1 

Technical Support Document 

Evaluation of the Arizona Infrastructure State Implementation Plan for Portions of the 2008 8-

hour Ozone and the 2008 Lead (Pb) NAAQS 

Jeff Buss and Noah Smith 

U.S. EPA, Region 9 

May 1, 2015 
2 
3 

Introduction 

This technical support document (TSD) summarizes EPA’s technical review of revisions to 

Arizona’s State Implementation Plan (SIP). Specifically, this TSD examines rules adopted by the 

Arizona Department of Environmental Quality (ADEQ) and submitted to EPA on October 29, 

2012. Supplemental information was submitted on September 6, 2013 and July 2, 2014. In this 

TSD, we examine whether the aforementioned submittals meet the requirements of Clean Air 

Act sections 110(a)(2)(C), (D), (J), and (K). Additionally, we analyze whether these submittals 

resolve the infrastructure SIP disapprovals set forth in our action: “Partial Approval and 

Disapproval of Air Quality Implementation Plans; Arizona; Infrastructure Requirements for 

Ozone and Fine Particulate Matter,” 77 FR 66398 (November 5, 2012). 

On October 14, 2011, the Arizona Department of Environmental Quality (ADEQ) submitted the 

“Arizona State Implementation Plan Revision under Clean Air Act Section 110(a)(1) and (2); 

2008 Lead NAAQS” (2011 Pb I-SIP Submittal) to address all of the CAA section 110(a)(2) 

requirements, which EPA commonly refers to as “infrastructure” except for section 110(a)(2)(G) 

for the 2008 Lead (Pb) national ambient air quality standards (NAAQS). Additionally, on 

December 27, 2012, ADEQ submitted the “Arizona State Implementation Plan Revision under 

Clean Air Act Section 110(a)(1) and (2); 2008 8-hour Ozone NAAQS” (2012 Ozone I-SIP 

Submittal) to address all of the CAA section 110(a)(2) requirements for the 2008 8-hour Ozone 

NAAQS. 

On October 29, 2012, ADEQ submitted “New Source Review State Implementation Plan 

Submission” and on July 2, 2014 submitted “Supplemental Information to 2012 New Source 

Review State Implementation Plan Submission”. These submissions relate to the prevention of 

significant deterioration (PSD) and minor new source review (NSR) portions of CAA sections 

110(a)(2)(C), (D), (J), and (K). 

Background 

CAA section 110(a)(1) and (2) requires states to address basic SIP requirements to implement, 

maintain and enforce the NAAQS no later than three years after the promulgation of a new or 

revised NAAQS. Many of the section 110(a)(2) SIP elements relate to the general information 

and authorities that constitute the "infrastructure" of a state's air quality management program 

and SIP submittals that address these requirements are referred to as “infrastructure SIPs” (ISIP). 

2008 Pb NAAQS 

On October 15, 2008, the U.S. Environmental Protection Agency (EPA) issued a revised 

NAAQS for Pb.1

 This action triggered a requirement for states to submit an infrastructure SIP to 

address the applicable requirements of section 110(a)(2) within three years of issuance of the 

 

1

 73 FR 66964 (November 12, 2008). The 1978 Pb standard (1.5 μg/m3 as a quarterly average) was modified to a 

rolling 3 month average not to be exceeded of 0.15 μg/m3. EPA also revised the secondary NAAQS to 0.15 

μg/m3

and made it identical to the revised primary standard. Id. 
4 

revised NAAQS. On October 14, 2011, EPA issued “Guidance on Section 110 Infrastructure 

SIPs for the 2008 Pb NAAQS”, referred to herein as EPA’s 2011 Pb Guidance.2 Depending on 

the timing of a given submittal, some states relied on the earlier draft version of this guidance, 

referred to herein as EPA’s 2011 Draft Pb Guidance.3

 EPA issued additional guidance on 

infrastructure SIPs on September 13, 2013.4 

On October 14, 2011, ADEQ submitted the 2011 Pb I-SIP which included the SIP revision, 

completeness checklist, copies of authorizing statutes, copies of public process documentation, 

and a commitment to adopt and submit a SIP revision to update Arizona’s New Source 

Review/Prevention of Significant Deterioration program to fully meet the requirements of CAA 

section 110(a)(2)(C) for the 2008 Pb NAAQS. 

2008 Ozone NAAQS 

On March 27, 2008, EPA issued a revised NAAQS for 8-hour Ozone.5 This action triggered a 

requirement for states to submit an infrastructure SIP to address the applicable requirements of 

section 110(a)(2) within three years of issuance of the revised NAAQS. EPA did not, however, 

prepare guidance at this time for states in submitting I-SIP revisions for the 2008 Ozone 

NAAQS.6 On September 13, 2013, EPA issued “Guidance of Infrastructure State 

Implementation Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2),” 

which provides “advice on the development of infrastructure SIPs for the 2008 ozone NAAQS . . 

. as well as infrastructure SIPs for new or revised NAAQS promulgated in the future.”7 

On December 27, 2012, ADEQ submitted the 2012 Ozone I-SIP which included the SIP 

revision, completeness checklist, copies of authorizing statutes, and copies of public process 

documentation. 

We have evaluated the 2011 Pb I-SIP and the 2012 Ozone I-SIP submittals in relation to the 

infrastructure SIP requirements (or “elements”) of CAA sections 110(a)(2)(C), (D), (J), and (K) 

for the 2008 Lead NAAQS and the 2008 Ozone NAAQS.8 In the following pages we describe 

 

2

 See Memorandum from Stephen D. Page, Director, Office of Air Quality Planning and Standards, to Regional Air 

Division Directors, Regions 1-10 (October 14, 2011).

3

 “DRAFT Guidance on SIP Elements Required Under Sections 110(a)(1) and (2) for the 2008 Lead (Pb) National 

Ambient Air Quality Standards (NAAQS),” June 17, 2011 version.

4 See Memorandum dated September 13, 2013 from Stephen D. Page, Director, EPA Office of Air Quality Planning

and Standards, to Regional Air Directors, EPA Regions 1-10, “Guidance on Infrastructure State Implementation 

Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2)” (referred to herein as “2013 

Infrastructure SIP Guidance”).

5

 73 FR 16436 (March 27, 2008). 

6

 Preparation of guidance for the 2008 Ozone NAAQS was postponed given EPA’s reconsideration of the standard. 

See 78 FR 34183 (June 6, 2013). 

7

 See Memorandum from Stephen D. Page, Director, Office of Air Quality Planning and Standards, to Regional Air 

Division Directors, Regions 1-10 (September 13, 2013). 

8

 Two section 110(a)(2) requirements are considered by EPA to be outside the scope of infrastructure SIP actions 

because they pertain to plan requirements for nonattainment areas: (1) section 110(a)(2)(C) to the extent it refers to 

permit programs under part D; and (2) section 110(a)(2)(I) in its entirety. Therefore, this TSD does not address these 

requirements. 
5 

the requirements, summarize the State’s submittals, and present our evaluation for each 

infrastructure SIP element.

On November 5, 2012, EPA partially approved and partially disapproved the Arizona I-SIP for 

the 1997 8-hour ozone, 1997 PM2.5 and the 2006 PM2.5 NAAQS. As explained in our proposed 

and final notices and associated TSD, our disapprovals related to sections 110(a)(2)(C), 

(D)(i)(II), (D)(ii), (J), and (K) resulted from the conclusion that the Arizona SIP does not fully 

satisfy the statutory and regulatory requirements for PSD permit programs under part C of title I 

of the Act. For these disapprovals, EPA found that both the Maricopa County Air Quality 

Department and the Pima County Department of Environmental Quality implemented the 

Federal PSD program in 40 CFR 52.21 for all regulated NSR pollutants, pursuant to delegation 

agreements with EPA. 40 CFR 52.144. Additionally, EPA found that ADEQ implemented a SIPapproved PSD program for all regulated NSR pollutants except for PM10, PM2.5 and GHGs (48 

FR 19878, May 3, 1983), and the Pinal County Air Quality Control District (PCAQCD) 

implemented a SIP-approved PSD program for all regulated NSR pollutants except for GHGs

(61 FR 15717, April 9, 1996, as amended by 65 FR 79742, December 20, 2000). In this TSD, we 

examine whether ADEQ’s October 29, 2012 submittal as well as the September 6, 2013 and July 

2, 2014 supplemental submittals resolve the deficiencies described in our 2012 I-SIP action9

 for 

elements 110(a)(2)(C), (D), (J), and (K). 

CAA Section 110(a)(2)(C): Program for enforcement of control measures and 

regulation of new and modified stationary sources. 

Section 110(a)(2)(C) requires SIPs to include a program to provide for enforcement of the 

measures set forth in Section 110(a)(2)(A), and regulation of the modification and construction 

of stationary sources, within the areas covered by the plan, as necessary to assure that NAAQS 

are achieved, including a permit program as required in parts C and D of CAA title I. 

EPA evaluated the State’s general enforcement authorities to determine if they provided an 

adequate infrastructure for SIP enforcement statewide of the States’ control measures. 

EPA also evaluated where the State had a program to provide for regulation of the modification 

and construction of stationary sources. EPA evaluated only the State’s minor NSR programs and 

certain “structural” elements of the State’s PSD programs under part C of CAA title I to 

determine whether these programs are adequate for infrastructure SIP purposes. EPA evaluated 

the Arizona SIP with respect to the following specific elements of the PSD program: 

1. Provisions identifying NOx as an ozone precursor consistent with the requirements of 

EPA’s Phase 2 implementation rule for the 1997 8-hour ozone NAAQS, 70 FR 71612 

(codified at 40 CFR 51.166(b)(1)(ii), (b)(2)(ii), (b)(23)(i), (b)(49)(i));

 

9

 77 FR 66398 (November 5, 2012) 
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2. Provisions to regulate PM2.5, including condensable PM, and its precursor emissions 

(sulfur dioxide (SO2) in all areas, and NOx and/or VOC as appropriate), consistent with 

the requirements of EPA’s NSR/PSD implementation rule for the 1997 PM2.5 NAAQS, 73 

FR 28321 (codified at 40 CFR 51.166(b)(23)(i), (b)(49)(i));

3. Provisions to regulate Greenhouse Gases (GHGs) consistent with EPA’s regulations 

and a recent decision by the U.S. Supreme Court, as discussed below.

Regarding GHGs, EPA established that beginning on January 2, 2011, new or modified sources 

of GHG emissions at or above certain thresholds are required to seek PSD permits. Four of these 

actions include, as they are commonly called, the “Endangerment Finding” and “Cause or 

Contribute Finding,” which EPA issued in a single final action,10 the “Johnson Memo 

Reconsideration,”11 the “Light-Duty Vehicle Rule,”12 and the “Tailoring Rule.”13 Taken together 

and in conjunction with the CAA, these actions established regulatory requirements for GHGs 

emitted from new motor vehicles and new motor vehicle engines; determined that such 

regulations, when they took effect on January 2, 2011, subjected GHGs emitted from stationary 

sources to PSD requirements; and limited the applicability of PSD requirements to GHG sources 

on a phased-in basis. 

However, on June 23, 2014, the U.S. Supreme Court issued a decision addressing the application 

of PSD permitting requirements to GHG emissions.14 The Supreme Court said that EPA may not 

treat GHGs as an air pollutant for purposes of determining whether a source is a major source 

required to obtain a PSD permit. The Court also said that EPA could continue to require that 

PSD permits, otherwise required based on emissions of pollutants other than GHGs, contain 

limitations on GHG emissions based on the application of Best Available Control Technology 

(BACT). In order to act consistently with its understanding of the Court’s decision, EPA is not 

currently applying EPA regulations that would require that SIPs include permitting requirements 

that the Supreme Court found impermissible. Specifically, EPA is not requiring that a state’s 

SIP-approved PSD program require sources to obtain PSD permits when GHGs are the only 

pollutant (i) that the source emits or has the potential to emit above the major source thresholds, 

or (ii) for which there is a significant emissions increase and a significant net emissions increase 

from a modification (e.g. 40 CFR 51.166(b)(48)(v)). 

Generally, section 110(a)(2)(C) requires that an infrastructure SIP for the 2008 8-hour ozone and 

2008 Pb NAAQS contain SIP-approved PSD, nonattainment New Source Review (NSR), and 

 

10 “Endangerment and Cause or Contribute Findings for Greenhouse Gases Under Section 202(a) of the Clean Air 

Act.” 74 FR 66496, December 15, 2009. 

11 “Interpretation of Regulations that Determine Pollutants Covered by Clean Air Act Permitting Programs.” 75 FR 

17004, April 2, 2010. 

12 “Light-Duty Vehicle Greenhouse Gas Emission Standards and Corporate Average Fuel Economy Standards; Final 

Rule.” 75 FR 25324, May 7, 2010. 

13 “Prevention of Significant Deterioration and Title V Greenhouse Gas Tailoring Rule; Final Rule.” 75 FR 31514, 

June 3, 2010. 

14 Utility Air Regulatory Group v. Environmental Protection Agency, 134 S. Ct. 2427. 
7 

minor NSR permitting programs adequate to implement these standards. As explained above, 

however, EPA is not evaluating part D nonattainment area requirements (such as the 

nonattainment NSR program) in this proposed action because these SIPs are due on a separate 

schedule under CAA section 172(b). Additionally, EPA is not proposing to approve or 

disapprove any state rules with regard to the NSR Reform requirements. EPA intends to act on 

SIP submittals that are made for purposes of adopting NSR Reform through a separate 

rulemaking process. 

Arizona’s responses to this requirement 

Arizona State and local agencies implement control and enforcement programs for permitted 

sources of air contaminants and for sources that are not regulated through permit programs (such 

as open uncontrolled burns, construction, and vacant land). Each agency that commits to 

implement an emission limitation or other control measure contained in the SIP is required to 

specify, in a resolution adopted by the governing body of the agency, its authority for 

implementing the measure and a program for enforcement of the limitation or measure. 2012 

Ozone I-SIP at 16. 

ADEQ and local agencies are authorized to implement preconstruction review and permitting 

programs under ARS title 49, chapter 3, articles 1, 2, and 3. ADEQ and county regulations 

implementing these permit program requirements are contained in AAC title 18, Chapter 2, 

Articles 2 and 4 or relevant county rules. 2012 Ozone I-SIP at 16. 

Authority to enforce permit programs and SIPs is contained in ARS 49-460 through 463 and 49-

510 through 513, under which the State or county may issue orders of abatement, and, through 

the Attorney General or County Attorney, seek injunctive relief for any violations of the air 

quality programs. 2012 Ozone I-SIP at 16. 

In ADEQ’s 2011 Pb I-SIP Arizona expressed a commitment to adopt and submit a SIP revision 

to update Arizona’s New Source Review/Prevention of Significant Deterioration program to 

fully meet the requirements of CAA section 110(a)(2)(C) for the 2008 Pb NAAQS. ADEQ 

provided the same commitment to update Arizona’s New Source Review/Prevention of 

Significant Deterioration program in its 2012 Ozone I-SIP Submittal. 

On October 29, 2012, ADEQ submitted “New Source Review State Implementation Plan 

Submission” and on July 2, 2014 submitted “Supplemental Information to 2012 New Source 

Review State Implementation Plan Submission” (“Arizona NSR Submittals”) to address and 

update the state’s NSR program. Accordingly, our review of element C is based in part on EPA’s 

proposed rule for the Arizona NSR Submittals “Revisions to Air Plan; Arizona; Stationary 

Sources; New Source Review” 80 FR 14044, March 18, 2015 (“Arizona NSR Proposed Rule”). 

In the Arizona NSR Proposed Rule, EPA generally proposed a limited approval and limited 

disapproval of ADEQ’s NSR Submittals, which addressed ADEQ’s minor NSR program and 

PSD program, as well as ADEQ’s major nonattainment NSR program. 

EPA Evaluation
8 

1. Program for enforcement of control measures 

Several Arizona statutes in title 49 establish ADEQ’s and the three counties’ authorities to 

provide for enforcement of air pollution control measures. For example, ARS 49-402 (“State 

and county control”) contains general provisions regarding the respective jurisdictions of ADEQ 

and the counties to issue and enforce permits, among other authorities. ARS 49-404(A) (“State 

implementation plan”) requires the director of ADEQ to maintain a SIP that “provides for 

implementation, maintenance and enforcement of national ambient air quality standards and 

protection of visibility as required by the clean air act.” ARS 49-406 (“Nonattainment area 

plan”) establishes a process for the designation of responsibilities among State, regional, and 

local agencies to develop, implement, and enforce SIPs for certain nonattainment or maintenance 

areas (ARS 49-406(A) through (D)), and requires each agency that commits to implement a SIP 

provision to describe its commitment in a resolution, which must specify, among other things, 

the agency’s legal authority for implementing the limitation or measure and “a program for the 

enforcement of the limitation or measure” (ARS 49-406(G)). EPA approved ARS 49-402, 49-

404, and 49-406 into the Arizona SIP on June 8, 2000. 65 FR 36353, 36358. ARS 49-479 

authorizes the board of supervisors for each county to adopt rules as it determines are necessary 

to control air pollution, which rules shall contain standards at “least equal to or more restrictive 

than those adopted by the director.” EPA approved this provision into the Arizona SIP on 

November 5, 2012. 77 FR 66398. 

In addition, ARS 49-422(A) (“Powers and Duties”) authorizes ADEQ to require sources of air 

contaminants to “monitor, sample or perform other studies to quantify emissions of air 

contaminants or levels of air pollution that may reasonably be attributable to that source” for 

purposes of determining whether the source is in violation of a control requirement or permit 

condition, among other things. ARS 49-476.01 contains similar authorities for Pima, Maricopa, 

and Pinal counties. These provisions were approved into the Arizona SIP on November 5, 2012. 

77 FR 66398. 

Finally, ARS 49-460 through 49-463 broadly authorize ADEQ to request compliance-related 

information from sources, to issue orders of abatement upon reasonable cause to believe a source 

has violated or is violating an air pollution control requirement, to establish injunctive relief, to 

establish civil penalties of up to $10,000 per day per violation, and to conduct criminal 

enforcement, as appropriate through the Attorney General. ARS 49-510 through 49-513 contain 

similar authorities for Pima, Maricopa, and Pinal counties. EPA approved these provisions into 

the Arizona SIP on November 5, 2012. 77 FR 66398. We note that these State and local 

enforcement authorities in the Arizona SIP have no effect on EPA’s independent authorities 

under sections 113 and 114 of the Act. 

2. Prevention of Significant Deterioration (PSD) permit program 

i. Regulation of Greenhouse Gases (GHGs) 

The entire State of Arizona is subject to the Federal PSD program in 40 CFR 52.21 for purposes 

of regulating the construction and modification of stationary sources of GHGs. Thus, although 
9 

the Arizona SIP remains deficient with respect to PSD requirements for GHG emission sources, 

this deficiency is adequately addressed by the incorporation of the Federal PSD program 

regulations into the SIP for this purpose. 40 CFR 52.144 and 52.37. 

ii. Regulation of ozone precursors

Both the MCAQD and the PDEQ currently implement the Federal PSD program in 40 CFR 

52.21 for all regulated NSR pollutants pursuant to delegation agreements. Thus, all PSD 

deficiencies are adequately addressed by the incorporation of the Federal PSD program 

regulations into both agencies’ respective portions of the Arizona SIP. 40 CFR 52.144. 

As discussed above, on March 18, 2015, EPA generally proposed a limited approval and limited 

disapproval of ADEQ’s PSD Program as part of its proposed action on ADEQ’s NSR 

Submittals. ADEQ’s submitted PSD program covers all regulated NSR pollutants except GHGs, 

as noted above. 80 FR 14044. ADEQ’s PSD program also identifies NOx as an ozone precursor. 

Thus, if our proposed limited approval and limited disapproval of ADEQ’s PSD program in the 

Arizona NSR Proposed Rule is finalized, that action will correct a previous deficiency 

concerning regulation of ozone precursors that was identified by EPA in our 2012 infrastructure 

SIP action. 77 FR 66398. We are proposing to approve Arizona’s Infrastructure SIP for areas 

under ADEQ jurisdiction with respect to regulation of ozone precursors on this basis, provided 

that our action on Arizona’s NSR Submittals is finalized consistent with this analysis with 

respect to the scope of the PSD program regulating ozone precursors. 

As part of its Arizona NSR Submittals, ADEQ clarified that they also have jurisdiction over 

Pinal County’s PSD program for all regulated NSR pollutants except GHGs.15 ADEQ has 

delegated implementation of the major source program to the Pinal County Air Quality Control 

District. 80 FR 14044, 14045. Accordingly, we are also proposing to approve Arizona’s 

Infrastructure SIP as to Pinal County with respect to regulation of ozone precursors, again 

provided that our action on Arizona’s NSR Submittals is finalized consistent with this analysis 

with respect to the scope of the program regulating ozone precursors. 

As noted previously, in our Arizona NSR Proposed Rule, EPA generally proposed a limited 

approval and limited disapproval of ADEQ’s NSR Submittals, including the PSD portion of 

those submittals, based on a number of specific deficiencies EPA identified with the programs as 

compared with specific statutory and regulatory requirements for NSR SIP submittals. This 

proposed approval of ADEQ’s Infrastructure SIP with respect to regulation of ozone precursors 

under ADEQ’s PSD program evaluates basic structural components of the Arizona SIP, and is 

not intended to, nor should it be construed to, evaluate or address whether ADEQ’s PSD 

program meets specific statutory and regulatory requirements for SIP-approved NSR programs 

or to modify in any respect EPA’s proposed determinations or action in the Arizona NSR 

Proposed Rule. 

 

15 See email from Steve Burr, Arizona Department of Environmental Quality, to Rory Mays, EPA Planning Office, 

April 21, 2014; see also EPA’s proposed rulemaking on Arizona’s NSR Submittals at 80 FR 14044, March 18, 

2015. 
10 

iii. Regulation of PM2.5 (including condensable PM) and its precursors 

Both the MCAQD and the PDEQ currently implement the Federal PSD program in 40 CFR 

52.21 for all regulated NSR pollutants pursuant to delegation agreements. Thus, all PSD 

deficiencies are adequately addressed by the incorporation of the Federal PSD program 

regulations into both agencies’ respective portions of the Arizona SIP. 40 CFR 52.144. 

As discussed above, on March 18, 2015, EPA generally proposed a limited approval and limited 

disapproval of ADEQ’s PSD Program as part of its proposed action on ADEQ’s NSR 

Submittals. ADEQ’s submitted PSD program covers all regulated NSR pollutants16 except 

GHGs. 80 FR 14044 (March 18, 2015). ADEQ’s submitted PSD program identifies PM2.5 and 

its precursors (NOx and SO2) as regulated NSR pollutants. We are proposing to approve 

Arizona’s Infrastructure SIP for areas under ADEQ jurisdiction with respect to regulation of 

PM2.5 (including condensable PM) and its precursors on this basis, provided that our proposed 

action on Arizona’s NSR submittals is finalized consistent with this analysis with respect to the 

scope of the PSD program regulating PM2.5 (including condensable PM) and its precursors. As 

part of its Arizona NSR Submittals, ADEQ clarified that they also have jurisdiction over Pinal 

County’s PSD program for all regulated NSR pollutants except GHGs. ADEQ has delegated 

implementation of the major source program to the Pinal County Air Quality Control District. 80 

CFR 14044, 14045. Accordingly, we are also proposing to approve Arizona’s Infrastructure SIP 

as to Pinal County with respect to regulation of PM2.5 (including condensable PM) and its 

precursors, again provided that our action on Arizona’s NSR Submittals is finalized consistent 

with this analysis with respect to the scope of the program regulating PM2.5 (including 

condensable PM) and its precursors. 

We reiterate that in our Arizona NSR Proposed Rule, EPA generally proposed a limited approval 

and limited disapproval of ADEQ’s NSR Submittals, including the PSD portion of those 

submittals, based on a number of specific deficiencies EPA identified with the programs as 

compared with specific statutory and regulatory requirements for NSR SIP submittals. This 

proposed approval of ADEQ’s Infrastructure SIP with respect to the regulation of PM2.5 

(including condensable PM) and its precursors under ADEQ’s PSD program evaluates basic 

structural components of the Arizona SIP, and is not intended to, nor should it be construed to, 

evaluate or address whether ADEQ’s PSD program meets specific statutory and regulatory 

requirements for SIP-approved NSR programs or to modify in any respect EPA’s proposed 

determinations or action in the Arizona NSR Proposed Rule. 

3. Minor New Source Review 

As discussed above, on March 18, 2015, EPA generally proposed a limited approval/limited 

disapproval of ADEQ’s minor NSR program as part of its proposed action on ADEQ’s NSR 

Submittals. Based on EPA’s proposed limited approval and limited disapproval of ADEQ’s 

minor NSR program, EPA proposes to find that ADEQ’s submitted minor NSR program is 

 

16 We note that ADEQ’s submitted PSD program also covers PM10 as a regulated NSR pollutant. 
11 

adequate to address the minor NSR component of an infrastructure SIP. . We note that the 

substantive portion of ADEQ’s minor NSR program rules are primarily contained in R18-2-

302.01 “Source Registration Requirements” and R18-2-334 “Minor New Source Review.” These 

and other and other administrative rules included in the minor NSR portion of the SIP submittal 

satisfy most of the statutory and regulatory requirements for minor NSR programs and 

substantially strengthen the SIP overall. 80 FR 14044, 14047-14048. 

Pima County’s SIP-approved minor NSR rules are contained in Pima County rules 171, 202, 

231, and 341. See 47 FR 16328 (April 16, 1982) and 53 FR 30220 (August 10, 1988). Maricopa 

County’s SIP-approved minor NSR rules are contained in Maricopa County Regulation 2, rules 

20 and 220, and in Regulation 1, Rule 3. See 37 FR 15081 (July 27, 1972), 57 FR 354 (January 

6, 1992), and 47 FR 15579 (April 12, 1982). Finally, Pinal County’s SIP-approved minor NSR 

rules are contained in Pinal County rules 3-1-040, 1-3-140, 3-1-060.2.d, and 3-1-070.A.1. See 

65 FR 79742 (December 20, 2000) and 67 FR 68764 (November 13, 2002). The State and EPA 

have relied on these approved minor NSR program to assure that new and modified sources not 

captured by the major NSR permitting programs do not interfere with attainment and 

maintenance of the NAAQS. 

In this action, EPA is proposing to approve Arizona’s 2011 Pb I-SIP and 2012 Ozone I-SIPs with 

respect to the general requirement in section 110(a)(2)(C) that Arizona’s SIP include a program 

that regulates the modification and construction of stationary sources. With respect to ADEQ 

specifically, this proposed approval may be finalized on this basis provided that we take final 

action to approve the minor NSR portion of Arizona’s NSR Submittals into the Arizona SIP, 

which may be in the form of a limited approval/limited disapproval as proposed in the Arizona 

NSR Proposed Rule. 

We note that for purposes of this I-SIP action, EPA is not closely reviewing, or proposing to 

approve or disapprove, the State and county minor NSR programs based on an analysis of 

whether they fully satisfy EPA’s regulations governing SIP-approved minor NSR programs. In 

addition, the counties may have minor NSR provisions that are contrary to current EPA 

regulations for this program. We note that because the three county (Pima, Pinal, and Maricopa) 

minor NSR programs were approved into the Arizona SIP many years ago, they contain outdated 

provisions and appear to have been superseded by new or revised regulations in some respects. 

We strongly encourage all three county permitting agencies to submit current permitting 

regulations to replace these outdated minor NSR SIP provisions as soon as possible. 

With respect to ADEQ, EPA has identified a number of specific deficiencies with respect to 

ADEQ’s minor NSR program as compared with Clean Air Act requirements for SIP-approved 

minor NSR programs, which are described in EPA’s proposed limited approval/limited 

disapproval action on ADEQ’s NSR SIP Submittals, where EPA generally proposed a limited 

approval and limited disapproval of ADEQ’s minor NSR SIP submittal on this basis. This 

proposed approval of ADEQ’s Infrastructure SIP with respect to the minor NSR program 

addresses whether ADEQ has a basic program in the SIP to regulate the construction and 

modification of stationary sources, and is not intended to, nor should it be construed to, evaluate 

or address whether ADEQ’s PSD program meets specific statutory and regulatory requirements 
12 

for SIP-approved NSR programs or to modify in any respect EPA’s proposed determinations or 

action in the Arizona NSR Proposed Rule. 

Conclusion as to 110(a)(2)(C) 

With respect to the requirement in section 110(a)(2)(C) to include a program to provide for the 

enforcement of control measures, EPA is proposing to approve the 2011 Pb I-SIP and 2012 

Ozone I-SIP based on our conclusion that the State’s general enforcement authorities provide an 

adequate infrastructure for SIP enforcement statewide. 

With respect to the requirement in section 110(a)(2)(C) to include a program to provide for 

regulation of the modification and construction of stationary sources, including a PSD program 

under part C of title I, EPA is proposing to: (1) disapprove the 2011 Pb and 2012 Ozone I-SIPs 

for ADEQ and Pinal County because the SIP-approved PSD programs lack the “structural” PSD 

program elements identified above, and (2) disapprove the 2011 Pb and 2012 Ozone I-SIPs for 

Maricopa and Pima counties, which do not have SIP-approved PSD programs. We note that 

although the SIP remains deficient with respect to PSD requirements for ADEQ, Pinal, 

Maricopa, and Pima counties, no further action is necessary for these purposes because the 

Federal PSD program at 40 CFR 52.21 addresses the deficiencies in all four areas. 

CAA Section 110(a)(2)(D) – Interstate transport 

Section 110(a)(2)(D) of the Act requires that each SIP “contain adequate provisions— 

(i) prohibiting, consistent with the provisions of this title, any source or other type of emissions 

activity within the State from emitting any air pollutant in amounts which will—(I) contribute 

significantly to nonattainment in, or interfere with maintenance by, any other State with respect 

to any such national primary or secondary ambient air quality standard, or (II) interfere with 

measures required to be included in the applicable implementation plan for any other State under 

part C to prevent significant deterioration of air quality or to protect visibility, and 

(ii) insuring compliance with the applicable requirements of sections 126 and 115 (relating to 

interstate and international pollution abatement).”

Section 126(a) of the Act requires notification to affected, nearby states of major proposed new 

or modified sources. Sections 126(b) and (c) pertain to petitions by affected states to EPA 

regarding sources violating the “interstate transport” provisions of CAA section 110(a)(2)(i). 

Section 115 of the Act similarly pertains to international transport of air pollution. 

CAA § 110(a)(2)(D)(i) 

With respect to the first two “prongs” of CAA section 110(a)(D)(i) (regarding significant 

contribution to nonattainment or interference with maintenance in any other State), EPA 

previously approved Arizona’s interstate transport SIP as satisfying the requirements of CAA 

section 110(a)(2)(D)(i)(I) for the 1997 8-hour ozone and 1997 PM2.5 NAAQS. 72 FR 41629 

(July 31, 2007). EPA intends to propose action on the I-SIP for the 2008 ozone NAAQS with 
13 

respect to these first two “prongs” of CAA section 110(a)(D)(i) in a separate rulemaking, and to 

take final action on these SIP elements no later than June 7, 2016. See Consent Decree entered 

April 22, 2015 in Sierra Club v. EPA, Case No. 4:14-cv-3198-YGR (N. Dist. CA). 

For purposes of the 2008 Pb NAAQS, the 2011 Pb I-SIP includes Arizona’s evaluation of the 

first two “prongs” of CAA section 110(a)(D)(i) (regarding significant contribution to 

nonattainment or interference with maintenance in any other State). EPA’s 2011 Pb I-SIP 

Guidance states that while it is possible for a source within a state to emit quantities of Pb in a 

location and in quantities that may contribute significantly to nonattainment in, or interfere with 

maintenance by, another state, it would only occur where large sources are in close proximity to 

state boundaries (i.e. within a few miles of another state).17 Arizona’s 2011 Pb I-SIP submittal 

states that the two largest emitters of Pb in Arizona are the ASARCO and Freeport McMoRan 

copper smelters in Hayden and Miami, Arizona, respectively, and that these sources are hundreds 

of miles from any state boundaries. Id. EPA also reviewed the 2011 National Emissions 

Inventory for the State of Arizona and verified that there are no sources emitting Pb in amounts 

greater than 0.5 tpy that are in close proximity to the state’s borders. As a result, Arizona’s 2011 

Pb I-SIP submittal provides a reasonable basis to conclude that sources in Arizona that emit Pb 

do not contribute significantly to nonattainment, or interfere with maintenance, of the 2008 Pb 

NAAQS in any other state. Therefore, we propose to find that Arizona meets the requirements of 

CAA section 110(a)(2)(D)(i)(I) for the 2008 Pb NAAQS. 

With respect to the third “prong” of CAA section 110(a)(D)(i) (regarding interference with 

measures required to be included in the applicable implementation plan for any other State to 

prevent significant deterioration of air quality), EPA’s evaluation of the Arizona SIP for 

purposes of the 2008 8-hour ozone and 2008 Pb NAAQS is contained in our evaluation of PSD 

SIP requirements under CAA section 110(a)(2)(C), above. 

Finally, with respect to the fourth prong of CAA section 110(a)(2)(D)(i), EPA believes that Pb 

emissions will contribute only negligibly to visibility impairment in Class I areas. 2011 I-SIP 

Guidance at 9. In its 2011 Pb I-SIP submittal, Arizona asserted that there are no Class I areas in 

close enough proximity to be affected by Pb emissions from the Hayden and Miami copper 

smelters. 2011 Pb I-SIP submittal at 11. EPA believes this statement, along with our analysis of 

the 2011 National Emissions Inventory, are a reasonable basis for concluding that Arizona meets 

the requirements of prong four of 110(a)(2)(D)(i) for the 2008 Pb NAAQS. 

For the 2008 ozone NAAQS, EPA intends to propose action on prong four of CAA section 

110(a)(D)(i) in a separate rulemaking, and to take final action no later than June 7, 2016. See 

Consent Decree entered April 22, 2015 in Sierra Club v. EPA, Case No. 4:14-cv-3198-YGR (N. 

Dist. CA). 

 

17 See Arizona’s 2011 Pb I-SIP submittal at 10; see also Guidance on Infrastructure State Implementation Plan (SIP) 

Elements Required Under Sections 110(a)(1) and 110(a)(2) for the 2008 Lead NAAQS, October 14, 2011 (2011 Pb 

I-SIP Guidance) at 8. 
14 

CAA § 110(a)(2)(D)(ii) 

With respect to the requirement in CAA section 110(a)(2)(D)(ii) regarding compliance with the 

applicable requirements of section 126 relating to interstate pollution abatement, we note that the 

requirements of section 126(b) and (c), which pertain to petitions by affected states to EPA 

regarding sources violating the “interstate transport” provisions of CAA section 110(a)(2)(D)(i), 

do not apply to our action because there are no such pending petitions relating to Arizona. We 

thus evaluate the 2011 Pb and 2012 ozone I-SIPs for purposes of compliance with only section 

126(a). 

EPA is proposing to partially approve and partially disapprove the 2011 Pb and 2012 ozone ISIPs for purposes of meeting the requirements of CAA section 126(a) regarding notification to 

affected, nearby states of major proposed new or modified sources. Specifically, ADEQ’s SIPapproved PSD rules at section R18-2-402 require the permitting agency to send a copy of the 

required public notice to the Administrator and to “the officials and agencies having cognizance 

over the location where the proposed major source or major alteration would occur.” R18-2-402, 

section I. EPA has proposed to approve R18-2-402 “General” into the Arizona SIP as part of its 

March 18, 2015 action on Arizona’s NSR Submittals. 80 FR 14044. These requirements for 

notice to nearby states are consistent with EPA’s requirements for PSD programs in 40 CFR 

51.166(q)(2)(iv). As noted in the PSD portion of our analysis on the requirements of 

110(a)(2)(C), ADEQ has recently clarified that it has authority over Pinal County’s PSD program 

and we therefore propose to find that both ADEQ and Pinal County meet the requirements of 

126(a) to provide notification to affected, nearby states of major proposed new or modified 

sources. 

Maricopa County and Pima County do not have SIP-approved PSD programs. Thus, the Arizona 

SIP remains deficient with respect to the PSD requirements in part C, title I of the Act and with 

respect to the requirement in CAA section 126(a) regarding notification to affected, nearby states 

of major proposed new or modified sources in these two areas. These deficiencies are, however, 

adequately addressed with respect to all regulated NSR pollutants in both areas by the Federal 

PSD program in 40 CFR 52.21 and no further action is required. 

For these reasons, we propose to partially approve and partially disapprove the 2011 Pb I-SIP 

and 2012 ozone I-SIP with respect to the requirement in CAA section 110(a)(2)(D)(ii) regarding 

compliance with the applicable requirements of sections 126 relating to interstate pollution 

abatement. 

CAA section 115 authorizes the Administrator to require a state to revise its SIP, in the case of a 

belief or allegation that any air pollutant emitted in the United States causes or contributes to air 

pollution which may reasonably be anticipated to endanger public health or welfare in a foreign 

country. Because there are no such pending actions pursuant to CAA section 115, EPA has no 

reason to approve or disapprove any existing state rules with regard to CAA section 115. 
15 

Conclusion as to 110(a)(2)(D) 

With respect to the first two “prongs” of CAA section 110(a)(D)(i) (regarding significant 

contribution to nonattainment or interference with maintenance in any other State), we are 

proposing approval for the 2008 Pb NAAQS for the reasons stated above. We are not proposing 

any action today on the first two prongs for the 2008 Ozone NAAQS. With respect to the third 

prong, EPA is proposing to disapprove the 2011 Pb and 2012 ozone I-SIPs for the reasons 

discussed above regarding PSD requirements under section 110(a)(2)(C). With respect to the 

fourth prong, EPA is proposing approval for the 2008 Pb NAAQS. EPA is not proposing any 

action on prong four today for the 2008 ozone NAAQS and will address this requirement in a 

subsequent rulemaking. Finally, with respect to the requirements of CAA section 

110(a)(2)(D)(ii), EPA is proposing to approve the 2011 Pb and 2012 ozone I-SIPs with respect to 

ADEQ and Pinal County, which both implement SIP-approved PSD programs that contain the 

required notice provisions, but to disapprove the SIP with respect to Maricopa County and Pima 

County, which are subject to the Federal PSD program in 40 CFR 52.21. 

CAA Section 110(a)(2)(J) – Consultation with government officials; public notification; and 

PSD and visibility protection 

CAA section 110(a)(2)(J) requires SIPs to “meet the applicable requirements of section 121 

(relating to consultation), section 127 (relating to public notification), and part C (relating to 

prevention of significant deterioration of air quality and visibility protection).” 

CAA section 121 requires SIPs, in carrying out the requirements under the CAA requiring SIPs 

to contain any transportation controls, air quality maintenance plan requirements or 

preconstruction review of direct sources of air pollution, or any measure referred to in part D or 

part C of title I,18 to provide a process of consultation with general purpose local governments, 

designated organizations of elected official of local governments and any Federal land manager 

having authority over Federal land to which the State plan applies. Such process shall be in 

accordance with regulations promulgated by EPA. 

CAA section 127 requires SIPs to contain measures to effectively notify the public during any 

calendar year on a regular basis of instances or areas in which any NAAQS is exceeded or was 

exceeded during any portion of the preceding calendar year, to advise the public of the health 

hazards associated with such pollution, and to enhance public awareness of the measures which 

can be taken to prevent such standards from being exceeded and the ways in which the public 

can participate in regulatory and other efforts to improve air quality. Such measures may include 

the posting of warning signs on interstate highway access points to metropolitan areas or 

television, radio, or press notices or information.

For a discussion of the CAA title I, part C requirements, see our evaluation of section 

110(a)(2)(C) above. 

 

18 Section 121 was added by the CAA Amendments of 1977, and it also refers to section 113(d) (relating to certain 

enforcement orders), but section 113(d) was significantly amended by the CAA Amendments of 1990, and as so 

amended, no longer relates to state enforcement orders. 
16 

Related EPA Regulations 

EPA’s regulations concerning public notification are set forth in set forth in subpart O 

(“Miscellaneous Plan Content Requirements”) of 40 CFR part 51, section 51.285 (“Public 

notification”). 

ADEQ’s response to this requirement 

Consultation 

 “Arizona agencies maintain appropriate consultation procedures with local 

governments, CAA Section 174 and metropolitan planning agencies, and federal 

land managers regarding implementation of CAA requirements. ARS §49-406 

requires the State, the metropolitan planning agency on behalf of affected local 

governments, county agencies, and the Department of Transportation to enter into 

a memorandum of agreement for the purpose of coordinating the development, 

implementation, and enforcement of nonattainment and maintenance plans. 

Additionally, opportunity for comment is provided through stakeholder meetings 

and public hearings held to solicit testimony from the public as well as federal 

and local air quality planning agencies prior to adoption of any revision to the 

Arizona SIP.” 

Public Notification 

“ADEQ and those counties with authority to implement portions of the SIP (Maricopa, 

Pinal, and Pima counties) certify to do now and will continue to notify the public on a 

regular basis of instances or areas in which any primary NAAQS was exceeded, 

consistent with the requirements of sections 110(a)(2)(J) and 127 of the Federal Clean 

Air Act.” 

PSD and Visibility Protection 

In ADEQ’s 2011 Pb I-SIP Arizona expressed a commitment to adopt and submit a SIP 

revision to update Arizona’s New Source Review/Prevention of Significant Deterioration 

program to fully meet the requirements of CAA section 110(a)(2)(C) for the 2008 Pb 

NAAQS. ADEQ provided the same commitment to update Arizona’s New Source 

Review/Prevention of Significant Deterioration program in its 2012 Ozone I-SIP 

Submittal. 

EPA Evaluation 

Consultation 
17 

The Arizona SIP contains many authorities that address the Clean Air Act requirements of 

section 121. 

Under 49-104.A.2., the department shall “[s]timulate and encourage all local, state, regional and 

federal governmental agencies and all private persons and enterprises that have similar and 

related objectives and purposes, cooperate with those agencies, persons and enterprises and 

correlate department plans, programs and operations with those of the agencies, persons and 

enterprises.” The department shall also “provide information and advice on request of any local, 

state or federal agencies” on matters within the scope of the department. ARS 49-104.A.4. 

Under ARS 49-104.B.3. the department, through the director, shall “utilize any medium of 

communication, publication and exhibition when disseminating information, advertising and 

publicity in any field of its purposes, objectives or duties.” Under ARS 49-104.B.5. the 

department shall “Contract with other agencies, including laboratories, in furthering any 

department program.” 

For transportation plans under 121(1), ARS 49-402.F. states that “[e]ach regional planning 

agency shall consult with the department of transportation to coordinate the plans developed 

pursuant to subsection E of this section with transportation plans developed by the department of 

transportation pursuant to any other law.” 

ARS § 49-406.E requires the State, the planning agency on behalf of affected local governments, 

the county air pollution control department or district, and the Department of Transportation to 

enter into a memorandum of agreement for the purpose of coordinating the development, 

implementation, and enforcement of nonattainment and maintenance plans. 49-406(F) cites to 

minimum information that the memorandum must contain, including the responsibilities and 

authorities of each organization, assurances for adequate plan implementation, and procedures 

and responsibilities for adoption of control measures and emissions limitations. 

More broadly, ARS 49-424.3 requires the department to establish substantive policy statements 

for identifying air quality exceptional events. These substantive policy statements “shall be 

developed with the planning agency certified pursuant to section 49-406, subsection A and the 

county air pollution control department or district.” The department shall also determine the 

standards for the quality of the ambient air and the limits of air contaminants necessary to protect 

the public health “and develop and transmit to the county boards of supervisors minimum state 

standards for air pollution control.” ARS 49-424.4. The department is required to hold hearings 

relating to any matter within their duties and consult with “persons or affected groups or other 

states to achieve the purposes of this chapter, including voluntary testing of actual or suspected 

sources of air pollution.” The department shall also “[e]ncourage political subdivisions of the 

state to handle air pollution problems within their respective jurisdictions, and provide as it 

deems necessary technical and consultative assistance therefor.” See ARS 49-424. 
18 

At the county level, under ARS 49-474 the board of supervisors of each county may authorize 

the board of health or health department of their respective counties in cooperation with the 

department of environmental quality to: “1. Study the problem of air pollution in the county; 2. 

Study possible effects on adjoining counties; 3. Cooperate with chambers of commerce, industry, 

agriculture, public officials and all other interested persons or organizations; 4. Hold public 

hearings if in their discretion such action is necessary; 5. The board of supervisors by resolution 

may establish an air pollution control district.” 

Public Notification 

As stated in its 2012 ozone I-SIP submittal, ADEQ certifies that it does now and will continue to 

notify the public on a regular basis of instances of areas in which any primary NAAQS is 

exceeded, consistent with the requirements of sections 110(a)(2)(J) and 127 of the Federal Clean 

Air Act. As noted by ADEQ: “Such notifications are and will be available on the state and 

county air quality websites, which are updated daily to identify exceedances of the NAAQS that 

occurred during the previous day or any portion of the preceding calendar year. We commit to 

continue, through these websites, to advise the public of the health hazards associated with such 

exceedances and to increase public awareness of: (1) measures which can be taken to prevent a 

primary standard from being exceeded, and (2) ways in which the public can participate in 

regulatory and other efforts to improve air quality.” 2012 Ozone I-SIP submittal at 25. 

Links to state and county websites that provide current air data and previous NAAQS 

exceedances, as well as other educational information, are available at: 

http://www.azdeq.gov/environ/air/. 

PSD and Visibility Protection 

With respect to the requirement in section 110(a)(2)(J) to meet the applicable requirements of 

part C of title I relating to prevention of significant deterioration of air quality and visibility, 

EPA’s evaluation of the Arizona SIP for purposes of the 2008 8-hour ozone and 2008 Pb 

NAAQS is contained in our evaluation of PSD SIP requirements under CAA section 

110(a)(2)(C), above. With regard to the applicable requirements for visibility protection, EPA 

recognizes that states are subject to visibility and regional haze program requirements under part 

C of the Act, but these program requirements do not change upon establishment of a new or 

revised NAAQS. Thus, there are no applicable visibility requirements under section 110(a)(2)(J) 

when a new or revised NAAQS becomes effective. 

Conclusion as to CAA 110(a)(2)(J)

Based on our review of the 2011 Pb and 2012 ozone I-SIP submittals and for the reasons given 

above, we propose to find that Arizona meets the requirements of sections 121 and 127 of the 

Clean Air Act but to disapprove it for failure to fully satisfy the requirements of part C relating to

PSD. 
19 

CAA Section 110(a)(2)(K) – Air quality modeling and submission of modeling 

data 

Section 110(a)(2)(K) requires SIPs to “provide for—(i) the performance of such air quality 

modeling as the Administrator may prescribe for the purpose of predicting the effect on ambient 

air quality of any emissions of any air pollutant for which the Administrator has established a 

national ambient air quality standard, and (ii) the submission, upon request, of data related to 

such air quality modeling to the Administrator.” 

To meet section 110(a)(2)(K), EPA recommends that, at a minimum, states identify the statutory 

or regulatory provisions that provide state and local air agencies with the authority to perform the 

following actions, along with a narrative explanation of how the provisions meet the 

requirements to (1) conduct air quality modeling to predict the effect on ambient air quality of 

any emissions of any air pollutant for which a NAAQS has been promulgated, and (2) provide 

such modeling data to the EPA Administrator upon request.19

Arizona’s response to this requirement: 

The 2012 ozone I-SIP states that Arizona retains authority to perform air quality modeling 

for predicting the effect of emissions on ambient air quality and that, “[w]here applicable, all 

modeling analyses for demonstrating attainment and maintenance of the NAAQS meet 

EPA’s most recent guidance on air quality models.” The 2012 ozone I-SIP also states that 

“[a]ll information and data are made available to EPA as required.” 

EPA Analysis: 

Arizona Department of Environmental Quality regulations 

The provisions addressing air quality models in ADEQ’s SIP-approved PSD program do not 

satisfy EPA’s current requirements for air quality modeling under CAA section 110(a)(2)(K). 

EPA’s 2013 I-SIP Guidance recommends that, at a minimum, states and counties identify the 

statutory or regulatory provisions that provide air agencies with the authority to (1) conduct air 

quality modeling to predict the effect on ambient air quality of any air pollutant for which a 

NAAQS has been promulgated, and (2) provide such modeling data to the EPA upon request. 

Arizona’s 2011 Pb and 2012 ozone I-SIPs contain a conclusory statement that ADEQ meets the 

requirements of CAA section 110(a)(2)(K). The submittals then identify broad authority in the 

Arizona Revised Statutes, but do not explain how this broad authority meets the requirements of 

CAA section 110(a)(2)(K). Arizona also pointed to its NSR submittals and stated that these 

would bring the state into compliance with the modeling requirements of 110(a)(2)(K) and 40 

CFR Part 51, subpart I. Arizona’s 2011 Pb and 2012 ozone I-SIPs do not provide information 

adequate to demonstrate that with respect to ADEQ, the Arizona SIP provides for (i) the 

performance of such air quality modeling as the Administrator may prescribe for the purpose of 

 

19 2013 Infrastructure SIP Guidance, p. 55. 
20 

predicting the effect on ambient air quality of any emissions of any air pollutant for which the 

Administrator has established a national ambient air quality standard, and (ii) the submission, 

upon request, of data related to such air quality modeling to the Administrator. 

We also note that while the requirements for modeling in the I-SIP context are not as detailed or 

comprehensive as they are in the context of a review for consistency with specific NSR 

requirements, EPA did find certain deficiencies under Part 51 with ADEQ’s modeling 

regulations in the context of EPA’s proposed limited approval/limited disapproval action on 

Arizona’s NSR Submittals.20 

ADEQ should provide a narrative explaining how existing Arizona statutes and regulations give 

ADEQ the requisite authority under 110(a)(2)(K) to address this deficiency in the I-SIP context. 

For the reasons stated above, we propose to disapprove the 2011 Pb and 2012 ozone I-SIPs for 

section 110(a)(2)(K) in areas under ADEQ jurisdiction. 

Maricopa County regulations 

EPA’s 2013 I-SIP Guidance recommends that, at a minimum, states and counties should identify 

the statutory or regulatory provisions that provide air agencies with the authority to (1) conduct 

air quality modeling to predict the effect on ambient air quality of any air pollutant for which a 

NAAQS has been promulgated, and (2) provide such modeling data to the EPA upon request. 

The 2011 Pb and 2012 ozone I-SIPs contain a conclusory statement that Arizona and its 

respective counties meet the requirements of CAA section 110(a)(2)(K). The submittals identify 

broad authority in the Arizona Revised Statutes, but do not explain how this broad authority 

meets the requirements of CAA section 110(a)(2)(K). Arizona’s 2011 Pb and 2012 ozone I-SIPs 

do not provide information adequate to demonstrate that with respect to Maricopa County, the 

Arizona SIP provides for (i) the performance of such air quality modeling as the Administrator 

may prescribe for the purpose of predicting the effect on ambient air quality of any emissions of 

any air pollutant for which the Administrator has established a national ambient air quality 

standard, and (ii) the submission, upon request, of data related to such air quality modeling to the 

Administrator. 

Maricopa County should provide a narrative explaining how existing statutes and regulations 

provide the requisite authority under 110(a)(2)(K) to address this deficiency in the I-SIP context. 

For the reasons stated above, we propose to disapprove the 2011 Pb and 2012 ozone I-SIPs for 

section 110(a)(2)(K) in Maricopa County. 

While we are proposing to disapprove the 2011 Pb and 2012 ozone I-SIPs for Maricopa County, 

we note that it currently implements the Federal PSD program in 40 CFR 52.21 for all regulated 

NSR pollutants (as defined in 40 CFR 52.21(b)(50)), pursuant to a delegation agreement 

executed in 1993. See 40 CFR 52.144; see also 59 FR 1730 (January 12, 1994) and “Agreement 

for Delegation of Authority of the Regulations for Prevention of Significant Deterioration of Air 

Quality (40 CFR 52.21) Between U.S. EPA and MC,” executed November 22, 1993. 

 

20 80 FR 14044 (March 18, 2015). 
21 

Accordingly, although the Maricopa County portion of the Arizona SIP remains deficient with 

respect to the PSD requirements of part C, title I of the Act, including the requirements related to 

air quality models under CAA section 110(a)(2)(K), these deficiencies are adequately addressed 

by the Federal PSD program. 

Pima County regulations 

EPA’s 2013 I-SIP Guidance recommends that, at a minimum, states and counties should identify 

the statutory or regulatory provisions that provide air agencies with the authority to (1) conduct 

air quality modeling to predict the effect on ambient air quality of any air pollutant for which a 

NAAQS has been promulgated, and (2) provide such modeling data to the EPA upon request. 

The 2011 Pb and 2012 ozone I-SIPs contain a conclusory statement that Arizona and its 

respective counties meet the requirements of 110(a)(2)(K). The submittals identify broad 

authority in the Arizona Revised Statutes, but do not explain how this broad authority meets the 

requirements of CAA section 110(a)(2)(K). Arizona’s 2011 Pb and 2012 ozone I-SIPs do not 

provide information adequate to demonstrate that with respect to Pima County, the Arizona SIP 

provides for (i) the performance of such air quality modeling as the Administrator may prescribe 

for the purpose of predicting the effect on ambient air quality of any emissions of any air 

pollutant for which the Administrator has established a national ambient air quality standard, and 

(ii) the submission, upon request, of data related to such air quality modeling to the 

Administrator. 

Pima County should provide a narrative explaining how existing statutes and regulations provide 

the requisite authority under 110(a)(2)(K) to address this deficiency in the I-SIP context. For the 

reasons stated above, we propose to disapprove the 2011 Pb and 2012 ozone I-SIPs for section 

110(a)(2)(K) in Pima County. 

While we are proposing to disapprove the 2011 Pb and 2012 ozone I-SIPs for Pima County, we 

note that it currently implements the Federal PSD program in 40 CFR 52.21 for all regulated 

NSR pollutants (as defined in 40 CFR 52.21(b)(50)), pursuant to a delegation agreement 

executed in 1994. See 40 CFR 52.144; see also “Agreement for Delegation of Authority of the 

Regulations for Prevention of Significant Deterioration of Air Quality (40 CFR 52.21) Between 

U.S. EPA and Pima County Air Quality Control District,” executed April 14, 1994. 

Accordingly, although the Pima County portion of the Arizona SIP remains deficient with 

respect to the PSD requirements of part C, title I of the Act, including the requirements related to 

air quality models under CAA section 110(a)(2)(K), these deficiencies are adequately addressed 

by the Federal PSD program. 

Pinal County regulations 

EPA’s 2013 I-SIP Guidance recommends that, at a minimum, states and counties should identify 

the statutory or regulatory provisions that provide air agencies with the authority to (1) conduct 

air quality modeling to predict the effect on ambient air quality of any air pollutant for which a 

NAAQS has been promulgated, and (2) provide such modeling data to the EPA upon request. 

The 2011 Pb and 2012 ozone I-SIPs contain a conclusory statement that Arizona and the 
22 

respective counties meet the requirements of CAA section 110(a)(2)(K). The submittals then 

identify broad authority in the Arizona Revised Statutes, but do not explain how this broad 

authority meets the requirements of CAA section 110(a)(2)(K). Arizona’s 2011 Pb and 2012 

ozone I-SIPs do not provide information adequate to demonstrate that with respect to Pinal 

County, the Arizona SIP provides for (i) the performance of such air quality modeling as the 

Administrator may prescribe for the purpose of predicting the effect on ambient air quality of 

any emissions of any air pollutant for which the Administrator has established a national ambient 

air quality standard, and (ii) the submission, upon request, of data related to such air quality 

modeling to the Administrator. 

Arizona should provide a narrative explaining how existing Arizona statutes and regulations give 

Pinal County the requisite authority under 110(a)(2)(K) to address this deficiency in the I-SIP 

context. For the reasons stated above, we propose to disapprove the 2011 Pb and 2012 ozone ISIPs for section 110(a)(2)(K) in Pinal County. 

 

Conclusion as to CAA 110(a)(2)(K) 

Based on our review of the 2011 Pb and 2012 ozone I-SIPs and the applicable Arizona SIP, and 

for the reasons given above, we propose to conclude that the Arizona SIP does not meet the 

requirements of CAA section 110(a)(2)(K) for the 2008 8-hour ozone NAAQS and the 2008 Pb 

NAAQS. We therefore propose to disapprove the 2011 Pb and 2012 ozone I-SIPs with respect to 

the requirements of CAA section 110(a)(2)(K). If finalized, this disapproval would not create 

any new FIP clocks as EPA previously disapproved ADEQ’s and Pinal County’s I-SIPs for CAA 

section 110(a)(2)(K).21 For sources under the jurisdiction of Maricopa and Pima counties, the 

Federal PSD program in 40 CFR 52.21 addresses this deficiency and therefore no further action 

is necessary. 

 

21 See 77 FR 66398 (November 5, 2012).