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Proposed Rule

Air Plan Approval; Indiana; Infrastructure SIP Requirements for the 2012 PM2.5

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Start Preamble


Environmental Protection Agency (EPA).


Proposed rule.


The Environmental Protection Agency (EPA) is proposing to approve elements of a State Implementation Plan (SIP) submission from Indiana regarding the infrastructure requirements of section 110 of the Clean Air Act (CAA) for the 2012 annual fine particulate matter (PM2.5) National Ambient Air Quality Standard (NAAQS or standard). The infrastructure requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibilities under the CAA. This action pertains specifically to infrastructure requirements concerning interstate transport provisions.


Comments must be received on or before August 29, 2019.


Submit your comments, identified by Docket ID No. EPA-R05-OAR-2016-0343 at, or via email to For comments submitted at, follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from For either manner of submission, EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. EPA will generally not consider comments or comment contents located outside of the primary submission (i.e. on the web, cloud, or other file sharing system). For additional submission methods, please contact the person identified in the For Further Information Contact section. For the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit​dockets/​commenting-epa-dockets.

Start Further Info


Samantha Panock, Environmental Scientist, Attainment Planning and Maintenance Section, Air Programs Branch (AR-18J), Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604, (312) 353-8973,

End Further Info End Preamble Start Supplemental Information


Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA. This supplementary information section is arranged as follows:

I. What is the background of this SIP submission?

II. What guidance/memoranda is EPA using to evaluate this SIP submission?

III. Indiana's Analysis and Conclusion

IV. EPA's Additional Analysis, Review, and Conclusion

V. What action is EPA taking?

VI. Statutory and Executive Order Reviews

I. What is the background of this SIP submission?

This rulemaking addresses a submission from the Indiana Department of Environmental Management (IDEM) dated June 10, 2016, supplemented on December 28, 2016, which relates to its requirements for an infrastructure SIP for the 2012 annual PM2.5 NAAQS (78 FR 3086). Specifically, this rulemaking concerns the portion of the submission dealing with interstate pollution transport under CAA section 110(a)(2)(D)(i), otherwise known as the “good neighbor” provision. The requirement for states to make a SIP submission of this type arises from section 110(a)(1) of the CAA. Pursuant to section 110(a)(1), states must submit “within 3 years (or such shorter period as the Administrator may prescribe) after the promulgation of a national primary ambient air quality standard (or any revision thereof),” a plan that provides for the “implementation, maintenance, and enforcement” of such NAAQS. The statute directly imposes on states the duty to make these SIP submissions, and the requirement to make the submissions is not conditioned upon EPA's taking any action other than promulgating a new or revised NAAQS. Section 110(a)(2) includes a list of specific elements that “[e]ach such plan” submission must address. EPA commonly refers to such state plans as “infrastructure SIPs.”

State plans must address four requirements of the good neighbor provisions (commonly referred to as “prongs”), including:

Prong one: Prohibiting any source or other type of emissions activity in one state from contributing significantly to nonattainment of the NAAQS in another state;

Prong two: Prohibiting any source or other type of emissions activity in one state from interfering with maintenance of the NAAQS in another state;

Prong three: Prohibiting any source or other type of emissions activity in Start Printed Page 36849one state from interfering with measures required to prevent significant deterioration (PSD) of air quality in another state; and

Prong four: Protecting visibility in another state.

In this rulemaking, EPA is evaluating whether Indiana's interstate transport provisions in its PM2.5 infrastructure SIP meet prongs one and two of the good neighbor requirements of the CAA. Prongs three and four will be evaluated in a separate rulemaking.

EPA has developed a consistent framework for addressing the prong one and prong two interstate transport requirements with respect to the PM2.5 NAAQS in several previous Federal rulemakings. The four basic steps of that framework are: (1) Identifying downwind receptors that are expected to have problems attaining or maintaining the NAAQS; (2) identifying which upwind states contribute to these identified problems in amounts sufficient to warrant further review and analysis; (3) for states identified as contributing to downwind air quality problems, identifying upwind emissions reductions necessary to prevent an upwind state from significantly contributing to nonattainment or interfering with maintenance of the NAAQS downwind; and (4) for states that are found to have emissions that significantly contribute to nonattainment or interfere with maintenance of the NAAQS downwind, reducing the identified upwind emissions through adoption of permanent and enforceable measures. With respect to PM2.5, this framework was applied in the August 8, 2011 Cross-State Air Pollution Rule (CSAPR) (76 FR 48208), designed to address both the 1997 and 2006 PM2.5 standards, as well as the 1997 and 2008 ozone standards.

II. What guidance/memoranda is EPA using to evaluate this SIP submission?

EPA highlighted the statutory requirement to submit infrastructure SIPs within three years of promulgation of a new NAAQS in an October 2, 2007, guidance document entitled “Guidance on SIP Elements Required Under Sections 110(a)(1) and (2) for the 1997 8-hour Ozone and PM2.5 National Ambient Air Quality Standards” (2007 Guidance). EPA has issued additional guidance, including a September 13, 2013, document titled “Guidance on Infrastructure State Implementation Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2)” (2013 Guidance).

The most recent relevant document is an EPA memorandum issued on March 17, 2016, titled “Information on the Interstate Transport “Good Neighbor” Provision for the 2012 Fine Particulate Matter National Ambient Air Quality Standards under Clean Air Act Section 110(a)(2)(D)(i)(I)” (2016 memorandum). The 2016 memorandum describes EPA's consistent approach over the years to address interstate transport and provides EPA's general review of relevant modeling data and air quality projections as they relate to the 2012 annual PM2.5 NAAQS.

The 2016 memorandum provides states and EPA regional offices with future year annual PM2.5 design values for monitors in the United States based on quality assured and certified ambient monitoring data and air quality modeling. The 2016 memorandum further describes how these projected potential design values can be used to help determine which monitors should be further evaluated to potentially address whether emissions from other states significantly contribute to nonattainment or interfere with maintenance of the 2012 annual PM2.5 NAAQS at those sites. Where a potential receptor is projected to show nonattainment or maintenance in 2017, but projected to show attainment in 2025, the 2016 memorandum suggests that additional analysis of the emissions and modeling may be needed to make a further judgement regarding the receptor status in 2021 (the attainment deadline for moderate PM2.5 areas).

The 2016 memorandum indicates that, for all but one monitoring site in the eastern United States with complete and valid PM2.5 design values from 2009 to 2013, the modeling data shows that monitors were expected to both attain and maintain the 2012 annual PM2.5 NAAQS in both 2017 and 2025. The modeling results provided in the 2016 memorandum show that out of seven PM2.5 monitors located in Allegheny County, Pennsylvania, one monitor is expected to be above the 2012 annual PM2.5 NAAQS in 2017. That monitor, the Liberty monitor (ID number 420030064), is projected to be above the NAAQS only under the model's maximum projected conditions (used in EPA's interstate transport framework to identify maintenance receptors) and is projected to both attain and maintain the NAAQS (along with all Allegheny County monitors) in 2025. The 2016 memorandum therefore indicates that, under such a condition, further analysis of the site should be performed to determine if the site contains nonattainment or maintenance receptor in 2021 (the attainment deadline for moderate PM2.5 areas). Since the Allegheny County, Pennsylvania, receptor is the only location considered downwind of Indiana, this Indiana submission focuses on that single receptor.

However, the 2016 memorandum also indicates that for five states (portions of Florida, Illinois, Idaho (outside of Shoshone County), Tennessee, and Kentucky) with incomplete ambient monitoring data, additional information, including the latest available data, should be analyzed to determine whether there are potential downwind air quality problems that may be impacted by transported emissions. With the exception of Florida, the data quality problems have subsequently been resolved for these areas, and they now have design values below the 2012 annual PM2.5 NAAQS. In addition, these areas are expected to maintain the NAAQS due to downward emission trends for nitrogen oxides (NOx) and sulfur dioxide (SO2). With respect to Florida, in the CSAPR modeling analysis for the 1997 PM2.5 NAAQS, Florida did not have any potential nonattainment or maintenance receptors identified for the 1997 or 2006 PM2.5 NAAQS. Due to the ambient monitoring data gaps in the 2009-2013 data, modeling was not performed to eliminate the potential for any PM2.5 nonattainment and maintenance receptors. It is anticipated, however, that due to the downward trend in emissions, Florida's receptor status has not changed. Therefore, Indiana does not need to perform further analysis for these areas listed above.

Indiana did not focus on potential contribution to other areas EPA identified as not attaining the 2012 annual PM2.5 NAAQS based on current monitor data in Alaska, California, Idaho, Nevada, or Hawaii or the 18 potential PM2.5 nonattainment or maintenance receptors, based on modeling projections from the 2016 memorandum, in the western United States. The distance between Indiana and these areas, coupled with the prevailing wind directions, leads EPA to propose that Indiana will not contribute significantly to any of the potential receptors in those states.

Indiana's submittal indicates that it used data from the 2016 memorandum and supplied its own additional information in its analysis. EPA considered the analysis from Indiana, as well as additional analysis conducted by EPA, in its review of the Indiana submittal.

III. Indiana's Analysis and Conclusion

Indiana's submittal contains a technical analysis of its interstate transport of pollution relative to the Start Printed Page 368502012 annual PM2.5 NAAQS. As reflected in the 2016 memorandum, the only receptor identified as nonattainment or maintenance on which Indiana might have an impact is the Liberty monitor (42-003-0064) in Allegheny County, Pennsylvania located in southwest Pennsylvania. In this technical analysis, Indiana examined meteorological conditions, backward trajectories, PM2.5 measurements, and source emissions within the southwest Pennsylvania airshed. As stated previously, Indiana's technical analysis considers CSAPR rule implementation and EPA guidance and memoranda. Since the Allegheny County, Pennsylvania receptor is the only location considered downwind of Indiana, this submission focuses on that single receptor. Indiana concluded that it has no significant impacts on the attainment and maintenance of the PM2.5 NAAQS in Allegheny County, Pennsylvania. Indiana satisfies the responsibilities under CAA section 110(a)(2)(D)(i)(I) based on these analyses presented in the Indiana submission:

—IDEM selected daily PM2.5 concentrations at the Liberty monitor that exceed the 2006 PM2.5 24-hour NAAQS of 35 μg/m3 (micrograms per cubic meter) for the years 2012 to 2015 for analysis. There were 26 days in this period that exceeded the standard. IDEM analyzed hourly PM2.5 concentrations from these 26 days to determine if there was a temporal pattern in elevated concentrations during these days. Based on the data collected and presented in the Indiana submittal, a clear pattern of high PM2.5 concentrations during the morning and occasional evening hours is evident at this monitor. In examining the hourly data for these 26 days, IDEM found the following: Of 283 hours of PM2.5 concentrations measured greater than 35 μg/m3, 68% occurred before 9 a.m.; of 91 hours of PM2.5 concentrations measured greater than 70 μg/m3, 78% of those hours occurred before 9 a.m.; of 29 hours of PM2.5 concentrations measured greater than 100 μg/m3, 90% occurred before 9 a.m. Moreover, the high PM2.5 concentrations seen in the morning and evening hours during colder months at the Liberty monitor led IDEM to investigate and ultimately determine that temperature inversions did occur during the days that high PM2.5 concentrations were measured. Temperature inversions occur when warmer air is present above a cooler layer of air at the ground level.

—Wind and pollution roses were analyzed for the 26 exceedance days and showed that high hourly PM2.5 values occurred with southernly and westerly winds. Several facilities that emit large quantities of PM2.5 and precursor emissions of NOX and SO2 were identified by IDEM and found to be located within four kilometers to the south and west of the Liberty monitor. Indiana presented maps of these locations in the submittal. More specifically, using available information on the Allegheny County Health Department website, IDEM determined that two large U.S. Steel facilities are located to the south and west of the monitor as well as two large NOX and SO2 emitting facilities also to the south.

—Back trajectory analyses conducted by Indiana determined that ambient air arriving at the Liberty monitor on high pollution days rarely traveled over Indiana. A back trajectory analysis using National Oceanic and Atmospheric Administration's HYSPLIT model was performed to evaluate Indiana's contribution to PM2.5 in Allegheny County, Pennsylvania. In total, 35,040 trajectories were run for 100, 500, and 1000 meters above ground level (AGL). Back trajectories were run starting at each hour of the day, every day, over a 4-year period from 2012 through 2015. The trajectories started in the center of Allegheny County and were run backwards over a 24-hour period. Meteorological data used in this analysis consisted of the North American Regional Reanalysis (NARR) dataset. In total, 31 values on 26 days from 2012-2015 at the Liberty monitor were identified as exceeding the 24-hour PM2.5 NAAQS. Moreover, individual exceedance days and their associated trajectories were also examined by Indiana. This analysis shows that at 100 meters AGL, which is closest to the level of the monitor recording the sample value, air arriving in Allegheny County passes through Indiana very infrequently. For air arriving at higher levels above the monitor, at 500 and 1000 meters, air flow has southerly and southwesterly flow. Of the 16,200 trajectory points associated with exceedances at the 100-meter level, only 49 points, or 0.03% passed through Indiana. At the 500-meter level, 617 out of the 16,200 points (3.8%) passed through Indiana. This analysis shows that Indiana does not contribute significantly to Allegheny County PM2.5 concentrations, and Indiana concludes that a corridor of probable transport exists elsewhere.

Indiana has concluded that that no further measures are necessary to satisfy its responsibilities under CAA section 110(a)(2)(D)(i)(I), because it does not contribute to projected nonattainment or maintenance issues at the Liberty monitor site. Instead, IDEM found that local meteorological conditions in the Allegheny county, temperature inversion, ambient air traveling from westerly and southernly winds, and air pollution transport from the Appalachian Mountain Range are more likely contributing to projected nonattainment or maintenance issues at the site.

IV. EPA's Additional Analysis, Review, and Conclusion

The modeling information contained in EPA's 2016 memorandum shows that one monitor in Allegheny County, Pennsylvania (the Liberty monitor, 420030064) may have a maintenance issue in 2017, but that the area is projected to both attain and maintain the NAAQS by 2025. A linear interpolation of the modeled design values to 2021 shows that the monitor is likely to demonstrate both attainment and maintenance of the standard by 2021. Emissions and air quality data trends help to corroborate this interpolation.

Over the last decade, local and regional emissions reductions of PM2.5, SO2, and NOX, have led to large reductions in annual PM2.5 design values in Allegheny County, Pennsylvania. In 2007, all of Allegheny County's PM2.5 monitors exceeded the level of the 2012 annual PM2.5 NAAQS (the 2005-2007 annual average design values ranged from 12.9-19.8 µg/m3, as shown in Table 1). The 2015-2017 annual average PM2.5 design values now show that only one monitor (Liberty, at 13.0 µg/m3) exceeds the annual PM2.5 NAAQS of 12.0 µg/m3.

Table 1—PM2.5 Annual Design Values in µg/m3

Avalon* 16.3* 14.713.411.410.610.6* 10.4* 10.2
South Fayette12.9* 11.811.711.* 8.5* 8.4
North Park* 13.0* 12.3* 11.3** 8.2* 8.2
Start Printed Page 36851
Harrison15.014.213.713.012.4* 11.710.610.
North Braddock16.215.214.313.312.712.5* 11.711.411.211.010.8
Parkway East Near-Road* 10.6* 10.6
Clairton15.314.313.212.4* 11.5* 10.9** 9.8* 9.8
* Value does not contain a complete year worth of data.

The Liberty monitor is already close to showing attainment of the NAAQS and expected emissions reductions in the next three years will lead to additional reductions in measured PM2.5 concentrations. There are both local and regional components to the measured PM2.5 levels in Allegheny County and the greater Pittsburgh area. Previous CSAPR modeling showed that regional emissions from upwind states, particularly SO2 and NOX emissions, contribute to PM2.5 nonattainment at the Liberty monitor. In recent years, large SO2 and NOX reductions from power plants have occurred in Pennsylvania and states upwind from the Greater Pittsburgh region. Based on existing CSAPR budgets, Pennsylvania's energy sector emissions of SO2 will have decreased 166,000 tons between 2015-2017 as a result of CSAPR implementation. This is due to both the installation of emissions controls and retirements of electric generating units (EGUs).

Between 2011 and 2016, 27.4 gigawatts of coal-fired EGUs have retired in Pennsylvania and the closest upwind states (West Virginia, Ohio, Kentucky, Indiana, Illinois, and Michigan) according to the Energy Information Administration's Preliminary Monthly Electric Generator Inventory, April 2017 (form EIA-860M, at​electricity/​data/​eia860m/​xls/​april_​generator2017.xlsx). In addition, between 2017 and 2021, an additional 8.8 gigawatts of coal-fired EGUs are expected to retire in the same upwind states. This includes large EGUs such as JM Stuart in Ohio (2,308 megawatts [MW]), Killen Station in Ohio (600 MW), WH Sammis in Ohio (720 MW), Michigan City in Indiana (469 MW), Will County in Illinois (510 MW), Baldwin Energy Complex in Illinois (576 MW), Paradise in Kentucky (1,230 MW), and Baily in Indiana (480 MW). These regional coal unit retirements will lead to further emissions reductions which will help ensure that Alleghany County monitors will not have nonattainment or maintenance issues by 2021.

In addition to regional emissions reductions and plant closures noted above, local reductions in both PM2.5 and SO2 emissions are also expected to occur and should also contribute to further declines at Allegheny County's PM2.5 monitor concentrations. For example, significant SO2 reductions will occur at U.S. Steel's integrated steel mill facilities in southern Allegheny County due to reductions required via federally enforceable permits issued by Allegheny County to support its attainment plan submitted to meet requirements in CAA section 172(c) for the 1-hour SO2 NAAQS. Reductions occurred in October 2018 largely due to declining sulfur content in the Clairton Coke Work's coke oven gas (COG) due to upgraded controls. Because this COG is burned at U.S. Steel's Clairton Coke Works, Irvin Mill, and Edgar Thompson Steel Mill, these reductions in sulfur content contribute to much lower PM2.5 formation from precursors in the immediate future after October 4, 2018 as SO2 is a precursor to PM2.5. Additionally, the expected retirement of the Bruce Mansfield Power Plant by June 2021 should reduce precursor emissions from neighboring Beaver County, PA. The Allegheny County and Beaver County SO2 SIP submissions, which EPA is currently reviewing pursuant to CAA requirements, also discuss expected lower SO2 emissions in the Allegheny County area resulting from reduced sulfur content requirements in vehicle fuels, reductions in general emissions due to declining population in the Greater Pittsburgh region, and several shutdowns of significant emitters of SO2 in Allegheny County.

Projected power plant closures and additional emissions controls in Pennsylvania and upwind states will help further reduce both PM2.5 and PM2.5 precursors. Regional emission reductions will continue to occur from current on-the-books Federal and state regulations such as the Federal on-road and non-road vehicle programs and various rules for major stationary emissions sources.

EPA modeling projections, the recent downward trend in local and upwind emissions reductions, the expected continued downward trend in emissions between 2018 and 2021, and the downward trend in monitored PM2.5 concentrations all indicate that the Liberty monitor will be able to show attainment and maintenance of m the 2012 annual PM2.5 NAAQS by 2021.

The conclusions of Indiana's analysis are consistent with EPA's expanded review of its submittal. The area (Allegheny County, Pennsylvania) that Indiana sources potentially contribute to is expected to attain and maintain the 2012 annual PM2.5 NAAQS, and as demonstrated in its submittal, Indiana will not contribute to projected nonattainment or maintenance issues at any sites in 2021. Indiana's analysis shows that, through permanent and enforceable measures currently contained in its SIP and other emissions reductions occurring in other states, monitored PM2.5 air quality in the identified area will continue to improve, and that no further measures are necessary to satisfy Indiana's responsibilities under CAA section 110(a)(2)(D)(i)(I). Therefore, EPA is proposing that prongs one and two of the interstate pollution transport element of Indiana's infrastructure SIP are approvable.

V. What action is EPA taking?

EPA is proposing to approve a portion of Indiana's June 10, 2016 submittal, supplemented on December 28, 2016, certifying that the current Indiana SIP is sufficient to meet the required transport elements of the infrastructure SIP requirements under CAA section 110(a)(2)(D)(i)(I), specifically prongs one and two, as set forth above.

VI. 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, EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this 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 action:Start Printed Page 36852

  • 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 (Pub. L. 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 application of those requirements would be inconsistent with the CAA; and
  • Does not provide 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 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).

Start List of Subjects

List of Subjects in 40 CFR Part 52

  • Environmental protection
  • Air pollution control
  • Incorporation by reference
  • Intergovernmental relations
  • Particulate matter
  • Reporting and recordkeeping requirements
End List of Subjects Start Signature

Dated: July 17, 2019.

Cathy Stepp,

Regional Administrator, Region 5.

End Signature End Supplemental Information

[FR Doc. 2019-16076 Filed 7-29-19; 8:45 am]