is stayed indefinitely. The stayed provisions will become effective immediately if the 

court terminates the stay. At that time, EPA will publish a document in the Federal Register 

advising the public of the termination of the stay.

(a)(1)(xlv) Fixed capital cost (xlv) Fixed capital cost means the capital needed to provide all the depreciable components. 

“Depreciable components” refers to all components of fixed capital cost and is calculated by 

subtracting land and working capital from the total capital investment, as defined in paragraph 

(a)(1)(xlvi) of this section.

Note to paragraph (a)(1)(xlv): By a court order on December 24, 2003, this paragraph 

(a)(1)(xlv) is stayed indefinitely. The stayed provisions will become effective immediately if the 

court terminates the stay. At that time, EPA will publish a document in the Federal Register 

advising the public of the termination of the stay.

(a)(1)(xlvi) Total capital 

investment

(xlvi) Total capital investment means the sum of the following: All costs required to purchase 

needed process equipment (purchased equipment costs); the costs of labor and materials for 

installing that equipment (direct installation costs); the costs of site preparation and buildings; 

other costs such as engineering, construction and field expenses, fees to contractors, startup and 

performance tests, and contingencies (indirect installation costs); land for the process equipment; 

and working capital for the process equipment.

Not included. These 

provisions were stayed 

indefinitely by the DC 

Circuit Court on 

December 24, 2003 and 

are not needed for a 

PSD program.

Not included. These 

provisions were stayed 

indefinitely by the DC 

Circuit Court on 

December 24, 2003 and 

are not needed for a 

PSD program.

Not included. These 

provisions were stayed 

indefinitely by the DC 

Circuit Court on 

December 24, 2003 and 

are not needed for a 

PSD program.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 27 of 112

Note to paragraph (a)(1)(xlvi): By a court order on December 24, 2003, this paragraph 

(a)(1)(xlvi) is stayed indefinitely. The stayed provisions will become effective immediately if the 

court terminates the stay. At that time, EPA will publish a document in the Federal Register 

advising the public of the termination of the stay.

(a)(2) Applicability 

procedures

(2) Applicability procedures. (i) Each plan shall adopt a preconstruction review program to satisfy 

the requirements of sections 172(c)(5) and 173 of the Act for any area designated nonattainment 

for any national ambient air quality standard under subpart C of 40 CFR part 81. Such a program 

shall apply to any new major stationary source or major modification that is major for the pollutant 

for which the area is designated nonattainment under section 107(d)(1)(A)(i) of the Act, if the 

stationary source or modification would locate anywhere in the designated nonattainment area.

R18-2-402(A), (B), and 

(C), R18-2-403(A). See 

discussion in Section 

5.7.2 of the TSD related 

to ADEQ's use of the 

term "proposed final 

permit." 

(ii) Each plan shall use the specific provisions of paragraphs (a)(2)(ii)(A) through (F) of this 

section. Deviations from these provisions will be approved only if the State specifically 

demonstrates that the submitted provisions are more stringent than or at least as stringent in all 

respects as the corresponding provisions in paragraphs (a)(2)(ii)(A) through (F) of this section.

R18-2-402(D)

(A) Except as otherwise provided in paragraphs (a)(2)(iii) and (iv) of this section, and 

consistent with the definition of major modification contained in paragraph (a)(1)(v)(A) of this 

section, a project is a major modification for a regulated NSR pollutant if it causes two types of 

emissions increases—a significant emissions increase (as defined in paragraph (a)(1)(xxvii) of 

this section), and a significant net emissions increase (as defined in paragraphs (a)(1)(vi) and 

(x) of this section). The project is not a major modification if it does not cause a significant 

emissions increase. If the project causes a significant emissions increase, then the project is a 

major modification only if it also results in a significant net emissions increase.

R18-2-402(D)(1)

(B) The procedure for calculating (before beginning actual construction) whether a significant 

emissions increase (i.e., the first step of the process) will occur depends upon the type of 

emissions units being modified, according to paragraphs (a)(2)(ii)(C) through (F) of this 

section. The procedure for calculating (before beginning actual construction) whether a 

significant net emissions increase will occur at the major stationary source (i.e., the second step 

of the process) is contained in the definition in paragraph (a)(1)(vi) of this section. Regardless 

of any such preconstruction projections, a major modification results if the project causes a 

significant emissions increase and a significant net emissions increase.

R18-2-402(D)(2)

(C) Actual-to-projected-actual applicability test for projects that only involve existing emissions 

units. A significant emissions increase of a regulated NSR pollutant is projected to occur if the 

sum of the difference between the projected actual emissions (as defined in paragraph 

(a)(1)(xxviii) of this section) and the baseline actual emissions (as defined in paragraphs 

(a)(1)(xxxv)(A) and (B) of this section, as applicable), for each existing emissions unit, equals 

or exceeds the significant amount for that pollutant (as defined in paragraph (a)(1)(x) of this 

section).

R18-2-402(D)(3)

PSD program.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 28 of 112

(D) Actual-to-potential test for projects that only involve construction of a new emissions 

unit(s). A significant emissions increase of a regulated NSR pollutant is projected to occur if the 

sum of the difference between the potential to emit (as defined in paragraph (a)(1)(iii) of this 

section) from each new emissions unit following completion of the project and the baseline 

actual emissions (as defined in paragraph (a)(1)(xxxv)(C) of this section) of these units before 

the project equals or exceeds the significant amount for that pollutant (as defined in paragraph 

(a)(1)(x) of this section).

R18-2-402(D)(4)

(E) [Reserved]

(F) Hybrid test for projects that involve multiple types of emissions units. A significant 

emissions increase of a regulated NSR pollutant is projected to occur if the sum of the 

emissions increases for each emissions unit, using the method specified in paragraphs 

(a)(2)(ii)(C) through (D) of this section as applicable with respect to each emissions unit, for 

each type of emissions unit equals or exceeds the significant amount for that pollutant (as 

defined in paragraph (a)(1)(x) of this section).

R18-2-402(D)(6) - only 

refers back to the test 

in (d) and not both (c) 

and (d). In all cases, 

these are at least as 

stringent so not an 

approvability issue, but 

may want to fix. May 

want to add cross 

references to defined 

terms for consistency 

with federal 

requirement.

(iii) The plan shall require that for any major stationary source for a PAL for a regulated NSR 

pollutant, the major stationary source shall comply with requirements under paragraph (f) of this 

section.

R18-2-402(E)

(a)(3) (3)(i) Each plan shall provide that for sources and modifications subject to any preconstruction 

review program adopted pursuant to this subsection the baseline for determining credit for 

emissions reductions is the emissions limit under the applicable State Implementation Plan in effect 

at the time the application to construct is filed, except that the offset baseline shall be the actual 

emissions of the source from which offset credit is obtained where;

R18-2-404(B) and 

(B)(1)

(A) The demonstration of reasonable further progress and attainment of ambient air quality 

standards is based upon the actual emissions of sources located within a designated 

nonattainment area for which the preconstruction review program was adopted; or

R18-2-404(B)(1)(a)

(B) The applicable State Implementation Plan does not contain an emissions limitation for that 

source or source category.

R18-2-404(B)(1)(b)

(ii) The plan shall further provide that: R18-2-404(B)(1)

(A) Where the emissions limit under the applicable State Implementation Plan allows greater 

emissions than the potential to emit of the source, emissions offset credit will be allowed only 

for control below this potential;

R18-2-404(B)(2)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 29 of 112

(B) For an existing fuel combustion source, credit shall be based on the allowable emissions 

under the applicable State Implementation Plan for the type of fuel being burned at the time 

the application to construct is filed. If the existing source commits to switch to a cleaner fuel at 

some future date, emissions offset credit based on the allowable (or actual) emissions for the 

fuels involved is not acceptable, unless the permit is conditioned to require the use of a 

specified alternative control measure which would achieve the same degree of emissions 

reduction should the source switch back to a dirtier fuel at some later date. The reviewing 

authority should ensure that adequate long-term supplies of the new fuel are available before 

granting emissions offset credit for fuel switches,

R18-2-404(C) 

(C)(1) Emissions reductions achieved by shutting down an existing emission unit or curtailing 

production or operating hours may be generally credited for offsets if they meet the 

requirements in paragraphs (a)(3)(ii)(C)(1)(i) through (ii) of this section.

R18-2-404(D)(1)

(i ) Such reductions are surplus, permanent, quantifiable, and federally enforceable. R18-2-404(D)(1)(a)

(ii ) The shutdown or curtailment occurred after the last day of the base year for the SIP 

planning process. For purposes of this paragraph, a reviewing authority may choose to 

consider a prior shutdown or curtailment to have occurred after the last day of the base 

year if the projected emissions inventory used to develop the attainment demonstration 

explicitly includes the emissions from such previously shutdown or curtailed emission units. 

However, in no event may credit be given for shutdowns that occurred before August 7, 

1977.

R18-2-404(D)(1)(b)

(2) Emissions reductions achieved by shutting down an existing emissions unit or curtailing 

production or operating hours and that do not meet the requirements in paragraph 

(a)(3)(ii)(C)(1)(ii) of this section may be generally credited only if:

R18-2-404(D)(2)

(i ) The shutdown or curtailment occurred on or after the date the construction permit 

application is filed; or

R18-2-404(D)(2)(a)

(ii ) The applicant can establish that the proposed new emissions unit is a replacement for 

the shutdown or curtailed emissions unit, and the emissions reductions achieved by the 

shutdown or curtailment met the requirements of paragraph (a)(3)(ii)(C)(1)(i) of this 

section.

R18-2-404(D)(2)(b)

(D) No emissions credit may be allowed for replacing one hydrocarbon compound with another 

of lesser reactivity, except for those compounds listed in Table 1 of EPA's “Recommended Policy 

on Control of Volatile Organic Compounds” (42 FR 35314, July 8, 1977; (This document is also 

available from Mr. Ted Creekmore, Office of Air Quality Planning and Standards, (MD-15) 

Research Triangle Park, NC 27711.))

R18-2-404(E)

(E) All emission reductions claimed as offset credit shall be federally enforceable; R18-2-404(F)

(F) Procedures relating to the permissible location of offsetting emissions shall be followed 

which are at least as stringent as those set out in 40 CFR part 51 appendix S section IV.D.

R18-2-404(G)

40 CFR 51, Appendix S, IV.D:
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 30 of 112

Location of offsetting emissions. The owner or operator of a new or modified major stationary 

source may comply with any offset requirement in effect under this Ruling for increased emissions 

of any air pollutant only by obtaining emissions reductions of such air pollutant from the same 

source or other sources in the same nonattainment area, except that the reviewing authority may 

allow the owner or operator of a source to obtain such emissions reductions in another 

nonattainment area if the conditions in IV.D.1 and 2 are met.

R18-2-404(G)

1. The other area has an equal or higher nonattainment classification than the area in which the 

source is located.

R18-2-404(G)(1)

2. Emissions from such other area contribute to a violation of the national ambient air quality 

standard in the nonattainment area in which the source is located.

R18-2-404(G)(2)

(G) Credit for an emissions reduction can be claimed to the extent that the reviewing authority 

has not relied on it in issuing any permit under regulations approved pursuant to 40 CFR part 

51 subpart I or the State has not relied on it in demonstration attainment or reasonable further 

progress.

R18-2-404(H). Does not 

include all permits 

under Subpart I (R18-2-

334 and R18-2-302.01)

(H) [Reserved

(I) [Reserved]

(J) The total tonnage of increased emissions, in tons per year, resulting from a major 

modification that must be offset in accordance with section 173 of the Act shall be determined 

by summing the difference between the allowable emissions after the modification (as defined 

by paragraph (a)(1)(xi) of this section) and the actual emissions before the modification (as 

defined in paragraph (a)(1)(xii) of this section) for each emissions unit.

R18-2-404(I). 

Recommend adding 

cross-reference to 

defined term for 

consistency with federal 

regulation.

(a)(4) (4) Each plan may provide that the provisions of this paragraph do not apply to a source or 

modification that would be a major stationary source or major modification only if fugitive 

emissions, to the extent quantifiable, are considered in calculating the potential to emit of the 

stationary source or modification and the source does not belong to any of the following categories:

R18-2-403(E)

(i) Coal cleaning plants (with thermal dryers);

(ii) Kraft pulp mills;

(iii) Portland cement plants;

(iv) Primary zinc smelters;

(v) Iron and steel mills;

(vi) Primary aluminum ore reduction plants;

(vii) Primary copper smelters;

(viii) Municipal incinerators capable of charging more than 250 tons of refuse per day;

(ix) Hydrofluoric, sulfuric, or citric acid plants;

(x) Petroleum refineries;

(xi) Lime plants;

(xii) Phosphate rock processing plants;
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 31 of 112

(xiii) Coke oven batteries;

(xiv) Sulfur recovery plants;

(xv) Carbon black plants (furnace process);

(xvi) Primary lead smelters;

(xvii) Fuel conversion plants;

(xviii) Sintering plants;

(xix) Secondary metal production plants;

(xx) Chemical process plants—The term chemical processing plant shall not include ethanol 

production facilities that produce ethanol by natural fermentation included in NAICS codes 

325193 or 312140;

(xxi) Fossil-fuel boilers (or combination thereof) totaling more than 250 million British thermal 

units per hour heat input;

(xxii) Petroleum storage and transfer units with a total storage capacity exceeding 300,000 

barrels;

(xxiii) Taconite ore processing plants;

(xxiv) Glass fiber processing plants;

(xxv) Charcoal production plants;

(xxvi) Fossil fuel-fired steam electric plants of more than 250 million British thermal units per 

hour heat input;

(xxvii) Any other stationary source category which, as of August 7, 1980, is being regulated 

under section 111 or 112 of the Act.

(a)(5) (5) Each plan shall include enforceable procedures to provide that:

(i) Approval to construct shall not relieve any owner or operator of the responsibility to comply 

fully with applicable provision of the plan and any other requirements under local, State or 

Federal law.

R18-2-403(I)

(ii) At such time that a particular source or modification becomes a major stationary source or 

major modification solely by virtue of a relaxation in any enforcement limitation which was 

established after August 7, 1980, on the capacity of the source or modification otherwise to emit 

a pollutant, such as a restriction on hours of operation, then the requirements of regulations 

approved pursuant to this section shall apply to the source or modification as though construction 

had not yet commenced on the source or modification;

R18-2-403(C)

(a)(6) (6) Each plan shall provide that, except as otherwise provided in paragraph (a)(6)(vi) of this 

section, the following specific provisions apply with respect to any regulated NSR pollutant emitted 

from projects at existing emissions units at a major stationary source (other than projects at a 

source with a PAL) in circumstances where there is a reasonable possibility, within the meaning of 

paragraph (a)(6)(vi) of this section, that a project that is not a part of a major modification may 

result in a significant emissions increase of such pollutant, and the owner or operator elects to use 

the method specified in paragraphs (a)(1)(xxviii)(B)(1) through (3) of this section for calculating 

projected actual emissions. Deviations from these provisions will be approved only if the State 

specifically demonstrates that the submitted provisions are more stringent than or at least as 

stringent in all respects as the corresponding provisions in paragraphs (a)(6)(i) through (vi) of this 

section.

R18-2-402(F)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 32 of 112

(i) Before beginning actual construction of the project, the owner or operator shall document and 

maintain a record of the following information:

R18-2-402(F)(1)

(A) A description of the project; R18-2-402(F)(1)(a)

(B) Identification of the emissions unit(s) whose emissions of a regulated NSR pollutant could 

be affected by the project; and

R18-2-402(F)(1)(b)

(C) A description of the applicability test used to determine that the project is not a major 

modification for any regulated NSR pollutant, including the baseline actual emissions, the 

projected actual emissions, the amount of emissions excluded under paragraph 

(a)(1)(xxviii)(B)(3) of this section and an explanation for why such amount was excluded, and 

any netting calculations, if applicable.

R18-2-402(F)(1)(c and 

d) Incorrect reference 

to R18-2-

401(20)(b)(iii), should 

be (b)(iv).

(ii) If the emissions unit is an existing electric utility steam generating unit, before beginning 

actual construction, the owner or operator shall provide a copy of the information set out in 

paragraph (a)(6)(i) of this section to the reviewing authority. Nothing in this paragraph (a)(6)(ii) 

shall be construed to require the owner or operator of such a unit to obtain any determination 

from the reviewing authority before beginning actual construction.

R18-2-402(F)(2). Typo - 

missing the word "in" 

before Subsection

(iii) The owner or operator shall monitor the emissions of any regulated NSR pollutant that could 

increase as a result of the project and that is emitted by any emissions units identified in 

paragraph (a)(6)(i)(B) of this section; and calculate and maintain a record of the annual 

emissions, in tons per year on a calendar year basis, for a period of 5 years following resumption 

of regular operations after the change, or for a period of 10 years following resumption of regular 

operations after the change if the project increases the design capacity or potential to emit of that 

regulated NSR pollutant at such emissions unit.

R18-2-402(F)(3)

(iv) If the unit is an existing electric utility steam generating unit, the owner or operator shall 

submit a report to the reviewing authority within 60 days after the end of each year during which 

records must be generated under paragraph (a)(6)(iii) of this section setting out the unit's annual 

emissions during the year that preceded submission of the report.

R18-2-402(F)(5)

(v) If the unit is an existing unit other than an electric utility steam generating unit, the owner or 

operator shall submit a report to the reviewing authority if the annual emissions, in tons per year, 

from the project identified in paragraph (a)(6)(i) of this section, exceed the baseline actual 

emissions (as documented and maintained pursuant to paragraph (a)(6)(i)(C) of this section, by a 

significant amount (as defined in paragraph (a)(1)(x) of this section) for that regulated NSR 

pollutant, and if such emissions differ from the preconstruction projection as documented and 

maintained pursuant to paragraph (a)(6)(i)(C) of this section. Such report shall be submitted to 

the reviewing authority within 60 days after the end of such year. The report shall contain the 

following:

R18-2-402(F)(4) - 

recommend revising 

reference to (F)(1)(a) to 

(F)(1).

(A) The name, address and telephone number of the major stationary source; R18-2-402(F)(4)(a) 

(B) The annual emissions as calculated pursuant to paragraph (a)(6)(iii) of this section; and R18-2-402(F)(4)(b)

(C) Any other information that the owner or operator wishes to include in the report (e.g., an 

explanation as to why the emissions differ from the preconstruction projection).

R18-2-402(F)(4)(c) 

(vi) A “reasonable possibility” under paragraph (a)(6) of this section occurs when the owner or 

operator calculates the project to result in either:

R18-2-402(F)(6)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 33 of 112

(A) A projected actual emissions increase of at least 50 percent of the amount that is a 

“significant emissions increase,” as defined under paragraph (a)(1)(xxvii) of this section 

(without reference to the amount that is a significant net emissions increase), for the regulated 

NSR pollutant; or

R18-2-402(F)(6)(a)

(B) A projected actual emissions increase that, added to the amount of emissions excluded 

under paragraph (a)(1)(xxviii)(B)(3), sums to at least 50 percent of the amount that is a 

“significant emissions increase,” as defined under paragraph (a)(1)(xxvii) of this section 

(without reference to the amount that is a significant net emissions increase), for the regulated 

NSR pollutant. For a project for which a reasonable possibility occurs only within the meaning of 

paragraph (a)(6)(vi)(B) of this section, and not also within the meaning of paragraph 

(a)(6)(vi)(A) of this section, then provisions (a)(6)(ii) through (v) do not apply to the project.

R18-2-402(F)(6)(b)

(a)(7) (7) Each plan shall provide that the owner or operator of the source shall make the information 

required to be documented and maintained pursuant to paragraph (a)(6) of this section available 

for review upon a request for inspection by the reviewing authority or the general public pursuant 

to the requirements contained in §70.4(b)(3)(viii) of this chapter.

Not included

(a)(8) (8) The plan shall provide that the requirements of this section applicable to major stationary 

sources and major modifications of volatile organic compounds shall apply to nitrogen oxides 

emissions from major stationary sources and major modifications of nitrogen oxides in an ozone 

transport region or in any ozone nonattainment area, except in ozone nonattainment areas or in 

portions of an ozone transport region where the Administrator has granted a NOX waiver applying 

the standards set forth under section 182(f) of the Act and the waiver continues to apply.

Requirements for ozone 

apply to VOC and NOX. 

R18-2-401(11), R18-2-

101(74), and R18-2-

10(122). Arizona is not 

an ozone transport 

region.

(a)(9) (9)(i) The plan shall require that in meeting the emissions offset requirements of paragraph (a)(3) 

of this section, the ratio of total actual emissions reductions to the emissions increase shall be at 

least 1:1 unless an alternative ratio is provided for the applicable nonattainment area in paragraphs 

(a)(9)(ii) through (a)(9)(iv) of this section.

R18-2-404(A). Must 

also reference 404(J). 

Incorrectly identifies the 

ratio as increases : 

decreases, when it 

should be decreases : 

increases. 

(ii) The plan shall require that in meeting the emissions offset requirements of paragraph (a)(3) 

of this section for ozone nonattainment areas that are subject to subpart 2, part D, title I of the 

Act, the ratio of total actual emissions reductions of VOC to the emissions increase of VOC shall 

be as follows:

(A) In any marginal nonattainment area for ozone—at least 1.1:1; R18-2-404(J)

(B) In any moderate nonattainment area for ozone—at least 1.15:1; R18-2-404(J)

(C) In any serious nonattainment area for ozone—at least 1.2:1; R18-2-405(E)

(D) In any severe nonattainment area for ozone—at least 1.3:1 (except that the ratio may be at 

least 1.2:1 if the approved plan also requires all existing major sources in such nonattainment 

area to use BACT for the control of VOC); and

R18-2-405(F)

(E) In any extreme nonattainment area for ozone—at least 1.5:1 (except that the ratio may be 

at least 1.2:1 if the approved plan also requires all existing major sources in such 

nonattainment area to use BACT for the control of VOC); and

Not included, but no 

extreme areas, 

approvable at this time.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 34 of 112

(iii) Notwithstanding the requirements of paragraph (a)(9)(ii) of this section for meeting the 

requirements of paragraph (a)(3) of this section, the ratio of total actual emissions reductions of 

VOC to the emissions increase of VOC shall be at least 1.15:1 for all areas within an ozone 

transport region that is subject to subpart 2, part D, title I of the Act, except for serious, severe, 

and extreme ozone nonattainment areas that are subject to subpart 2, part D, title I of the Act.

Not in the ozone 

transport region

(iv) The plan shall require that in meeting the emissions offset requirements of paragraph (a)(3) 

of this section for ozone nonattainment areas that are subject to subpart 1, part D, title I of the 

Act (but are not subject to subpart 2, part D, title I of the Act, including 8-hour ozone 

nonattainment areas subject to 40 CFR 51.902(b)), the ratio of total actual emissions reductions 

of VOC to the emissions increase of VOC shall be at least 1:1.

R18-2-404(A)

(a)(10) (10) The plan shall require that the requirements of this section applicable to major stationary 

sources and major modifications of PM-10 shall also apply to major stationary sources and major 

modifications of PM-10 precursors, except where the Administrator determines that such sources do 

not contribute significantly to PM-10 levels that exceed the PM-10 ambient standards in the area.

See discussion in 

Section 5.7.3.2 of the 

TSD.

(a)(11) (11) The plan shall require that in meeting the emissions offset requirements of paragraph (a)(3) of 

this section, the emissions offsets obtained shall be for the same regulated NSR pollutant unless 

interprecursor offsetting is permitted for a particular pollutant as specified in this paragraph. The 

plan may allow the offset requirements in paragraph (a)(3) of this section for direct PM2.5 

emissions or emissions of precursors of PM2.5 to be satisfied by offsetting reductions in direct 

PM2.5 emissions or emissions of any PM2.5 precursor identified under paragraph (a)(1)(xxxvii)(C) 

of this section if such offsets comply with the interprecursor trading hierarchy and ratio established 

in the approved plan for a particular nonattainment area.

No interprecursor 

language included in 

submittal. Submittal 

must also clarify that 

offsets shall be for the 

same pollutant.

(b)(1) (b)(1) Each plan shall include a preconstruction review permit program or its equivalent to satisfy 

the requirements of section 110(a)(2)(D)(i) of the Act for any new major stationary source or 

major modification as defined in paragraphs (a)(1) (iv) and (v) of this section. Such a program 

shall apply to any such source or modification that would locate in any area designated as 

attainment or unclassifiable for any national ambient air quality standard pursuant to section 107 of 

the Act, when it would cause or contribute to a violation of any national ambient air quality 

standard.

R18-2-406(B)

(2) A major source or major modification will be considered to cause or contribute to a violation of 

a national ambient air quality standard when such source or modification would, at a minimum, 

exceed the following significance levels at any locality that does not or would not meet the 

applicable national standard:

R18-2-406(A)(5)(b) and 

R18-2-401(25)

See Table 4 below

(3) Such a program may include a provision which allows a proposed major source or major 

modification subject to paragraph (b) of this section to reduce the impact of its emissions upon air 

quality by obtaining sufficient emission reductions to, at a minimum, compensate for its adverse 

ambient impact where the major source or major modification would otherwise cause or contribute 

to a violation of any national ambient air quality standard. The plan shall require that, in the 

absence of such emission reductions, the State or local agency shall deny the proposed 

construction.

Does not appear to 

allow, not required to. 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 35 of 112

(4) The requirements of paragraph (b) of this section shall not apply to a major stationary source 

or major modification with respect to a particular pollutant if the owner or operator demonstrates 

that, as to that pollutant, the source or modification is located in an area designated as 

nonattainment pursuant to section 107 of the Act.

R18-2-406(B)

(c)-(e) Reserved (c)-(e) [Reserved]

Actuals PALs (f) Actuals PALs. The plan shall provide for PALs according to the provisions in paragraphs (f)(1) 

through (15) of this section.

(1) Applicability. (i) The reviewing authority may approve the use of an actuals PAL for any 

existing major stationary source (except as provided in paragraph (f)(1)(ii) of this section) if the 

PAL meets the requirements in paragraphs (f)(1) through (15) of this section. The term “PAL” 

shall mean “actuals PAL” throughout paragraph (f) of this section.

R18-2-412(A)(1)

(ii) The reviewing authority shall not allow an actuals PAL for VOC or NOX for any major 

stationary source located in an extreme ozone nonattainment area.

Not included, but not 

required to have an 

extreme ozone 

nonattainment area 

program.

(iii) Any physical change in or change in the method of operation of a major stationary source 

that maintains its total source-wide emissions below the PAL level, meets the requirements in 

paragraphs (f)(1) through (15) of this section, and complies with the PAL permit:

R18-2-412(A)(2)

(A) Is not a major modification for the PAL pollutant; R18-2-412(A)(2)(a)

(B) Does not have to be approved through the plan's nonattainment major NSR program; and Not included (only 

reference to PSD 

program). Recommend 

referencing R18-2-403 

to meet this 

requirement.

(C) Is not subject to the provisions in paragraph (a)(5)(ii) of this section (restrictions on 

relaxing enforceable emission limitations that the major stationary source used to avoid 

applicability of the nonattainment major NSR program).

R18-2-412(A)(2)(c)

(iv) Except as provided under paragraph (f)(1)(iii)(C) of this section, a major stationary source 

shall continue to comply with all applicable Federal or State requirements, emission limitations, 

and work practice requirements that were established prior to the effective date of the PAL.

R18-2-412(A)(3)

(f)(2) Definitions (2) Definitions. The plan shall use the definitions in paragraphs (f)(2)(i) through (xi) of this 

section for the purpose of developing and implementing regulations that authorize the use of 

actuals PALs consistent with paragraphs (f)(1) through (15) of this section. When a term is not 

defined in these paragraphs, it shall have the meaning given in paragraph (a)(1) of this section or 

in the Act.

Actuals PAL (i) Actuals PAL for a major stationary source means a PAL based on the baseline actual 

emissions (as defined in paragraph (a)(1)(xxxv) of this section) of all emissions units (as 

defined in paragraph (a)(1)(vii) of this section) at the source, that emit or have the potential to 

emit the PAL pollutant.

R18-2-401(13)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 36 of 112

Allowable emissions (ii) Allowable emissions means “allowable emissions” as defined in paragraph (a)(1)(xi) of this 

section, except as this definition is modified according to paragraphs (f)(2)(ii)(A) through (B) of 

this section.

(A) The allowable emissions for any emissions unit shall be calculated considering any 

emission limitations that are enforceable as a practical matter on the emissions unit's 

potential to emit.

(B) An emissions unit's potential to emit shall be determined using the definition in paragraph 

(a)(1)(iii) of this section, except that the words “or enforceable as a practical matter” should 

be added after “federally enforceable.”

Small emissions (iii) 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, as defined in 

paragraph (a)(1)(x) of this section or in the Act, whichever is lower.

R18-2-401(26). 

Recommended adding 

reference to definition 

for significant level

Major emissions 

unit

(iv) Major emissions unit means:

(A) Any emissions unit that emits or has the potential to emit 100 tons per year or more of the 

PAL pollutant in an attainment area; or

(B) Any emissions unit that emits or has the potential to emit the PAL pollutant in an amount 

that is equal to or greater than the major source threshold for the PAL pollutant as defined by 

the Act for nonattainment areas. For example, in accordance with the definition of major 

stationary source in section 182(c) of the Act, an emissions unit would be a major emissions 

unit for VOC if the emissions unit is located in a serious ozone nonattainment area and it emits 

or has the potential to emit 50 or more tons of VOC per year.

PAL (v) Plantwide applicability limitation (PAL) means an emission limitation expressed in tons per 

year, for a pollutant at a major stationary source, that is enforceable as a practical matter and 

established source-wide in accordance with paragraphs (f)(1) through (f)(15) of this section.

R18-2-401(13)

PAL effective date (vi) 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 emissions unit which is part of the PAL major 

modification becomes operational and begins to emit the PAL pollutant.

R18-2-401(15)

PAL effective period (vii) PAL effective period means the period beginning with the PAL effective date and ending 10 

years later.

R18-2-401(16)

PAL major 

modification

(viii) PAL major modification means, notwithstanding paragraphs (a)(1)(v) and (vi) of this section 

(the definitions for major modification and net emissions increase), any 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.

R18-2-401(17)

PAL permit (ix) PAL permit means the major NSR permit, the minor NSR permit, or the State operating 

permit under a program that is approved into the plan, or the title V permit issued by the 

reviewing authority that establishes a PAL for a major stationary source.

R18-2-401(18). should 

reference under "Article 

3 or 4".

PAL pollutant (x) PAL pollutant means the pollutant for which a PAL is established at a major stationary source. R18-2-401(19)

R18-2-401(14). Should 

consistently use "PAL 

allowable emissons" 

term in R18-2-412(H).

Did not include
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 37 of 112

Significant 

emissions

(xi) Significant emission s 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 (as defined in 

paragraph (a)(1)(x) of this section or in the Act, whichever is lower) for that PAL pollutant, but 

less than the amount that would qualify the unit as a major emissions unit as defined in 

paragraph (f)(2)(iv) of this section.

R18-2-401(24) 

Recommend adding 

reference to definition 

for significant level.

(f)(3) Permit application 

requirements.

(3) Permit application requirements. As part of a permit application requesting a PAL, the owner or 

operator of a major stationary source shall submit the following information to the reviewing 

authority for approval:

(i) A list of all emissions units at the source designated as small, significant or major based on 

their potential to emit. In addition, the owner or operator of the source shall indicate which, if 

any, Federal or State applicable requirements, emission limitations or work practices apply to 

each unit.

(ii) Calculations of the baseline actual emissions (with supporting documentation). Baseline actual 

emissions are to include emissions associated not only with operation of the unit, but also 

emissions associated with startup, shutdown and malfunction.

(iii) The calculation procedures that the major stationary source owner or operator proposes to 

use to convert the monitoring system data to monthly emissions and annual emissions based on a 

12-month rolling total for each month as required by paragraph (f)(13)(i) of this section.

(f)(4) General 

requirements for 

establishing PALS

(4) General requirements for establishing PALs. (i) The plan allows the reviewing authority to 

establish a PAL at a major stationary source, provided that at a minimum, the requirements in 

paragraphs (f)(4)(i)(A) through (G) of this section are met.

(A) The PAL shall impose an annual emission limitation in tons per year, that is enforceable as a 

practical matter, for the entire major stationary source. For each month during the PAL effective 

period after the first 12 months of establishing a PAL, the major stationary source owner or 

operator shall show that the sum of the monthly emissions from each emissions unit under the 

PAL for the previous 12 consecutive months is less than the PAL (a 12-month average, rolled 

monthly). For each month during the first 11 months from the PAL effective date, the major 

stationary source owner or operator shall show that the sum of the preceding monthly 

emissions from the PAL effective date for each emissions unit under the PAL is less than the 

PAL.

(B) The PAL shall be established in a PAL permit that meets the public participation 

requirements in paragraph (f)(5) of this section.

(C) The PAL permit shall contain all the requirements of paragraph (f)(7) of this section.

(D) The PAL shall include fugitive emissions, to the extent quantifiable, from all emissions units 

that emit or have the potential to emit the PAL pollutant at the major stationary source.

(E) Each PAL shall regulate emissions of only one pollutant.

(F) Each PAL shall have a PAL effective period of 10 years.

(G) The owner or operator of the major stationary source with a PAL shall comply with the 

monitoring, recordkeeping, and reporting requirements provided in paragraphs (f)(12) through 

(14) of this section for each emissions unit under the PAL through the PAL effective period.

R18-2-412(B). In 

412(B)(2), did not 

include second sentence 

in (f)(3)(ii).

R18-2-412('C)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 38 of 112

(ii) At no time (during or after the PAL effective period) are emissions reductions of a PAL 

pollutant, which occur during the PAL effective period, creditable as decreases for purposes of 

offsets under paragraph (a)(3)(ii) of this section unless the level of the PAL is reduced by the 

amount of such emissions reductions and such reductions would be creditable in the absence of 

the PAL.

(f)(5) Public participation (5) Public participation requirement for PALs. PALs for existing major stationary sources shall be 

established, renewed, or increased through a procedure that is consistent with §§51.160 and 

51.161 of this chapter. This includes the requirement that the reviewing authority provide the 

public with notice of the proposed approval of a PAL permit and at least a 30-day period for 

submittal of public comment. The reviewing authority must address all material comments before 

taking final action on the permit.

R18-2-412(D)

(f)(6) Setting the actuals 

PAL

(6) Setting the 10-year actuals PAL level. (i) Except as provided in paragraph (f)(6)(ii) of this 

section, the plan shall provide that the actuals PAL level for a major stationary source shall be 

established as the sum of the baseline actual emissions (as defined in paragraph (a)(1)(xxxv) of 

this section) of the PAL pollutant for each emissions unit at the source; plus an amount equal to the 

applicable significant level for the PAL pollutant under paragraph (a)(1)(x) of this section or under 

the Act, whichever is lower. When establishing the actuals PAL level, for a PAL pollutant, only one 

consecutive 24-month period must be used to determine the baseline actual emissions for all 

existing emissions units. However, a different consecutive 24-month period may be used for each 

different PAL pollutant. Emissions associated with units that were permanently shut down after this 

24-month period must be subtracted from the PAL level. The reviewing authority shall specify a 

reduced PAL level(s) (in tons/yr) in the PAL permit to become effective on the future compliance 

date(s) of any applicable Federal or State regulatory requirement(s) that the reviewing authority is 

aware of prior to issuance of the PAL permit. For instance, if the source owner or operator will be 

required to reduce emissions from industrial boilers in half from baseline emissions of 60 ppm NOX 

to a new rule limit of 30 ppm, then the permit shall contain a future effective PAL level that is equal 

to the current PAL level reduced by half of the original baseline emissions of such unit(s).

(ii) For newly constructed units (which do not include modifications to existing units) on which 

actual construction began after the 24-month period, in lieu of adding the baseline actual 

emissions as specified in paragraph (f)(6)(i) of this section, the emissions must be added to the 

PAL level in an amount equal to the potential to emit of the units.

(f)(7) Contents of PAL 

permit

(7) Contents of the PAL permit. The plan shall require that the PAL permit contain, at a minimum, 

the information in paragraphs (f)(7)(i) through (x) of this section.

(i) The PAL pollutant and the applicable source-wide emission limitation in tons per year.

(ii) The PAL permit effective date and the expiration date of the PAL (PAL effective period).

(iii) Specification in the PAL permit that if a major stationary source owner or operator applies to 

renew a PAL in accordance with paragraph (f)(10) of this section before the end of the PAL 

effective period, then the PAL shall not expire at the end of the PAL effective period. It shall 

remain in effect until a revised PAL permit is issued by the reviewing authority.

(iv) A requirement that emission calculations for compliance purposes include emissions from 

startups, shutdowns and malfunctions.

R18-2-412(E). For 

412(E)(1), recommend 

adding reference to 

definition for 

significance level

R18-2-412(F)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 39 of 112

(v) A requirement that, once the PAL expires, the major stationary source is subject to the 

requirements of paragraph (f)(9) of this section.

(vi) The calculation procedures that the major stationary source owner or operator shall use to 

convert the monitoring system data to monthly emissions and annual emissions based on a 12-

month rolling total for each month as required by paragraph (f)(13)(i) of this section.

(vii) A requirement that the major stationary source owner or operator monitor all emissions units 

in accordance with the provisions under paragraph (f)(12) of this section.

(viii) A requirement to retain the records required under paragraph (f)(13) of this section on site. 

Such records may be retained in an electronic format.

(ix) A requirement to submit the reports required under paragraph (f)(14) of this section by the 

required deadlines.

(x) Any other requirements that the reviewing authority deems necessary to implement and 

enforce the PAL.

(f)(8) PAL effective 

period; reopening

(8) PAL effective period and reopening of the PAL permit. The plan shall require the information in 

paragraphs (f)(8)(i) and (ii) of this section.

(i) PAL effective period. The reviewing authority shall specify a PAL effective period of 10 years.

(ii) Reopening of the PAL permit. (A) During the PAL effective period, the plan shall require the 

reviewing authority to reopen the PAL permit to:

(1) Correct typographical/calculation errors made in setting the PAL or reflect a more accurate 

determination of emissions used to establish the PAL.

(2) Reduce the PAL if the owner or operator of the major stationary source creates creditable 

emissions reductions for use as offsets under paragraph (a)(3)(ii) of this section.

(3) Revise the PAL to reflect an increase in the PAL as provided under paragraph (f)(11) of 

this section.

(B) The plan shall provide the reviewing authority discretion to reopen the PAL permit for the 

following:

(1) Reduce the PAL to reflect newly applicable Federal requirements (for example, NSPS) with 

compliance dates after the PAL effective date.

(2) Reduce the PAL consistent with any other requirement, that is enforceable as a practical 

matter, and that the State may impose on the major stationary source under the plan.

(3) Reduce the PAL if the reviewing authority determines that a reduction is necessary to 

avoid causing or contributing to a NAAQS or PSD increment violation, or to an adverse impact 

on an air quality related value that has been identified for a Federal Class I area by a Federal 

Land Manager and for which information is available to the general public.

(C) Except for the permit reopening in paragraph (f)(8)(ii)(A)(1) of this section for the 

correction of typographical/calculation errors that do not increase the PAL level, all other 

reopenings shall be carried out in accordance with the public participation requirements of 

paragraph (f)(5) of this section.

(f)(9) Expiration of a PAL (9) Expiration of a PAL . Any PAL which is not renewed in accordance with the procedures in 

paragraph (f)(10) of this section shall expire at the end of the PAL effective period, and the 

requirements in paragraphs (f)(9)(i) through (v) of this section shall apply.

R18-2-412(G)

R18-2-412(H) - 

Incorrect citation in 

(H)(4). Should 

reference definition for 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 40 of 112

(i) Each emissions unit (or each group of emissions units) that existed under the PAL shall comply 

with an allowable emission limitation under a revised permit established according to the 

procedures in paragraphs (f)(9)(i)(A) through (B) of this section.

(A) Within the time frame specified for PAL renewals in paragraph (f)(10)(ii) of this section, the 

major stationary source shall submit a proposed allowable emission limitation for each 

emissions unit (or each group of emissions units, if such a distribution is more appropriate as 

decided by the reviewing authority) by distributing the PAL allowable emissions for the major 

stationary source among each of the emissions units that existed under the PAL. If the PAL had 

not yet been adjusted for an applicable requirement that became effective during the PAL 

effective period, as required under paragraph (f)(10)(v) of this section, such distribution shall 

be made as if the PAL had been adjusted.

(B) The reviewing authority shall decide whether and how the PAL allowable emissions will be 

distributed and issue a revised permit incorporating allowable limits for each emissions unit, or 

each group of emissions units, as the reviewing authority determines is appropriate.

(ii) Each emissions unit(s) shall comply with the allowable emission limitation on a 12-month 

rolling basis. The reviewing authority may approve the use of monitoring systems (source testing, 

emission factors, etc.) other than CEMS, CERMS, PEMS or CPMS to demonstrate compliance with 

the allowable emission limitation.

(iii) Until the reviewing authority issues the revised permit incorporating allowable limits for each 

emissions unit, or each group of emissions units, as required under paragraph (f)(9)(i)(A) of this 

section, the source shall continue to comply with a source-wide, multi-unit emissions cap 

equivalent to the level of the PAL emission limitation.

(iv) Any physical change or change in the method of operation at the major stationary source will 

be subject to the nonattainment major NSR requirements if such change meets the definition of 

major modification in paragraph (a)(1)(v) of this section.

(v) The major stationary source owner or operator shall continue to comply with any State or 

Federal applicable requirements (BACT, RACT, NSPS, etc.) that may have applied either during 

the PAL effective period or prior to the PAL effective period except for those emission limitations 

that had been established pursuant to paragraph (a)(5)(ii) of this section, but were eliminated by 

the PAL in accordance with the provisions in paragraph (f)(1)(iii)(C) of this section.

(f)(10) Renewal of a PAL (10) Renewal of a PAL. (i) The reviewing authority shall follow the procedures specified in 

paragraph (f)(5) of this section in approving any request to renew a PAL for a major stationary 

source, and shall provide both the proposed PAL level and a written rationale for the proposed PAL 

level to the public for review and comment. During such public review, any person may propose a 

PAL level for the source for consideration by the reviewing authority.

reference definition for 

major modification. 

Also, uses "eliminated" 

in (H)(5) instead of 

"established." 

Recommend adding 

"whether and how" to 

(i)(b). 412(H)(5) is not 

consistent with (v).

R18-2-412(I) Should 

reference 412(D) 

instead of (F) in 

(I)(1).Should reference 

412(E) instead of (F) in 

(I)(4)(a).
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 41 of 112

(ii) Application deadline. The plan shall require that a major stationary source owner or operator 

shall submit a timely application to the reviewing authority to request renewal of a PAL. A timely 

application is one that is submitted at least 6 months prior to, but not earlier than 18 months 

from, the date of permit expiration. This deadline for application submittal is to ensure that the 

permit will not expire before the permit is renewed. If the owner or operator of a major 

stationary source submits a complete application to renew the PAL within this time period, then 

the PAL shall continue to be effective until the revised permit with the renewed PAL is issued.

(iii) Application requirements. The application to renew a PAL permit shall contain the information 

required in paragraphs (f)(10)(iii)(A) through (D) of this section.

(A) The information required in paragraphs (f)(3)(i) through (iii) of this section.

(B) A proposed PAL level.

(C) The sum of the potential to emit of all emissions units under the PAL (with supporting 

documentation).

(D) Any other information the owner or operator wishes the reviewing authority to consider in 

determining the appropriate level for renewing the PAL.

(iv) PAL adjustment. In determining whether and how to adjust the PAL, the reviewing authority 

shall consider the options outlined in paragraphs (f)(10)(iv)(A) and (B) of this section. However, 

in no case may any such adjustment fail to comply with paragraph (f)(10)(iv)(C) of this section.

(A) If the emissions level calculated in accordance with paragraph (f)(6) of this section is equal 

to or greater than 80 percent of the PAL level, the reviewing authority may renew the PAL at 

the same level without considering the factors set forth in paragraph (f)(10)(iv)(B) of this 

section; or

(B) The reviewing authority may set the PAL at a level that it determines to be more 

representative of the source's baseline actual emissions, or that it determines to be appropriate 

considering air quality needs, advances in control technology, anticipated economic growth in 

the area, desire to reward or encourage the source's voluntary emissions reductions, or other 

factors as specifically identified by the reviewing authority in its written rationale.

(C) Notwithstanding paragraphs (f)(10)(iv)(A) and (B) of this section,

(1) If the potential to emit of the major stationary source is less than the PAL, the reviewing 

authority shall adjust the PAL to a level no greater than the potential to emit of the source; 

and

(2) The reviewing authority shall not approve a renewed PAL level higher than the current 

PAL, unless the major stationary source has complied with the provisions of paragraph (f)(11) 

of this section (increasing a PAL).

(v) If the compliance date for a State or Federal requirement that applies to the PAL source 

occurs during the PAL effective period, and if the reviewing authority has not already adjusted for 

such requirement, the PAL shall be adjusted at the time of PAL permit renewal or title V permit 

renewal, whichever occurs first.

(f)(11) (11) Increasing a PAL during the PAL effective period. (i) The plan shall require that the reviewing 

authority may increase a PAL emission limitation only if the major stationary source complies with 

the provisions in paragraphs (f)(11)(i)(A) through (D) of this section.

R18-2-412(J)

(I)(4)(a).
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 42 of 112

(A) The owner or operator of the major stationary source shall submit a complete application to 

request an increase in the PAL limit for a PAL major modification. Such application shall identify 

the emissions unit(s) contributing to the increase in emissions so as to cause the major 

stationary source's emissions to equal or exceed its PAL.

(B) As part of this application, the major stationary source owner or operator shall demonstrate 

that the sum of the baseline actual emissions of the small emissions units, plus the sum of the 

baseline actual emissions of the significant and major emissions units assuming application of 

BACT equivalent controls, plus the sum of the allowable emissions of the new or modified 

emissions unit(s) exceeds the PAL. The level of control that would result from BACT equivalent 

controls on each significant or major emissions unit shall be determined by conducting a new 

BACT analysis at the time the application is submitted, unless the emissions unit is currently 

required to comply with a BACT or LAER requirement that was established within the preceding 

10 years. In such a case, the assumed control level for that emissions unit shall be equal to the 

level of BACT or LAER with which that emissions unit must currently comply.

(C) The owner or operator obtains a major NSR permit for all emissions unit(s) identified in 

paragraph (f)(11)(i)(A) of this section, regardless of the magnitude of the emissions increase 

resulting from them (that is, no significant levels apply). These emissions unit(s) shall comply 

with any emissions requirements resulting from the nonattainment major NSR program process 

(for example, LAER), even though they have also become subject to the PAL or continue to be 

subject to the PAL.

(D) The PAL permit shall require that the increased PAL level shall be effective on the day any 

emissions unit that is part of the PAL major modification becomes operational and begins to 

emit the PAL pollutant.

(ii) The reviewing authority shall calculate the new PAL as the sum of the allowable emissions for 

each modified or new emissions unit, plus the sum of the baseline actual emissions of the 

significant and major emissions units (assuming application of BACT equivalent controls as 

determined in accordance with paragraph (f)(11)(i)(B)), plus the sum of the baseline actual 

emissions of the small emissions units.

(iii) The PAL permit shall be revised to reflect the increased PAL level pursuant to the public notice 

requirements of paragraph (f)(5) of this section.

(f)(12) Monitoring 

requirements

(12) Monitoring requirements for PALs—(i) General requirements. (A) Each PAL permit must contain 

enforceable requirements for the monitoring system that accurately determines plantwide 

emissions of the PAL pollutant in terms of mass per unit of time. Any monitoring system authorized 

for use in the PAL permit must be based on sound science and meet generally acceptable scientific 

procedures for data quality and manipulation. Additionally, the information generated by such 

system must meet minimum legal requirements for admissibility in a judicial proceeding to enforce 

the PAL permit.

(B) The PAL monitoring system must employ one or more of the four general monitoring 

approaches meeting the minimum requirements set forth in paragraphs (f)(12)(ii)(A) through 

(D) of this section and must be approved by the reviewing authority.

R18-2-412(J)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 43 of 112

(C) Notwithstanding paragraph (f)(12)(i)(B) of this section, you may also employ an alternative 

monitoring approach that meets paragraph (f)(12)(i)(A) of this section if approved by the 

reviewing authority.

(D) Failure to use a monitoring system that meets the requirements of this section renders the 

PAL invalid.

(ii) Minimum Performance Requirements for Approved Monitoring Approaches. The following are 

acceptable general monitoring approaches when conducted in accordance with the minimum 

requirements in paragraphs (f)(12)(iii) through (ix) of this section:

(A) Mass balance calculations for activities using coatings or solvents;

(B) CEMS;

(C) CPMS or PEMS; and

(D) Emission Factors.

(iii) Mass Balance Calculations. An owner or operator using mass balance calculations to monitor 

PAL pollutant emissions from activities using coating or solvents shall meet the following 

requirements:

(A) Provide a demonstrated means of validating the published content of the PAL pollutant that 

is contained in or created by all materials used in or at the emissions unit;

(B) Assume that the emissions unit emits all of the PAL pollutant that is contained in or created 

by any raw material or fuel used in or at the emissions unit, if it cannot otherwise be accounted 

for in the process; and

(C) Where the vendor of a material or fuel, which is used in or at the emissions unit, publishes a 

range of pollutant content from such material, the owner or operator must use the highest 

value of the range to calculate the PAL pollutant emissions unless the reviewing authority 

determines there is site-specific data or a site-specific monitoring program to support another 

content within the range.

(iv) CEMS. An owner or operator using CEMS to monitor PAL pollutant emissions shall meet the 

following requirements:

(A) CEMS must comply with applicable Performance Specifications found in 40 CFR part 60, 

appendix B; and

(B) CEMS must sample, analyze and record data at least every 15 minutes while the emissions 

unit is operating.

(v) CPMS or PEMS. An owner or operator using CPMS or PEMS to monitor PAL pollutant emissions 

shall meet the following requirements:

(A) The CPMS or the PEMS must be based on current site-specific data demonstrating a 

correlation between the monitored parameter(s) and the PAL pollutant emissions across the 

range of operation of the emissions unit; and

(B) Each CPMS or PEMS must sample, analyze, and record data at least every 15 minutes, or at 

another less frequent interval approved by the reviewing authority, while the emissions unit is 

operating.

(vi) Emission factors. An owner or operator using emission factors to monitor PAL pollutant 

emissions shall meet the following requirements:

(A) All emission factors shall be adjusted, if appropriate, to account for the degree of 

uncertainty or limitations in the factors' development;

(B) The emissions unit shall operate within the designated range of use for the emission factor, 

if applicable; and
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 44 of 112

(C) If technically practicable, the owner or operator of a significant emissions unit that relies on 

an emission factor to calculate PAL pollutant emissions shall conduct validation testing to 

determine a site-specific emission factor within 6 months of PAL permit issuance, unless the 

reviewing authority determines that testing is not required.

(vii) A source owner or operator must record and report maximum potential emissions without 

considering enforceable emission limitations or operational restrictions for an emissions unit 

during any period of time that there is no monitoring data, unless another method for 

determining emissions during such periods is specified in the PAL permit.

(viii) Notwithstanding the requirements in paragraphs (f)(12)(iii) through (vii) of this section, 

where an owner or operator of an emissions unit cannot demonstrate a correlation between the 

monitored parameter(s) and the PAL pollutant emissions rate at all operating points of the 

emissions unit, the reviewing authority shall, at the time of permit issuance:

(A) Establish default value(s) for determining compliance with the PAL based on the highest 

potential emissions reasonably estimated at such operating point(s); or

(B) Determine that operation of the emissions unit during operating conditions when there is no 

correlation between monitored parameter(s) and the PAL pollutant emissions is a violation of 

the PAL.

(ix) Re-validation. All data used to establish the PAL pollutant must be re-validated through 

performance testing or other scientifically valid means approved by the reviewing authority. Such 

testing must occur at least once every 5 years after issuance of the PAL.

(f)(13) Recordkeeping 

requirements

(13) Recordkeeping requirements. (i) The PAL permit shall require an owner or operator to retain a 

copy of all records necessary to determine compliance with any requirement of paragraph (f) of this 

section and of the PAL, including a determination of each emissions unit's 12-month rolling total 

emissions, for 5 years from the date of such record.

(ii) The PAL permit shall require an owner or operator to retain a copy of the following records for 

the duration of the PAL effective period plus 5 years:

(A) A copy of the PAL permit application and any applications for revisions to the PAL; and

(B) Each annual certification of compliance pursuant to title V and the data relied on in 

certifying the compliance.

(f)(14) Reporting and 

notification

(14) Reporting and notification requirements. The owner or operator shall submit semi-annual 

monitoring reports and prompt deviation reports to the reviewing authority in accordance with the 

applicable title V operating permit program. The reports shall meet the requirements in paragraphs 

(f)(14)(i) through (iii).

(i) Semi-Annual Report. The semi-annual report shall be submitted to the reviewing authority 

within 30 days of the end of each reporting period. This report shall contain the information 

required in paragraphs (f)(14)(i)(A) through (G) of this section.

(A) The identification of owner and operator and the permit number.

(B) Total annual emissions (tons/year) based on a 12-month rolling total for each month in the 

reporting period recorded pursuant to paragraph (f)(13)(i) of this section.

R18-2-412(L)

R18-2-412(M)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 45 of 112

(C) All data relied upon, including, but not limited to, any Quality Assurance or Quality Control 

data, in calculating the monthly and annual PAL pollutant emissions.

(D) A list of any emissions units modified or added to the major stationary source during the 

preceding 6-month period.

(E) The number, duration, and cause of any deviations or monitoring malfunctions (other than 

the time associated with zero and span calibration checks), and any corrective action taken.

(F) A notification of a shutdown of any monitoring system, whether the shutdown was 

permanent or temporary, the reason for the shutdown, the anticipated date that the monitoring 

system will be fully operational or replaced with another monitoring system, and whether the 

emissions unit monitored by the monitoring system continued to operate, and the calculation of 

the emissions of the pollutant or the number determined by method included in the permit, as 

provided by paragraph (f)(12)(vii) of this section.

(G) A signed statement by the responsible official (as defined by the applicable title V operating 

permit program) certifying the truth, accuracy, and completeness of the information provided in 

the report.

(ii) Deviation report. The major stationary source owner or operator shall promptly submit reports 

of any deviations or exceedance of the PAL requirements, including periods where no monitoring 

is available. A report submitted pursuant to §70.6(a)(3)(iii)(B) of this chapter shall satisfy this 

reporting requirement. The deviation reports shall be submitted within the time limits prescribed 

by the applicable program implementing §70.6(a)(3)(iii)(B) of this chapter. The reports shall 

contain the following information:

(A) The identification of owner and operator and the permit number;

(B) The PAL requirement that experienced the deviation or that was exceeded;

(C) Emissions resulting from the deviation or the exceedance; and

(D) A signed statement by the responsible official (as defined by the applicable title V operating 

permit program) certifying the truth, accuracy, and completeness of the information provided in 

the report.

(iii) Re-validation results. The owner or operator shall submit to the reviewing authority the 

results of any re-validation test or method within 3 months after completion of such test or 

method.

(f)(15) Transition 

requirements

(15) Transition requirements. (i) No reviewing authority may issue a PAL that does not comply with 

the requirements in paragraphs (f)(1) through (15) of this section after the Administrator has 

approved regulations incorporating these requirements into a plan.

Not included, doesn't 

seem necessary

(ii) The reviewing authority may supersede any PAL which was established prior to the date of 

approval of the plan by the Administrator with a PAL that complies with the requirements of 

paragraphs (f)(1) through (15) of this section.

Not included, doesn't 

seem necessary

(g) (g) If any provision of this section, or the application of such provision to any person or 

circumstance, is held invalid, the remainder of this section, or the application of such provision to 

persons or circumstances other than those as to which it is held invalid, shall not be affected 

thereby.

R18-2-306(A)(7) - all 

permits issued by ADEQ 

contain a severability 

clause
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 46 of 112

(h) (h) Equipment replacement provision. Without regard to other considerations, routine maintenance, 

repair and replacement includes, but is not limited to, the replacement of any component of a 

process unit with an identical or functionally equivalent component(s), and maintenance and repair 

activities that are part of the replacement activity, provided that all of the requirements in 

paragraphs (h)(1) through (3) of this section are met.

(1) Capital Cost threshold for Equipment Replacement. (i) For an electric utility steam generating 

unit, as defined in §51.165(a)(1)(xx), the fixed capital cost of the replacement component(s) plus 

the cost of any associated maintenance and repair activities that are part of the replacement shall 

not exceed 20 percent of the replacement value of the process unit, at the time the equipment is 

replaced. For a process unit that is not an electric utility steam generating unit the fixed capital 

cost of the replacement component(s) plus the cost of any associated maintenance and repair 

activities that are part of the replacement shall not exceed 20 percent of the replacement value of 

the process unit, at the time the equipment is replaced.

(ii) In determining the replacement value of the process unit; and, except as otherwise allowed 

under paragraph (h)(1)(iii) of this section, the owner or operator shall determine the 

replacement value of the process unit on an estimate of the fixed capital cost of constructing a 

new process unit, or on the current appraised value of the process unit.

(iii) As an alternative to paragraph (h)(1)(ii) of this section for determining the replacement 

value of a process unit, an owner or operator may choose to use insurance value (where the 

insurance value covers only complete replacement), investment value adjusted for inflation, or 

another accounting procedure if such procedure is based on Generally Accepted Accounting 

Principles, provided that the owner or operator sends a notice to the reviewing authority. The 

first time that an owner or operator submits such a notice for a particular process unit, the 

notice may be submitted at any time, but any subsequent notice for that process unit may be 

submitted only at the beginning of the process unit's fiscal year. Unless the owner or operator 

submits a notice to the reviewing authority, then paragraph (h)(1)(ii) of this section will be used 

to establish the replacement value of the process unit. Once the owner or operator submits a 

notice to use an alternative accounting procedure, the owner or operator must continue to use 

that procedure for the entire fiscal year for that process unit. In subsequent fiscal years, the 

owner or operator must continue to use this selected procedure unless and until the owner or 

operator sends another notice to the reviewing authority selecting another procedure consistent 

with this paragraph or paragraph (h)(1)(ii) of this section at the beginning of such fiscal year.

(2) Basic design parameters. The replacement does not change the basic design parameter(s) of 

the process unit to which the activity pertains.

Note to paragraph (h): By a court order on December 24, 2003, this paragraph (h) is stayed 

indefinitely. The stayed provisions will become effective immediately if the court terminates the 

stay. At that time, EPA will publish a document in the Federal Register advising the public of the 

termination of the stay.

Not included. These 

provisions were vacated 

by the D.C. Circuit 

Court of Appeals - NY, 

et al v. EPA, No. 03-

1238 (March 17, 2006). 

Definition of basic 

design parameter still 

inadvertently included. 

See discussion in 

Section 5.7.1 TSD.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 47 of 112

(i) Except as provided in paragraph (h)(2)(iii) of this section, 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 British Thermal 

Units content shall be used for determining the basic design parameter(s) for a coal-fired 

electric utility steam generating unit.

(ii) Except as provided in paragraph (h)(2)(iii) of this section, the basic design parameter(s) for 

any process unit that is not at a steam 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 and raw materials, the owner or operator should consider the primary product or 

primary raw material when selecting a basic design parameter.

(iii) If the owner or operator believes the basic design parameter(s) in paragraphs (h)(2)(i) and 

(ii) of this section is not appropriate for a specific industry or type of process unit, the owner or 

operator may propose to the reviewing authority an alternative basic design parameter(s) for 

the source's process unit(s). If the reviewing authority approves of the use of an alternative 

basic design parameter(s), the reviewing authority shall issue a permit that is legally 

enforceable that records such basic design parameter(s) and requires the owner or operator to 

comply with such parameter(s).

(iv) The owner or operator shall use credible information, such as results of historic maximum 

capability tests, design information from the manufacturer, or engineering calculations, in 

establishing the magnitude of the basic design parameter(s) specified in paragraphs (h)(2)(i) 

and (ii) of this section.

(v) If design information is not available for a process unit, then the owner or operator shall 

determine the process unit's basic design parameter(s) using the maximum value achieved by 

the process unit in the five-year period immediately preceding the planned activity.

(vi) Efficiency of a process unit is not a basic design parameter.

(3) 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.

[51 FR 40669, Nov. 7, 1986]

Editorial Note: For Federal Register citations affecting §51.165, see the List of CFR Sections 

Affected, which appears in the Finding Aids section of the printed volume and at www.fdsys.gov.

Effective Date Note: At 76 FR 17552, Mar. 30, 2011, §51.165, paragraphs (a)(1)(v)(G) and 

(v)(1)(vi)(C) (3) are stayed indefinitely.

Section 173 of the Act

(a) In general, The permit program required by section 7502 (b)(6) [1] of this title shall provide that 

permits to construct and operate may be issued if—
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 48 of 112

(1) in accordance with regulations issued by the Administrator for the determination of baseline 

emissions in a manner consistent with the assumptions underlying the applicable implementation 

plan approved under section 7410 of this title and this part [section 110 of the Act], the permitting 

agency determines that—

These regulations are 

reviewed above - 40 CFR 

51.165

(A) by the time the source is to commence operation, sufficient offsetting emissions reductions have 

been obtained, such that total allowable emissions from existing sources in the region, from new or 

modified sources which are not major emitting facilities, and from the proposed source will be 

sufficiently less than total emissions from existing sources (as determined in accordance with the 

regulations under this paragraph) prior to the application for such permit to construct or modify so 

as to represent (when considered together with the plan provisions required under section 7502 of 

this title) reasonable further progress (as defined in section 7501 of this title); or

R18-2-403(A)(3), R18-2-

404(A) and (B), R18-2-

404(G)

(B) in the case of a new or modified major stationary source which is located in a zone (within the 

nonattainment area) identified by the Administrator, in consultation with the Secretary of Housing 

and Urban Development, as a zone to which economic development should be targeted, that 

emissions of such pollutant resulting from the proposed new or modified major stationary source 

will not cause or contribute to emissions levels which exceed the allowance permitted for such 

pollutant for such area from new or modified major stationary sources under section 7502 (c) of this 

title;

No economic 

development zones in 

Arizona

(2) the proposed source is required to comply with the lowest achievable emission rate; R18-2-403(A)(1)

(3) the owner or operator of the proposed new or modified source has demonstrated that all major 

stationary sources owned or operated by such person (or by any entity controlling, controlled by, or 

under common control with such person) in such State are subject to emission limitations and are in 

compliance, or on a schedule for compliance, with all applicable emission limitations and standards 

under this chapter; and [2]

R18-2-403(A)(2)

(4) the Administrator has not determined that the applicable implementation plan is not being 

adequately implemented for the nonattainment area in which the proposed source is to be 

constructed or modified in accordance with the requirements of this part; and

Not included.

(5) an analysis of alternative sites, sizes, production processes, and environmental control 

techniques for such proposed source demonstrates that benefits of the proposed source 

significantly outweigh the environmental and social costs imposed as a result of its location, 

construction, or modification.

R18-2-403(B)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 49 of 112

Any emission reductions required as a precondition of the issuance of a permit under paragraph (1) 

shall be federally enforceable before such permit may be issued.

R18-2-404(F). 

Recommend clarifying 

the language in (F) 

when the "proposed 

final permit" issue is 

addressed. Unclear 

whether final or 

proposed final permit is 

being referred to. 

(b) Prohibition on use of old growth allowances

Any growth allowance included in an applicable implementation plan to meet the requirements of 

section 7502 (b)(5) of this title (as in effect immediately before November 15, 1990) shall not be 

valid for use in any area that received or receives a notice under section 7410 (a)(2)(H)(ii) of this title 

(as in effect immediately before November 15, 1990) or under section 7410 (k)(1) of this title that its 

applicable implementation plan containing such allowance is substantially inadequate.

Submittal does not 

contain allowance for 

growth allowances

(c) Offsets

(1) The owner or operator of a new or modified major stationary source may comply with any offset 

requirement in effect under this part for increased emissions of any air pollutant only by obtaining 

emission reductions of such air pollutant from the same source or other sources in the same 

nonattainment area, except that the State may allow the owner or operator of a source to obtain 

such emission reductions in another nonattainment area if

R18-2-404

(A) the other area has an equal or higher nonattainment classification than the area in which the 

source is located and

R18-2-404(G)(1)

(B) emissions from such other area contribute to a violation of the national ambient air quality 

standard in the nonattainment area in which the source is located. Such emission reductions shall 

be, by the time a new or modified source commences operation, in effect and enforceable and shall 

assure that the total tonnage of increased emissions of the air pollutant from the new or modified 

source shall be offset by an equal or greater reduction, as applicable, in the actual emissions of such 

air pollutant from the same or other sources in the area.

R18-2-404(G)(2) and 

R18-2-404(F)

(2) Emission reductions otherwise required by this chapter shall not be creditable as emissions 

reductions for purposes of any such offset requirement. Incidental emission reductions which are 

not otherwise required by this chapter shall be creditable as emission reductions for such purposes 

if such emission reductions meet the requirements of paragraph (1).

R18-2-404 (A-D)

(d) Control technology information
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal 50 of 112

The State shall provide that control technology information from permits issued under this section 

will be promptly submitted to the Administrator for purposes of making such information available 

through the RACT/BACT/LAER clearinghouse to other States and to the general public.

R18-2-403(H)

(e) Rocket engines or motors

The permitting authority of a State shall allow a source to offset by alternative or innovative means 

emission increases from rocket engine and motor firing, and cleaning related to such firing, at an 

existing or modified major source that tests rocket engines or motors under the following 

conditions:

(1) Any modification proposed is solely for the purpose of expanding the testing of rocket engines or 

motors at an existing source that is permitted to test such engines on November 15, 1990.

(2) The source demonstrates to the satisfaction of the permitting authority of the State that it has 

used all reasonable means to obtain and utilize offsets, as determined on an annual basis, for the 

emissions increases beyond allowable levels, that all available offsets are being used, and that 

sufficient offsets are not available to the source.

(3) The source has obtained a written finding from the Department of Defense, Department of 

Transportation, National Aeronautics and Space Administration or other appropriate Federal 

agency, that the testing of rocket motors or engines at the facility is required for a program 

essential to the national security.

(4) The source will comply with an alternative measure, imposed by the permitting authority, 

designed to offset any emission increases beyond permitted levels not directly offset by the source. 

In lieu of imposing any alternative offset measures, the permitting authority may impose an 

emissions fee to be paid to such authority of a State which shall be an amount no greater than 1.5 

times the average cost of stationary source control measures adopted in that area during the 

previous 3 years. The permitting authority shall utilize the fees in a manner that maximizes the 

emissions reductions in that area.

Section 172(c)(5) of 

the Act

Permits for new and modified major stationary sources - Such plan provisions shall require permits 

for the construction and operation of new or modified major stationary sources anywhere in the 

nonattainment area, in accordance with section 7503 (section 173) of this title.

R18-2-402(B)

Not necessary for 

approval of NA-NSR 

program. Can adopt at a 

later date if needed.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 51of 112

51.166 Requirements of 40 CFR 51.166 for a SIP approved PSD program Where included in AZ 

NSR Rules

(a)(1) Plan requirements (1) Plan requirements. In accordance with the policy of section 101(b)(1) of the Act and the 

purposes of section 160 of the Act, each applicable State Implementation Plan and each 

applicable Tribal Implementation Plan shall contain emission limitations and such other measures 

as may be necessary to prevent significant deterioration of air quality.

With this action the 

District would adopt new 

a PSD program into the 

AZ SIP

(a)(2) Plan revisions (2) Plan revisions. If a State Implementation Plan revision would result in increased air quality 

deterioration over any baseline concentration, the plan revision shall include a demonstration that 

it will not cause or contribute to a violation of the applicable increment(s). If a plan revision 

proposing less restrictive requirements was submitted after August 7, 1977 but on or before any 

applicable baseline date and was pending action by the Administrator on that date, no such 

demonstration is necessary with respect to the area for which a baseline date would be 

established before final action is taken on the plan revision. Instead, the assessment described in 

paragraph (a)(4) of this section, shall review the expected impact to the applicable increment(s).

Not applicable to this 

action - no increase over 

a baseline concentration 

associated with this 

submittal

(a)(3) Required plan 

revision

(3) Required plan revision. If the State or the Administrator determines that a plan is 

substantially inadequate to prevent significant deterioration or that an applicable increment is 

being violated, the plan shall be revised to correct the inadequacy or the violation. The plan shall 

be revised within 60 days of such a finding by a State or within 60 days following notification by 

the Administrator, or by such later date as prescribed by the Administrator after consultation with 

the State.

Not applicable to this 

action. No determination 

that the plan is 

substantially inadequate 

has been made, or that 

an increment has been 

violated. 

(a)(4) Plan assessment (4) Plan assessment. The State shall review the adequacy of a plan on a periodic basis and within 

60 days of such time as information becomes available that an applicable increment is being 

violated.

Not applicable to review 

of SIP submittal package.

(a)(5) Public 

participation

(5) Public participation. Any State action taken under this paragraph shall be subject to the 

opportunity for public hearing in accordance with procedures equivalent to those established in 

§51.102.

October 29, 2012 

submittal held a hearing 

on December 8, 2011. 

July 2, 2014 submittal 

was public noticed with 

an opportunity for a 

hearing on June 30, 

2014.

(a)(6) Amendments (6) Amendments. 

(i) Any State required to revise its implementation plan by reason of an amendment to this 

section, with the exception of amendments to add new maximum allowable increases or other 

measures pursuant to section 166(a) of the Act, shall adopt and submit such plan revision to 

the Administrator for approval no later than 3 years after such amendment is published in the 

Federal Register. With regard to a revision to an implementation plan by reason of an 

amendment to paragraph (c) of this section to add maximum allowable increases or other 

measures, the State shall submit such plan revision to the Administrator for approval within 21 

months after such amendment is published in the Federal Register.

All current requirements, 

as of January 2014, were 

evaluated, unless 

identified otherwise 

below.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 52of 112

(ii) Any revision to an implementation plan that would amend the provisions for the prevention 

of significant air quality deterioration in the plan shall specify when and as to what sources and 

modifications the revision is to take effect.

ADEQ's SIP submittal 

under review represents 

a complete revision to 

the existing plan for PSD. 

As such, these revisions 

apply to the construction 

of new major sources or 

modifications at existing 

major sources. The rules 

submitted related to PSD 

are currently effective. 

Each rule submitted by 

ADEQ identifies the 

effective date - at the 

bottom of each rule 

under "Historical Note".

(iii) Any revision to an implementation plan that an amendment to this section required shall 

take effect no later than the date of its approval and may operate prospectively.

Rules will become 

effective in the SIP upon 

EPA approval - as will be 

specified in a Federal 

Register notice 

announcing our final 

action on this submittal. 

All rules pertaining to 

PSD being reviewed are 

already effective.

(a)(7) Applicability (7) Applicability. Each plan shall contain procedures that incorporate the requirements in 

paragraphs (a)(7)(i) through (vi) of this section.

(i) The requirements of this section apply to the construction of any new major stationary 

source (as defined in paragraph (b)(1) of this section) or any project at an existing major 

stationary source in an area designated as attainment or unclassifiable under sections 

107(d)(1)(A)(ii) or (iii) of the Act.

R18-2-402(A-B), R18-2-

406(A)

(ii) The requirements of paragraphs (j) through (r) of this section apply to the construction of 

any new major stationary source or the major modification of any existing major stationary 

source, except as this section otherwise provides.

R18-2-402(A-B), R18-2-

406(A)

(iii) No new major stationary source or major modification to which the requirements of 

paragraphs (j) through (r)(5) of this section apply shall begin actual construction without a 

permit that states that the major stationary source or major modification will meet those 

requirements.

R18-2-402(C) - contains 

a reference to proposed 

final permit, see 

discussion in Section 

5.8.2 of the TSD.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 53of 112

(iv) Each plan shall use the specific provisions of paragraphs (a)(7)(iv)( a ) through ( f ) of this 

section. Deviations from these provisions will be approved only if the State specifically 

demonstrates that the submitted provisions are more stringent than or at least as stringent in 

all respects as the corresponding provisions in paragraphs (a)(7)(iv)( a ) through ( f ) of this 

section.

See below.

( a ) Except as otherwise provided in paragraphs (a)(7)(v) and (vi) of this section, and 

consistent with the definition of major modification contained in paragraph (b)(2) of this 

section, a project is a major modification for a regulated NSR pollutant if it causes two types 

of emissions increases—a significant emissions increase (as defined in paragraph (b)(39) of 

this section), and a significant net emissions increase (as defined in paragraphs (b)(3) and 

(b)(23) of this section). The project is not a major modification if it does not cause a 

significant emissions increase. If the project causes a significant emissions increase, then the 

project is a major modification only if it also results in a significant net emissions increase.

R18-2-402(D)(1). May 

want to add cross 

references to defined 

terms for consistence 

with federal requirement.

( b ) The procedure for calculating (before beginning actual construction) whether a 

significant emissions increase ( i.e. , the first step of the process) will occur depends upon 

the type of emissions units being modified, according to paragraphs (a)(7)(iv)( c ) through ( 

f ) of this section. The procedure for calculating (before beginning actual construction) 

whether a significant net emissions increase will occur at the major stationary source ( i.e. , 

the second step of the process) is contained in the definition in paragraph (b)(3) of this 

section. Regardless of any such preconstruction projections, a major modification results if 

the project causes a significant emissions increase and a significant net emissions increase.

R18-2-402(D)(2)

( c ) Actual-to-projected-actual applicability test for projects that only involve existing 

emissions units. A significant emissions increase of a regulated NSR pollutant is projected to 

occur if the sum of the difference between the projected actual emissions (as defined in 

paragraph (b)(40) of this section) and the baseline actual emissions (as defined in paragraphs 

(b)(47)(i) and (ii) of this section) for each existing emissions unit, equals or exceeds the 

significant amount for that pollutant (as defined in paragraph (b)(23) of this section).

R18-2-402(D)(3)

( d ) Actual-to-potential test for projects that only involve construction of a new emissions 

unit(s). A significant emissions increase of a regulated NSR pollutant is projected to occur if 

the sum of the difference between the potential to emit (as defined in paragraph (b)(4) of 

this section) from each new emissions unit following completion of the project and the 

baseline actual emissions (as defined in paragraph (b)(47)(iii) of this section) of these units 

before the project equals or exceeds the significant amount for that pollutant (as defined in 

paragraph (b)(23) of this section).

R18-2-402(D)(4)

( e ) [Reserved]
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 54of 112

( f ) Hybrid test for projects that involve multiple types of emissions units. A significant 

emissions increase of a regulated NSR pollutant is projected to occur if the sum of the 

emissions increases for each emissions unit, using the method specified in paragraphs 

(a)(7)(iv)( c ) through ( d ) of this section as applicable with respect to each emissions unit, 

for each type of emissions unit equals or exceeds the significant amount for that pollutant (as 

defined in paragraph (b)(23) of this section).

R18-2-402(D)(6) - only 

refers back to the test in 

(d) and not both (c) and 

(d). In all cases, these is 

at least as stringent so 

not an approvability 

issue, but may want to 

fix. May want to add 

cross references to 

defined terms for 

consistency with federal 

requirement.

(v) The plan shall require that for any major stationary source for a PAL for a regulated NSR 

pollutant, the major stationary source shall comply with requirements under paragraph (w) of 

this section.

R18-2-402(E)

(b) Definitions (b) Definitions. All State plans shall use the following definitions for the purposes of this section. 

Deviations from the following wording will be approved only if the State specifically demonstrates 

that the submitted definition is more stringent, or at least as stringent, in all respects as the 

corresponding definitions below:

(b)(1) Major stationary 

source

(1)(i) Major stationary source means: R18-2-401(11) - uses the 

term "major source" but 

seems to inadvertently 

refer to "major stationary 

source" within the 

definition at (e)

( a ) Any of the following stationary sources of air pollutants which emits, or has the potential 

to emit, 100 tons per year or more of any regulated NSR pollutant: Fossil fuel-fired steam 

electric plants of more than 250 million British thermal units per hour heat input, coal 

cleaning plants (with thermal dryers), kraft pulp mills, portland cement plants, primary zinc 

smelters, iron and steel mill plants, primary aluminum ore reduction plants (with thermal 

dryers), primary copper smelters, municipal incinerators capable of charging more than 250 

tons of refuse per day, hydrofluoric, sulfuric, and nitric acid plants, petroleum refineries, lime 

plants, phosphate rock processing plants, coke oven batteries, sulfur recovery plants, carbon 

black plants (furnace process), primary lead smelters, fuel conversion plants, sintering plants, 

secondary metal production plants, chemical process plants (which does not include ethanol 

production facilities that produce ethanol by natural fermentation included in NAICS codes 

325193 or 312140), fossil-fuel boilers (or combinations thereof) totaling more than 250 

million British thermal units per hour heat input, petroleum storage and transfer units with a 

total storage capacity exceeding 300,000 barrels, taconite ore processing plants, glass fiber 

processing plants, and charcoal production plants;

R18-2-401(11)(b), list of 

source categories is in 

R18-2-101(23). Also, 

includes sources of lead 

with PTE of 5 tpy or more 

in definition. The list of 

source categories in R18-

2-101(23) refers to 

"taconite ore processing" 

as "taconite 

preprocessing". 

Recommend revising for 

consistency.

( b ) Notwithstanding the stationary source size specified in paragraph (b)(1)(i)( a ) of this 

section, any stationary source which emits, or has the potential to emit, 250 tons per year or 

more of a regulated NSR pollutant; or

R18-2-401(11)(b) - Also, 

includes sources with PTE 

of 5 tpy or more in 

definition.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 55of 112

(b)(1)(i) ( c ) Any physical change that would occur at a stationary source not otherwise qualifying 

under paragraph (b)(1) of this section, as a major stationary source if the change would 

constitute a major stationary source by itself.

Not in submittal

(ii) A major source that is major for volatile organic compounds or NOXshall be considered 

major for ozone.

R18-2-401(11)(d)

(iii) 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 one of the following categories of stationary sources:

( a ) Coal cleaning plants (with thermal dryers);

( b ) Kraft pulp mills;

( c ) Portland cement plants;

( d ) Primary zinc smelters;

( e ) Iron and steel mills;

( f ) Primary aluminum ore reduction plants;

( g ) Primary copper smelters;

( h ) Municipal incinerators capable of charging more than 250 tons of refuse per day;

( i ) Hydrofluoric, sulfuric, or nitric acid plants;

( j ) Petroleum refineries;

( k ) Lime plants;

( l ) Phosphate rock processing plants;

( m ) Coke oven batteries;

( n ) Sulfur recovery plants;

( o ) Carbon black plants (furnace process);

( p ) Primary lead smelters;

( q ) Fuel conversion plants;

( r ) Sintering plants;

( s ) Secondary metal production plants;

( t ) Chemical process plants—The term chemical processing plant shall not include ethanol 

production facilities that produce ethanol by natural fermentation included in NAICS codes 

325193 or 312140;

( u ) Fossil-fuel boilers (or combination thereof) totaling more than 250 million British 

thermal units per hour heat input;

( v ) Petroleum storage and transfer units with a total storage capacity exceeding 300,000 

barrels;

( w ) Taconite ore processing plants;

( x ) Glass fiber processing plants;

( y ) Charcoal production plants;

( z ) Fossil fuel-fired steam electric plants of more that 250 million British thermal units per 

hour heat input;

( aa ) Any other stationary source category which, as of August 7, 1980, is being regulated 

under section 111 or 112 of the Act.

R18-2-401(11)(e) - list of 

source categories is in 

R18-2-101(128). Likely 

contains a typo - refers 

to "this section" when it 

should be all of Article 4. 

Also, recommend adding 

a cross reference to 

definition for "Section 

302(j) category" as it is 

not obvious this is a term 

defined in Article 1. See 

Section 5.8.2 of the TSD 

regarding references to 

Artiles 9 and 11.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 56of 112

(b)(2) Major modification (2)(i) 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 (as defined in 

paragraph (b)(39) of this section) of a regulated NSR pollutant (as defined in paragraph (b)(49) 

of this section); and a significant net emissions increase of that pollutant from the major 

stationary source.

R18-2-101(74)(a)

(ii) Any significant emissions increase (as defined at paragraph (b)(39) of this section) from 

any emissions units or net emissions increase (as defined in paragraph (b)(3) of this section) at 

a major stationary source that is significant for volatile organic compounds or NOXshall be 

considered significant for ozone.

R18-2-101(74)(b)

(iii) A physical change or change in the method of operation shall not include: R18-2-101(74)(c)

( a ) Routine maintenance, repair and replacement. Routine maintenance, repair and 

replacement shall include, but not be limited to, any activity(s) that meets the requirements 

of the equipment replacement provisions contained in paragraph (y) of this section;

Note to paragraph (b)(2)(iii)( a ): On December 24, 2003, the second sentence of this 

paragraph (b)(2)(iii)( a ) is stayed indefinitely by court order. The stayed provisions will 

become effective immediately if the court terminates the stay. At that time, EPA will publish a 

document in the Federal Register advising the public of the termination of the stay.

( b ) Use of an alternative fuel or raw material by reason of any order under section 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;

R18-2-101(74)(c)(ii)

( c ) Use of an alternative fuel by reason of an order or rule under section 125 of the Act; R18-2-101(74)(c)(iii)

( d ) Use of an alternative fuel at a steam generating unit to the extent that the fuel is 

generated from municipal solid waste;

R18-2-101(74)(c)(iv)

(b)(2)(iii) ( e ) Use of an alternative fuel or raw material by a stationary source which:

( 1 ) The source was capable of accommodating before January 6, 1975, unless such 

change would be prohibited under any federally enforceable permit condition which was 

established after January 6, 1975 pursuant to 40 CFR 52.21 or under regulations approved 

pursuant to 40 CFR subpart I or §51.166; or

( 2 ) The source is approved to use under any permit issued under 40 CFR 52.21 or under 

regulations approved pursuant to 40 CFR 51.166;

( f ) An increase in the hours of operation or in the production rate, unless such change 

would be prohibited under any federally enforceable permit condition which was established 

after January 6, 1975, pursuant to 40 CFR 52.21 or under regulations approved pursuant to 

40 CFR subpart I or §51.166.

R18-2-101(74)(c)(vi). 

Should refer to December 

12, 1976 instead or 

reference 1/6/1975 for 

PSD and 12/12/1976 for 

NNSR. 

( g ) Any change in ownership at a stationary source. R18-2-101(74)(c)(vii)

( h ) [Reserved]

( i ) The installation, operation, cessation, or removal of a temporary clean coal technology 

demonstration project, provided that the project complies with:

( 1 ) The State implementation plan for the State in which the project is located; and

R18-2-101(74)(c)(i) - 

consistent with the stay, 

only adopted first 

sentence.

R18-2-101(74)(c)(v) and 

R18-2-303

R18-2-101(74)(c)(ix). 

ADEQ's rules do not 

include the 2012 PM2.5 

NAAQS.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 57of 112

( 2 ) Other requirements necessary to attain and maintain the national ambient air quality 

standards during the project and after it is terminated.

( j ) The installation or operation of a permanent clean coal technology demonstration project 

that constitutes repowering, provided that the project does not result in an increase in the 

potential to emit of any regulated pollutant emitted by the unit. This exemption shall apply on 

a pollutant-by-pollutant basis.

R18-2-101(74)(c)(x)

( k ) The reactivation of a very clean coal-fired electric utility steam generating unit. R18-2-101(74)(c)(xi)

(iv) This definition shall not apply with respect to a particular regulated NSR pollutant when the 

major stationary source is complying with the requirements under paragraph (w) of this section 

for a PAL for that pollutant. Instead, the definition at paragraph (w)(2)(viii) of this section shall 

apply.

R18-2-101(74)(d)

(v) Fugitive emissions shall not be included in determining for any of the purposes of this 

section whether a physical change in or change in the method of operation of a major 

stationary source is a major modification, unless the source belongs to one of the source 

categories listed in paragraph (b)(1)(iii) of this section. NOTE: By court order, this provision 

has been stayed indefinitely.

Not included in definition, 

consistent with stay.

(b)(3) Net emissions 

increase

(3)(i) Net emissions increase means, with respect to any regulated NSR pollutant emitted by a 

major stationary source, the amount by which the sum of the following exceeds zero:

R18-2-101(87)(a)

( a ) The increase in emissions from a particular physical change or change in the method of 

operation at a stationary source as calculated pursuant to paragraph (a)(7)(iv) of this 

section; and

R18-2-101(87)(a)(i)

( b ) Any other increases and decreases in actual emissions at the major stationary source 

that are contemporaneous with the particular change and are otherwise creditable. Baseline 

actual emissions for calculating increases and decreases under this paragraph (b)(3)(i)( b ) 

shall be determined as provided in paragraph (b)(47), except that paragraphs (b)(47)(i)( c ) 

and (b)(47)(ii)( d ) of this section shall not apply.

R18-2-101(87)(a)(ii and 

iii)

(ii) An increase or decrease in actual emissions is contemporaneous with the increase from the 

particular change only if it occurs within a reasonable period (to be specified by the State) 

before the date that the increase from the particular change occurs.

R18-2-101(87)(b) - 5 

years

(iii) An increase or decrease in actual emissions is creditable only if: R18-2-101(87)(b) - 

( a ) It occurs within a reasonable period (to be specified by the reviewing authority); and R18-2-101(87)(b) - 5 

years

NAAQS.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 58of 112

( b ) The reviewing authority has not relied on it in issuing a permit for the source under 

regulations approved pursuant to this section, which permit is in effect when the increase in 

actual emissions from the particular change occurs; and

R18-2-101(87)(c). This 

definition applies to all 

aspects of ADEQ's rules, 

so it does not specify that 

creditable increases and 

decreases must not have 

been relied on under a 

PSD permit. This means 

increases and decreases 

under the minor NSR 

program would not be 

available for use. 

( c ) The increase or decrease in emissions did not occur at a Clean Unit, except as provided 

in paragraphs (t)(8) and (u)(10) of this section.

Did not adopt - consistent 

with court decision to 

vacate the Clean Unit 

provisions - D.C. Circuit, 

June 24, 2005. 

( d ) As it pertains to an increase or decrease in fugitive emissions (to the extent 

quantifiable), it occurs at an emissions unit that is part of one of the source categories listed 

in paragraph (b)(1)(iii) of this section or it occurs at an emission unit that is located at a 

major stationary source that belongs to one of the listed source categories. Fugitive emission 

increases or decreases are not included for those emissions units located at a facility whose 

primary activity is not represented by one of the source categories listed in paragraph 

(b)(1)(iii) of this section and that are not, by themselves, part of a listed source category. 

NOTE: This paragraph has been stayed by court order indefinitely.

Did not adopt - consistent 

with stay. See 76 FR 

17552, Mar. 30, 2011.

(b)(3) (iv) An increase or decrease in actual emissions of sulfur dioxide, particulate matter, or 

nitrogen oxides that occurs before the applicable minor source baseline date is creditable only if 

it is required to be considered in calculating the amount of maximum allowable increases 

remaining available.

R18-2-101(87)(d) - 

References PM10 instead 

of particulate matter. 

Recommend adding a 

reference to PM2.5 and 

"minor source baseline 

date" instead of 

"applicable baseline 

date."

(v) An increase in actual emissions is creditable only to the extent that the new level of actual 

emissions exceeds the old level.

R18-2-101(87)(e)

(vi) A decrease in actual emissions is creditable only to the extent that: R18-2-101(87)(f)

( a ) The old level of actual emissions or the old level of allowable emissions, whichever is 

lower, exceeds the new level of actual emissions;

R18-2-101(87)(f)(i)

( b ) It is enforceable as a practical matter at and after the time that actual construction on 

the particular change begins;

R18-2-101(87)(f)(ii)

( c ) It has approximately the same qualitative significance for public health and welfare as 

that attributed to the increase from the particular change; and

R18-2-101(87)(f)(iii)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 59of 112

(vii) An increase that results from a physical change at a source 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.

R18-2-101(87)(g). 

Recommend revising this 

refer to a "replacement 

unit" instead of "unit that 

replaces an existing unit".

(b)(3) (viii) Paragraph (b)(21)(ii) of this section shall not apply for determining creditable increases 

and decreases.

Not included in 

definition.

(b)(4) Potential to emit (4) 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 if the limitation or the effect it would have on emissions is federally 

enforceable. Secondary emissions do not count in determining the potential to emit of a 

stationary source.

R18-2-101(109) - See 

http://www.epa.gov/regi

on07/air/title5/t5memos/

pottoemi.pdf regarding 

federal enforceability of 

PTE. Consistent with 

guidance.

(b)(5) Stationary source (5) Stationary source means any building, structure, facility, or installation which emits or may 

emit a regulated NSR pollutant.

R18-2-101(139). 

Definition references "any 

air pollutant" instead of 

"regulated NSR 

pollutant." This is 

generally okay, but air 

pollutant is not a term 

defined by ADEQ. In 

addition, contains a 

reference to ADEQ 

permitting statute -49-

426(A). See discussion in 

Section 5.8.2 of the TSD.

(b)(6) Building, 

structure, facility, 

or installation

(6) Building, structure, facility, or installation means all of the pollutant-emitting activities which 

belong to the same industrial grouping, are located on one or more contiguous or adjacent 

properties, and are under the control of the same person (or persons under common control) 

except the activities of any vessel. Pollutant-emitting activities shall be considered as part of the 

same industrial grouping if they belong to the same Major Group ( i.e. , which have the same 

two-digit code) as described in the Standard Industrial Classification Manual, 1972, as amended 

by the 1977 Supplement (U.S. Government Printing Office stock numbers 4101–0066 and 

003–005–00176–0, respectively).

R18-2-101(139). 

References the 1987 

Manual - which is the 

current version. 

Acceptable.

(b)(7) Emissions unit (7) Emissions unit means any part of a stationary source that emits or would have the potential 

to emit any regulated NSR pollutant and includes an electric utility steam generating unit as 

defined in paragraph (b)(30) of this section. For purposes of this section, there are two types of 

emissions units as described in paragraphs (b)(7)(i) and (ii) of this section.

R18-2-101(48)

(i) A new emissions unit is any emissions unit that is (or will be) newly constructed and that has 

existed for less than 2 years from the date such emissions unit first operated.

R18-2-401(12)
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(ii) An existing emissions unit is any emissions unit that does not meet the requirements in 

paragraph (b)(7)(i) of this section. A replacement unit, as defined in paragraph (b)(32) of this 

section, is an existing emissions unit.

R18-2-401(6)

(b)(8) Construction (8) Construction means any physical change or change in the method of operation (including 

fabrication, erection, installation, demolition, or modification of an emissions unit) that would 

result in a change in emissions.

R18-2-101(32). Uses the 

term "actual emissions" 

instead of "emissions." 

Actual emissions is a 

defined term, 

recommend revising for 

consistency.

(b)(9) Commence (9) 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:

(i) Begun, or caused to begin, a continuous program of actual on-site construction of the 

source, to be completed within a reasonable time; or

(ii) Entered into binding agreements or contractual obligations, which cannot be cancelled or 

modified without substantial loss to the owner or operator, to undertake a program of actual 

construction of the source to be completed within a reasonable time.

(b)(10) Necessary 

preconstruction 

approvals or 

permits

(10) Necessary preconstruction approvals or permits means those permits or approvals required 

under Federal air quality control laws and regulations and those air quality control laws and 

regulations which are part of the applicable State Implementation Plan.

R18-2-101(86)

(b)(11) Begin actual 

construction

(11) Begin actual construction means, in general, initiation of physical on-site construction 

activities on an emissions unit which are of a permanent nature. Such activities include, but are 

not limited to, 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 term refers to those on-site activities, other than preparatory activities, which 

mark the initiation of the change.

R18-2-101(20)

R18-2-101(31)
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(b)(12) Best available 

control technology

(12) Best available control technology means an emissions limitation (including a visible 

emissions standard) based on the maximum degree of reduction for each a regulated NSR 

pollutant which would be emitted from any proposed major stationary source or major 

modification which the reviewing authority, on a case-by-case basis, taking into account energy, 

environmental, and economic impacts and other costs, determines is achievable for such 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 such pollutant. In no event shall application of best available control technology result 

in emissions of any pollutant which would exceed the emissions allowed by any applicable 

standard under 40 CFR parts 60 and 61. If the reviewing authority 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 thereof, may be prescribed instead to satisfy the 

requirement for the application of best available control technology. Such standard shall, to the 

degree possible, set forth the emissions reduction achievable by implementation of such design, 

equipment, work practice or operation, and shall provide for compliance by means which achieve 

equivalent results.

R18-2-101(21). See also 

R18-2-406(A)(4) which is 

referenced in (21). 

Contains a typo -"air" 

where the federal 

regulation has "a". The 

"a" in the federal reg is a 

typo - "air" should be 

deleted. See Section 

5.8.2 of the TSD 

regarding references to 

Artiles 9 and 11.

(b)(13) Baseline 

concentration

(13)(i) Baseline concentration means that ambient concentration level that exists in the baseline 

area at the time of the applicable minor source baseline date. A baseline concentration is 

determined for each pollutant for which a minor source baseline date is established and shall 

include:

R18-2-218(B)(1). 

Contains a typo "data" 

instead of "date."

( a ) The actual emissions, as defined in paragraph (b)(21) of this section, representative of 

sources in existence on the applicable minor source baseline date, except as provided in 

paragraph (b)(13)(ii) of this section;

R18-2-218(B)(3)(a). 

Recommending including 

cross-references for 

consistency with federal 

regulation

( b ) The allowable emissions of major stationary sources that commenced construction 

before the major source baseline date, but were not in operation by the applicable minor 

source baseline date.

R18-2-218(B)(3)(b)

(ii) The following will not be included in the baseline concentration and will affect the applicable 

maximum allowable increase(s):

R18-2-218(B)(4). 

Recommend including 

cross references to 

defined terms for 

consistency with federal 

reg.

( a ) Actual emissions, as defined in paragraph (b)(21) of this section, from any major 

stationary source on which construction commenced after the major source baseline date; 

and

R18-2-218(B)(4)(a)

( b ) Actual emissions increases and decreases, as defined in paragraph (b)(21) of this 

section, at any stationary source occurring after the minor source baseline date.

R18-2-218(B)(4)(b)

(b)(14) Major source 

baseline date

(14)(i) Major source baseline date means: R18-2-218(B)(1)

( a ) In the case of PM10and sulfur dioxide, January 6, 1975; R18-2-218(B)(1)(a)

( b ) In the case of nitrogen dioxide, February 8, 1988; and R18-2-218(B)(1)(b)
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( c ) In the case of PM2.5,October 20, 2010. R18-2-218(B)(1)(c)

(ii) Minor source baseline date means the earliest date after the trigger date on which a major 

stationary source or a major modification subject to 40 CFR 52.21 or to regulations approved 

pursuant to 40 CFR 51.166 submits a complete application under the relevant regulations. The 

trigger date is:

R18-2-218(B)(2)

( a ) In the case of PM10and sulfur dioxide, August 7, 1977; R18-2-218(B)(2)(a)

( b ) In the case of nitrogen dioxide, February 8, 1988; and R18-2-218(B)(2)(b)

( c ) In the case of PM2.5,October 20, 2011. R18-2-218(B)(2)(c)

(iii) The baseline date is established for each pollutant for which increments or other equivalent 

measures have been established if:

R18-2-218(c). Consistent 

with federal regulation, 

but ADEQ rules have not 

otherwise introduced the 

term increment. Instead 

use maximum allowable 

increase. 

( a ) The area in which the proposed source or modification would construct is designated as 

attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the Act for the pollutant 

on the date of its complete application under 40 CFR 52.21 or under regulations approved 

pursuant to 40 CFR 51.166; and

R18-2-218(C)(1)

( b ) In the case of a major stationary source, the pollutant would be emitted in significant 

amounts, or, in the case of a major modification, there would be a significant net emissions 

increase of the pollutant.

R18-2-218(C)(2)

(iv) Any minor source baseline date established originally for the TSP increments shall remain in 

effect and shall apply for purposes of determining the amount of available PM-10 increments, 

except that the reviewing authority may rescind any such minor source baseline date where it 

can be shown, to the satisfaction of the reviewing authority, that the emissions increase from the 

major stationary source, or the net emissions increase from the major modification, responsible 

for triggering that date did not result in a significant amount of PM-10 emissions.

Not included in 

definition.

(b)(15) Baseline area (15)(i) Baseline area means any intrastate area (and every part thereof) designated as 

attainment or unclassifiable under section 107(d)(1)(A)(ii) or (iii) of the Act in which the major 

source or major modification establishing the minor source baseline date would construct or 

would have an air quality impact for the pollutant for which the baseline date is established, as 

follows: Equal to or greater than 1 μg/m3(annual average) for SO2,NO2, or PM10; or equal or 

greater than 0.3 μg/m3(annual average) for PM2.5.

R18-2-218(D). 
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(ii) Area redesignations under section 107(d)(1)(A)(ii) or (iii) of the Act cannot intersect or be 

smaller than the area of impact of any major stationary source or major modification which:

R18-2-218(D). Contains 

an incorrect reference to 

R18-2-217 - which 

designates attainment 

areas as Class I, II, or 

III. The federal regulation 

is referring to designation 

of attainment or 

unclassifiable air quality 

control regions. 

( a ) Establishes a minor source baseline date; or R18-2-218(D)(1)

( b ) Is subject to 40 CFR 52.21 or under regulations approved pursuant to 40 CFR 51.166, 

and would be constructed in the same State as the State proposing the redesignation.

R18-2-218(D)(2)

(iii) Any baseline area established originally for the TSP increments shall remain in effect and 

shall apply for purposes of determining the amount of available PM–10 increments, except that 

such baseline area shall not remain in effect if the permit authority rescinds the corresponding 

minor source baseline date in accordance with paragraph (b)(14)(iv) of this section.

Not included.

(b)(16) Allowable 

emissions

(16) Allowable emissions means the emissions rate of a stationary source 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:

R18-2-101(13)

(i) The applicable standards as set forth in 40 CFR parts 60 and 61; R18-2-101(13)(a). 

Recommend revising to 

use "and" instead of "or" 

for consistency with 

federal reg. See Section 

5.8.2 of the TSD 

regarding references to 

Artiles 9 and 11.

(b)(16) (ii) The applicable State Implementation Plan emissions limitation, including those with a future 

compliance date; or

R18-2-101(13)(b) - does 

not include "future 

compliance date" 

language. 

(iii) The emissions rate specified as a federally enforceable permit condition. R18-2-101(13)(b)(3) 
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(b)(17) Federally 

enforceable

(17) Federally enforceable means all limitations and conditions which are enforceable by the 

Administrator, including those requirements developed pursuant to 40 CFR parts 60 and 61, 

requirements within any applicable State implementation plan, 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 an EPA-approved program that is 

incorporated into the State implementation plan and expressly requires adherence to any permit 

issued under such program.

R18-2-101(53) - (53)(d) 

contains clarifications for 

requirements pursuant to 

R18-2-306.01 or R18-2-

306.02. See discusssion 

in Section 5.8.2 of the 

TSD. Also, see Section 

5.8.2 of the TSD 

regarding references to 

Artiles 9 and 11.

(b)(18) Secondary 

emissions

(18) Secondary emissions means emissions which occur as a result of the construction or 

operation of a major stationary source or major modification, but do not come from the major 

stationary source or major modification itself. For the purposes of this section, secondary 

emissions must be specific, well defined, quantifiable, and impact the same general areas the 

stationary source modification which causes the secondary emissions. Secondary emissions 

include emissions from any offsite support facility which would not be constructed or increase its 

emissions except as a result of the construction or operation of the major stationary source or 

major modification. Secondary emissions do not include any emissions which come directly from 

a mobile source, such as emissions from the tailpipe of a motor vehicle, from a train, or from a 

vessel.

R18-2-101(127). Missing 

the word "except" in the 

third sentence.

(b)(19) Innovative control 

technology

(19) Innovative control technology means any system of air pollution control that has not been 

adequately demonstrated 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 nonair quality 

environmental impacts.

R18-2-401(8)

(b)(20) Fugitive emissions (20) Fugitive emissions means those emissions which could not reasonably pass through a stack, 

chimney, vent, or other functionally equivalent opening.

R18-2-101(59)

(b)(21) Actual emissions (21)(i) Actual emissions means the actual rate of emissions of a regulated NSR pollutant from an 

emissions unit, as determined in accordance with paragraphs (b)(21)(ii) through (iv) of this 

section, except that this definition shall not apply for calculating whether a significant emissions 

increase has occurred, or for establishing a PAL under paragraph (w) of this section. Instead, 

paragraphs (b)(40) and (b)(47) of this section shall apply for those purposes.

R18-2-101(2)(a) and (e)

(ii) In general, actual emissions as of a particular date shall equal 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. The 

reviewing authority shall allow the use of a different time period upon a determination that it is 

more representative of normal source operation. Actual emissions shall be calculated using the 

unit's actual operating hours, production rates, and types of materials processed, stored, or 

combusted during the selected time period.

R18-2-101(2)(a)

(iii) The reviewing authority may presume that source-specific allowable emissions for the unit 

are equivalent to the actual emissions of the unit.

R18-2-101(2)(b)
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(b)(21) (iv) For any emissions unit that has not begun normal operations on the particular date, actual 

emissions shall equal the potential to emit of the unit on that date.

R18-2-101(2)(c) - 

references to Class I and 

Class II sources, no 

definition for Class I or 

Class II source.Could 

consider revising to 

reference "source with a 

Class I or Class II 

permit". 

(b)(22) Complete (22) Complete means, in reference to an application for a permit, that the application contains all 

the information necessary for processing the application. Designating an application complete for 

purposes of permit processing does not preclude the reviewing authority from requesting or 

accepting any additional information.

R18-2-401(4) and R18-2-

301(5). However, R18-2-

401 does not include the 

second sentence - this is 

the definition that 

governs for major NSR 

purposes - and needs to 

be added

(b)(23) Significant (23)(i) Significant means, in reference to a net emissions increase or the potential of a source to 

emit any of the following pollutants, a rate of emissions that would equal or exceed any of the 

following rates:

Pollutant and Emissions Rate

Carbon monoxide: 100 tons per year (tpy)

Nitrogen oxides: 40 tpy

Sulfur dioxide: 40 tpy

Particulate matter: 25 tpy of particulate matter emissions. 15 tpy of PM10emissions

PM2.5: 10 tpy of direct PM2.5emissions; 40 tpy of sulfur dioxide emissions; 40 tpy of nitrogen 

oxide emissions unless demonstrated not to be a PM2.5precursor under paragraph (b)(49) of 

this section

Ozone: 40 tpy of volatile organic compounds or nitrogen oxides

Lead: 0.6 tpy

Fluorides: 3 tpy

Sulfuric acid mist: 7 tpy

Hydrogen sulfide (H2S): 10 tpy

Total reduced sulfur (including H2S): 10 tpy

Reduced sulfur compounds (including H2S): 10 tpy

Municipal waste combustor organics (measured as total tetra-through octa-chlorinated 

dibenzo-p-dioxins and dibenzofurans): 3.2 × 10–−6megagrams per year (3.5 × 10−6tons per 

year)

Municipal waste combustor metals (measured as particulate matter): 14 megagrams per year 

(15 tons per year)

Municipal waste combustor acid gases (measured as sulfur dioxide and hydrogen chloride): 

36 megagrams per year (40 tons per year)

R18-2-101(130)(a)
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Municipal solid waste landfill emissions (measured as nonmethane organic compounds): 45 

megagrams per year (50 tons per year)

(ii) Significant means, in reference to a net emissions increase or the potential of a source to 

emit a regulated NSR pollutant that paragraph (b)(23)(i) of this section, does not list, any 

emissions rate.

R18-2-101(130)(d)

(iii) Notwithstanding paragraph (b)(23)(i) of this section, significant means any emissions rate 

or any net emissions increase associated with a major stationary source or major modification, 

which would construct within 10 kilometers of a Class I area, and have an impact on such area 

equal to or greater than 1 μg/m3(24-hour average).

R18-2-101(130)(e). 

Allows impacts of 1 

milligram (mg) instead of 

only 1 microgram (μg). 

(b)(24) Federal Land 

Manager

(24) Federal Land Manager means, with respect to any lands in the United States, the Secretary 

of the department with authority over such lands.

R18-2-101(52)

(b)(25) High terrain (25) High terrain means any area having an elevation 900 feet or more above the base of the 

stack of a source.

R18-2-401(7)

(b)(26) Low terrain (26) Low terrain means any area other than high terrain. R18-2-401(9)

(b)(27) Indian 

Reservation

(27) Indian Reservation means any federally recognized reservation established by Treaty, 

Agreement, Executive Order, or Act of Congress.

R18-2-101(67)

(b)(28) Indian Governing 

Body

(28) Indian Governing Body means the governing body of any tribe, band, or group of Indians 

subject to the jurisdiction of the United States and recognized by the United States as possessing 

power of self-government.

R18-2-101(66)

(b)(29) VOC (29) Volatile organic compounds (VOC) is as defined in §51.100(s) of this part. R18-2-101(152) - a few 

exemptions from 

definition are missing, 

but does not make less 

stringent

(b)(30) Electric utility 

steam generating 

unit

(30) Electric utility steam generating unit means any steam electric generating unit that is 

constructed for the purpose of supplying more than one-third of its potential electric output 

capacity and more than 25 MW electrical 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 steamelectric generator that would produce electrical energy for sale is also considered in determining 

the electrical energy output capacity of the affected facility.

R18-2-101(45)

(b)(31) (31) [Reserved]

(b)(32) Replacement unit (32) Replacement unit means an emissions unit for which all the criteria listed in paragraphs 

(b)(32)(i) through (iv) of this section are met. No creditable emission reductions shall be 

generated from shutting down the existing emissions unit that is replaced.

(i) The emissions unit is a reconstructed unit within the meaning of §60.15(b)(1) of this 

chapter, or the emissions unit completely takes the place of an existing emissions unit.

(ii) The emissions unit is identical to or functionally equivalent to the replaced emissions unit.

(iii) The replacement does not change the basic design parameter(s) (as discussed in paragraph 

(y)(2) of this section) of the process unit.

(iv) The replaced emissions unit is permanently removed from the major stationary 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.

R18-2-401(22)
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(b)(33) Clean coal 

technology 

(33) Clean coal technology means any technology, including technologies applied at the 

precombustion, combustion, or post combustion stage, at a new or existing facility which will 

achieve significant reductions in air emissions of sulfur dioxide or oxides of nitrogen associated 

with the utilization of coal in the generation of electricity, or process steam which was not in 

widespread use as of November 15, 1990.

R18-2-101(27)

(b)(34) Clean coal 

technology 

demonstration 

project

(34) Clean coal technology demonstration project means a project using funds appropriated 

under the heading “Department of Energy—Clean Coal Technology”, up to a total amount of 

$2,500,000,000 for commercial demonstration of clean coal technology, or similar projects 

funded through appropriations for the Environmental Protection Agency. The Federal contribution 

for a qualifying project shall be at least 20 percent of the total cost of the demonstration project.

R18-2-101(28)

(b)(35) Temporary clean 

coal technology 

demonstration 

project

(35) Temporary clean coal technology demonstration project means a clean coal technology 

demonstration project that is operated for a period of 5 years or less, and which complies with 

the State implementation plan for the State in which the project is located and other 

requirements necessary to attain and maintain the national ambient air quality standards during 

and after the project is terminated.

R18-2-101(141). ADEQ's 

rules do not include the 

2012 PM2.5 NAAQS.

(b)(36) Repowering (36)(i) Repowering means replacement of an existing coal-fired boiler with one of the following 

clean coal technologies: atmospheric or pressurized fluidized bed combustion, integrated 

gasification combined cycle, magnetohydrodynamics, direct and indirect coal-fired turbines, 

integrated gasification fuel cells, or as determined by the Administrator, in consultation with the 

Secretary of Energy, a derivative of one or more of these technologies, and any other technology 

capable of controlling multiple combustion emissions simultaneously with improved boiler or 

generation efficiency and with significantly greater waste reduction relative to the performance of 

technology in widespread commercial use as of November 15, 1990.

(ii) Repowering shall also include any oil and/or gas-fired unit which has been awarded clean 

coal technology demonstration funding as of January 1, 1991, by the Department of Energy.

(iii) The reviewing authority shall give expedited consideration to permit applications for any 

source that satisfies the requirements of this subsection and is granted an extension under 

section 409 of the Clean Air Act.

(b)(37) Reactivation (37) Reactivation of a very clean coal-fired electric utility steam generating unit means any 

physical change or change in the method of operation associated with the commencement of 

commercial operations by a coal-fired utility unit after a period of discontinued operation where 

the unit:

(i) Has not been in operation for the two-year period prior to the enactment of the Clean Air Act 

Amendments of 1990, and the emissions from such unit continue to be carried in the permitting 

authority's emissions inventory at the time of enactment;

(ii) Was equipped prior to shutdown with a continuous system of emissions control that 

achieves a removal efficiency for sulfur dioxide of no less than 85 percent and a removal 

efficiency for particulates of no less than 98 percent;

(iii) Is equipped with low-NOXburners prior to the time of commencement of operations 

following reactivation; and

(iv) Is otherwise in compliance with the requirements of the Clean Air Act.

R18-2-101(115)

R18-2-101(123)
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(b)(38) Pollution 

prevention

(38) Pollution prevention means any activity that through process changes, product 

reformulation or redesign, or substitution of less polluting raw materials, eliminates or reduces 

the release of air pollutants (including fugitive emissions) and other pollutants to the environment 

prior to recycling, treatment, or disposal; it does not mean recycling (other than certain “inprocess recycling” practices), energy recovery, treatment, or disposal.

Not included, but phrase 

no longer applicable to 

the rest of 51.166. 

Phrase was used for 

pollution control projects 

(PCPs) rule revisions, 

which were vacated in 

2006.

(b)(39) Significant 

emissions

(39) Significant emissions increase means, for a regulated NSR pollutant, an increase in 

emissions that is significant (as defined in paragraph (b)(23) of this section) for that pollutant.

R18-2-101(131)

(b)(40) Projected actual 

emissions

(40)(i) 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 (12-month period) 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 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 stationary source.

R18-2-401(20)(a)

(ii) In determining the projected actual emissions under paragraph (b)(40)(i) of this section 

(before beginning actual construction), the owner or operator of the major stationary source:

R18-2-401(20)(b)

( a ) Shall consider all relevant information, including but not limited to, historical operational 

data, the company's own representations, the company's expected business activity and the 

company's highest projections of business activity, the company's filings with the State or 

Federal regulatory authorities, and compliance plans under the approved plan; and

R18-2-401(20)(b)(i)

( b ) Shall include fugitive emissions to the extent quantifiable, and emissions associated with 

startups, shutdowns, and malfunctions; and

R18-2-401(20)(b)(ii) and 

(iii). Does not include 

malfunctions. 

( c ) Shall exclude, in calculating any increase in emissions that results from the particular 

project, that portion of the 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 under paragraph (b)(47) of this section and that are also unrelated to the 

particular project, including any increased utilization due to product demand growth; or,

R18-2-401(20)(b)(iv)

( d ) In lieu of using the method set out in paragraphs (b)(40)(ii)( a ) through ( c ) of this 

section, may elect to use the emissions unit's potential to emit, in tons per year, as defined 

under paragraph (b)(4) of this section.

R18-2-401(20)(c)

(b)(41) (41) [Reserved]
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(b)(42) PSD Program (42) Prevention of Significant Deterioration Program (PSD) program means a major source 

preconstruction permit program that has been approved by the Administrator and incorporated 

into the plan to implement the requirements of this section, or the program in §52.21 of this 

chapter. Any permit issued under such a program is a major NSR permit.

Not included in submittal. 

PSD program is 

referenced in one place - 

R18-2-412(2)(b). 

Recommend revising 412 

or adding definition.

(b)(43) CEMS (43) Continuous emissions monitoring system (CEMS) means all of the equipment that may be 

required to meet the data acquisition and availability requirements of this section, to sample, 

condition (if applicable), analyze, and provide a record of emissions on a continuous basis.

R18-2-101(34)

(b)(44) PEMS (44) Predictive emissions monitoring system (PEMS) means all of the equipment necessary to 

monitor process and control device operational parameters (for example, control device 

secondary voltages and electric currents) and other information (for example, gas flow rate, O2 

or CO2concentrations), and calculate and record the mass emissions rate (for example, lb/hr) on 

a continuous basis.

R18-2-101(102). Does 

not include examples 

provided in federal 

regulation. Definition is 

less clear. 

(b)(45) CPMS (45) Continuous parameter monitoring system (CPMS) means all of the equipment necessary to 

meet the data acquisition and availability requirements of this section, to monitor process and 

control device operational parameters (for example, control device secondary voltages and 

electric currents) and other information (for example, gas flow rate, O2 or CO2concentrations), 

and to record average operational parameter value(s) on a continuous basis.

R18-2-101(36). Does not 

include examples 

provided in federal 

regulation. 

(b)(46) CERMS (46) Continuous emissions rate monitoring system (CERMS) means the total equipment required 

for the determination and recording of the pollutant mass emissions rate (in terms of mass per 

unit of time).

R18-2-101(35)

(b)(47) Baseline actual 

emissions

(47) Baseline actual emissions means the rate of emissions, in tons per year, of a regulated NSR 

pollutant, as determined in accordance with paragraphs (b)(47)(i) through (iv) of this section.

R18-2-401(2). Typo in 

first line, should 

reference a-d not a-c.

(i) 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 5-year period 

immediately preceding when the owner or operator begins actual construction of the project. 

The reviewing authority shall allow the use of a different time period upon a determination that 

it is more representative of normal source operation.

R18-2-401(2)(a)

( a ) The average rate shall include fugitive emissions to the extent quantifiable, and 

emissions associated with startups, shutdowns, and malfunctions.

R18-2-401(2)(a)(i)

( b ) The average rate shall be adjusted downward to exclude any non-compliant emissions 

that occurred while the source was operating above an emission limitation that was legally 

enforceable during the consecutive 24-month period.

R18-2-401(2)(a)(ii)

( c ) 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.

R18-2-401(2)(a)(iii)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 70of 112

( d ) 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 amount if required by paragraph (b)(47)(i)( b ) of this section.

R18-2-401(2)(a)(iv)

(ii) For an 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 emissions unit actually 

emitted the pollutant during any 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 reviewing authority for a permit required either under this section or under a plan 

approved by the Administrator, whichever is earlier, except that the 10-year period shall not 

include any period earlier than November 15, 1990.

R18-2-401(2)(b)

( a ) The average rate shall include fugitive emissions to the extent quantifiable, and 

emissions associated with startups, shutdowns, and malfunctions.

R18-2-401(2)(b)(i)

( b ) The average rate shall be adjusted downward to exclude any non-compliant emissions 

that occurred while the source was operating above an emission limitation that was legally 

enforceable during the consecutive 24-month period.

R18-2-401(2)(b)(ii)

(b)(47) ( c ) The average rate shall be adjusted downward to exclude any emissions that would have 

exceeded an emission limitation with which the major stationary source must currently 

comply, had such major stationary source been required to comply with such limitations 

during the consecutive 24-month period. However, if an emission limitation is part of a 

maximum achievable control technology standard that the Administrator proposed or 

promulgated under part 63 of this chapter, the baseline actual emissions need only be 

adjusted if the State has taken credit for such emissions reductions in an attainment 

demonstration or maintenance plan consistent with the requirements of §51.165(a)(3)(ii)(G).

R18-2-401(2)(b)(iii) - 

references section 

110(a)(1) instead of 

51.165(a)(3)(ii)(G). Not 

less stringent. Should 

consider referencing 

"110(a)." See Section 

5.8.2 of the TSD 

regarding references to 

Artiles 9 and 11.

( d ) 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.

R18-2-401(2)(b)(iv)

( e ) 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 amount if required by paragraphs (b)(47)(ii)(b) and (c) of this section.

R18-2-401(2)(b)(v)

(iii) 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 such unit shall 

equal zero; and thereafter, for all other purposes, shall equal the unit's potential to emit.

R18-2-401(2)(c)

(iv) For a PAL for a stationary source, the baseline actual emissions shall be calculated for 

existing electric utility steam generating units in accordance with the procedures contained in 

paragraph (b)(47)(i) of this section, for other existing emissions units in accordance with the 

procedures contained in paragraph (b)(47)(ii) of this section, and for a new emissions unit in 

accordance with the procedures contained in paragraph (b)(47)(iii) of this section.

R18-2-401(2)(d)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 71of 112

(b)(48) Subject to 

regulation

(48) Subject to regulation means, for any air pollutant, that the pollutant is subject to either a 

provision in the Clean Air Act, or a nationally-applicable regulation codified by the Administrator 

in subchapter C of this chapter, that requires actual control of the quantity of emissions of that 

pollutant, and that such a control requirement has taken effect and is operative to control, limit 

or restrict the quantity of emissions of that pollutant released from the regulated activity. Except 

that:

By state law can't adopt 

GHG's into program, but 

still need the first 

sentence. FIP in place for 

GHGs - 40 CFR 52.37. 

See discussionin Section 

5.8.2 of the TSD.

(i) Greenhouse gases (GHGs), the air pollutant defined in §86.1818–12(a) of this chapter as 

the aggregate group of six greenhouse gases: Carbon dioxide, nitrous oxide, methane, 

hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride, shall not be subject to 

regulation except as provided in paragraphs (b)(48)(iv) through (v) of this section.

(ii) For purposes of paragraphs (b)(48)(iii) through (v) of this section, the term tpy CO 2 

equivalent emissions (CO 2 e) shall represent an amount of GHGs emitted, and shall be 

computed as follows:

(a) Multiplying the mass amount of emissions (tpy), for each of the six greenhouse gases in 

the pollutant GHGs, by the gas's associated global warming potential published at Table A–1 

to subpart A of part 98 of this chapter—Global Warming Potentials. For purposes of this 

paragraph (b)(48)(ii)(a), prior to July 21, 2014, the mass of the greenhouse gas carbon 

dioxide shall not include carbon dioxide emissions resulting from the combustion or 

decomposition of non-fossilized and biodegradable organic material originating from plants, 

animals, or micro-organisms (including products, by-products, residues and waste from 

agriculture, forestry and related industries as well as the non-fossilized and biodegradable 

organic fractions of industrial and municipal wastes, including gases and liquids recovered 

from the decomposition of non-fossilized and biodegradable organic material).

( b ) Sum the resultant value from paragraph (b)(48)(ii)( a ) of this section for each gas to 

compute a tpy CO2e.

(iii) The term emissions increase as used in paragraphs (b)(48)(iv) through (v) of this section 

shall mean that both a significant emissions increase (as calculated using the procedures in 

(a)(7)(iv) of this section) and a significant net emissions increase (as defined in paragraphs 

(b)(3) and (b)(23) of this section) occur. For the pollutant GHGs, an emissions increase shall be 

based on tpy CO2e, and shall be calculated assuming the pollutant GHGs is a regulated NSR 

pollutant, and “significant” is defined as 75,000 tpy CO2e instead of applying the value in 

paragraph (b)(23)(ii) of this section.

(iv) Beginning January 2, 2011, the pollutant GHGs is subject to regulation if:

( a ) The stationary source is a new major stationary source for a regulated NSR pollutant 

that is not GHGs, and also will emit or will have the potential to emit 75,000 tpy CO2e or 

more; or

( b ) The stationary source is an existing major stationary source for a regulated NSR 

pollutant that is not GHGs, and also will have an emissions increase of a regulated NSR 

pollutant, and an emissions increase of 75,000 tpy CO2e or more; and,
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 72of 112

(v) Beginning July 1, 2011, in addition to the provisions in paragraph (b)(48)(iv) of this section, 

the pollutant GHGs shall also be subject to regulation:

( a ) At a new stationary source that will emit or have the potential to emit 100,000 tpy 

CO2e; or

( b ) At an existing stationary source that emits or has the potential to emit 100,000 tpy 

CO2e, when such stationary source undertakes a physical change or change in the method of 

operation that will result in an emissions increase of 75,000 tpy CO2e or more.

(b)(49) Regulated NSR 

pollutant

(49) Regulated NSR pollutant, for purposes of this section, means the following: R18-2-101(122)

(i) Any pollutant for which a national ambient air quality standard has been promulgated. This 

includes, but is not limited to, the following:

R18-2-101(122)

( a ) PM2.5 emissions and PM10 emissions shall include gaseous emissions from a source or 

activity which condense to form particulate matter at ambient temperatures. On or after 

January 1, 2011, such condensable particulate matter shall be accounted for in applicability 

determinations and in establishing emissions limitations for PM2.5 and PM10 in PSD permits. 

Compliance with emissions limitations for PM2.5 and PM10 issued prior to this date shall not 

be based on condensable particulate matter unless required by the terms and conditions of 

the permit or the applicable implementation plan. Applicability determinations made prior to 

this date without accounting for condensable particulate matter shall not be considered in 

violation of this section unless the applicable implementation plan required condensable 

particulate matter to be included;

R18-2-101(122)(f) - 

contains references to 

particulate matter that 

have been removed from 

51.166. Consider 

revising. See discussion 

in Section 5.8.3 of the 

TSD.

( b ) Any pollutant identified under this paragraph (b)(49)(i)( b ) as a constituent or 

precursor to a pollutant for which a national ambient air quality standard has been 

promulgated. Precursors identified by the Administrator for purposes of NSR are the 

following:

R18-2-101(122)(a)

( 1 ) Volatile organic compounds and nitrogen oxides are precursors to ozone in all 

attainment and unclassifiable areas.

R18-2-101(122)(a)(i)

( 2 ) Sulfur dioxide is a precursor to PM2.5 in all attainment and unclassifiable areas. R18-2-101(122)(a)(ii)

( 3 ) Nitrogen oxides are presumed to be precursors to PM2.5 in all attainment and 

unclassifiable areas, unless the State demonstrates to the Administrator's satisfaction or EPA 

demonstrates that emissions of nitrogen oxides from sources in a specific area are not a 

significant contributor to that area's ambient PM2.5 concentrations.

R18-2-101(122)(a)(iii)

( 4 ) Volatile organic compounds are presumed not to be precursors to PM2.5 in any 

attainment or unclassifiable area, unless the State demonstrates to the Administrator's 

satisfaction or EPA demonstrates that emissions of volatile organic compounds from sources 

in a specific area are a significant contributor to that area's ambient PM2.5 concentrations.

NA, no demonstration

(ii) Any pollutant that is subject to any standard promulgated under section 111 of the Act; R18-2-101(122)(b). See 

Section 5.8.2 of the TSD 

regarding references to 

Artiles 9 and 11.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 73of 112

(iii) Any Class I or II substance subject to a standard promulgated under or established by title 

VI of the Act;

R18-2-101(122)(C). 

Recommend updating 

referenced date.

(iv) Any pollutant that otherwise is subject to regulation under the Act as defined in paragraph 

(b)(48) of this section.

Not included in 

submittal. See also 

definition of "subject to 

regulation" above - 

(b)(48).

(v) Notwithstanding paragraphs (b)(49)(i) through (iv) of this section, the term regulated NSR 

pollutant shall not include any or all hazardous air pollutants either listed in section 112 of the 

Act, or added to the list pursuant to section 112(b)(2) of the Act, and which have not been 

delisted pursuant to section 112(b)(3) of the Act, unless the listed hazardous air pollutant is 

also regulated as a constituent or precursor of a general pollutant listed under section 108 of 

the Act.

R18-2-101(122)(e). 

References HAPs listed in 

R18-2-1101, but this 

regulation does not 

contain a list of HAPs, 

only a list of NESHAP 

standards. Should also 

update "as of" date.

(b)(50) Reviewing 

authority

(50) Reviewing authority means the State air pollution control agency, local agency, other State 

agency, Indian tribe, or other agency authorized by the Administrator to carry out a permit 

program under §51.165 and this section, or the Administrator in the case of EPA-implemented 

permit programs under §52.21 of this chapter.

Uses the term Director or 

Department - which carry 

out the SIP. All 

references to reviewing 

authority in 51.166 

pertain to the specific 

reviewing authority 

submitting the SIP. That 

is, it is not "any" 

reviewing authority, but 

"the" reviewing authority.

(b)(51) Project (51) Project means a physical change in, or change in method of operation of, an existing major 

stationary source.

R18-2-101(112)

(b)(52) LAER (52) Lowest achievable emission rate (LAER) is as defined in §51.165(a)(1)(xiii). R18-2-401(10). 

(b)(53) Process unit (53)(i) In general, process unit means any collection of structures and/or equipment that 

processes, assembles, applies, blends, or otherwise uses material inputs to produce or store an 

intermediate or a completed product. A single stationary source may contain more than one 

process unit, and a process unit may contain more than one emissions unit.

(ii) Pollution control equipment is not part of the process unit, unless it serves a dual function 

as both process and control equipment. Administrative and warehousing facilities are not part 

of the process unit.

(iii) For replacement cost purposes, components shared between two or more process units are 

proportionately allocated based on capacity.

(iv) The following list identifies the process units at specific categories of stationary sources.

Not included. These 

provisions were stayed 

indefinitely by the DC 

Circuit Court on 

December 24, 2003 and 

are not needed for a PSD 

program.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 74of 112

( a ) For a steam electric generating facility, the process unit consists of those portions of the 

plant that contribute directly to the production of electricity. For example, at a pulverized coalfired facility, the process unit would generally be the combination of those systems from the 

coal receiving equipment through the emission stack (excluding post-combustion pollution 

controls), including the coal handling equipment, pulverizers or coal crushers, feedwater 

heaters, ash handling, boiler, burners, turbine-generator set, condenser, cooling tower, water 

treatment system, air preheaters, and operating control systems. Each separate generating 

unit is a separate process unit.

( b ) For a petroleum refinery, there are several categories of process units: those that 

separate and/or distill petroleum feedstocks; those that change molecular structures; 

petroleum treating processes; auxiliary facilities, such as steam generators and hydrogen 

production units; and those that load, unload, blend or store intermediate or completed 

products.

( c ) For an incinerator, the process unit would consist of components from the feed pit or 

refuse pit to the stack, including conveyors, combustion devices, heat exchangers and steam 

generators, quench tanks, and fans.

Note to paragraph (b)(53): By a court order on December 24, 2003, this paragraph (b)(53) is 

stayed indefinitely. The stayed provisions will become effective immediately if the court 

terminates the stay. At that time, EPA will publish a document in the Federal Register 

advising the public of the termination of the stay.

(b)(54) Functionally 

equivalent 

component

(54) Functionally equivalent component means a component that serves the same purpose as 

the replaced component.

Note to paragraph (b)(54): By a court order on December 24, 2003, this paragraph (b)(54) is 

stayed indefinitely. The stayed provisions will become effective immediately if the court 

terminates the stay. At that time, EPA will publish a document in the Federal Register advising 

the public of the termination of the stay.

(b)(55) Fixed capital cost (55) Fixed capital cost means the capital needed to provide all the depreciable components. 

“Depreciable components” refers to all components of fixed capital cost and is calculated by 

subtracting land and working capital from the total capital investment, as defined in paragraph 

(b)(56) of this section.

Note to paragraph (b)(55): By a court order on December 24, 2003, this paragraph (b)(55) is 

stayed indefinitely. The stayed provisions will become effective immediately if the court 

terminates the stay. At that time, EPA will publish a document in the Federal Register advising 

the public of the termination of the stay.

(b)(56) Total capital 

investment

(56) Total capital investment means the sum of the following: all costs required to purchase 

needed process equipment (purchased equipment costs); the costs of labor and materials for 

installing that equipment (direct installation costs); the costs of site preparation and buildings; 

other costs such as engineering, construction and field expenses, fees to contractors, startup and 

performance tests, and contingencies (indirect installation costs); land for the process 

equipment; and working capital for the process equipment.

Not included. These 

provisions were stayed 

indefinitely by the DC 

Circuit Court on 

December 24, 2003 and 

are not needed for a PSD 

program.

Not included. These 

provisions were stayed 

indefinitely by the DC 

Circuit Court on 

December 24, 2003 and 

are not needed for a PSD 

program.

Not included. These 

provisions were stayed 

indefinitely by the DC 

Circuit Court on 

December 24, 2003 and 

are not needed for a PSD 

program.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 75of 112

Note to paragraph (b)(56): By a court order on December 24, 2003, this paragraph (b)(56) is 

stayed indefinitely. The stayed provisions will become effective immediately if the court 

terminates the stay. At that time, EPA will publish a document in the Federal Register advising 

the public of the termination of the stay.

(c ) Ambient air 

increments and 

other measures

(c) Ambient air increments and other measures. R18-2-218 - See 

discussion in Section 

5.8.2 of the TSD 

regarding references to 

"increments."

(1) The plan shall contain emission limitations and such other measures as may be necessary to 

assure that in areas designated as Class I, II, or III, increases in pollutant concentrations over 

the baseline concentration shall be limited to the following:

See Table 1 below.

For any period other than an annual period, the applicable maximum allowable increase may be 

exceeded during one such period per year at any one location.

(2) Where the State can demonstrate that it has alternative measures in its plan other than 

maximum allowable increases as defined under paragraph (c)(1) of this section, that satisfy the 

requirements in sections 166(c) and 166(d) of the Clean Air Act for a regulated NSR pollutant for 

which the Administrator has established maximum allowable increases pursuant to section 166(a) 

of the Act, the requirements for maximum allowable increases for that pollutant under paragraph 

(c)(1) of this section shall not apply upon approval of the plan by the Administrator. The following 

regulated NSR pollutants are eligible for such treatment:

(i) Nitrogen dioxide.

(ii) PM2.5.

(d) Ambient air 

ceilings

(d) Ambient air ceilings. The plan shall provide that no concentration of a pollutant shall exceed: R18-2-406(A)(5), R18-2-

218(E).

(1) The concentration permitted under the national secondary ambient air quality standard, or R18-2-406(A)(5)

(2) The concentration permitted under the national primary ambient air quality standard, 

whichever concentration is lowest for the pollutant for a period of exposure.

R18-2-406(A)(5). ADEQ's 

rules do not include the 

2012 PM2.5 NAAQS.

(e) Restrictions on 

area 

classifications

(e) Restrictions on area classifications. The plan shall provide that— R18-2-217

(e) (1) All of the following areas which were in existence on August 7, 1977, shall be Class I areas 

and may not be redesignated:

R18-2-217(B) - has 

additional language about 

before March 12, 1993. 

ADEQ needs to update to 

a more current citation 

for consistency with the 

Act. 

(i) International parks, R18-2-217(B)(1)

R18-2-218(A) and R18-2-

406(A)(5)(a)

No such demonstration 

has been made

program.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 76of 112

(ii) National wilderness areas which exceed 5,000 acres in size, R18-2-217(B)(2)

(iii) National memorial parks which exceed 5,000 acres in size, and R18-2-217(B)(3)

(iv) National parks which exceed 6,000 acres in size. R18-2-217(B)(4)

(e) (2) Areas which were redesignated as Class I under regulations promulgated before August 7, 

1977, shall remain Class I, but may be redesignated as provided in this section.

Not included in ADEQ's 

rules

(3) Any other area, unless otherwise specified in the legislation creating such an area, is initially 

designated Class II, but may be redesignated as provided in this section.

R18-2-217(D). Not 

completely incorporated - 

missing "unless otherwise 

specified in the legislation 

creating such an area". 

Subsection not clear what 

"all other areas" refers to 

or that this is the "initial" 

designation.

(4) The following areas may be redesignated only as Class I or II: R18-2-217(C)(1)

(i) An area which as of August 7, 1977, exceeded 10,000 acres in size and was a national 

monument, a national primitive area, a national preserve, a national recreational area, a 

national wild and scenic river, a national wildlife refuge, a national lakeshore or seashore; and

R18-2-217(C)(1)

(ii) A national park or national wilderness area established after August 7, 1977, which exceeds 

10,000 acres in size.

R18-2-217(C)(2)

(f) Exclusions from 

increment 

consumption

(f) Exclusions from increment consumption. R18-2-218(F)

(1) The plan may provide that the following concentrations shall be excluded in determining 

compliance with a maximum allowable increase:

(i) Concentrations attributable to the increase in emissions from stationary sources which have 

converted from the use of petroleum products, natural gas, or both by reason of an order in 

effect under section 2 (a) and (b) of the Energy Supply and Environmental Coordination Act of 

1974 (or any superseding legislation) over the emissions from such sources before the effective 

date of such an order;

R18-2-218(F)(1) - 

(ii) Concentrations attributable to the increase in emissions from sources which have converted 

from using natural gas by reason of natural gas curtailment plan in effect pursuant to the 

Federal Power Act over the emissions from such sources before the effective date of such plan;

R18-2-218(F)(2)

(f) (iii) Concentrations of particulate matter attributable to the increase in emissions from 

construction or other temporary emission-related activities of new or modified sources;

R18-2-218(F)(3) - only 

identifies pm10, consider 

including PM2.5 - 

recommend adding 

"emission-related" 

activities.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 77of 112

(iv) The increase in concentrations attributable to new sources outside the United States over 

the concentrations attributable to existing sources which are included in the baseline 

concentration; and

R18-2-218(F)(4)

(v) Concentrations attributable to the temporary increase in emissions of sulfur dioxide, 

particulate matter, or nitrogen oxides from stationary sources which are affected by plan 

revisions approved by the Administrator as meeting the criteria specified in paragraph (f)(4) of 

this section.

R18-2-218(F)(5) - does 

not contain approvable 

language that meets 

(f)(4) below. See 

disucssion in Section 

5.8.2 of the TSD.

(2) If the plan provides that the concentrations to which paragraph (f)(1) (i) or (ii) of this 

section, refers shall be excluded, it shall also provide that no exclusion of such concentrations 

shall apply more than five years after the effective date of the order to which paragraph (f)(1)(i) 

of this section, refers or the plan to which paragraph (f)(1)(ii) of this section, refers, whichever is 

applicable. If both such order and plan are applicable, no such exclusion shall apply more than 

five years after the later of such effective dates.

R18-2-218(F)(6)

(3) [Reserved]

(4) For purposes of excluding concentrations pursuant to paragraph (f)(1)(v) of this section, the 

Administrator may approve a plan revision that:

(i) Specifies the time over which the temporary emissions increase of sulfur dioxide, particulate 

matter, or nitrogen oxides would occur. Such time is not to exceed 2 years in duration unless a 

longer time is approved by the Administrator.

(ii) Specifies that the time period for excluding certain contributions in accordance with 

paragraph (f)(4)(i) of this section, is not renewable;

(iii) Allows no emissions increase from a stationary source which would:

( a ) Impact a Class I area or an area where an applicable increment is known to be violated; 

or

( b ) Cause or contribute to the violation of a national ambient air quality standard;

(iv) Requires limitations to be in effect the end of the time period specified in accordance with 

paragraph (f)(4)(i) of this section, which would ensure that the emissions levels from stationary 

sources affected by the plan revision would not exceed those levels occurring from such 

sources before the plan revision was approved.

(g) Redesignation (g) Redesignation. R18-2-217(A)

R18-2-218(F)(5) - Only 

requires ADEQ approval 

for the temporary source 

to be allowed more than 

2 years. EPA approval is 

required. Contains an 

outdated reference to 

"operating permit".
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 78of 112

(1) The plan shall provide that all areas of the State (except as otherwise provided under 

paragraph (e) of this section) shall be designated either Class I, Class II, or Class III. Any 

designation other than Class II shall be subject to the redesignation procedures of this 

paragraph. Redesignation (except as otherwise precluded by paragraph (e) of this section) may 

be proposed by the respective States or Indian Governing Bodies, as provided below, subject to 

approval by the Administrator as a revision to the applicable State implementation plan.

R18-2-217(A) and R18-2-

217(E), R18-2-217(G). 

However, R18-2-217(A) 

is limited to designated 

attainment areas. All 

areas of the State must 

be designated as Class I, 

II, or III irrespective of 

their attainment 

designation under Section 

107 of the Act. 

(2) The plan may provide that the State may submit to the Administrator a proposal to 

redesignate areas of the State Class I or Class II: Provided, That:

(i) At least one public hearing has been held in accordance with procedures established in 

§51.102.

R18-2-217(E)(1). Needs 

to include a reference to 

the procedures that will 

be used for the public 

hearing. 

(ii) Other States, Indian Governing Bodies, and Federal Land Managers whose lands may be 

affected by the proposed redesignation were notified at least 30 days prior to the public 

hearing;

R18-2-217(E)(2)

(iii) A discussion of the reasons for the proposed redesignation, including a satisfactory 

description and analysis of the health, environmental, economic, social, and energy effects of 

the proposed redesignation, was prepared and made available for public inspection at least 30 

days prior to the hearing and the notice announcing the hearing contained appropriate 

notification of the availability of such discussion;

R18-2-217(E)(3)

(iv) Prior to the issuance of notice respecting the redesignation of an area that includes any 

Federal lands, the State has provided written notice to the appropriate Federal Land Manager 

and afforded adequate opportunity (not in excess of 60 days) to confer with the State 

respecting the redesignation and to submit written comments and recommendations. In 

redesignating any area with respect to which any Federal Land Manager had submitted written 

comments and recommendations, the State shall have published a list of any inconsistency 

between such redesignation and such comments and recommendations (together with the 

reasons for making such redesignation against the recommendation of the Federal Land 

Manager); and

R18-2-217(E)(4)

(v) The State has proposed the redesignation after consultation with the elected leadership of 

local and other substate general purpose governments in the area covered by the proposed 

redesignation.

R18-2-217(E)(5)

(3) The plan may provide that any area other than an area to which paragraph (e) of this section 

refers may be redesignated as Class III if—

R18-2-217(F) and (G). 

Does not specify which 

areas can be 

redesignated.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 79of 112

(i) The redesignation would meet the requirements of provisions established in accordance with 

paragraph (g)(2) of this section;

R18-2-217(F)(1)

(ii) The redesignation, except any established by an Indian Governing Body, has been 

specifically approved by the Governor of the State, after consultation with the appropriate 

committees of the legislature, if it is in session, or with the leadership of the legislature, if it is 

not in session (unless State law provides that such redesignation must be specifically approved 

by State legislation) and if general purpose units of local government representing a majority of 

the residents of the area to be redesignated enact legislation (including resolutions where 

appropriate) concurring in the redesignation;

R18-2-217(F)(2) and(3). 

Rule incorrectly allows for 

the governor's designee 

to make the 

redesignation. Rule 

should include language 

relating to State 

legislation or confirm that 

State law does not 

require a legislative 

action to redesignate an 

area.

(iii) The redesignation would not cause, or contribute to, a concentration of any air pollutant 

which would exceed any maximum allowable increase permitted under the classification of any 

other area or any national ambient air quality standard; and

R18-2-217(F)(4). Doesn't 

include "or any national 

ambient air quality 

standard" but referes to 

state standards and 

applies them to "any 

area". Interpreted as 

applying state standards 

outside the State. ADEQ's 

rules do not include the 

2012 PM2.5 NAAQS.

(g)(3) (iv) Any permit application for any major stationary source or major modification subject to 

provisions established in accordance with paragraph (l) of this section which could receive a 

permit only if the area in question were redesignated as Class III, and any material submitted 

as part of that application, were available, insofar as was practicable, for public inspection prior 

to any public hearing on redesignation of any area as Class III.

R18-2-217(F)(5). Must 

be clarified so that it is 

clear that the public 

hearing is the public 

hearing on the 

redesignation. 

Recommend revising 

"permit application or 

related material" to 

"permit application and 

related material" for 

consistency with federal 

regulation. (4) The plan shall provide that lands within the exterior boundaries of Indian Reservations may 

be redesignated only by the appropriate Indian Governing Body. The appropriate Indian 

Governing Body may submit to the Administrator a proposal to redesignate areas Class I, Class 

II, or Class III: Provided, That:

R18-2-217(H)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 80of 112

(i) The Indian Governing Body has followed procedures equivalent to those required of a State 

under paragraphs (g) (2), (3)(iii), and (3)(iv) of this section; and

Not necessary for a state 

program, includes 

requirement that only 

Indian Governing Body 

can redesignate these 

areas

(ii) Such redesignation is proposed after consultation with the State(s) in which the Indian 

Reservation is located and which border the Indian Reservation.

Not necessary for a state 

program, includes 

requirement that only 

Indian Governing Body 

can redesignate these 

areas

(5) The Administrator shall disapprove, within 90 days of submission, a proposed redesignation 

of any area only if he finds, after notice and opportunity for public hearing, that such 

redesignation does not meet the procedural requirements of this section or is inconsistent with 

paragraph (e) of this section. If any such disapproval occurs, the classification of the area shall 

be that which was in effect prior to the redesignation which was disapproved.

Not necessarily required 

for approval, but may 

want to add to 

regulations.

(6) If the Administrator disapproves any proposed area designation, the State or Indian 

Governing Body, as appropriate, may resubmit the proposal after correcting the deficiencies 

noted by the Administrator.

No necessarily required 

for approval, but may 

want to add to 

regulations.

(h) Stack heights (h) Stack heights. The plan shall provide, as a minimum, that the degree of emission limitation 

required for control of any air pollutant under the plan shall not be affected in any manner by—

(1) So much of a stack height, not in existence before December 31, 1970, as exceeds good 

engineering practice, or

(2) Any other dispersion technique not implemented before then.

(i) Exemptions (i) Exemptions. 

(1) The plan may provide that requirements equivalent to those contained in paragraphs (j) 

through (r) of this section do not apply to a particular major stationary source or major 

modification if:

(i) The major stationary source would be a nonprofit health or nonprofit educational institution 

or a major modification that would occur at such an institution; or

R18-2-406(D). May want 

to specify "owner or 

operator" as nonprofits 

are generally not 

"owned."

(ii) The source or modification would be a major stationary source or major modification only if 

fugitive emissions, to the extent quantifiable, are considered in calculating the potential to emit 

of the stationary source or modification and such source does not belong to any of the following 

categories:

( a ) Coal cleaning plants (with thermal dryers);

( b ) Kraft pulp mills;

( c ) Portland cement plants;

( d ) Primary zinc smelters;

R18-2-406(C). Contains 

an inadvertent reference 

to "1980." See Section 

5.8.2 of the TSD 

regarding references to 

Artiles 9 and 11.

R18-2-402(G)(5) 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 81of 112

( e ) Iron and steel mills;

( f ) Primary aluminum ore reduction plants;

( g ) Primary copper smelters;

( h ) Municipal incinerators capable of charging more than 250 tons of refuse per day;

( i ) Hydrofluoric, sulfuric, or nitric acid plants;

( j ) Petroleum refineries;

( k ) Lime plants;

( l ) Phosphate rock processing plants;

( m ) Coke oven batteries;

( n ) Sulfur recovery plants;

( o ) Carbon black plants (furnace process);

( p ) Primary lead smelters;

( q ) Fuel conversion plants;

( r ) Sintering plants;

( s ) Secondary metal production plants;

( t ) Chemical process plants—The term chemical processing plant shall not include ethanol 

production facilities that produce ethanol by natural fermentation included in NAICS codes 

325193 or 312140;

( u ) Fossil-fuel boilers (or combination thereof) totaling more than 250 million British 

thermal units per hour heat input;

( v ) Petroleum storage and transfer units with a total storage capacity exceeding 300,000 

barrels;

( w ) Taconite ore processing plants;

( x ) Glass fiber processing plants;

( y ) Charcoal production plants;

( z ) Fossil fuel-fired steam electric plants of more than 250 million British thermal units per 

hour heat input;

( aa ) Any other stationary source category which, as of August 7, 1980, is being regulated 

under section 111 or 112 of the Act; or

(iii) The source or modification is a portable stationary source which has previously received a 

permit under requirements equivalent to those contained in paragraphs (j) through (r) of this 

section, if:

R18-2-406(E). See 

discussion in Section 

5.8.2 of the TSD. 

( a ) The source proposes to relocate and emissions of the source at the new location would 

be temporary; and

R18-2-406(E) Defines 

temporary to be 24 

months, acceptable.

( b ) The emissions from the source would not exceed its allowable emissions; and R18-2-406(E)

( c ) The emissions from the source would impact no Class I area and no area where an 

applicable increment is known to be violated; and

R18-2-406(E)

( d ) Reasonable notice is given to the reviewing authority prior to the relocation identifying 

the proposed new location and the probable duration of operation at the new location. Such 

notice shall be given to the reviewing authority not less than 10 days in advance of the 

proposed relocation unless a different time duration is previously approved by the reviewing 

authority.

R18-2-406(E)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 82of 112

(2) The plan may provide that requirements equivalent to those contained in paragraphs (j) 

through (r) of this section do not apply to a major stationary source or major modification with 

respect to a particular pollutant if the owner or operator demonstrates that, as to that pollutant, 

the source or modification is located in an area designated as nonattainment under section 107 of 

the Act.

R18-2-406(B)

(3) The plan may provide that requirements equivalent to those contained in paragraphs (k), 

(m), and (o) of this section do not apply to a proposed major stationary source or major 

modification with respect to a particular pollutant, if the allowable emissions of that pollutant 

from a new source, or the net emissions increase of that pollutant from a modification, would be 

temporary and impact no Class I area and no area where an applicable increment is known to be 

violated.

Provisions not included, 

ok since this section is 

optional

(4) The plan may provide that requirements equivalent to those contained in paragraphs (k), 

(m), and (o) of this section as they relate to any maximum allowable increase for a Class II area 

do not apply to a modification of a major stationary source that was in existence on March 1, 

1978, if the net increase in allowable emissions of each a regulated NSR pollutant from the 

modification after the application of best available control technology would be less than 50 tons 

per year.

Provisions not included, 

ok since this section is 

optional

(5) The plan may provide that the reviewing authority may exempt a proposed major stationary 

source or major modification from the requirements of paragraph (m) of this section, with 

respect to monitoring for a particular pollutant, if:

R18-2-407(H)

(i) The emissions increase of the pollutant from a new stationary source or the net emissions 

increase of the pollutant from a modification would cause, in any area, air quality impacts less 

than the following amounts:

R18-2-407(H)(1)

( a ) Carbon monoxide—575 ug/m3, 8-hour average; R18-2-407(H)(1)(a)

( b ) Nitrogen dioxide—14 ug/m3, annual average; R18-2-407(H)(1)(b)

( c ) PM2.5–0 μg/m3, 24-hour average; R18-2-407(H)(1)(C). 

Inconsistent with federal 

regulation. See 

discussion in Section 

5.8.1.1 of the TSD.

NOTE to paragraph (i)(5)(i)(c): In accordance with Sierra Club v. EPA, 706 F.3d 428 (D.C. 

Cir. 2013), no exemption is available with regard to PM2.5.

( d ) PM10–10 μg/m3, 24-hour average; R18-2-407(H)(1)(d)

( e ) Sulfur dioxide—13 ug/m3, 24-hour average; R18-2-407(H)(1)(e)

( f ) Ozone;1 R18-2-407(H)(1)(k) - 

recommend revising to 

"net emissions increases" 

for clarity.

1 No de minimis air quality level is provided for ozone. However, any net emissions increase 

of 100 tons per year or more of volatile organic compounds or nitrogen oxides subject to PSD 

would be required to perform an ambient impact analysis, including the gathering of air 

quality data.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 83of 112

( g ) Lead—0.1 μg/m3, 3-month average. R18-2-407(H)(1)(f). Uses 

an averaging period of 24 

hours. Federal regulation 

only requires 3-month 

average

( h ) Fluorides—0.25 μg/m3, 24-hour average; R18-2-407(H)(1)(g)

( i ) Total reduced sulfur—10 μg/m3, 1-hour average R18-2-407(H)(1)(h)

( j ) Hydrogen sulfide—0.2 μg/m3, 1-hour average; R18-2-407(H)(1)(i) - 

0.04 instead of 0.02

( k ) Reduced sulfur compounds—10 μg/m3, 1-hour average; or R18-2-407(H)(1)(j)

(ii) The concentrations of the pollutant in the area that the source or modification would affect 

are less than the concentrations listed in paragraph (i)(5)(i) of this section; or

R18-2(407)(H)(2)

(iii) The pollutant is not listed in paragraph (i)(5)(i) of this section. Did not include; ok since 

this section is optional.

(6) If EPA approves a plan revision under 40 CFR 51.166 as in effect before August 7, 1980, any 

subsequent revision which meets the requirements of this section may contain transition 

provisions which parallel the transition provisions of 40 CFR 52.21(i)(9), (i)(10) and (m)(1)(v) as 

in effect on that date, which provisions relate to requirements for best available control 

technology and air quality analyses. Any such subsequent revision may not contain any transition 

provision which in the context of the revision would operate any less stringently than would its 

counterpart in 40 CFR 52.21.

Provisions not included, 

ok since this section is 

optional

(7) If EPA approves a plan revision under §51.166 as in effect [before July 31, 1987], any 

subsequent revision which meets the requirements of this section may contain transition 

provisions which parallel the transition provisions of §52.21 (i)(11), and (m)(1) (vii) and (viii) of 

this chapter as in effect on that date, these provisions being related to monitoring requirements 

for particulate matter. Any such subsequent revision may not contain any transition provision 

which in the context of the revision would operate any less stringently than would its counterpart 

in §52.21 of this chapter.

Provisions not included, 

ok since this section is 

optional

(8) The plan may provide that the permitting requirements equivalent to those contained in 

paragraph (k)(1)(ii) of this section do not apply to a stationary source or modification with 

respect to any maximum allowable increase for nitrogen oxides if the owner or operator of the 

source or modification submitted an application for a permit under the applicable permit program 

approved or promulgated under the Act before the provisions embodying the maximum allowable 

increase took effect as part of the plan and the permitting authority subsequently determined 

that the application as submitted before that date was complete.

Provisions not included, 

ok since this section is 

optional
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 84of 112

(9) The plan may provide that the permitting requirements equivalent to those contained in 

paragraph (k)(1)(ii) of this section shall not apply to a stationary source or modification with 

respect to any maximum allowable increase for PM–10 if (i) the owner or operator of the source 

or modification submitted an application for a permit under the applicable permit program 

approved under the Act before the provisions embodying the maximum allowable increases for 

PM–10 took effect as part of the plan, and (ii) the permitting authority subsequently determined 

that the application as submitted before that date was complete. Instead, the applicable 

requirements equivalent to paragraph (k)(1)(ii) shall apply with respect to the maximum 

allowable increases for TSP as in effect on the date the application was submitted.

Provisions not included, 

ok since this section is 

optional

(10) The plan may provide that the requirements of paragraph (k)(1) of this section shall not 

apply to a stationary source or modification with respect to the national ambient air quality 

standards for PM2.5 in effect on March 18, 2013 if:

Provisions not included, 

ok since this section is 

optional

(i) The reviewing authority has determined a permit application subject to this section to be 

complete on or before December 14, 2012. Instead, the requirements in paragraph (k)(1) of 

this section shall apply with respect to the national ambient air quality standards for PM2.5 in 

effect at the time the reviewing authority determined the permit application to be complete; or

(ii) The reviewing authority has first published before March 18, 2013 a public notice of a 

preliminary determination for the permit application subject to this section. Instead, the 

requirements in paragraph (k)(1) of this section shall apply with respect to the national 

ambient air quality standards for PM2.5 in effect at the time of first publication of a public notice 

on the preliminary determination.

(j) Control 

technology review

(j) Control technology review. The plan shall provide that: Contains a reference to 

an exemption under R18-

2-408 (innovative control 

technology), but not in 

SIP submittal. 

Recommend revising R18-

2-406(A) to refer to (B) 

through (E) instead of (B)-

(G)

(1) A major stationary source or major modification shall meet each applicable emissions 

limitation under the State Implementation Plan and each applicable emission standards and 

standard of performance under 40 CFR parts 60 and 61.

R18-2-406(A)(4), R18-2-

406(G). Also, R18-2-

306(A). See Section 

5.8.2 of the TSD 

regarding references to 

Artiles 9 and 11.

(2) A new major stationary source shall apply best available control technology for each a 

regulated NSR pollutant that it would have the potential to emit in significant amounts.

R18-2-406(A)(1)

(3) A major modification shall apply best available control technology for each a regulated NSR 

pollutant for which it would be a significant net emissions increase at the source. This 

requirement applies to each proposed emissions unit at which a net emissions increase in the 

pollutant would occur as a result of a physical change or change in the method of operation in the 

unit.

R18-2-406(A)(2)
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(4) For phased construction projects, the determination of best available control technology shall 

be reviewed and modified as appropriate at the least reasonable time which occurs no later than 

18 months prior to commencement of construction of each independent phase of the project. At 

such time, the owner or operator of the applicable stationary source may be required to 

demonstrate the adequacy of any previous determination of best available control technology for 

the source.

R18-2-406(A)(3)

(k) Source impact 

analysis

(k) Source impact analysis —

(1) Required demonstration. The plan shall provide that the owner or operator of the proposed 

source or modification shall demonstrate that allowable emission increases from the proposed 

source or modification, in conjunction with all other applicable emissions increases or reduction 

(including secondary emissions), would not cause or contribute to air pollution in violation of:

R18-2-406(A)(5)(a)

(i) Any national ambient air quality standard in any air quality control region; or

(ii) Any applicable maximum allowable increase over the baseline concentration in any area.

(l) Air quality models (l) Air quality models. The plan shall provide for procedures which specify that—

(1) All applications of air quality modeling involved in this subpart shall be based on the 

applicable models, data bases, and other requirements specified in appendix W of this part 

(Guideline on Air Quality Models).

R18-2-406(A)(6)(a) - 

updated through July 

2011 - no revisions since 

then. Contains a typo - 

"data basis" instead of 

"databases."

(2) Where an air quality model specified in appendix W of this part (Guideline on Air Quality 

Models) is inappropriate, the model may be modified or another model substituted. Such a 

modification or substitution of a model may be made on a case-by-case basis or, where 

appropriate, on a generic basis for a specific State program. Written approval of the 

Administrator must be obtained for any modification or substitution. In addition, use of a 

modified or substituted model must be subject to notice and opportunity for public comment 

under procedures set forth in §51.102.

R18-2-406(A)(6)(b). 

Needs to specify public 

noticing procedures that 

will be used.

(m) Air quality 

analysis

(m) Air quality analysis — May want to review 

Article 4 to confirm 

exemptions under R18-2-

406(B) - (E) provide 

exemption from R18-2-

407. 

(1) Preapplication analysis. R18-2-407(A)

(i) The plan shall provide that any application for a permit under regulations approved pursuant 

to this section shall contain an analysis of ambient air quality in the area that the major 

stationary source or major modification would affect for each of the following pollutants:

R18-2-407(A). ADEQ's 

rules do not include the 

2012 PM2.5 NAAQS.

( a ) For the source, each pollutant that it would have the potential to emit in a significant 

amount;

R18-2-407(A)(1)

( b ) For the modification, each pollutant for which it would result in a significant net 

emissions increase.

R18-2-407(A)(2)

R18-2-406(A)(5)(a) - 

Uses "or" for 

406(A)(5)(a) and (b) 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 86of 112

(ii) The plan shall provide that, with respect to any such pollutant for which no National 

Ambient Air Quality Standard exists, the analysis shall contain such air quality monitoring data 

as the reviewing authority determines is necessary to assess ambient air quality for that 

pollutant in any area that the emissions of that pollutant would affect.

R18-2-407(B)

(iii) The plan shall provide that with respect to any such pollutant (other than nonmethane 

hydrocarbons) for which such a standard does exist, the analysis shall contain continuous air 

quality monitoring data gathered for purposes of determining whether emissions of that 

pollutant would cause or contribute to a violation of the standard or any maximum allowable 

increase.

R18-2-407)(C)

(iv) The plan shall provide that, in general, the continuous air monitoring data that is required 

shall have been gathered over a period of one year and shall represent the year preceding 

receipt of the application, except that, if the reviewing authority determines that a complete 

and adequate analysis can be accomplished with monitoring data gathered over a period 

shorter than one year (but not to be less than four months), the data that is required shall have 

been gathered over at least that shorter period.

R18-2-407(D)

(v) The plan may provide that the owner or operator of a proposed major stationary source or 

major modification of volatile organic compounds who satisfies all conditions of 40 CFR part 51 

appendix S, section IV may provide postapproval monitoring data for ozone in lieu of providing 

preconstruction data as required under paragraph (m)(1) of this section.

R18-2-407(E)

(2) Post-construction monitoring. The plan shall provide that the owner or operator of a major 

stationary source or major modification shall, after construction of the stationary source or 

modification, conduct such ambient monitoring as the reviewing authority determines is 

necessary to determine the effect emissions from the stationary source or modification may 

have, or are having, on air quality in any area.

R18-2-407(F)

(3) Operation of monitoring stations. The plan shall provide that the owner or operator of a 

major stationary source or major modification shall meet the requirements of appendix B to part 

58 of this chapter during the operation of monitoring stations for purposes of satisfying 

paragraph (m) of this section.

R18-2-407(G)

(n) Source 

information

(n) Source information. 

(1) The plan shall provide that the owner or operator of a proposed source or modification shall 

submit all information necessary to perform any analysis or make any determination required 

under procedures established in accordance with this section.

Not included. 

Recommend adding to 

R18-2-402 or 406

(2) The plan may provide that such information shall include:

(i) A description of the nature, location, design capacity, and typical operating schedule of the 

source or modification, including specifications and drawings showing its design and plant 

layout;

(ii) A detailed schedule for construction of the source or modification;

(iii) A detailed description as to what system of continuous emission reduction is planned by the 

source or modification, emission estimates, and any other information as necessary to 

determine that best available control technology as applicable would be applied;

(3) The plan shall provide that upon request of the State, the owner or operator shall also 

provide information on:

Optional 

Not included. 

Recommend adding to 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 87of 112

(i) The air quality impact of the source or modification, including meteorological and 

topographical data necessary to estimate such impact; and

(ii) The air quality impacts and the nature and extent of any or all general commercial, 

residential, industrial, and other growth which has occurred since August 7, 1977, in the area 

the source or modification would affect.

(o) Additional impact 

analyses

(o) Additional impact analyses. The plan shall provide that— R18-2-407(I)

(1) The owner or operator shall provide an analysis of the impairment to visibility, soils, and 

vegetation that would occur as a result of the source or modification and general commercial, 

residential, industrial, and other growth associated with the source or modification. The owner or 

operator need not provide an analysis of the impact on vegetation having no significant 

commercial or recreational value.

R18-2-407(I)(1)

(2) The owner or operator shall provide an analysis of the air quality impact projected for the 

area as a result of general commercial, residential, industrial, and other growth associated with 

the source or modification.

R18-2-407(I)(2)

(p) Sources impacting 

Federal Class I 

areas

(p) Sources impacting Federal Class I areas—additional requirements —

(1) Notice to EPA. The plan shall provide that the reviewing authority shall transmit to the 

Administrator a copy of each permit application relating to a major stationary source or major 

modification and provide notice to the Administrator of every action related to the consideration 

of such permit.

Existing SIP at R18-2-

304(H) only provides 

notice at time of 

preliminary decision. 

(ADEQ rule not 

submitted:R18-2-

410(c)(2) - Need to add 

sending information to 

EPA at the same time as 

FLM.)

(2) Federal Land Manager. The Federal Land Manager and the Federal official charged with direct 

responsibility for management of Class I lands have an affirmative responsibility to protect the air 

quality related values (including visibility) of any such lands and to consider, in consultation with 

the Administrator, whether a proposed source or modification would have an adverse impact on 

such values.

Not included, recommend 

adding.

R18-2-402 or 406
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 88of 112

(3) Denial—impact on air quality related values. The plan shall provide a mechanism whereby a 

Federal Land Manager of any such lands may present to the State, after the reviewing authority's 

preliminary determination required under procedures developed in accordance with paragraph (r) 

of this section, a demonstration that the emissions from the proposed source or modification 

would have an adverse impact on the air quality-related values (including visibility) of any 

Federal mandatory Class I lands, notwithstanding that the change in air quality resulting from 

emissions from such source or modification would not cause or contribute to concentrations 

which would exceed the maximum allowable increases for a Class I area. If the State concurs 

with such demonstration, the reviewing authority shall not issue the permit.

R9-3-304(H)(1). Contains 

outdated maximum 

allowable increases. 

(Existing ADEQ rule not 

submitted for review: 

R18-2-410(C)(3) and 

R18-2-406(F)(1)- ADEQ 

modeled this 

"mechanism" after 52.21, 

so it is satisfactory. R18-

2-410(C)(3) contains a 

reference to "Federal 

Mandatory" area. 

Consider revising to 

"Federal mandatory Class 

I area.")

(4) Class I Variances. The plan may provide that the owner or operator of a proposed source or 

modification may demonstrate to the Federal Land Manager that the emissions from such source 

would have no adverse impact on the air quality related values of such lands (including visibility), 

notwithstanding that the change in air quality resulting from emissions from such source or 

modification would cause or contribute to concentrations which would exceed the maximum 

allowable increases for a Class I area. If the Federal land manager concurs with such 

demonstration and so certifies to the State, the reviewing authority may: Provided, That 

applicable requirements are otherwise met, issue the permit with such emission limitations as 

may be necessary to assure that emissions of sulfur dioxide, PM2.5, PM10, and nitrogen oxides 

would not exceed the following maximum allowable increases over minor source baseline 

concentration for such pollutants:

R9-3-304(H)(2) of 

existing SIP. (Existing 

ADEQ rule not submitted) 

Also R18-2-406(F)(2). 

Includes the word 

"significant," which is not 

in the federal regulation. 

See Section 5.8.2 of the 

TSD.

See Table 2 below.

(5) Sulfur dioxide variance by Governor with Federal Land Manager's concurrence. The plan may 

provide that—

(i) The owner or operator of a proposed source or modification which cannot be approved 

under procedures developed pursuant to paragraph (q)(4) of this section may demonstrate to 

the Governor that the source or modification cannot be constructed by reason of any maximum 

allowable increase for sulfur dioxide for periods of twenty-four hours or less applicable to any 

Class I area and, in the case of Federal mandatory Class I areas, that a variance under this 

clause would not adversely affect the air quality related values of the area (including visibility);

(ii) The Governor, after consideration of the Federal Land Manager's recommendation (if any) 

and subject to his concurrence, may grant, after notice and an opportunity for a public hearing, 

a variance from such maximum allowable increase; and

(iii) If such variance is granted, the reviewing authority may issue a permit to such source or 

modification in accordance with provisions developed pursuant to paragraph (q)(7) of this 

section: Provided, That the applicable requirements of the plan are otherwise met.

Did not adopt and not 

required to. 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 89of 112

(6) Variance by the Governor with the President's concurrence. The plan may provide that—

(i) The recommendations of the Governor and the Federal Land Manager shall be transferred to 

the President in any case where the Governor recommends a variance in which the Federal 

Land Manager does not concur;

(ii) The President may approve the Governor's recommendation if he finds that such variance is 

in the national interest; and

(iii) If such a variance is approved, the reviewing authority may issue a permit in accordance 

with provisions developed pursuant to the requirements of paragraph (q)(7) of this section: 

Provided, That the applicable requirements of the plan are otherwise met.

(7) Emission limitations for Presidential or gubernatorial variance. The plan shall provide that in 

the case of a permit issued under procedures developed pursuant to paragraph (q) (5) or (6) of 

this section, the source or modification shall comply with emission limitations as may be 

necessary to assure that emissions of sulfur dioxide from the source or modification would not 

(during any day on which the otherwise applicable maximum allowable increases are exceeded) 

cause or contribute to concentrations which would exceed the following maximum allowable 

increases over the baseline concentration and to assure that such emissions would not cause or 

contribute to concentrations which exceed the otherwise applicable maximum allowable increases 

for periods of exposure of 24 hours or less for more than 18 days, not necessarily consecutive, 

during any annual period:

Did not adopt and not 

required to.

See Table 3 below.

(q) Public 

participation

(q) Public participation. The plan shall provide that—

(1) The reviewing authority shall notify all applicants within a specified time period as to the 

completeness of the application or any deficiency in the application or information submitted. In 

the event of such a deficiency, the date of receipt of the application shall be the date on which 

the reviewing authority received all required information.

R18-2-402(I)(1) - 

Introductory clause is 

awkward. Recommend 

revising for clarity. Not 

clear which requirements 

under Article 3 are being 

referring to (application 

processing and public 

notice?)

(2) Within one year after receipt of a complete application, the reviewing authority shall: R18-2-402(I)(3)

(i) Make a preliminary determination whether construction should be approved, approved with 

conditions, or disapproved.

In existing SIP at R9-3-

301(I). Recommend 

adding to current rules 

and submitting for 

approval.

Did not adopt and not 

required to.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 90of 112

(ii) Make available in at least one location in each region in which the proposed source would be 

constructed a copy of all materials the applicant submitted, a copy of the preliminary 

determination, and a copy or summary of other materials, if any, considered in making the 

preliminary determination.

R18-2-330(D)(11). The 

requirement to be 

available in each region is 

not clearly met at there 

are only two ADEQ 

offices. See 

recommendation under 

review of 51.161.

(iii) Notify the public, by advertisement in a newspaper of general circulation in each region in 

which the proposed source would be constructed, of the application, the preliminary 

determination, the degree of increment consumption that is expected from the source or 

modification, and of the opportunity for comment at a public hearing as well as written public 

comment.

R18-2-330(D) - no 

increment consumption 

required in notice or 

preliminary decision to 

issue or deny, but in 

existing SIP at R9-3-

301(K). Recommend 

adding requirements 

from R9-3-301(K) from 

existing SIP to current 

rules and submitting for 

approval.

(iv) Send a copy of the notice of public comment to the applicant, the Administrator and to 

officials and agencies having cognizance over the location where the proposed construction 

would occur as follows: Any other State or local air pollution control agencies, the chief 

executives of the city and county where the source would be located; any comprehensive 

regional land use planning agency, and any State, Federal Land Manager, or Indian Governing 

body whose lands may be affected by emissions from the source or modification.

R18-2-402(I)(2)

(v) Provide opportunity for a public hearing for interested persons to appear and submit written 

or oral comments on the air quality impact of the source, alternatives to it, the control 

technology required, and other appropriate considerations.

R18-2-330(D)(9) 

(vi) Consider all written comments submitted within a time specified in the notice of public 

comment and all comments received at any public hearing(s) in making a final decision on the 

approvability of the application. The reviewing authority shall make all comments available for 

public inspection in the same locations where the reviewing authority made available 

preconstruction information relating to the proposed source or modification.

R18-2-330(G). Need a 

requirement to put final 

decision documents in 

the same locations as 

preliminary documents.

(vii) Make a final determination whether construction should be approved, approved with 

conditions, or disapproved.

R18-2-402(I)(3). See 

discussion in Section 

5.8.2 of the TSD 

regarding "proposed final 

permits."
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 91of 112

(viii) Notify the applicant in writing of the final determination and make such notification 

available for public inspection at the same location where the reviewing authority made 

available preconstruction information and public comments relating to the source.

R18-2-330 and R18-2-

402(I)(3). Need a 

requirement to put final 

decision documents in 

the same locations as 

preliminary documents.

(r ) Source obligation (r) Source obligation. 

(1) The plan shall include enforceable procedures to provide that approval to construct shall not 

relieve any owner or operator of the responsibility to comply fully with applicable provisions of 

the plan and any other requirements under local, State or Federal law.

R18-2-406(G)

(2) The plan shall provide that at such time that a particular source or modification becomes a 

major stationary source or major modification solely by virtue of a relaxation in any enforceable 

limitation which was established after August 7, 1980, on the capacity of the source or 

modification otherwise to emit a pollutant, such as a restriction on hours of operation, then the 

requirements of paragraphs (j) through (s) of this section shall apply to the source or 

modification as though construction had not yet commenced on the source or modification.

R18-2-406(H)

(3)–(5) [Reserved]

(6) Each plan shall provide that, except as otherwise provided in paragraph (r)(6)(vi) of this 

section, the following specific provisions apply with respect to any regulated NSR pollutant 

emitted from projects at existing emissions units at a major stationary source (other than 

projects at a source with a PAL) in circumstances where there is a reasonable possibility, within 

the meaning of paragraph (r)(6)(vi) of this section, that a project that is not a part of a major 

modification may result in a significant emissions increase of such pollutant, and the owner or 

operator elects to use the method specified in paragraphs (b)(40)(ii)( a ) through ( c ) of this 

section for calculating projected actual emissions. Deviations from these provisions will be 

approved only if the State specifically demonstrates that the submitted provisions are more 

stringent than or at least as stringent in all respects as the corresponding provisions in 

paragraphs (r)(6)(i) through (vi) of this section.

R18-2-402(F)

(i) Before beginning actual construction of the project, the owner or operator shall document 

and maintain a record of the following information:

R18-2-402(F)(1)

( a ) A description of the project; R18-2-402(F)(1)(a)

( b ) Identification of the emissions unit(s) whose emissions of a regulated NSR pollutant 

could be affected by the project; and

R18-2-402(F)(1)(b)

( c ) A description of the applicability test used to determine that the project is not a major 

modification for any regulated NSR pollutant, including the baseline actual emissions, the 

projected actual emissions, the amount of emissions excluded under paragraph (b)(40)(ii)( c 

) of this section and an explanation for why such amount was excluded, and any netting 

calculations, if applicable.

R18-2-402(F)(1)(c and 

d). Incorrect reference to 

R18-2-401(20)(b)(iii), 

should be (b)(iv). 
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 92of 112

(ii) If the emissions unit is an existing electric utility steam generating unit, before beginning 

actual construction, the owner or operator shall provide a copy of the information set out in 

paragraph (r)(6)(i) of this section to the reviewing authority. Nothing in this paragraph 

(r)(6)(ii) shall be construed to require the owner or operator of such a unit to obtain any 

determination from the reviewing authority before beginning actual construction.

R18-2-402(F)(2). Typo - 

missing the word "in" 

before Subsection

(iii) The owner or operator shall monitor the emissions of any regulated NSR pollutant that 

could increase as a result of the project and that is emitted by any emissions unit identified in 

paragraph (r)(6)(i)( b ) of this section; and calculate and maintain a record of the annual 

emissions, in tons per year on a calendar year basis, for a period of 5 years following 

resumption of regular operations after the change, or for a period of 10 years following 

resumption of regular operations after the change if the project increases the design capacity 

or potential to emit of that regulated NSR pollutant at such emissions unit.

R18-2-402(F)(3). 

(iv) If the unit is an existing electric utility steam generating unit, the owner or operator shall 

submit a report to the reviewing authority within 60 days after the end of each year during 

which records must be generated under paragraph (r)(6)(iii) of this section setting out the 

unit's annual emissions during the calendar year that preceded submission of the report.

R18-2-402(F)(5)

(v) If the unit is an existing unit other than an electric utility steam generating unit, the owner 

or operator shall submit a report to the reviewing authority if the annual emissions, in tons per 

year, from the project identified in paragraph (r)(6)(i) of this section, exceed the baseline 

actual emissions (as documented and maintained pursuant to paragraph (r)(6)(i)( c ) of this 

section) by a significant amount (as defined in paragraph (b)(23) of this section) for that 

regulated NSR pollutant, and if such emissions differ from the preconstruction projection as 

documented and maintained pursuant to paragraph (r)(6)(i)( c ) of this section. Such report 

shall be submitted to the reviewing authority within 60 days after the end of such year. The 

report shall contain the following:

R18-2-402(F)(4) - 

recommend revising 

reference to (F)(1)(a) to 

(F)(1).

( a ) The name, address and telephone number of the major stationary source; R18-2-402(F)(4)(a)

( b ) The annual emissions as calculated pursuant to paragraph (r)(6)(iii) of this section; and R18-2-402(F)(4)(b)

( c ) Any other information that the owner or operator wishes to include in the report (e.g., 

an explanation as to why the emissions differ from the preconstruction projection).

R18-2-402(F)(4)©

(vi) A “reasonable possibility” under paragraph (r)(6) of this section occurs when the owner or 

operator calculates the project to result in either:

R18-2-402(F)(6)

( a ) A projected actual emissions increase of at least 50 percent of the amount that is a 

“significant emissions increase,” as defined under paragraph (b)(39) of this section (without 

reference to the amount that is a significant net emissions increase), for the regulated NSR 

pollutant; or

R18-2-402(F)(6)(a)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 93of 112

( b ) A projected actual emissions increase that, added to the amount of emissions excluded 

under paragraph (b)(40)(ii)( c ), sums to at least 50 percent of the amount that is a 

“significant emissions increase,” as defined under paragraph (b)(39) of this section (without 

reference to the amount that is a significant net emissions increase), for the regulated NSR 

pollutant. For a project for which a reasonable possibility occurs only within the meaning of 

paragraph (r)(6)(vi)( b ) of this section, and not also within the meaning of paragraph 

(a)(6)(vi)( a ) of this section, then provisions (a)(6)(ii) through (v) do not apply to the 

project.

R18-2-402(F)(6)(b)

(7) Each plan shall provide that the owner or operator of the source shall make the information 

required to be documented and maintained pursuant to paragraph (r)(6) of this section available 

for review upon request for inspection by the reviewing authority or the general public pursuant 

to the requirements contained in §70.4(b)(3)(viii) of this chapter.

Not included.

(s) Innovative control 

technology

(s) Innovative control technology. Did not include in 

submittal; ok since this 

section is optional. 

However, rule is 

referenced in other parts 

of SIP submittal - R18-2-

406(A). ADEQ has a rule 

for this, review of this 

rule is below.

(1) The plan may provide that an owner or operator of a proposed major stationary source or 

major modification may request the reviewing authority to approve a system of innovative 

control technology. R18-2-408(A)

(2) The plan may provide that the reviewing authority may, with the consent of the Governor(s) 

of other affected State(s), determine that the source or modification may employ a system of 

innovative control technology, if: R18-2-408(B)(6) 

(i) The proposed control system would not cause or contribute to an unreasonable risk to public 

health, welfare, or safety in its operation or function; R18-2-408(B)(1)

(ii) The owner or operator agrees to achieve a level of continuous emissions reduction 

equivalent to that which would have been required under paragraph (j)(2) of this section, by a 

date specified by the reviewing authority. Such date shall not be later than 4 years from the 

time of startup or 7 years from permit issuance;

R18-2-408(B)(2). Should 

reference (A)(1) and 

(A)(2).

(iii) The source or modification would meet the requirements equivalent to those in paragraphs 

(j) and (k) of this section, based on the emissions rate that the stationary source employing the 

system of innovative control technology would be required to meet on the date specified by the 

reviewing authority; R18-2-408(B)(3)

(iv) The source or modification would not before the date specified by the reviewing authority:

R18-2-408(B)(4)

( a ) Cause or contribute to any violation of an applicable national ambient air quality standard; 

or R18-2-408(B)(4)(a)

( b ) Impact any area where an applicable increment is known to be violated; R18-2-408(B)(4)(b)

(v) All other applicable requirements including those for public participation have been met.

R18-2-408(B)(5)
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(vi) The provisions of paragraph (p) of this section (relating to Class I areas) have been 

satisfied with respect to all periods during the life of the source or modification.

R18-2-408(B)(7). 

However, the 

requirements of 

51.166(p) are not 

necessarily in R18-2-218. 

Should add additional 

references.

(3) The plan shall provide that the reviewing authority shall withdraw any approval to employ a 

system of innovative control technology made under this section, if: R18-2-408(c )

(i) The proposed system fails by the specified date to achieve the required continuous 

emissions reduction rate; or R18-2-408(c)(1)

(ii) The proposed system fails before the specified date so as to contribute to an unreasonable 

risk to public health, welfare, or safety; or R18-2-408(c)(2)

(iii) The reviewing authority decides at any time that the proposed system is unlikely to achieve 

the required level of control or to protect the public health, welfare, or safety.

R18-2-408(3)

(4) The plan may provide that if a source or modification fails to meet the required level of 

continuous emissions reduction within the specified time period, or if the approval is withdrawn in 

accordance with paragraph (s)(3) of this section, the reviewing authority may allow the source or 

modification up to an additional 3 years to meet the requirement for the application of best 

available control technology through use of a demonstrated system of control.

R18-2-408(D)

(t)-(v) (t)–(v) [Reserved]

(w) Actuals PALs (w) Actuals PALs. The plan shall provide for PALs according to the provisions in paragraphs 

(w)(1) through (15) of this section.

R18-2-412

(1) Applicability. R18-2-412(A)

(i) The reviewing authority may approve the use of an actuals PAL for any existing major 

stationary source if the PAL meets the requirements in paragraphs (w)(1) through (15) of this 

section. The term “PAL” shall mean “actuals PAL” throughout paragraph (w) of this section.

R18-2-412(A)(1)

(ii) Any physical change in or change in the method of operation of a major stationary source 

that maintains its total source-wide emissions below the PAL level, meets the requirements in 

paragraphs (w)(1) through (15) of this section, and complies with the PAL permit:

( a ) Is not a major modification for the PAL pollutant;

( b ) Does not have to be approved through the plan's major NSR program; and

( c ) Is not subject to the provisions in paragraph (r)(2) of this section (restrictions on 

relaxing enforceable emission limitations that the major stationary source used to avoid 

applicability of the major NSR program).

(iii) Except as provided under paragraph (w)(1)(ii)(c) of this section, a major stationary source 

shall continue to comply with all applicable Federal or State requirements, emission limitations, 

and work practice requirements that were established prior to the effective date of the PAL.

R18-2-412(A)(3)

R18-2-412(A)(2)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 95of 112

(2) Definitions. The plan shall use the definitions in paragraphs (w)(2)(i) through (xi) of this 

section for the purpose of developing and implementing regulations that authorize the use of 

actuals PALs consistent with paragraphs (w)(1) through (15) of this section. When a term is not 

defined in these paragraphs, it shall have the meaning given in paragraph (b) of this section or in 

the Act.

(i) Actuals PAL for a major stationary source means a PAL based on the baseline actual 

emissions (as defined in paragraph (b)(47) of this section) of all emissions units (as defined in 

paragraph (b)(7) of this section) at the source, that emit or have the potential to emit the PAL 

pollutant.

R18-2-401(13)

(ii) Allowable emissions means “allowable emissions” as defined in paragraph (b)(16) of this 

section, except as this definition is modified according to paragraphs (w)(2)(ii)( a ) and ( b ) of 

this section.

( a ) The allowable emissions for any emissions unit shall be calculated considering any 

emission limitations that are enforceable as a practical matter on the emissions unit's 

potential to emit.

( b ) An emissions unit's potential to emit shall be determined using the definition in 

paragraph (b)(4) of this section, except that the words “or enforceable as a practical matter” 

should be added after “federally enforceable.”

(iii) 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, as defined in 

paragraph (b)(23) of this section or in the Act, whichever is lower.

R18-2-401(26). 

Recommended adding 

reference to definition for 

significant level

(iv) Major emissions unit means: Not included

( a ) Any emissions unit that emits or has the potential to emit 100 tons per year or more of 

the PAL pollutant in an attainment area; or

( b ) Any emissions unit that emits or has the potential to emit the PAL pollutant in an 

amount that is equal to or greater than the major source threshold for the PAL pollutant as 

defined by the Act for nonattainment areas. For example, in accordance with the definition of 

major stationary source in section 182(c) of the Act, an emissions unit would be a major 

emissions unit for VOC if the emissions unit is located in a serious ozone nonattainment area 

and it emits or has the potential to emit 50 or more tons of VOC per year.

(v) Plantwide applicability limitation (PAL) means an emission limitation expressed in tons per 

year, for a pollutant at a major stationary source, that is enforceable as a practical matter and 

established source-wide in accordance with paragraphs (w)(1) through (15) of this section.

R18-2-401(13)

(vi) 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 emissions unit that is part of the PAL 

major modification becomes operational and begins to emit the PAL pollutant.

R18-2-401(15)

(vii) PAL effective period means the period beginning with the PAL effective date and ending 10 

years later.

R18-2-401(16)

(viii) PAL major modification means, notwithstanding paragraphs (b)(2) and (b)(3) of this 

section (the definitions for major modification and net emissions increase), any 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.

R18-2-401(17)

R18-2-401(14). Should 

consistently use this term 

"PAL allowable emissions" 

in R18-2-412(H).
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 96of 112

(ix) PAL permit means the major NSR permit, the minor NSR permit, or the State operating 

permit under a program that is approved into the plan, or the title V permit issued by the 

reviewing authority that establishes a PAL for a major stationary source.

R18-2-401(18). Should 

reference under "Article 3 

or 4".

(x) PAL pollutant means the pollutant for which a PAL is established at a major stationary 

source.

R18-2-401(19)

(xi) Significant 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 (as defined in 

paragraph (b)(23) of this section or in the Act, whichever is lower) for that PAL pollutant, but 

less than the amount that would qualify the unit as a major emissions unit as defined in 

paragraph (w)(2)(iv) of this section.

R18-2-401(24). 

Recommend adding 

reference to definition for 

significant level.

(3) Permit application requirements. As part of a permit application requesting a PAL, the owner 

or operator of a major stationary source shall submit the following information in paragraphs 

(w)(3)(i) through (iii) of this section to the reviewing authority for approval.

R18-2-412(B)

(i) A list of all emissions units at the source designated as small, significant or major based on 

their potential to emit. In addition, the owner or operator of the source shall indicate which, if 

any, Federal or State applicable requirements, emission limitations, or work practices apply to 

each unit.

R18-2-412(B)(1)

(ii) Calculations of the baseline actual emissions (with supporting documentation). Baseline 

actual emissions are to include emissions associated not only with operation of the unit, but 

also emissions associated with startup, shutdown, and malfunction.

R18-2-412(B)(2). Did not 

include second sentence

(iii) The calculation procedures that the major stationary source owner or operator proposes to 

use to convert the monitoring system data to monthly emissions and annual emissions based 

on a 12-month rolling total for each month as required by paragraph (w)(13)(i) of this section.

R18-2-412(B)(3)

(4) General requirements for establishing PALs. R18-2-412(C)

(i) The plan allows the reviewing authority to establish a PAL at a major stationary source, 

provided that at a minimum, the requirements in paragraphs (w)(4)(i)(a) through (g) of this 

section are met.

R18-2-412(C)(1)

( a ) The PAL shall impose an annual emission limitation in tons per year, that is enforceable 

as a practical matter, for the entire major stationary source. For each month during the PAL 

effective period after the first 12 months of establishing a PAL, the major stationary source 

owner or operator shall show that the sum of the monthly emissions from each emissions unit 

under the PAL for the previous 12 consecutive months is less than the PAL (a 12-month 

average, rolled monthly). For each month during the first 11 months from the PAL effective 

date, the major stationary source owner or operator shall show that the sum of the preceding 

monthly emissions from the PAL effective date for each emissions unit under the PAL is less 

than the PAL.

( b ) The PAL shall be established in a PAL permit that meets the public participation 

requirements in paragraph (w)(5) of this section.

( c ) The PAL permit shall contain all the requirements of paragraph (w)(7) of this section.

( d ) The PAL shall include fugitive emissions, to the extent quantifiable, from all emissions 

units that emit or have the potential to emit the PAL pollutant at the major stationary source.

R18-2-412(C)(1)
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( e ) Each PAL shall regulate emissions of only one pollutant.

( f ) Each PAL shall have a PAL effective period of 10 years.

( g ) The owner or operator of the major stationary source with a PAL shall comply with the 

monitoring, recordkeeping, and reporting requirements provided in paragraphs (w)(12) 

through (14) of this section for each emissions unit under the PAL through the PAL effective 

period.

(ii) At no time (during or after the PAL effective period) are emissions reductions of a PAL 

pollutant that occur during the PAL effective period creditable as decreases for purposes of 

offsets under §51.165(a)(3)(ii) of this chapter unless the level of the PAL is reduced by the 

amount of such emissions reductions and such reductions would be creditable in the absence of 

the PAL.

R18-2-412(C)(2)

(5) Public participation requirements for PALs. PALs for existing major stationary sources shall be 

established, renewed, or increased, through a procedure that is consistent with §§51.160 and 

51.161 of this chapter. This includes the requirement that the reviewing authority provide the 

public with notice of the proposed approval of a PAL permit and at least a 30-day period for 

submittal of public comment. The reviewing authority must address all material comments before 

taking final action on the permit.

R18-2-412(D), R18-2-

330.

(6) Setting the 10-year actuals PAL level. R18-2-412(E)

(i) Except as provided in paragraph (w)(6)(ii) of this section, the plan shall provide that the 

actuals PAL level for a major stationary source shall be established as the sum of the baseline 

actual emissions (as defined in paragraph (b)(47) of this section) of the PAL pollutant for each 

emissions unit at the source; plus an amount equal to the applicable significant level for the 

PAL pollutant under paragraph (b)(23) of this section or under the Act, whichever is lower. 

When establishing the actuals PAL level, for a PAL pollutant, only one consecutive 24-month 

period must be used to determine the baseline actual emissions for all existing emissions units. 

However, a different consecutive 24-month period may be used for each different PAL 

pollutant. Emissions associated with units that were permanently shut down after this 24-month 

period must be subtracted from the PAL level. The reviewing authority shall specify a reduced 

PAL level(s) (in tons/yr) in the PAL permit to become effective on the future compliance date(s) 

of any applicable Federal or State regulatory requirement(s) that the reviewing authority is 

aware of prior to issuance of the PAL permit. For instance, if the source owner or operator will 

be required to reduce emissions from industrial boilers in half from baseline emissions of 60 

ppm NOXto a new rule limit of 30 ppm, then the permit shall contain a future effective PAL 

level that is equal to the current PAL level reduced by half of the original baseline emissions of 

such unit(s).

R18-2-412(E)(1). 

Recommend adding 

reference to definition for 

significance level

(ii) For newly constructed units (which do not include modifications to existing units) on which 

actual construction began after the 24-month period, in lieu of adding the baseline actual 

emissions as specified in paragraph (w)(6)(i) of this section, the emissions must be added to 

the PAL level in an amount equal to the potential to emit of the units.

R18-2-412(E)(2)

(7) Contents of the PAL permit. The plan shall require that the PAL permit contain, at a 

minimum, the information in paragraphs (w)(7)(i) through (x) of this section.

(i) The PAL pollutant and the applicable source-wide emission limitation in tons per year.

R18-2-412(F)
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(ii) The PAL permit effective date and the expiration date of the PAL (PAL effective period).

(iii) Specification in the PAL permit that if a major stationary source owner or operator applies 

to renew a PAL in accordance with paragraph (w)(10) of this section before the end of the PAL 

effective period, then the PAL shall not expire at the end of the PAL effective period. It shall 

remain in effect until a revised PAL permit is issued by the reviewing authority.

(iv) A requirement that emission calculations for compliance purposes include emissions from 

startups, shutdowns and malfunctions.

(v) A requirement that, once the PAL expires, the major stationary source is subject to the 

requirements of paragraph (w)(9) of this section.

(vi) The calculation procedures that the major stationary source owner or operator shall use to 

convert the monitoring system data to monthly emissions and annual emissions based on a 12-

month rolling total for each month as required by paragraph (w)(3)(i) of this section.

(vii) A requirement that the major stationary source owner or operator monitor all emissions 

units in accordance with the provisions under paragraph (w)(13) of this section.

(viii) A requirement to retain the records required under paragraph (w)(13) of this section on 

site. Such records may be retained in an electronic format.

(ix) A requirement to submit the reports required under paragraph (w)(14) of this section by 

the required deadlines.

(x) Any other requirements that the reviewing authority deems necessary to implement and 

enforce the PAL.

(8) PAL effective period and reopening of the PAL permit. The plan shall require the information 

in paragraphs (w)(8)(i) and (ii) of this section.

(i) PAL effective period. The reviewing authority shall specify a PAL effective period of 10 

years.

(ii) Reopening of the PAL permit. 

( a ) During the PAL effective period, the plan shall require the reviewing authority to reopen 

the PAL permit to:

( 1 ) Correct typographical/calculation errors made in setting the PAL or reflect a more 

accurate determination of emissions used to establish the PAL;

( 2 ) Reduce the PAL if the owner or operator of the major stationary source creates 

creditable emissions reductions for use as offsets under §51.165(a)(3)(ii) of this chapter; 

and

( 3 ) Revise the PAL to reflect an increase in the PAL as provided under paragraph (w)(11) 

of this section.

( b ) The plan shall provide the reviewing authority discretion to reopen the PAL permit for 

the following:

( 1 ) Reduce the PAL to reflect newly applicable Federal requirements (for example, NSPS) 

with compliance dates after the PAL effective date;

( 2 ) Reduce the PAL consistent with any other requirement, that is enforceable as a 

practical matter, and that the State may impose on the major stationary source under the 

plan; and

R18-2-412(G)
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( 3 ) Reduce the PAL if the reviewing authority determines that a reduction is necessary to 

avoid causing or contributing to a NAAQS or PSD increment violation, or to an adverse 

impact on an AQRV that has been identified for a Federal Class I area by a Federal Land 

Manager and for which information is available to the general public.

( c ) Except for the permit reopening in paragraph (w)(8)(ii)( a )( 1 ) of this section for the 

correction of typographical/calculation errors that do not increase the PAL level, all 

reopenings shall be carried out in accordance with the public participation requirements of 

paragraph (w)(5) of this section.

(9) Expiration of a PAL. Any PAL that is not renewed in accordance with the procedures in 

paragraph (w)(10) of this section shall expire at the end of the PAL effective period, and the 

requirements in paragraphs (w)(9)(i) through (v) of this section shall apply.

(i) Each emissions unit (or each group of emissions units) that existed under the PAL shall 

comply with an allowable emission limitation under a revised permit established according to 

the procedures in paragraphs (w)(9)(i)( a ) and ( b ) of this section.

( a ) Within the time frame specified for PAL renewals in paragraph (w)(10)(ii) of this section, 

the major stationary source shall submit a proposed allowable emission limitation for each 

emissions unit (or each group of emissions units, if such a distribution is more appropriate as 

decided by the reviewing authority) by distributing the PAL allowable emissions for the major 

stationary source among each of the emissions units that existed under the PAL. If the PAL 

had not yet been adjusted for an applicable requirement that became effective during the PAL 

effective period, as required under paragraph (w)(10)(v) of this section, such distribution 

shall be made as if the PAL had been adjusted.

( b ) The reviewing authority shall decide whether and how the PAL allowable emissions will 

be distributed and issue a revised permit incorporating allowable limits for each emissions 

unit, or each group of emissions units, as the reviewing authority determines is appropriate.

(ii) Each emissions unit(s) shall comply with the allowable emission limitation on a 12-month 

rolling basis. The reviewing authority may approve the use of monitoring systems (source 

testing,emission factors, etc.) other than CEMS, CERMS, PEMS or CPMS to demonstrate 

compliance with the allowable emission limitation.

(iii) Until the reviewing authority issues the revised permit incorporating allowable limits for 

each emissions unit, or each group of emissions units, as required under paragraph (w)(9)(i)( 

b ) of this section, the source shall continue to comply with a source-wide, multi-unit emissions 

cap equivalent to the level of the PAL emission limitation.

(iv) Any physical change or change in the method of operation at the major stationary source 

will be subject to major NSR requirements if such change meets the definition of major 

modification in paragraph (b)(2) of this section.

(v) The major stationary source owner or operator shall continue to comply with any State or 

Federal applicable requirements (BACT, RACT, NSPS, etc.) that may have applied either during 

the PAL effective period or prior to the PAL effective period except for those emission 

limitations that had been established pursuant to paragraph (r)(2) of this section, but were 

eliminated by the PAL in accordance with the provisions in paragraph (w)(1)(ii)(c) of this 

section.

R18-2-412(H) - Incorrect 

citation in (H)(4). Should 

reference definition for 

major modification. 

Recommend adding 

"whether and how" to 

(i)(b ). 412(H)(5) is not 

consistent with (v) - uses 

"eliminated" instead of 

"established.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 100of 112

(10) Renewal of a PAL. 

(i) The reviewing authority shall follow the procedures specified in paragraph (w)(5) of this 

section in approving any request to renew a PAL for a major stationary source, and shall 

provide both the proposed PAL level and a written rationale for the proposed PAL level to the 

public for review and comment. During such public review, any person may propose a PAL level 

for the source for consideration by the reviewing authority.

(ii) Application deadline. The plan shall require that a major stationary source owner or 

operator shall submit a timely application to the reviewing authority to request renewal of a 

PAL. A timely application is one that is submitted at least 6 months prior to, but not earlier than 

18 months from, the date of permit expiration. This deadline for application submittal is to 

ensure that the permit will not expire before the permit is renewed. If the owner or operator of 

a major stationary source submits a complete application to renew the PAL within this time 

period, then the PAL shall continue to be effective until the revised permit with the renewed 

PAL is issued.

(iii) Application requirements. The application to renew a PAL permit shall contain the 

information required in paragraphs (w)(10)(iii) ( a ) through ( d ) of this section.

( a ) The information required in paragraphs (w)(3)(i) through (iii) of this section.

( b ) A proposed PAL level.

( c ) The sum of the potential to emit of all emissions units under the PAL (with supporting 

documentation).

( d ) Any other information the owner or operator wishes the reviewing authority to consider 

in determining the appropriate level for renewing the PAL.

(iv) PAL adjustment. In determining whether and how to adjust the PAL, the reviewing 

authority shall consider the options outlined in paragraphs (w)(10)(iv) ( a ) and ( b ) of this 

section. However, in no case may any such adjustment fail to comply with paragraph 

(w)(10)(iv)( c ) of this section.

( a ) If the emissions level calculated in accordance with paragraph (w)(6) of this section is 

equal to or greater than 80 percent of the PAL level, the reviewing authority may renew the 

PAL at the same level without considering the factors set forth in paragraph (w)(10)(iv)( b ) 

of this section; or

( b ) The reviewing authority may set the PAL at a level that it determines to be more 

representative of the source's baseline actual emissions, or that it determines to be 

appropriate considering air quality needs, advances in control technology, anticipated 

economic growth in the area, desire to reward or encourage the source's voluntary emissions 

reductions, or other factors as specifically identified by the reviewing authority in its written 

rationale.

( c ) Notwithstanding paragraphs (w)(10)(iv) ( a ) and ( b ) of this section:

( 1 ) If the potential to emit of the major stationary source is less than the PAL, the 

reviewing authority shall adjust the PAL to a level no greater than the potential to emit of 

the source; and

( 2 ) The reviewing authority shall not approve a renewed PAL level higher than the current 

PAL, unless the major stationary source has complied with the provisions of paragraph 

(w)(11) of this section (increasing a PAL).

R18-2-412(I). Should 

reference 412(D) instead 

of (F) in (I)(1).Should 

reference 412(E) instead 

of (F) in (I)(4)(a).
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 101of 112

(v) If the compliance date for a State or Federal requirement that applies to the PAL source 

occurs during the PAL effective period, and if the reviewing authority has not already adjusted 

for such requirement, the PAL shall be adjusted at the time of PAL permit renewal or title V 

permit renewal, whichever occurs first.

(11) Increasing a PAL during the PAL effective period. 

(i) The plan shall require that the reviewing authority may increase a PAL emission limitation 

only if the major stationary source complies with the provisions in paragraphs (w)(11)(i) ( a ) 

through ( d ) of this section.

( a ) The owner or operator of the major stationary source shall submit a complete 

application to request an increase in the PAL limit for a PAL major modification. Such 

application shall identify the emissions unit(s) contributing to the increase in emissions so as 

to cause the major stationary source's emissions to equal or exceed its PAL.

( b ) As part of this application, the major stationary source owner or operator shall 

demonstrate that the sum of the baseline actual emissions of the small emissions units, plus 

the sum of the baseline actual emissions of the significant and major emissions units 

assuming application of BACT equivalent controls, plus the sum of the allowable emissions of 

the new or modified emissions unit(s), exceeds the PAL. The level of control that would result 

from BACT equivalent controls on each significant or major emissions unit shall be determined 

by conducting a new BACT analysis at the time the application is submitted, unless the 

emissions unit is currently required to comply with a BACT or LAER requirement that was 

established within the preceding 10 years. In such a case, the assumed control level for that 

emissions unit shall be equal to the level of BACT or LAER with which that emissions unit 

must currently comply.

( c ) The owner or operator obtains a major NSR permit for all emissions unit(s) identified in 

paragraph (w)(11)(i)( a ) of this section, regardless of the magnitude of the emissions 

increase resulting from them (that is, no significant levels apply). These emissions unit(s) 

shall comply with any emissions requirements resulting from the major NSR process (for 

example, BACT), even though they have also become subject to the PAL or continue to be 

subject to the PAL.

( d ) The PAL permit shall require that the increased PAL level shall be effective on the day 

any emissions unit that is part of the PAL major modification becomes operational and begins 

to emit the PAL pollutant.

(ii) The reviewing authority shall calculate the new PAL as the sum of the allowable emissions 

for each modified or new emissions unit, plus the sum of the baseline actual emissions of the 

significant and major emissions units (assuming application of BACT equivalent controls as 

determined in accordance with paragraph (w)(11)(i)( b ) of this section), plus the sum of the 

baseline actual emissions of the small emissions units.

(iii) The PAL permit shall be revised to reflect the increased PAL level pursuant to the public 

notice requirements of paragraph (w)(5) of this section.

(12) Monitoring requirements for PALs —

R18-2-412(J)

R18-2-412(K)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 102of 112

(i) General requirements. emissions of the PAL pollutant in terms of mass per unit of time. Any 

monitoring system authorized for use in the PAL permit must be based on sound science and 

meet generally acceptable scientific procedures for data quality and manipulation. Additionally, 

the information generated by such system must meet minimum legal requirements for 

admissibility in a judicial proceeding to enforce the PAL permit.

( a ) Each PAL permit must contain enforceable requirements for the monitoring system that 

accurately determines plantwide 

( b ) The PAL monitoring system must employ one or more of the four general monitoring 

approaches meeting the minimum requirements set forth in paragraphs (w)(12)(ii) ( a ) 

through ( d ) of this section and must be approved by the reviewing authority.

( c ) Notwithstanding paragraph (w)(12)(i)( b ) of this section, you may also employ an 

alternative monitoring approach that meets paragraph (w)(12)(i)( a ) of this section if 

approved by the reviewing authority.

( d ) Failure to use a monitoring system that meets the requirements of this section renders 

the PAL invalid.

(ii) Minimum performance requirements for approved monitoring approaches. The following are 

acceptable general monitoring approaches when conducted in accordance with the minimum 

requirements in paragraphs (w)(12)(iii) through (ix) of this section:

( a ) Mass balance calculations for activities using coatings or solvents;

( b ) CEMS;

( c ) CPMS or PEMS; and

( d ) Emission factors.

(iii) Mass balance calculations. An owner or operator using mass balance calculations to monitor 

PAL pollutant emissions from activities using coating or solvents shall meet the following 

requirements:

( a ) Provide a demonstrated means of validating the published content of the PAL pollutant 

that is contained in or created by all materials used in or at the emissions unit;

( b ) Assume that the emissions unit emits all of the PAL pollutant that is contained in or 

created by any raw material or fuel used in or at the emissions unit, if it cannot otherwise be 

accounted for in the process; and

( c ) Where the vendor of a material or fuel, which is used in or at the emissions unit, 

publishes a range of pollutant content from such material, the owner or operator must use 

the highest value of the range to calculate the PAL pollutant emissions unless the reviewing 

authority determines there is site-specific data or a site-specific monitoring program to 

support another content within the range.

(iv) CEMS. An owner or operator using CEMS to monitor PAL pollutant emissions shall meet the 

following requirements:

( a ) CEMS must comply with applicable Performance Specifications found in 40 CFR part 60, 

appendix B; and

( b ) CEMS must sample, analyze, and record data at least every 15 minutes while the 

emissions unit is operating.

(v) CPMS or PEMS. An owner or operator using CPMS or PEMS to monitor PAL pollutant 

emissions shall meet the following requirements:
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 103of 112

( a ) The CPMS or the PEMS must be based on current site-specific data demonstrating a 

correlation between the monitored parameter(s) and the PAL pollutant emissions across the 

range of operation of the emissions unit; and

( b ) Each CPMS or PEMS must sample, analyze, and record data at least every 15 minutes, 

or at another less frequent interval approved by the reviewing authority, while the emissions 

unit is operating.

(vi) Emission factors. An owner or operator using emission factors to monitor PAL pollutant 

emissions shall meet the following requirements:

( a ) All emission factors shall be adjusted, if appropriate, to account for the degree of 

uncertainty or limitations in the factors' development;

( b ) The emissions unit shall operate within the designated range of use for the emission 

factor, if applicable; and

( c ) If technically practicable, the owner or operator of a significant emissions unit that relies 

on an emission factor to calculate PAL pollutant emissions shall conduct validation testing to 

determine a site-specific emission factor within 6 months of PAL permit issuance, unless the 

reviewing authority determines that testing is not required.

(vii) A source owner or operator must record and report maximum potential emissions without 

considering enforceable emission limitations or operational restrictions for an emissions unit 

during any period of time that there is no monitoring data, unless another method for 

determining emissions during such periods is specified in the PAL permit.

(viii) Notwithstanding the requirements in paragraphs (w)(12)(iii) through (vii) of this section, 

where an owner or operator of an emissions unit cannot demonstrate a correlation between the 

monitored parameter(s) and the PAL pollutant emissions rate at all operating points of the 

emissions unit, the reviewing authority shall, at the time of permit issuance:

( a ) Establish default value(s) for determining compliance with the PAL based on the highest 

potential emissions reasonably estimated at such operating point(s); or

( b ) Determine that operation of the emissions unit during operating conditions when there 

is no correlation between monitored parameter(s) and the PAL pollutant emissions is a 

violation of the PAL.

(ix) Re-validation. All data used to establish the PAL pollutant must be re-validated through 

performance testing or other scientifically valid means approved by the reviewing authority. 

Such testing must occur at least once every 5 years after issuance of the PAL.

(13) Recordkeeping requirements. 

(i) The PAL permit shall require an owner or operator to retain a copy of all records necessary 

to determine compliance with any requirement of paragraph (w) of this section and of the PAL, 

including a determination of each emissions unit's 12-month rolling total emissions, for 5 years 

from the date of such record.

(ii) The PAL permit shall require an owner or operator to retain a copy of the following records, 

for the duration of the PAL effective period plus 5 years:

( a ) A copy of the PAL permit application and any applications for revisions to the PAL; and

( b ) Each annual certification of compliance pursuant to title V and the data relied on in 

certifying the compliance.

R18-2-412(L)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 104of 112

(14) Reporting and notification requirements. The owner or operator shall submit semi-annual 

monitoring reports and prompt deviation reports to the reviewing authority in accordance with 

the applicable title V operating permit program. The reports shall meet the requirements in 

paragraphs (w)(14)(i) through (iii) of this section.

(i) Semi-annual report. The semi-annual report shall be submitted to the reviewing authority 

within 30 days of the end of each reporting period. This report shall contain the information 

required in paragraphs (w)(14)(i)( a ) through ( g ) of this section.

( a ) The identification of owner and operator and the permit number.

( b ) Total annual emissions (tons/year) based on a 12-month rolling total for each month in 

the reporting period recorded pursuant to paragraph (w)(13)(i) of this section.

( c ) All data relied upon, including, but not limited to, any Quality Assurance or Quality 

Control data, in calculating the monthly and annual PAL pollutant emissions.

( d ) A list of any emissions units modified or added to the major stationary source during the 

preceding 6-month period.

( e ) The number, duration, and cause of any deviations or monitoring malfunctions (other 

than the time associated with zero and span calibration checks), and any corrective action 

taken.

( f ) A notification of a shutdown of any monitoring system, whether the shutdown was 

permanent or temporary, the reason for the shutdown, the anticipated date that the 

monitoring system will be fully operational or replaced with another monitoring system, and 

whether the emissions unit monitored by the monitoring system continued to operate, and 

the calculation of the emissions of the pollutant or the number determined by method 

included in the permit, as provided by paragraph (w)(12)(vii) of this section.

( g ) A signed statement by the responsible official (as defined by the applicable title V 

operating permit program) certifying the truth, accuracy, and completeness of the 

information provided in the report.

(ii) Deviation report. The major stationary source owner or operator shall promptly submit 

reports of any deviations or exceedance of the PAL requirements, including periods where no 

monitoring is available. A report submitted pursuant to §70.6(a)(3)(iii)(B) of this chapter shall 

satisfy this reporting requirement. The deviation reports shall be submitted within the time 

limits prescribed by the applicable program implementing §70.6(a)(3)(iii)(B) of this chapter. 

The reports shall contain the following information:

( a ) The identification of owner and operator and the permit number;

( b ) The PAL requirement that experienced the deviation or that was exceeded;

( c ) Emissions resulting from the deviation or the exceedance; and

( d ) A signed statement by the responsible official (as defined by the applicable title V 

operating permit program) certifying the truth, accuracy, and completeness of the 

information provided in the report.

(iii) Re-validation results. The owner or operator shall submit to the reviewing authority the 

results of any re-validation test or method within three months after completion of such test or 

method.

R18-2-412(M)
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 105of 112

(15) Transition requirements. 

(i) No reviewing authority may issue a PAL that does not comply with the requirements in 

paragraphs (w)(1) through (15) of this section after the Administrator has approved regulations 

incorporating these requirements into a plan.

Not included. PAL 

provisions will be 

effective upon approval.

(ii) The reviewing authority may supersede any PAL which was established prior to the date of 

approval of the plan by the Administrator with a PAL that complies with the requirements of 

paragraphs (w)(1) through (15) of this section.

Not included. The 

reviewing authority 

"may". Ok.

(x) (x) If any provision of this section, or the application of such provision to any person or 

circumstance, is held invalid, the remainder of this section, or the application of such provision to 

persons or circumstances other than those as to which it is held invalid, shall not be affected 

thereby.

Not a requirement for the 

"plan".

(y) (y) Equipment replacement provision. Without regard to other considerations, routine 

maintenance, repair and replacement includes, but is not limited to, the replacement of any 

component of a process unit with an identical or functionally equivalent component(s), and 

maintenance and repair activities that are part of the replacement activity, provided that all of 

the requirements in paragraphs (y)(1) through (3) of this section are met.

(1) Capital Cost threshold for Equipment Replacement. 

(i) For an electric utility steam generating unit, as defined in §51.166(b)(30), the fixed capital 

cost of the replacement component(s) plus the cost of any associated maintenance and repair 

activities that are part of the replacement shall not exceed 20 percent of the replacement value 

of the process unit, at the time the equipment is replaced. For a process unit that is not an 

electric utility steam generating unit the fixed capital cost of the replacement component(s) 

plus the cost of any associated maintenance and repair activities that are part of the 

replacement shall not exceed 20 percent of the replacement value of the process unit, at the 

time the equipment is replaced.

(ii) In determining the replacement value of the process unit; and, except as otherwise allowed 

under paragraph (y)(1)(iii) of this section, the owner or operator shall determine the 

replacement value of the process unit on an estimate of the fixed capital cost of constructing a 

new process unit, or on the current appraised value of the process unit.

Generally, not included. 

These provisions were 

vacated by the D.C. 

Circuit Court of Appeals - 

NY, et al v. EPA , No. 03-

1238 (March 17, 2006). 

Defintion of basic design 

parameter still 

inadvertantly included. 

See discussion in Section 

5.8.1.2 of the TSD.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 106of 112

(iii) As an alternative to paragraph (y)(1)(ii) of this section for determining the replacement 

value of a process unit, an owner or operator may choose to use insurance value (where the 

insurance value covers only complete replacement), investment value adjusted for inflation, or 

another accounting procedure if such procedure is based on Generally Accepted Accounting 

Principles, provided that the owner or operator sends a notice to the reviewing authority. The 

first time that an owner or operator submits such a notice for a particular process unit, the 

notice may be submitted at any time, but any subsequent notice for that process unit may be 

submitted only at the beginning of the process unit's fiscal year. Unless the owner or operator 

submits a notice to the reviewing authority, then paragraph (y)(1)(ii) of this section will be 

used to establish the replacement value of the process unit. Once the owner or operator 

submits a notice to use an alternative accounting procedure, the owner or operator must 

continue to use that procedure for the entire fiscal year for that process unit. In subsequent 

fiscal years, the owner or operator must continue to use this selected procedure unless and 

until the owner or operator sends another notice to the reviewing authority selecting another 

procedure consistent with this paragraph or paragraph (y)(1)(ii) of this section at the beginning 

of such fiscal year.

(2) Basic design parameters. The replacement does not change the basic design parameter(s) of 

the process unit to which the activity pertains.

(i) Except as provided in paragraph (y)(2)(iii) of this section, 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 British Thermal 

Units content shall be used for determining the basic design parameter(s) for a coal-fired 

electric utility steam generating unit.

(ii) Except as provided in paragraph (y)(2)(iii) of this section, the basic design parameter(s) for 

any process unit that is not at a steam 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 and raw materials, the owner or operator should consider the primary product or 

primary raw material when selecting a basic design parameter.

(iii) If the owner or operator believes the basic design parameter(s) in paragraphs (y)(2)(i) and 

(ii) of this section is not appropriate for a specific industry or type of process unit, the owner or 

operator may propose to the reviewing authority an alternative basic design parameter(s) for 

the source's process unit(s). If the reviewing authority approves of the use of an alternative 

basic design parameter(s), the reviewing authority shall issue a permit that is legally 

enforceable that records such basic design parameter(s) and requires the owner or operator to 

comply with such parameter(s).

(iv) The owner or operator shall use credible information, such as results of historic maximum 

capability tests, design information from the manufacturer, or engineering calculations, in 

establishing the magnitude of the basic design parameter(s) specified in paragraphs (y)(2)(i) 

and (ii) of this section.
EPA Region 9 Evaluation of 40 CFR 51.160-51.166 and the ADEQ NSR Submittal (October 2012) Page 107of 112

(v) If design information is not available for a process unit, then the owner or operator shall 

determine the process unit's basic design parameter(s) using the maximum value achieved by 

the process unit in the five-year period immediately preceding the planned activity.

(vi) Efficiency of a process unit is not a basic design parameter.

(3) 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.

Note to paragraph (y): By a court order on December 24, 2003, this paragraph (y) is stayed 

indefinitely. The stayed provisions will become effective immediately if the court terminates the 

stay. At that time, EPA will publish a document in the Federal Register advising the public of 

the termination of the stay.

(Secs. 101(b)(1), 110, 160–169, 171–178, and 301(a), Clean Air Act, as amended (42 U.S.C. 

7401(b)(1), 7410, 7470–7479, 7501–7508, and 7601(a)); sec. 129(a), Clean Air Act 

Amendments of 1977 (Pub. L. 95–95, 91 Stat. 685 (Aug. 7, 1977)))

[43 FR 26382, June 19, 1978]

Editorial Note: For Federal Register citations affecting §51.166, see the List of CFR Sections 

Affected, which appears in the Finding Aids section of the printed volume and at www.fdsys.gov .

Effective Date Note: At 76 FR 17553, Mar. 30, 2011, §51.166 paragraphs (b)(2)(v) and 

(b)(3)(iii) (d) are stayed indefinitely.
Table 1

Pollutant

Maximum allowable 

increase (mg/m3)

PM2.5:

Annual arithmetic mean 1

24-hr maximum 2

PM10:

Annual arithmetic mean 4

24-hr maximum 8

Sulfur dioxide:

Annual arithmetic mean 2

24-hr maximum 5

3-hr maximum 25

Nitrogen dioxide:

Annual arithmetic mean 2.5

PM2.5:

Annual arithmetic mean 4

24-hr maximum 9

PM10:

Annual arithmetic mean 17

24-hr maximum 30

Sulfur dioxide:

Annual arithmetic mean 20

24-hr maximum 91

3-hr maximum 512

Nitrogen dioxide:

Annual arithmetic mean 25

Class I Area

Class II Area

Class III Area

PM2.5:
Annual arithmetic mean 8

24-hr maximum 18

PM10:

Annual arithmetic mean 34

24-hr maximum 60

Sulfur dioxide:

Annual arithmetic mean 40

24-hr maximum 182

3-hr maximum 700

Nitrogen dioxide:

Annual arithmetic mean 50
Table 2

Pollutant

Maximum allowable 

increase [microgram 

per cubic meater]

PM2.5:

Annual 

arithmetic 

mean 4

24-hr 

maximum 9

PM10:

Annual 

arithmetic 

mean 17

24-hr 

maximum 30

Sulfur dioxide:

Annual 

arithmetic 

mean 20

24-hr 

maximum 91

3-hr maximum 325

Nitrogen dioxide:

Annual 

arithmetic 

mean 25
Table 3

Low High

24-hr 

maximum 36 62

3-hr 

maximum 130 221

Period of 

exposure

Terrain areas

Maximum Allowable Increase 

[Micrograms per cubic meter]
Table 4

24 8 3 1

SO2

1.0 μg/m35 μg/m325 μg/m3

PM10 1.0 μg/m3

5 μg/m3

PM2.5 0.3 μg/m3

1.2 μg/m3

NO2

1.0 μg/m3

CO 0.5 mg/m3

2 mg/m3

Averaging time (hours) Pollutant Annual