Air Plan Approval; Indiana; Attainment Plan for the Morgan County Sulfur Dioxide Nonattainment Area, 32672-32678 [2019-14474]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 84, Number 131 (Tuesday, July 9, 2019)]
[Proposed Rules]
[Pages 32672-32678]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-14474]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R05-OAR-2015-0700; FRL-9996-34-Region 5]


Air Plan Approval; Indiana; Attainment Plan for the Morgan County 
Sulfur Dioxide Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve as a State Implementation Plan (SIP) revision the Morgan 
County-related elements of an Indiana submission to EPA dated October 
2, 2015, as supplemented on February 8, 2019. The October 2015 
submission addresses attainment of the 2010 sulfur dioxide 
(SO2) national ambient air quality standard (NAAQS) for four 
areas. The February 8, 2019 supplement provides additional modeling 
information regarding the adequacy of the plan for Morgan County. EPA 
proposes to conclude that Indiana has appropriately demonstrated that 
the plan provisions provided for attainment of the 2010 SO2 
NAAQS in the Morgan County area by the applicable attainment date and 
that the plan meets the other applicable requirements under the Clean 
Air Act.

DATES: Comments must be received on or before August 8, 2019.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2015-0700 at https://www.regulations.gov, or via email to 
[email protected]. For comments submitted at Regulations.gov, 
follow the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from Regulations.gov. 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

[[Page 32673]]

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 https://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: John Summerhays, 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) 886-6067, 
[email protected].

SUPPLEMENTARY INFORMATION: The following outline is provided to aid in 
locating information in this preamble.

Table of Contents

I. Why was Indiana required to submit an SO2 plan for 
Morgan County?
II. Requirements for SO2 Nonattainment Area Plans
III. Requirements for Attainment Demonstrations
IV. Review of Indiana's Modeled Attainment Plan for Morgan County
    A. Model Selection and General Model Inputs
    B. Meteorological Data
    C. Emissions Data
    D. Emission Limits
    E. Background Concentrations
    F. Summary of Results
V. Review of Other Plan Requirements
    A. Emissions Inventory
    B. RACM/RACT
    C. New Source Review (NSR)
    D. RFP
    E. Contingency Measures
VI. EPA's Proposed Action
VII. Incorporation by Reference
VIII. Statutory and Executive Order Reviews

I. Why was Indiana required to submit an SO2 plan for Morgan 
County?

    On June 22, 2010, EPA promulgated a new 1-hour primary 
SO2 NAAQS of 75 parts per billion (ppb), which is met at an 
ambient air quality monitoring site when the 3-year average of the 
annual 99th percentile of daily maximum 1-hour average concentrations 
does not exceed 75 ppb, as determined in accordance with appendix T of 
40 CFR part 50. See 75 FR 35520, codified at 40 CFR 50.17(a)-(b). On 
August 5, 2013, EPA designated a first set of 29 areas of the country 
as nonattainment for the 2010 SO2 NAAQS, including the 
Indianapolis (Marion County), Morgan County, Southwest Indiana (Daviess 
and Pike Counties), and Terre Haute (Vigo County) areas within Indiana. 
See 78 FR 47191, codified at 40 CFR part 81, subpart C. These area 
designations were effective October 4, 2013. Section 191(a) of the 
Clean Air Act directs states to submit SIPs for areas designated as 
nonattainment for the SO2 NAAQS to EPA within 18 months of 
the effective date of the designation, i.e., by no later than April 4, 
2015 in this case. Under Clean Air Act section 192(a), the states are 
required to demonstrate that their respective areas will attain the 
NAAQS as expeditiously as practicable, but no later than five years 
from the effective date of designation, which is October 4, 2018.
    In response to the requirement for SO2 nonattainment 
plan submittals, Indiana submitted nonattainment plans for the above 
four areas on October 2, 2015. EPA published proposed action on three 
of these areas, namely the Indianapolis, Southwest Indiana, and Terre 
Haute areas on August 15, 2018, at 83 FR 40487, and published final 
action on two of these areas (Indianapolis and Terre Haute) on March 
22, 2019, at 84 FR 10692. Today's action does not address those three 
areas, but addresses the fourth area, in Morgan County. The remainder 
of this preamble describes the requirements that SO2 
nonattainment plans must meet in order to obtain EPA approval, provides 
a review of the state's plan for Morgan County with respect to these 
requirements, and describes EPA's proposed action on the plan for 
Morgan County.
    In addition to its submittal, Indiana sent multiple supplemental 
letters addressing the Morgan County SO2 nonattainment plan. 
On November 15, 2017, Indiana provided clarifications on the derivation 
of emissions inventories and on other issues pertinent to the Morgan 
County plan as well as to the other three plans in the state's October 
2, 2015 submittal. On June 7, 2017, Indiana withdrew the control 
requirements for Hydraulic Press Brick from consideration as part of 
the Morgan County SIP. However, on February 12, 2019, Indiana 
reactivated its request for action on these control requirements. Also, 
on February 8, 2019, Indiana submitted additional technical information 
in support of a conclusion that the Morgan County plan provides for 
attainment even when analyzed with a more conservative background 
concentration.

II. Requirements for SO2 Nonattainment Area Plans

    Nonattainment SIPs must meet the applicable requirements of the 
Clean Air Act, specifically Clean Air Act sections 110, 172, 191 and 
192. EPA's regulations governing nonattainment SIPs are set forth at 40 
CFR part 51, with specific procedural requirements and control strategy 
requirements residing at subparts F and G, respectively. Soon after 
Congress enacted the 1990 Amendments to the Clean Air Act, EPA issued 
comprehensive guidance on SIPs, in a document entitled the ``General 
Preamble for the Implementation of Title I of the Clean Air Act 
Amendments of 1990,'' published at 57 FR 13498 (April 16, 1992) 
(General Preamble). Among other things, the General Preamble addressed 
SO2 SIPs and fundamental principles for SIP control 
strategies. Id., at 57 FR 13545-13549, 13567-13568. On April 23, 2014, 
EPA issued guidance for meeting the statutory requirements in 
SO2 SIPs submitted under the 2010 NAAQS, in a document 
entitled, ``Guidance for 1-Hour SO2 Nonattainment Area SIP 
Submissions,'' available at https://www.epa.gov/sites/production/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf. In this 
guidance EPA described the statutory requirements for a complete 
nonattainment area SO2 SIP, which includes: An accurate 
emissions inventory of current emissions for all sources of 
SO2 within the nonattainment area; an attainment 
demonstration; demonstration of reasonable further progress (RFP); 
implementation of reasonably available control measures (RACM) 
(including reasonably available control techniques (RACT)); new source 
review (NSR); enforceable emissions limitations and control measures; 
and adequate contingency measures for the affected area. A synopsis of 
these requirements is also provided in the notice of proposed 
rulemaking on the Illinois SO2 nonattainment plans, 
published on October 5, 2017 at 82 FR 46434.
    In order for EPA to fully approve a SIP as meeting the requirements 
of Clean Air Act sections 110, 172 and 191-192 and EPA's regulations at 
40 CFR part 51, the SIP for the affected area needs to demonstrate to 
EPA's satisfaction that each of the aforementioned requirements have 
been met. Under Clean Air Act sections 110(l) and 193, EPA may not 
approve a SIP that would interfere with any applicable requirement 
concerning NAAQS attainment and RFP, or any other applicable 
requirement, and no requirement in effect (or required to be adopted by 
an order, settlement, agreement, or plan in effect before November 15, 
1990) in any area which is a nonattainment area for any air pollutant, 
may be modified in any manner unless it ensures equivalent or

[[Page 32674]]

greater emission reductions of such air pollutant.

III. Requirements for Attainment Demonstrations

    Clean Air Act sections 172(c)(1), 172(c)(6) and 192(a) direct 
states with SO2 areas designated as nonattainment to 
demonstrate that the submitted plan provides for attainment of the 
NAAQS. 40 CFR part 51 subpart G further delineates the control strategy 
requirements that SIPs must meet, and EPA has long required that all 
SIPs and control strategies reflect four fundamental principles of 
quantification, enforceability, replicability, and accountability. 
General Preamble, at 13567-68. SO2 attainment plans must 
consist of two components: (1) Emission limits and other control 
measures that assure implementation of permanent, enforceable and 
necessary emission controls, and (2) a modeling analysis which meets 
the requirements of 40 CFR part 51, appendix W (Guideline on Air 
Quality Models) and demonstrates that these emission limits and control 
measures provide for timely attainment of the primary SO2 
NAAQS as expeditiously as practicable, but by no later than the 
attainment date for the affected area. In all cases, the emission 
limits and control measures must be accompanied by appropriate methods 
and conditions to determine compliance with the respective emission 
limits and control measures and must be quantifiable (i.e., a specific 
amount of emission reduction can be ascribed to the measures), fully 
enforceable (specifying clear, unambiguous and measurable requirements 
for which compliance can be practicably determined), replicable (the 
procedures for determining compliance are sufficiently specific and 
objective so that two independent entities applying the procedures 
would obtain the same result), and accountable (source specific limits 
must be permanent and must reflect the assumptions used in the SIP 
demonstrations).
    EPA's April 2014 guidance recommends that the emission limits be 
expressed as short-term average limits (e.g., addressing emissions 
averaged over one or three hours), but also describes the option to 
utilize emission limits with longer averaging times of up to 30 days so 
long as the state meets various suggested criteria. Indiana's plan for 
Morgan County involves mostly work practice requirements (i.e., 
requirements that the primary boilers at Indianapolis Power and Light-
Eagle Valley burn natural gas and that Hydraulic Press Brick employ 
sorbent injection generally achieving 50 percent emission control) and 
does not rely on any longer term average limits.
    Preferred air quality models for use in regulatory applications are 
described in appendix A of EPA's Guideline on Air Quality Models.\1\ In 
2005, EPA promulgated AERMOD as the Agency's preferred near-field 
dispersion modeling for a wide range of regulatory applications 
addressing stationary sources (for example in estimating SO2 
concentrations) in all types of terrain based on extensive 
developmental and performance evaluation. Supplemental guidance on 
modeling for purposes of demonstrating attainment of the SO2 
standard is provided in appendix A to the April 23, 2014 SO2 
nonattainment area SIP guidance document referenced above. Appendix A 
provides extensive guidance on the modeling domain, the source inputs, 
assorted types of meteorological data, and background concentrations. 
Consistency with the recommendations in this guidance is generally 
necessary for the attainment demonstration to offer adequately reliable 
assurance that the plan provides for attainment.
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    \1\ EPA published revisions to the Guideline on Air Quality 
Models on January 17, 2017.
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    As stated previously, attainment demonstrations for the 2010 
SO2 NAAQS must demonstrate future attainment and maintenance 
of the NAAQS in the entire area designated as nonattainment (i.e., not 
just at the violating monitor) by using air quality dispersion modeling 
(see Guideline on Air Quality Models) to show that the mix of sources 
and enforceable control measures and emission rates in an identified 
area will not lead to a violation of the SO2 NAAQS. For a 
short-term (i.e., 1-hour) standard, EPA believes that dispersion 
modeling, using allowable emissions and addressing stationary sources 
in the affected area (and in some cases those sources located outside 
the nonattainment area which may affect attainment in the area) is 
technically appropriate, efficient and effective in demonstrating 
attainment in nonattainment areas because it takes into consideration 
combinations of meteorological and emission source operating conditions 
that may contribute to peak ground-level concentrations of 
SO2.
    The meteorological data used in the analysis should generally be 
processed with the most recent version of AERMET. Estimated 
concentrations should include ambient background concentrations, should 
follow the form of the standard, and should be calculated as described 
in section 2.6.1.2 of the August 23, 2010 clarification memo on 
``Applicability of Appendix W Modeling Guidance for the 1-hr 
SO2 National Ambient Air Quality Standard''.

IV. Review of Indiana's Modeled Attainment Plan for Morgan County

    The following discussion evaluates various features of the modeling 
that Indiana used in its attainment demonstration for Morgan County.

A. Model Selection and General Model Inputs

    Indiana's attainment demonstrations used AERMOD, the preferred 
model for these applications as identified in the Guideline on Air 
Quality Models. Indiana's October 2015 submittal used version 14134 of 
this model, which was the most recent version at the time the state 
conducted its nonattainment planning. However, the supplemental 
modeling that Indiana submitted in February 2019 used the current 
version of AERMOD, version 18081. Indiana utilized the regulatory 
default mode for all air quality modeling runs.
    Indiana's receptor grid and modeling domain for the Morgan County 
area generally followed the recommended approaches from the Guideline 
on Air Quality Models. Receptor spacing for each modeled facility fence 
line was every 50 meters, then 100-meter spacing of receptors out to a 
distance of 0.5 kilometers, every 250 meters out to 2.5 kilometers, 
every 500 meters out to 5 kilometers, and every 1000 meters out to 10 
kilometers from each facility. The resulting receptor grid contained 
10,445 receptors. An examination of the modest modeled spatial 
gradients near the facility boundaries leads to the conclusion that no 
facility in the area contributes to violations within any other 
facility's property, so that the exclusion of receptors within facility 
fencelines was acceptable.
    Indiana determined that Morgan County should be modeled with rural 
dispersion characteristics. Indiana did not provide an Auer analysis or 
provide other rationale for this selection. Nevertheless, the 
nonattainment area, consisting of two townships (Clay and Washington 
Townships) have a 2016 estimated population of 21,379 people in an area 
of 232.3 square kilometers, an average population density of 92 people 
per square kilometer. By comparison, the Guideline on Air Quality 
Models suggests that areas with less than 750 people per square 
kilometer warrant being modeled with rural dispersion characteristics. 
Therefore, EPA concurs with Indiana's determination that this

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area warrants being modeled with rural dispersion coefficients.

B. Meteorological Data

    Indiana used the Indianapolis National Weather Service (NWS) 
surface data and the Lincoln, Illinois upper air station (WBAN 048233) 
data for modeling Morgan County. EPA finds these selections 
appropriate.

C. Emissions Data

    Indiana identified two sources in Morgan County emitting over 100 
tons per year. Indianapolis Power and Light's Eagle Valley power plant, 
which conducts continuous SO2 emissions monitoring, emitted 
3,436 tons of SO2 in 2012. Hydraulic Press Brick, a 
manufacturer of building aggregate, has a less certain emission rate 
(in part due to uncertainties in the quantity of sulfur in the shale 
that is a raw material in the process), but was estimated to have 
emitted 350 tons of SO2 in 2010. Further discussion of the 
modeled emissions is provided below.

D. Emission Limits

    An important prerequisite for approval of an attainment plan is 
that the emission limits that provide for attainment be quantifiable, 
fully enforceable, replicable, and accountable. See General Preamble at 
13567-68.
    In preparing its plans, Indiana adopted revisions to a previously 
approved state regulation governing emissions of SO2. These 
rule revisions were adopted by the Indiana Environmental Rules Board 
following established, appropriate public review procedures. For Eagle 
Valley, the revised rule identifies the four primary emission sources 
and requires these sources to burn natural gas. The nominal compliance 
date for this requirement is January 1, 2017, but in fact Eagle Valley 
stopped burning coal in April 2016, after which all electricity 
generation at this facility has been based on burning natural gas. For 
Hydraulic Press Brick, the revised rule requires use of a limestone 
injection system to achieve either 50 percent control efficiency or 2.5 
pounds of SO2 per million British thermal units (lbs/MMBTU), 
and in no case to emit more than 6.0 lbs/MMBTU. These requirements were 
also effective on January 1, 2017. These limits are codified in 326 IAC 
7, titled ``Sulfur Dioxide Rules,'' specifically in 326 Indiana 
Administrative Code 7-4-11.1 (326 IAC 7-4-11.1). Indiana also submitted 
rules specifying the compliance date for these requirements (in 326 IAC 
7-1.1-3) and the associated monitoring, testing, and recordkeeping and 
reporting requirements (in 326 IAC 7-2-1). The rule provisions provide 
unambiguous, permanent requirements for emission control which, if 
violated, would be clear grounds for an enforcement action.
    Given the requirement for Eagle Valley to burn natural gas, EPA 
finds the low emission rate that Indiana modeled for this plant to be 
an appropriate reflection of allowable emissions. Indiana did not 
explicitly model Hydraulic Press Brick, choosing instead to address 
this source as part of the background concentration. The adequacy of 
Indiana's background concentration to reflect the impact of this source 
and other unmodeled emissions in the area is addressed in the following 
section.

E. Background Concentrations

    Indiana determined background concentrations for Morgan County 
using hourly measurements at the Centerton School monitor (site number 
18-109-1001). In its original analysis, documented in its submittal of 
October 2, 2015, Indiana determined background concentrations for this 
area by selecting the 99th percentile of a monitoring data set that 
excluded values when the monitor was downwind of either the Eagle 
Valley plant or Hydraulic Press Brick, except that values below 10 ppb 
were retained in the analysis. The 99th percentile among the pertinent 
values was 9.4 ppb, or 24.6 micrograms per cubic meter ([mu]g/m\3\).
    The purpose of background concentrations in a model simulation is 
to represent the impact of emissions from sources that are not 
explicitly modeled. Indiana explicitly modeled the allowable emissions 
from Eagle Valley, and so Indiana's approach, determining background 
concentrations in a manner that excluded occasions with significant 
impacts from Eagle Valley, was appropriate for avoiding double counting 
the impacts of this source. However, Indiana did not explicitly model 
Hydraulic Press Brick, choosing instead to represent this source as 
part of the background concentration in the modeling. For this reason, 
EPA found it inappropriate that Indiana excluded occasions with impacts 
from Hydraulic Press Brick in its determination of a background 
concentration.
    To address this concern, Indiana conducted additional analyses to 
identify background concentrations that would better represent the 
impacts of Hydraulic Press Brick and minor other SO2 sources 
in the area, which it submitted on February 8, 2019. This analysis used 
data from the same monitoring site as Indiana's prior analysis (site 
number 18-109-1001), using data from the most recent available three 
calendar years of data (2015 to 2017). Indiana again used 
meteorological data from the Indianapolis National Weather Service site 
for this analysis.
    Examination of these data led to the finding that aside from 
occasions when Eagle Valley was upwind of the monitor, the highest 
concentrations were observed when winds were in a relatively narrow 
band of wind directions approximately centered on Hydraulic Press Brick 
being upwind of the monitor. Ordinarily background concentrations are 
determined by examining concentrations for almost all wind directions, 
excluding data for a modest set of directions when modeled sources are 
upwind. However, in this case Indiana followed the reverse approach, 
excluding occasions when Hydraulic Press Brick was not upwind of the 
monitor and considering concentrations only for a relatively small band 
of wind directions in which the largest unmodeled source (Hydraulic 
Press Brick) was most directly upwind. In particular, the data set used 
in this analysis included concentrations when the winds were from 
between 25 degrees and 60 degrees (roughly from NNE to ENE). This 
approach was designed to estimate the maximum background concentration 
that could be attributed to unmodeled sources in the area, including a 
conservative representation of the impacts of Hydraulic Press Brick.
    EPA guidance offers both the option to determine a single 
background concentration, to be used for all seasons and all hours, and 
the option to determine separate season- and hour-specific background 
concentrations. Indiana applied both options in this case. The 
resulting single background concentration was 96.0 [mu]g/m\3\, or 36.7 
ppb. The resulting season- and hour-specific background concentrations 
ranged from 2.8 to 114.5 [mu]g/m\3\ (1.1 ppb to 43.7 ppb). Indiana then 
used these background concentrations in additional model runs to 
provide a supplemental assessment of whether its plan provides for 
attainment.

F. Summary of Results

    Modeling for Morgan County in Indiana's October 2, 2015 submittal 
showed a design value of 35.9 [mu]g/m\3\ (13.7 ppb). Modeling in 
Indiana's February 8, 2019 submittal used two approaches that provided 
a more conservative representation of background concentrations. The

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modeling run using a single background concentration for all seasons 
and hours showed a design value of 103.69 [mu]g/m\3\ (39.6 ppb). The 
modeling run using season- and hour-specific background concentrations 
yielded a design value of 117.33 [mu]g/m\3\ (44.8 ppb), slightly higher 
than the run using a single background concentration. Both of these 
runs show design values well below 196.4 [mu]g/m\3\ (75 ppb). 
Therefore, EPA concludes that Indiana's plan provides for attainment in 
this area.
    Pursuant to the requirements in Indiana's rules, Hydraulic Press 
Brick began sorbent injection, to achieve either 50 percent control or 
2.5 lbs/MMBTU of SO2, beginning by January 1, 2017. With 
this approximate start date, the period from 2015 to 2017 used in 
Indiana's assessment of background concentrations reflected two years 
without this control measure and one year with it. While insufficient 
data are available to estimate the air quality benefits of this control 
measure, the continued implementation of this measure is expected to 
result in lower future background concentrations and to assure that 
background concentrations will not increase above these levels. 
Indiana's letter of February 12, 2019 requests EPA approval of the 
control requirements for Hydraulic Press Brick, which will help assure 
that background concentrations will remain at or below the level in 
Indiana's estimate, thereby helping assure that Indiana's plan provides 
for attainment.

V. Review of Other Plan Requirements

A. Emissions Inventory

    The emissions inventory and source emission rate data for an area 
serve as the foundation for air quality modeling and other analyses 
that enable states to: (1) Estimate the degree to which different 
sources within a nonattainment area contribute to violations within the 
affected area; and (2) assess the expected improvement in air quality 
within the nonattainment area due to the adoption and implementation of 
control measures. As noted above, the state must develop and submit to 
EPA a comprehensive, accurate and current inventory of actual emissions 
from all sources of SO2 emissions in each nonattainment 
area, as well as any sources located outside the nonattainment area 
which may affect attainment in the area. See Clean Air Act section 
172(c)(3).
    Indiana provided a comprehensive, accurate, and current inventory 
of SO2 emissions for Morgan County. Indiana identified two 
sources in the county that emitted over 100 tons of SO2 per 
year, namely Eagle Valley and Hydraulic Press Brick. Indiana also 
summarized emissions in the following source categories: Electric-
generating units (EGUs), non-EGUs (point), non-point (area), non-road, 
and on-road sources of SO2. This summary of emissions is 
shown in Table 1. Indiana uploads point source emissions to the 
National Emissions Inventory (NEI) annually. For the 2011 base year 
inventory, emissions from EGU and non-EGUs are actual reported 
emissions. Data for airport, area, non-road, and on-road emissions were 
compiled from the EPA Emissions Modeling Clearinghouse (SO2 
NAAQS Emissions Modeling platform 2007/2007v5) for the 2008 NEI and the 
2018 projected inventory year. Data were interpolated between 2008 and 
2014 to determine the airport, area, non-road, and on-road emissions 
2011 inventory and between 2014-2020 for 2018. These inventories can be 
found in appendix H of the submitted attainment demonstration. Also, 
for each of the four areas addressed in its submittal, including Morgan 
County, Indiana provided modeling inputs that include a listing of the 
individual sources with sufficient proximity to and impact on the 
nonattainment areas to warrant being explicitly included in the 
modeling analysis.
    Indiana's emission inventory indicated that Eagle Valley in 2012 
emitted 3,436 tons of SO2. This precisely matches the 
emissions quantity that Eagle Valley reported to EPA under applicable 
emissions monitoring and reporting requirements. Indiana indicated that 
Hydraulic Press Brick in 2010 emitted 350 tons of SO2. This 
is similar to the SO2 emission rate reported in the 2011 
National Emission Inventory, though no emissions of SO2 are 
reported in the 2014 National Emission Inventory. Notwithstanding the 
difficulty of estimating emissions from this source, particularly as it 
relates to the quantity of SO2 emissions that arises from 
sulfur in the shale that the facility uses as a raw material, EPA 
believes that Indiana's SIP submittal provides a suitable estimate of 
the emissions from this source for planning purposes.

       Table 1--2011 Actual Emissions Inventory for Morgan County
------------------------------------------------------------------------
                                                       2011 Emissions in
                                                         Morgan County
                                                             (tpy)
------------------------------------------------------------------------
EGU..................................................             10,875
Other Point..........................................                387
Area.................................................                 24
Non-road.............................................                  1
On-road..............................................                 10
                                                      ------------------
    Total............................................             11,297
------------------------------------------------------------------------

    By providing a comprehensive, accurate, and current inventory of 
SO2 emissions for Morgan County, Indiana has met the 
emission inventory requirement of Clean Air Act section 172(c)(3) for 
this area. This inventory represents emissions in 2011, a time when the 
areas were violating the standard. The state also provided allowable 
attainment year emissions in its modeling analysis.

B. RACM/RACT

    In its submission, Indiana discusses its rationale for concluding 
that the nonattainment plans meet the RACM/RACT requirements in 
accordance with EPA guidance. For most criteria pollutants, RACT is 
control technology as needed to meet the NAAQS that is reasonably 
available considering technological and economic feasibility. However, 
Indiana cites EPA guidance that the definition of RACT for 
SO2 is, simply, ``that control technology which is necessary 
to achieve the NAAQS (40 CFR 51.100(o))''. See General Preamble, 57 FR 
13547 (April 16, 1992), synopsizing the SO2 RACT requirement 
in 40 CFR 51.100(o). Indiana in fact requires the control technology 
that modeling shows to be necessary to ensure attainment of the 
SO2 NAAQS by the applicable attainment date.
    In addition, Indiana has adopted and submitted limits that require 
effective control of the most significant sources in Morgan County. The 
requirement for Eagle Valley to burn natural gas brings the emissions 
of this source nearly to zero. The requirement for Hydraulic Press 
Brick to operate a sorbent injection system in a manner that generally 
achieves 50 percent emission control requires operating a control that 
is cost effective and achieves a relatively high degree of control for 
this type of source. Thus, while Indiana did not conduct a cost 
effectiveness analysis of these controls, and EPA does not require such 
an analysis, the controls required in this area appear to represent a 
full set of reasonably available emission control.
    Indiana has determined that these measures suffice to provide for 
timely attainment. EPA concurs and proposes

[[Page 32677]]

to conclude that the state has satisfied the requirements in sections 
172(c)(1) and (6) to adopt and submit all RACT/RACM and emission 
limitations and control measures as needed to attain the standards as 
expeditiously as practicable.

C. New Source Review (NSR)

    As Indiana's submittal explains, EPA approved Indiana's 
nonattainment new source review rules on October 7, 1994 (94 FR 24838). 
As Indiana notes, these rules provide for appropriate new source review 
for SO2 sources undergoing construction (or major 
modification) in the Morgan County area. No modification of the 
approved rules is necessary to meet the NSR requirements. Therefore, 
EPA concludes that this requirement has already been met for these 
areas.

D. RFP

    Indiana's adopted rules in 326 IAC 7 require that control measures 
be implemented no later than January 1, 2017. Indiana has concluded 
that this plan requires that affected sources implement appropriate 
control measures as expeditiously as practicable in order to ensure 
attainment of the standard by the applicable attainment date. Indiana 
concludes that this plan therefore provides for RFP in accordance with 
the approach to RFP described in EPA's guidance. EPA concurs and 
proposes to conclude that the plan provides for RFP.

E. Contingency Measures

    Indiana's approach to contingency measures is one of the subjects 
of a clarification memo that Indiana submitted on November 15, 2017. In 
this memo, Indiana explained its rationale for concluding that its 
plans met the requirement for contingency measures in accordance with 
EPA guidance. Specifically, Indiana relies on EPA's guidance, noting 
the special circumstances that apply to SO2, and explaining 
on that basis why the contingency measures requirement in Clean Air Act 
section 172(c)(9) is met for SO2 by having a comprehensive 
program to identify sources of violations of the SO2 NAAQS 
and to undertake an aggressive follow-up for compliance and enforcement 
of applicable emissions limitations. Indiana stated that it has such an 
enforcement program as codified in Indiana Code Title 13, Articles 14 
and 15, identifying violators and taking prompt, appropriate 
enforcement action. On this basis, EPA proposes to conclude that 
Indiana's nonattainment plans satisfy contingency measure requirements 
for the Morgan County nonattainment area.
    Indiana's rules also provide for additional contingency measures as 
necessary, following a review of any air quality problems that become 
identified and following a review of options for mitigating the 
problems that arise. However, Indiana is not relying on these 
provisions to satisfy the requirements for contingency measures.

VI. EPA's Proposed Action

    EPA is proposing to approve Indiana's SIP submission, which the 
state submitted to EPA on October 2, 2015 and supplemented on November 
15, 2017, June 7, 2017, February 8, 2019, and February 12, 2019, for 
attaining the 2010 1-hour SO2 NAAQS for the Morgan County 
area. This SO2 nonattainment plan includes Indiana's 
attainment demonstration for this area. The nonattainment plan also 
addresses requirements for emission inventories, RACT/RACM, RFP, and 
contingency measures. Indiana has previously addressed requirements 
regarding nonattainment area NSR. EPA has determined that Indiana's 
SO2 nonattainment plan for Morgan County meets the 
applicable requirements of Clean Air Act sections 110, 172, 191, and 
192.
    The rules that underpin Indiana's attainment plan for Morgan County 
include Indiana Administrative Code, Title 326, Rule 7-4-11.1 (326 IAC 
7-4-11.1, entitled ``Morgan County sulfur dioxide emission 
limitations''), as well as Rule 326 IAC 7-1.1-3 (entitled ``Compliance 
date'') and Rule 326 IAC 7-2-1 (entitled ``Reporting requirements; 
methods to determine compliance''). EPA has already approved the latter 
two rules, as part of its rulemaking on the plans for Marion and Vigo 
Counties. These rules provide compliance dates and recordkeeping and 
compliance determination provisions that apply to all four areas in 
Indiana's original submittal. Because these latter two rules are 
already part of the Indiana SIP, and no further action on these rules 
is necessary, EPA is proposing only to approve 326 IAC 7-4-11.1.
    EPA is taking public comments for thirty days following the 
publication of this proposed action in the Federal Register. EPA will 
take all comments into consideration in our final action.

VII. Incorporation by Reference

    In this rule, EPA is proposing to include in a final EPA rule 
regulatory text that includes incorporation by reference. In accordance 
with requirements of 1 CFR 51.5, EPA is proposing to incorporate by 
reference 326 IAC 7-4-11.1, ``Morgan County sulfur dioxide emission 
limitations'', effective at the state on October 2, 2015. EPA has made, 
and will continue to make, these documents generally available through 
www.regulations.gov, and at the EPA Region 5 Office. (Please contact 
the person identified in the FOR FURTHER INFORMATION CONTACT section of 
this preamble for more information.)

VIII. Statutory and Executive Order Reviews

    Under the Clean Air Act, the Administrator is required to approve a 
SIP submission that complies with the provisions of the Act 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 Clean Air Act. 
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 Order 
12866 58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
2011);
     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 Clean Air Act; and
     Does not provide EPA with the discretionary authority to 
address, as

[[Page 32678]]

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).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
Reference, Intergovernmental relations, Reporting and recordkeeping 
requirements, Sulfur oxides.

    Dated: June 26, 2019.
Cheryl L. Newton,
Acting Regional Administrator, Region 5.
[FR Doc. 2019-14474 Filed 7-8-19; 8:45 am]
 BILLING CODE 6560-50-P