2020-19207. Air Plan Approval; Idaho: Infrastructure Requirements for the 2015 Ozone Standard

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

Whenever the Environmental Protection Agency (EPA) promulgates a new or revised National Ambient Air Quality Standard (NAAQS), the Clean Air Act requires each State to make a State Implementation Plan (SIP) submission to establish that its SIP provides for the implementation, maintenance, and enforcement of the revised NAAQS. This type of SIP submission is commonly referred to as an infrastructure SIP submission. The EPA is approving the State of Idaho's September 27, 2018, SIP submission as meeting applicable infrastructure requirements for the 2015 ozone NAAQS.

DATES:

The final rule is effective October 16, 2020.

ADDRESSES:

The EPA has established a docket for this action under Docket ID No. EPA-R10-OAR-2018-0766. All documents in the docket are listed on the https://www.regulations.gov website. Although listed in the index, some information is not publicly available, e.g., CBI or other information the disclosure of which is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and is publicly available only in hard copy form. Publicly available docket materials are available at https://www.regulations.gov,, or please contact the person identified in the FOR FURTHER INFORMATION CONTACT section for additional availability information.

FOR FURTHER INFORMATION CONTACT:

Matthew Jentgen at [phone], or [e-mail].

SUPPLEMENTARY INFORMATION:

Throughout this document wherever “we,” “us,” or “our” is used, it is intended to refer to the EPA.

I. Background Information

On April 9, 2019, the EPA proposed to approve Idaho's September 27, 2018, SIP submission as meeting certain infrastructure requirements of the Clean Air Act (CAA) for the 2015 ozone NAAQS (84 FR 14067). The initial public comment period for this proposed action ended on May 9, 2019. Due to an administrative error, the EPA omitted certain documents relevant to the proposed action from the docket during the initial comment period, open from April 9, 2019 to May 9, 2019. The EPA corrected the administrative error and on May 28, 2019, we provided an additional 30 days for public comment on the proposed action (84 FR 24420). The public comment period ended on June 27, 2019. The EPA received adverse comments on the proposal.

II. Response to Comments

The EPA received adverse comments during the initial comment period related to our administrative docket error that left out documents relevant to the proposed action. The EPA addressed these comments by including the relevant documents in the docket and providing an additional 30-day comment period. The EPA received one comment during the second comment period. We have summarized and responded to the remaining adverse comments below. The full text of the submitted comments may be found in the docket for this action.

Comment—Ozone NAAQS Violations

Summary - The Idaho Conservation League (ICL) asserted that monitoring data indicates Idaho's efforts to prevent a violation of the 2015 ozone NAAQS are ineffective. ICL further asserted that the EPA's approval of the 2015 ozone infrastructure SIP submission should be contingent upon the State's “creation and implementation of new management strategies to address ozone in Idaho.”

Specifically, ICL pointed to Idaho's infrastructure SIP submission, at appendix B, Table B-1, indicating the 2015-2017 design value for ozone measured at the Boise—White Pine air monitoring station was 0.070 parts per million (ppm), equal to the 2015 ozone NAAQS. Moreover, ICL stated that in more recent years the monitor has shown exceedances and that the 2016-2018 design value is likely to violate the 2015 ozone NAAQS. ICL concluded that the laws, rules, and regulations referenced by Idaho in its 2015 ozone infrastructure SIP submission do not appear adequate. Thus, the commenter advocated that the EPA's approval of this SIP submission should be contingent upon Idaho's creation and implementation of new emissions management strategies to address ozone in Idaho.

Response—The EPA agrees that that the monitor data identified by the commenter indicates that there may be violations of the 2015 ozone NAAQS at this monitor, but disagrees that this is an issue that the State should address in the context of an infrastructure SIP submission. We have reviewed monitoring data at the Boise—White Pine Elementary monitor (Site ID: 160010017) and the design value for the most recent three-year period (2016-2018) is 0.072 ppm, which is over the 2015 ozone NAAQS of 0.070 ppm. At this point in time, all areas of Idaho are designated attainment for the 2015 ozone NAAQS. The EPA designated the entire State of Idaho as attainment/unclassifiable for the 2015 ozone NAAQS, based on 2013-2015 design value data (82 FR 54232, at page 54243). Each of the three monitors in Idaho that rely on Federal Reference Method (FRM) ozone monitoring data (Boise-White Pine, Meridian-St Luke's, and Craters of the Moon) had 2013-2015 design values below the 0.070 ppm ozone NAAQS. If there are now violations of the 2015 ozone NAAQS at any monitors, then either Idaho or the EPA may need to consider the need for a redesignation under section 107(d)(3), or other proactive actions to address the ambient ozone concentrations in the area.

The existence of possible violations of the NAAQS does not, however, directly affect Idaho's September 27, 2018, infrastructure SIP submission. As stated in the proposal, the EPA's longstanding position is that infrastructure SIP submissions are intended to address basic SIP requirements to implement, maintain, and enforce a NAAQS in general, and are not intended to address nonattainment plan requirements for individual areas of a state that may be violating the NAAQS.^[1] Infrastructure SIPs are due within three years of adoption or revision of a particular NAAQS, according to CAA sections 110(a)(1) and (2). The separate nonattainment plan SIP submissions to address the emission limits and other control measures needed to attain a particular NAAQS in an area designated nonattainment are due on a separate schedule, pursuant to CAA section 172 and the various pollutant-specific subparts 2 through 5 of part D.^[2]

Comment—Adequacy of Idaho's ozone monitoring network

Summary— ICL stated that the EPA's approval of Idaho's SIP is inconsistent with EPA's previous comments regarding Idaho's ambient air monitoring network and compliance with CAA 110(a)(2)(B).

Specifically, for the Idaho Falls metropolitan statistical area (MSA), ICL cited the EPA's November 8, 2017, Air Monitoring Network Plan approval letter that noted monitoring network deficiencies, including a lack of a state and local air monitoring station (SLAMS) for ozone in Idaho Falls. Additionally, ICL stated that, pursuant to 40 CFR part 58, appendix D, Table D-2, cities with a population size greater than 50,000 with 3-year average ozone concentrations exceeding 85 percent of the NAAQS are required to have, at a minimum, one ozone monitor. ICL asserted that Idaho Falls meets this criterion.

ICL also referenced 40 CFR part 58, appendix D, Table D-2 and asserted that the Pocatello MSA, with a population of 54,441 and 3-year average ozone concentrations exceeding 85 percent of the NAAQS, is required to have, at a minimum, one ozone monitor. ICL also stated that Pocatello particularly needs a dedicated ozone monitor because the EPA's Environmental Justice Screening and Mapping tool, EJSCREEN, shows that the city of Pocatello is in the 90th percentile for ozone concentrations relative to the rest of the State.

ICL also cited the EPA's November 8, 2017, Air Monitoring Network Plan approval letter that noted a lack of ozone monitoring in the Logan, UT-ID MSA. ICL also noted that another developing metropolitan area in Idaho, Twin Falls (population: 47,468), needs an ozone monitor based on the criteria in 40 CFR part 58, appendix D, Table D-2.

Response— The EPA disagrees that there are current deficiencies in the ozone monitoring network in Idaho that require disapproval of the State's infrastructure SIP submission for the 2015 ozone NAAQS. First, in the context of an infrastructure SIP submission, the EPA interprets CAA section 110(a)(2)(B) to require states to have SIP provisions that provide for the establishment and operation of ambient air quality monitors, collecting and analyzing ambient air quality data, and making these data available to the EPA upon request. In our proposed action, we stated that Idaho has a comprehensive air quality monitoring network plan, originally approved by the EPA into the Idaho SIP on July 28, 1982 (40 CFR 52.670). We also determined that the plan includes statutory and regulatory authority to establish and operate an air quality monitoring network, including ozone monitoring (84 FR 14067, April 9, 2019, at page 14068). The EPA recently approved Idaho's comprehensive monitoring network plan, further discussed in this document, on January 16, 2020. In practice, Idaho operates an ozone monitoring network, compiles and analyzes collected data, and submits the data to the EPA's Air Quality System on a quarterly basis.

Second, in the context of infrastructure SIP submissions, the EPA considers whether the State has met the monitoring requirements for the NAAQS at issue. With respect to monitor siting, Idaho regularly assesses the adequacy of the State monitoring network for each NAAQS pollutant and submits that assessment to the EPA for review (“Annual Network Plan”). The Annual Network Plan provides details of the State's air quality monitor system and evaluates whether the State's ambient air quality monitoring network is achieving its monitoring objectives, along with a discussion of any needed modifications. The commenter pointed to specific ozone monitoring network issues identified by the EPA in its November 2017 Annual Network Plan response letter. We will explain further in this document how the State has recently addressed each of the issues identified by the EPA concerning the adequacy of the State's ozone monitoring network and cited in ICL's comments on the proposed rulemaking. As a result, the EPA concludes here that the State has satisfactorily addressed the issues that the agency identified in the November 8, 2017, letter and do not present a basis for a finding that Idaho's SIP does not meet the requirements of CAA 110(a)(2)(B). These recent updates to Idaho's monitoring network system are described as follows:

The commenter expressed concerns about the potential need for additional ozone monitors in various locations in Idaho. With respect to the commenter's concerns about ozone monitoring in Idaho Falls, the EPA likewise disagrees that this is necessary at this time. In the 2019 Annual Network Plan response letter, included in this docket, the EPA granted a waiver of the requirement to install a State and Local Air Monitoring Stations (SLAMS) ozone monitor in Idaho Falls through the end of 2023. The EPA and Idaho will review the available eastern Idaho ozone monitoring data for calendar years 2020 and 2021 to re-assess the potential need to establish an ozone monitoring station in this MSA in 2023.

With respect to ozone monitoring in Pocatello, the EPA notes that the State has already addressed this concern. In Idaho's 2019 Annual Network Plan, Idaho DEQ acknowledged, based on recent modeling, the need to install an ozone monitor in Pocatello, ID. In accordance with appendix D to 40 CFR part 58, Idaho has since installed a monitor in that location.^[3] The EPA notes that while the commenter cited information derived from the agency's EJSCREEN tool that combines environmental and demographic indicators for a particular area, the fact that Pocatello is in the 90th percentile for ozone concentrations relative to the rest of the State, that statistical comparison is not a monitor siting criteria under 40 CFR part 58, appendix D.^[4] The relevant factors for ozone monitor siting are population size and estimated ambient level relative to the ozone NAAQS (greater than or equal to 85 percent of the ozone NAAQS), see 40 CFR part 58, appendix D, Table D-2.

With respect to the commenter's concerns about monitoring in the Logan, UT-ID area, the EPA disagrees with the commenter concerning the need for an ozone monitor at this point in time. Idaho recently requested, and the EPA approved in a letter dated May 12, 2020, an agreement, consistent with 40 CFR. part 58, appendix D, Section 2(e), to waive the requirement to locate an ozone monitor in the Idaho portion of the Logan, UT-ID MSA. This May 12, 2020, letter is included in the docket for this action. Idaho demonstrated that monitoring by the State of Utah currently meets the monitoring requirements for the Logan, UT-ID MSA. This waiver is effective for five years (CY-2020 through CY-2024) and is supported by modeling that demonstrates the location of maximum ozone concentrations is expected to be in Cache County, Utah and not in Franklin County, Idaho. Accordingly, the EPA agreed that additional monitoring performed by Idaho Department of Environmental Quality (DEQ) in Franklin County would not be necessary at this time to ensure the adequacy of the Logan UT-ID MSA ozone monitoring network.

Finally, with respect to the commenter's concerns about monitoring in Twin Falls, Idaho, the EPA disagrees with the need for such a monitor for purposes of the 2015 ozone NAAQS at this time. The ozone design criteria for state and local air monitors, 40 CFR part 58, appendix D, Section 4.1, directs states to operate ozone monitoring sites for various locations depending upon area size (in terms of population and geographic characteristics) and typical peak concentrations. The MSAs that meet these criteria are discussed above. Contrary to the commenter's assertions, Idaho is not required to locate an additional monitor in the Twin Falls area because its population does not exceed 50,000.

Based on the resolution of the monitoring issues identified by the commenter as described above, the EPA concludes that Idaho has met the infrastructure SIP monitoring requirement of CAA section 110(a)(2)(B) for the 2015 ozone NAAQS, and is finalizing the proposed approval with respect to this requirement.

Comment—Idaho's SO₂ monitoring network and data

Summary— An anonymous commenter stated that EPA guidance requires that Idaho must have a fully approved monitoring network for all pollutants for the EPA to approve the monitoring network requirements in section 110(a)(2)(B). In particular, the commenter asserted that sulfur dioxide (SO₂) monitors in the State are not sited correctly, and until monitor siting issues are addressed, the EPA should not approve the Idaho infrastructure SIP submission for the 2015 ozone NAAQS for purposes of CAA section 110(a)(2)(F). The commenter cited EPA statements related to SO₂ NAAQS designations in which the agency indicated that it did not have sufficient information to determine whether existing monitors were located in an area of maximum concentration around specific SO₂ sources. The commenter stated it was for this reason the EPA could not designate the entire State as attainment for the SO₂ NAAQS. The commenter further asserted that by designating the State as “unclassifiable/attainment” for the SO₂ NAAQS, the EPA had determined that Idaho does not have an adequate SO₂ monitoring network.

Response—The EPA disagrees with the commenter's interpretation of the EPA's 2013 Guidance as it pertains to monitoring network requirements. The EPA's Guidance does not interpret CAA section 110(a)(2)(B) to require consideration of the adequacy of an SO₂ NAAQS monitoring network in the context of evaluating the State's infrastructure SIP submission for the ozone NAAQS.

When the EPA promulgates a new or revised NAAQS, it triggers the requirement for each state to submit an infrastructure SIP submission that addresses basic SIP requirements for the implementation, maintenance, and enforcement of such standard. The infrastructure SIP submission must meet the requirements of CAA section 110(a)(1) and (2), as applicable. The ozone NAAQS was revised on October 1, 2015, thus triggering the requirement for Idaho to submit an infrastructure SIP with respect to the 2015 ozone NAAQS, including addressing the monitoring requirement of CAA section 110(a)(2)(B).

Although some infrastructure SIP elements are not NAAQS specific, e.g., CAA section 110(a)(2)(C) with respect to PSD permitting programs, many other elements are NAAQS specific. The EPA interprets CAA section 110(a)(2)(B) to be such a NAAQS specific requirement, and thus only requires states to address the relevant NAAQS in an infrastructure SIP submission, which in this action is the 2015 ozone NAAQS.^[5]

In addition, the EPA notes that it most recently revised the SO₂ NAAQS in 2010. Idaho submitted an infrastructure SIP submission for purposes of the 2010 SO₂ NAAQS, and the EPA approved the submission as meeting CAA section 110(a)(2)(B) for the 2010 SO₂ NAAQS on August 11, 2014 (79 FR 46707). Because the comments pertain to the SO₂ NAAQS, they are outside of the scope of this action, given that the EPA is not revisiting its prior approval of the Idaho SO₂ infrastructure SIP for CAA section 110(a)(2)(B).

The commenter also expressed concern that Idaho has incorrectly sited SO₂ monitors and therefore they must be corrected in order to comply with CAA section 110(a)(2)(F). CAA section 110(a)(2)(F) requires owners or operators of stationary sources to monitor emissions from such sources, provide periodic reports on the nature and amounts of emissions and emissions-related data from such sources, and correlate those reports with any emission limitations or standards established pursuant to the CAA. The CAA further requires that those reports shall be available at reasonable times for public inspection. As previously explained, however, the infrastructure SIP submission at issue in this action addresses the 2015 ozone NAAQS. As with CAA section 110(a)(2)(B), however, the EPA interprets CAA section 110(2)(F) in the context of infrastructure SIP submissions to pertain only to the NAAQS at issue in such SIP submission, i.e., in this case with respect to the 2015 ozone NAAQS. Moreover, the EPA previously approved the Idaho SIP for purposes of CAA section 110(a)(2)(F) for the 2010 SO₂ NAAQS on August 11, 2014, (79 FR 46707). The comment is, thus, outside the scope of the present action.

The EPA has considered the concerns raised by this commenter with respect to CAA section 110(a)(2)(B) and section 110(a)(2)(F), but has concluded that approval of Idaho's September 27, 2018, SIP submission is appropriate for the reasons explained above.

Comment—Adequate resources

Summary— An anonymous commenter stated that, in its proposed approval of CAA section 110(a)(2)(E), the EPA failed to evaluate adequate funding and resources necessary to carry out the functions delegated to the State and required by the State to carry out the functions of the SIP. The commenter asserts that the EPA must audit Idaho's finances and accounting to make an affirmative determination as to whether the State has the necessary funding and resources. The anonymous commenter also stated that the EPA should affirmatively determine whether Idaho actually has the necessary personnel to carry out and operate programs required under the SIP, rather than solely relying on the Idaho director's ability to hire personnel.

Response—CAA section 110(a)(2)(E)(i) requires each state to provide necessary assurances that the state will have adequate personnel, funding, and authority under state law to carry out the SIP. CAA section 110 does not mandate a specific methodology for the EPA to evaluate the adequacy of resources to implement the SIP. See 76 FR 42549 (July 19, 2011), at 42554. The commenter did not identify a specific factual basis for concerns that Idaho lacks adequate personnel, funding, and authority under State law to carry out the SIP. The EPA disagrees with the commenter's assertion that an audit of the State's finances and accounting practices is required in order to satisfy the requirements of 110(a)(2)(E)(i). The EPA's role in approving a SIP submission is to determine whether the submission addresses the necessary requirements of the Act, not to evaluate the way in which a SIP is being implemented. See Montana Envtl. Info. Ctr. v. Thomas, 902 F.3d 971, 978 (9th Cir. 2018).

In our proposed action, we identified Idaho Code 39-106 as providing the Idaho DEQ Director authority to hire personnel to carry out duties of the department. According to Idaho DEQ's Fiscal Year 2019 Performance Report, Idaho DEQ received $56 million overall to perform its core functions ($23 million from federal funds, $20 million from State funds, and $13 million from other permit and fee programs). Specifically, Idaho receives CAA sections 103 and 105 grant funds from the EPA and provides State matching funds necessary to carry out SIP requirements.

The EPA finds that Idaho has provided the necessary assurances of adequate sources of personnel, funding, and authority under State law to implement its SIP for purposes of the 2015 ozone NAAQS. Therefore, it is appropriate to finalize the proposed finding that Idaho's SIP satisfies the requirements of CAA section 110(a)(2)(E).

III. Final Action

The EPA is approving Idaho's September 27, 2018, infrastructure SIP submission as meeting specific infrastructure requirements of the CAA. We find that the Idaho SIP meets the following CAA section 110(a)(2) infrastructure elements for the 2015 ozone NAAQS: (A), (B), (C), (D)(i)(II), (D)(ii), (E), (F), (G), (H), (J), (K), (L), and (M), as applicable.

IV. Statutory and Executive Order Reviews

Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the CAA and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, the EPA's role is to approve State choices, provided that they meet the criteria of the CAA. Accordingly, this proposed action merely approves State law as meeting Federal requirements and does not impose additional requirements beyond those imposed by State law. For that reason, this proposed action:

• Is not a “significant regulatory action” subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
• Is not an Executive Order 13771 (82 FR 9339, February 2, 2017) regulatory action because SIP approvals are exempted under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Public Law 104-4);
• Does not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• Is not subject to requirements of Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because it does not involve technical standards; and
• Does not provide the EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).

In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where the EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the rule does not have tribal implications and will not impose substantial direct costs on tribal governments or preempt tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, to each House of the Congress and to the Comptroller General of the United States. The EPA will submit a report containing this action and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the United States prior to publication of the rule in the Federal Register. A major rule cannot take effect until 60 days after it is published in the Federal Register. This action is not a “major rule” as defined by 5 U.S.C. 804(2).

Under section 307(b)(1) of the Clean Air Act, petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by November 16, 2020. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this action for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed, and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. (See section 307(b)(2)).

List of Subjects in 40 CFR Part 52

• Environmental protection
• Air pollution control
• Incorporation by reference
• Intergovernmental relations
• Lead
• Nitrogen dioxide
• Ozone
• Particulate matter
• Reporting and recordkeeping requirements
• Sulfur oxides
• Volatile organic compounds

Authority: 42 U.S.C. 7401 et seq.

Dated: August 26, 2020.

Christopher Hladick,

Regional Administrator, Region 10.

For the reasons set forth in the preamble, 40 CFR part 52 is amended as follows:

PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

1. The authority citation for Part 52 continues to read as follows:

Authority: 42 U.S.C. 7401 et seq.

Subpart N—Idaho

2. In § 52.670, the table in paragraph (e) is amended by adding an entry at the end of the table for “Section 110(a)(2) Infrastructure Requirements—2015 ozone NAAQS.” to read as follows:

§ 52.670

Identification of plan.

* * * * *

(e) * * *

EPA—Approved Idaho Nonregulatory Provisions and Quasi-Regulatory Measures

Name of SIP provision	Applicable geographic or nonattainment area	State submittal date	EPA approval date	Comments
*         *         *         *         *         *         *
Section 110(a)(2) Infrastructure Requirements—2015 ozone NAAQS	State-wide	9/27/2018	9/16/2020, [Insert Federal Register citation]	Approves SIP for purposes of CAA sections 110(a)(2)(A), (B), (C), (D)(i)(II), (D)(ii), (E), (F), (G), (H), (J), (K), (L), and (M) for the 2015 ozone NAAQS.

Footnotes

1.  See 84 FR 14067, April 9, 2019, at page 14068.

2.  See 2013 infrastructure guidance: Stephen D. Page, Director, Office of Air Quality Planning and Standards. “Guidance on Infrastructure State Implementation Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2).” Memorandum to EPA Air Division Directors, Regions 1-10, September 13, 2013.

3.  DEQ expands air quality monitoring in Pocatello, Idaho Department of Environmental Quality, news release, April 28, 2020, https://www.deq.idaho.gov/​news-archives/​air-ozone-monitoring-pocatello-0420/​.

4.  EJSCREEN is an environmental justice mapping and screening tool that provides the EPA with a nationally consistent dataset and approach for combining environmental and demographic indicators. EJSCREEN users choose a geographic area; the tool then provides demographic and environmental information for that area. See https://www.epa.gov/​ejscreen/​what-ejscreen#:~:text=​EJSCREEN%20is%20an%20environmental%20justice,environmental%20information%20for%20that%20area.

5.  See 2013 infrastructure guidance: Stephen D. Page, Director, Office of Air Quality Planning and Standards. “Guidance on Infrastructure State Implementation Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2).” Memorandum to EPA Air Division Directors, Regions 1—10, September 13, 2013. Page 6.