82_FR_40249 82 FR 40086 - Approval of Iowa's Air Quality Implementation Plan; Muscatine Sulfur Dioxide Nonattainment Area

82 FR 40086 - Approval of Iowa's Air Quality Implementation Plan; Muscatine Sulfur Dioxide Nonattainment Area

ENVIRONMENTAL PROTECTION AGENCY

Federal Register Volume 82, Issue 163 (August 24, 2017)

Page Range40086-40103
FR Document2017-17736

The Environmental Protection Agency (EPA) is proposing to approve the State Implementation Plan (SIP) revision, which the State of Iowa (the state) submitted to the EPA on May 26, 2016, for attaining the 1-hour sulfur dioxide (SO<INF>2</INF>) primary National Ambient Air Quality Standard (NAAQS) for the Muscatine nonattainment area. This plan (herein called a ``nonattainment plan'') includes the state's attainment demonstration and other elements required under Clean Air Act (CAA) sections 172, 191, and 192. In addition to an attainment demonstration, the plan addresses the requirement for meeting reasonable further progress (RFP) toward attainment of the NAAQS, reasonably available control measures and reasonably available control technology (RACM/RACT), base-year and projection-year emission inventories, and contingency measures. The EPA proposes to conclude that the state has appropriately demonstrated that the plan provisions provide for attainment of the 2010 1-hour primary SO<INF>2</INF> NAAQS in the Muscatine nonattainment area by the applicable attainment date and that the plan meets the other applicable requirements under CAA sections 172, 191, and 192.

Federal Register, Volume 82 Issue 163 (Thursday, August 24, 2017)
[Federal Register Volume 82, Number 163 (Thursday, August 24, 2017)]
[Proposed Rules]
[Pages 40086-40103]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2017-17736]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R07-OAR-2017-0416; FRL-9966-60-Region 7]


Approval of Iowa's Air Quality Implementation Plan; Muscatine 
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 the State Implementation Plan (SIP) revision, which the State 
of Iowa (the state) submitted to the EPA on May 26, 2016, for attaining 
the 1-hour sulfur dioxide (SO2) primary National Ambient Air 
Quality Standard (NAAQS) for the Muscatine nonattainment area. This 
plan (herein called a ``nonattainment plan'') includes the state's 
attainment demonstration and other elements required under Clean Air 
Act (CAA) sections 172, 191, and 192. In addition to an attainment 
demonstration, the plan addresses the requirement for meeting 
reasonable further progress (RFP) toward attainment of the NAAQS, 
reasonably available control measures and reasonably available control 
technology (RACM/RACT), base-year and projection-year emission 
inventories, and contingency measures. The EPA proposes to conclude 
that the state has appropriately demonstrated that the plan provisions 
provide for attainment of the 2010 1-hour primary SO2 NAAQS 
in the Muscatine nonattainment area by the applicable attainment date 
and that the plan meets the other applicable requirements under CAA 
sections 172, 191, and 192.

DATES: Comments must be received on or before September 25, 2017.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R07-
OAR-2017-0416 to https://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. The 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. The 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, 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: Tracey Casburn, Environmental 
Protection Agency, Air Planning and Development Branch, 11201 Renner 
Boulevard, Lenexa, Kansas 66219 at (913) 551-7016, or by email at 
[email protected].

SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,'' 
``us,'' and ``our'' is used, we mean the EPA.
    Organization of this document. The following outline is provided to 
aid in locating information in this preamble.

Table of Contents

I. Why was Iowa required to submit an SO2 plan for the 
Muscatine area?
II. Requirements for SO2 Nonattainment Area Plans
III. Attainment Demonstration and Longer Term Averaging
IV. Review of Modeled Attainment Plan
    A. Model Selection
    B. Meteorological Data
    C. Emissions Data
    D. Emission Limits
    1. Enforceability
    2. Longer Term Averaging
    E. Background Concentrations
    F. Summary of Results
    1. Phase 1--Preliminary Analysis
    2. Phase 2--Control Strategy Development
V. Review of Other Plan Requirements
    A. Emissions Inventory and the Quantification of Emissions
    B. RACM/RACT

[[Page 40087]]

    C. Nonattainment New Source Review (NNSR)
    D. Reasonable Further Progress (RFP)
    E. Contingency Measures
VI. Additional Elements of the State's Submittal
    A. Compliance With Section 110(a)(2) of the CAA
    B. Equivalent Techniques
VII. EPA's Proposed Action
VIII. Incorporation by Reference
IX. Statutory and Executive Order Reviews

I. Why was Iowa required to submit an SO2 plan for the 
Muscatine area?

    On June 22, 2010, the 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 1-hour daily maximum 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, the EPA designated 29 areas of the country as nonattainment for 
the 2010 SO2 NAAQS, including the Muscatine area in the 
State of Iowa. See 78 FR 47191, codified at 40 CFR part 81, subpart C. 
These area designations were effective October 4, 2013. Section 191 of 
the CAA directs states to submit SIPs for areas designated as 
nonattainment for the SO2 NAAQS to the EPA within 18 months 
of the effective date of the designation, i.e., by no later than April 
4, 2015. These SIPs must demonstrate that the respective areas will 
attain the NAAQS as expeditiously as practicable, but no later than 5 
years from the effective date of designation, which is October 4, 2018.
    On March 18, 2016, the EPA published an action that the State of 
Iowa failed to submit the required SO2 nonattainment plan 
for the Muscatine area by the SIP submittal deadline. See 81 FR 14736. 
This finding initiated a deadline under CAA section 179(a) for the 
potential imposition of new source and highway funding sanctions. 
However, pursuant to Iowa's submittal of May 26, 2016, and the SIP 
becoming complete by operation of law on November 26, 2016, the 
sanctions under section 179(a) will not be imposed. Additionally, under 
CAA section 110(c), the finding triggers a requirement that the EPA 
promulgate a Federal Implementation Plan (FIP) within two years of the 
finding unless, by that time (a) the state has made the necessary 
complete submittal and (b) EPA has approved the submittal as meeting 
applicable requirements. This FIP obligation will not apply if EPA 
makes final the approval action proposed here by March 18, 2018.
    The remainder of this preamble describes the requirements that 
nonattainment SIPs must meet in order to obtain EPA approval, provides 
a review of the state's plan with respect to these requirements, and 
describes the EPA's proposed action on the plan.

II. Requirements for SO2 Nonattainment Area Plans

    Nonattainment SIPs must meet the applicable requirements of the 
CAA, and specifically CAA sections 172, 191 and 192. The 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 CAA, 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 13545-49, 13567-68. On April 23, 2014, the EPA 
issued recommended guidance for meeting the statutory requirements in 
SO2 SIPs, in a document entitled, ``Guidance for 1-Hour 
SO2 Nonattainment Area SIP Submissions,'' (April 2014 
guidance) available at https://www.epa.gov/sites/production/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf. In this guidance 
the EPA described the statutory requirements for a complete 
nonattainment area SIP, which includes: An accurate emissions inventory 
of current emissions for all sources of SO2 within the 
nonattainment area; an attainment demonstration; demonstration of RFP; 
implementation of RACM (including RACT); new source review (NSR) and, 
adequate contingency measures for the affected area.
    In order for the EPA to fully approve a SIP as meeting the 
requirements of CAA 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 CAA sections 110(l) and 193, the 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 insures equivalent or greater emission 
reductions of such air pollutant.

III. Attainment Demonstration and Longer Term Averaging

    CAA section 172(c)(1) directs states with 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 
which 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 measureable requirements for which 
compliance can be practicably determined), replicable (the procedures 
for determining compliance are sufficiently specific and non-subjective 
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).
    The 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. See 2014 guidance, 
pp. 22 to 39. The guidance recommends that--should states and sources 
utilize longer averaging times--

[[Page 40088]]

the longer term average limit should be set at an adjusted level that 
reflects a stringency comparable to the 1-hour average limit at the 
critical emission value shown to provide for attainment that the plan 
otherwise would have set.
    The April 2014 guidance provides an extensive discussion of the 
EPA's rationale for concluding that appropriately set comparably 
stringent limitations based on averaging times as long as 30 days can 
be found to provide for attainment of the 2010 SO2 NAAQS. In 
evaluating this option, the EPA considered the nature of the standard, 
conducted detailed analyses of the impact of use of 30-day average 
limits on the prospects for attaining the standard, and carefully 
reviewed how best to achieve an appropriate balance among the various 
factors that warrant consideration in judging whether a state's plan 
provides for attainment. Id. at pp. 22 to 39. See also id. at 
Appendices B, C, and D.
    As specified in 40 CFR 50.17(b), the 1-hour primary SO2 
NAAQS is met at an ambient air quality monitoring site when the 3-year 
average of the annual 99th percentile of daily maximum 1-hour 
concentrations is less than or equal to 75 parts per billion. In a year 
with 365 days of valid monitoring data, the 99th percentile would be 
the fourth highest daily maximum 1-hour value. The 2010 SO2 
NAAQS, including this form of determining compliance with the standard, 
was upheld by the U.S. Court of Appeals for the District of Columbia 
Circuit in Nat'l Envt'l Dev. Ass'n's Clean Air Project v. EPA, 686 F.3d 
803 (D.C. Cir. 2012). Because the standard has this form, a single 
exceedance does not create a violation of the standard. Instead, at 
issue is whether a source operating in compliance with a properly set 
longer term average could cause exceedances, and if so the resulting 
frequency and magnitude of such exceedances, and in particular whether 
the EPA can have reasonable confidence that a properly set longer term 
average limit will provide that the average fourth highest daily 
maximum value will be at or below 75 ppb. A synopsis of how EPA judges 
whether such plans ``provide for attainment,'' based on modeling of 
projected allowable emissions and in light of the NAAQS' form for 
determining attainment at monitoring sites, follows.
    For plans for SO2 based on 1-hour emission limits, the 
standard approach is to conduct modeling using fixed emission rates. 
The maximum emission rate that would be modeled to result in attainment 
(i.e., in an ``average year'' \1\ shows three, not four days with 
maximum hourly levels exceeding 75 ppb) is labeled the ``critical 
emission value.'' The modeling process for identifying this critical 
emissions value inherently considers the numerous variables that affect 
ambient concentrations of SO2, such as meteorological data, 
background concentrations, and topography. In the standard approach, 
the state would then provide for attainment by setting a continuously 
applicable 1-hour emission limit at this critical emission value.
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    \1\ An ``average year'' is used to mean a year with average air 
quality. While 40 CFR 50 appendix T provides for averaging three 
years of 99th percentile daily maximum values (e.g., the fourth 
highest maximum daily concentration in a year with 365 days with 
valid data), this discussion and an example below uses a single 
``average year'' in order to simplify the illustration of relevant 
principles.
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    The EPA recognizes that some sources have highly variable 
emissions, for example due to variations in fuel sulfur content and 
operating rate, that can make it extremely difficult, even with a well-
designed control strategy, to ensure in practice that emissions for any 
given hour do not exceed the critical emission value. The EPA also 
acknowledges the concern that longer term emission limits can allow 
short periods with emissions above the ``critical emissions value,'' 
which, if coincident with meteorological conditions conducive to high 
SO2 concentrations, could in turn create the possibility of 
a NAAQS exceedance occurring on a day when an exceedance would not have 
occurred if emissions were continuously controlled at the level 
corresponding to the critical emission value. However, for several 
reasons, the EPA believes that the approach recommended in its April 
2014 guidance document suitably addresses this concern. First, from a 
practical perspective, the EPA expects the actual emission profile of a 
source subject to an appropriately set longer term average limit to be 
similar to the emission profile of a source subject to an analogous 1-
hour average limit. The EPA expects this similarity because it has 
recommended that the longer term average limit be set at a level that 
is comparably stringent to the otherwise applicable 1-hour limit 
(reflecting a downward adjustment from the critical emissions value) 
and that takes the source's emissions profile into account. As a 
result, the EPA expects either form of emission limit to yield 
comparable air quality.
    Second, from a more theoretical perspective, the EPA has compared 
the likely air quality with a source having maximum allowable emissions 
under an appropriately set longer term limit, as compared to the likely 
air quality with the source having maximum allowable emissions under 
the comparable 1-hour limit. In this comparison, in the 1-hour average 
limit scenario, the source is presumed at all times to emit at the 
critical emission level, and in the longer term average limit scenario, 
the source is presumed occasionally to emit more than the critical 
emission value but on average, and presumably at most times, to emit 
well below the critical emission value. In an ``average year,'' 
compliance with the 1-hour limit is expected to result in three 
exceedance days (i.e., three days with hourly values above 75 ppb) and 
a fourth day with a maximum hourly value at 75 ppb. By comparison, with 
the source complying with a longer term limit, it is possible that 
additional exceedances would occur that would not occur in the 1-hour 
limit scenario (if emissions exceed the critical emission value at 
times when meteorology is conducive to poor air quality). However, this 
comparison must also factor in the likelihood that exceedances that 
would be expected in the 1-hour limit scenario would not occur in the 
longer term limit scenario. This result arises because the longer term 
limit requires lower emissions most of the time (because the limit is 
set well below the critical emission value), so a source complying with 
an appropriately set longer term limit is likely to have lower 
emissions at critical times than would be the case if the source were 
emitting as allowed with a 1-hour limit.
    As a hypothetical example to illustrate these points, suppose a 
source that always emits 1000 pounds of SO2 per hour, which 
results in air quality at the level of the NAAQS (i.e., results in a 
design value of 75 ppb). Suppose further that in an ``average year,'' 
these emissions cause the 5 highest maximum daily average 1-hour 
concentrations to be 100 ppb, 90 ppb, 80 ppb, 75 ppb, and 70 ppb. Then 
suppose that the source becomes subject to a 30-day average emission 
limit of 700 pounds per hour. It is theoretically possible for a source 
meeting this limit to have emissions that occasionally exceed 1000 
pounds per hour, but with a typical emissions profile emissions would 
much more commonly be between 600 and 800 pounds per hour. In this 
simplified example, assume a zero background concentration, which 
allows one to assume a linear relationship between emissions and air 
quality. (A nonzero background concentration would make the mathematics 
more difficult but would give similar results.) Air quality

[[Page 40089]]

will depend on what emissions happen on what critical hours, but 
suppose that emissions at the relevant times on these 5 days are 800 
pounds/hour, 1100 pounds per hour, 500 pounds per hour, 900 pounds per 
hour, and 1200 pounds per hour, respectively. (This is a conservative 
example because the average of these emissions, 900 pounds per hour, is 
well over the 30-day average emission limit.) These emissions would 
result in daily maximum 1-hour concentrations of 80 ppb, 99 ppb, 40 
ppb, 67.5 ppb, and 84 ppb. In this example, the fifth day would have an 
exceedance that would not otherwise have occurred, but the third and 
fourth days would not have exceedances that otherwise would have 
occurred. In this example, the fourth highest maximum daily 
concentration under the 30-day average would be 67.5 ppb.
    This simplified example illustrates the findings of a more 
complicated statistical analysis that EPA conducted using a range of 
scenarios using actual plant data. As described in appendix B of EPA's 
April 2014 SO2 nonattainment planning guidance, the EPA 
found that the requirement for lower average emissions is highly likely 
to yield better air quality than is required with a comparably 
stringent 1-hour limit. Based on analyses described in appendix B of 
its April 2014 guidance, the EPA expects that an emission profile with 
maximum allowable emissions under an appropriately set comparably 
stringent 30-day average limit is likely to have the net effect of 
having a lower number of exceedances and better air quality than an 
emission profile with maximum allowable emissions under a 1-hour 
emission limit at the critical emission value. This result provides a 
compelling policy rationale for allowing the use of a longer averaging 
period, in appropriate circumstances where the facts indicate this 
result can be expected to occur.
    The question then becomes whether this approach--which is likely to 
produce a lower number of overall exceedances even though it may 
produce some unexpected exceedances above the critical emission value--
meets the requirement in section 110(a)(1) and 172(c)(1) for state 
implementation plans to ``provide for attainment'' of the NAAQS. For 
SO2, as for other pollutants, it is generally impossible to 
design a nonattainment plan in the present that will guarantee that 
attainment will occur in the future. A variety of factors can cause a 
well-designed attainment plan to fail and unexpectedly not result in 
attainment, for example if meteorology occurs that is more conducive to 
poor air quality than was anticipated in the plan. Therefore, in 
determining whether a plan meets the requirement to provide for 
attainment, the EPA's task is commonly to judge not whether the plan 
provides absolute certainty that attainment will in fact occur, but 
rather whether the plan provides an adequate level of confidence of 
prospective NAAQS attainment. From this perspective, in evaluating use 
of a 30-day average limit, EPA must weigh the likely net effect on air 
quality. Such an evaluation must consider the risk that occasions with 
meteorology conducive to high concentrations will have elevated 
emissions leading to exceedances that would not otherwise have 
occurred, and must also weigh the likelihood that the requirement for 
lower emissions on average will result in days not having exceedances 
that would have been expected with emissions at the critical emissions 
value. Additional policy considerations, such as in this case the 
desirability of accommodating real world emissions variability without 
significant risk of violations, are also appropriate factors for the 
EPA to weigh in judging whether a plan provides a reasonable degree of 
confidence that the plan will lead to attainment. Based on these 
considerations, especially given the high likelihood that a 
continuously enforceable limit averaged over as long as 30 days, 
determined in accordance with the EPA's April 2014 guidance, will 
result in attainment, the EPA believes as a general matter that such 
limits, if appropriately determined, can reasonably be considered to 
provide for attainment of the 2010 SO2 NAAQS.
    The April 2014 guidance offers specific recommendations for 
determining an appropriate longer term average limit. The recommended 
method starts with determination of the 1-hour emission limit that 
would provide for attainment (i.e., the critical emission value), and 
applies an adjustment factor to determine the (lower) level of the 
longer term average emission limit that would be estimated to have a 
stringency comparable to the otherwise necessary 1-hour emission limit. 
This method uses a database of continuous emission data reflecting the 
type of control that the source will be using to comply with the SIP 
emission limits, which (if compliance requires new controls) may 
require use of an emission database from another source. The 
recommended method involves using these data to compute a complete set 
of emission averages, computed according to the averaging time and 
averaging procedures of the prospective emission limitation. In this 
recommended method, the ratio of the 99th percentile among these long 
term averages to the 99th percentile of the 1-hour values represents an 
adjustment factor that may be multiplied by the candidate 1-hour 
emission limit to determine a longer term average emission limit that 
may be considered comparably stringent.\2\ The April 2014 guidance also 
addresses a variety of related topics, such as the potential utility of 
setting supplemental emission limits, such as mass-based limits, to 
reduce the likelihood and/or magnitude of elevated emission levels that 
might occur under the longer term emission rate limit.
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    \2\ For example, if the critical emission value is 1000 pounds 
of SO2 per hour, and a suitable adjustment factor is 
determined to be 70 percent, the recommended longer term average 
limit would be 700 pounds per hour.
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    Preferred air quality models for use in regulatory applications are 
described in appendix A of the EPA's Guideline on Air Quality Models 
(40 CFR part 51, appendix W (appendix W)). In 2005, the EPA promulgated 
the American Meteorological Society/Environmental Protection Agency 
Regulatory Model (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 2014 guidance. 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.
    As stated previously, attainment demonstrations for the 2010 1-hour 
primary 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 appendix W to 40 CFR part 51) 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, the EPA believes that 
dispersion modeling, using allowable emissions and addressing 
stationary sources in the

[[Page 40090]]

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 
``Applicability of Appendix W Modeling Guidance for the 1-hr 
SO2 National Ambient Air Quality Standard'' (U. S. EPA, 
2010a) (August 2010 1-hour SO2 clarification memo).

IV. Review of Modeled Attainment Plan

    The following discussion evaluates various features of the modeling 
that Iowa used in its attainment demonstration.

A. Model Selection

    Iowa's attainment demonstration used the most current version of 
AERMOD available during each phase of its analysis (i.e., the 
determining sources culpable to nonattainment phase and the control 
strategy phase). As previously stated, AERMOD is the preferred model 
for this application. The final control strategy modeling analysis 
utilized version 15181. The state asserts that all analyses were 
conducted with EPA's regulatory default options and considering EPA's 
guidance documents including the August 2010 1-hour SO2 
clarification memo; the ``Additional Clarification Regarding 
Application of Appendix W Modeling Guidance for the 1-hour 
NO2 National Ambient Air Quality Standard'' memo (March 2011 
1-hour NO2 clarification memo); and the December 2013 
SO2 Modeling Technical Assistance Document (TAD).\3\ The 
receptor grid was centered on the Musser Park monitor, and extended out 
to the edges of the nonattainment area.\4\ Those portions of the fence 
lines of the facilities being evaluated that fell outside of the 
nonattainment area were omitted from the analysis. Finer grid spacing 
of 50 meters was used to resolve modeled impacts around other nearby 
individual facilities included in the analyses, but finer grid spacing 
was applied only around sources within the confines of the 
nonattainment area. Receptors were excluded from areas within the 
property boundaries of each facility in the analysis. The most recent 
version of AERMAP (11103) was used to import terrain and source 
elevations from the National Elevation Dataset (NED). All building 
downwash analyses were conducted using the most recent version (04274) 
of EPA's Building Profile Input Program with Plume Rise Enhancements 
(BPIP-Prime). EPA finds the selection and use of these inputs to 
AERMOD, AERMAP and BPIP-Prime to be appropriate and in accordance with 
appendix W and applicable EPA guidance, such as the TAD.\5\
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    \3\ SO2 NAAQS Designations Modeling Technical 
Assistance Document, December 2013.
    \4\ The Musser Park monitor was the violating monitor utilized 
during the designations process.
    \5\ The state utilized the December 2013 version of the modeling 
TAD when completing its technical analysis. The modeling TAD has 
been revised since then; the TAD was revised in February 2016 and 
then again in August 2016.
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B. Meteorological Data

    Modeling for the Muscatine 1-hr SO2 nonattainment SIP 
was conducted using the surface station and upper air data from the 
Davenport airport, and used consecutive years from 2008-2012.\6\ This 
represents the most recent, readily available 5-year period at the time 
of the initial analysis per section 8.3.1.2 of 40 CFR part 51 appendix 
W. The most current version of AERMET available during each phase of 
the analysis was used. The final control strategy analysis utilized 
data processed with AERMET version 14134. The state utilized AERMINUTE 
to process 1-minute ASOS wind data to generate hourly average winds for 
input to AERMET. EPA finds the selection and use of these inputs to 
AERMET to be appropriate and in accordance with appendix W and 
applicable EPA guidance, such as the TAD.
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    \6\ A detailed analysis to support the use of the Davenport 
meteorological data from the Davenport airport was previously 
approved by EPA for use in the PM2.5 Muscatine SIP 
analysis. See 79 FR 46742. EPA finds use of the Davenport airport 
site meteorological data to be appropriate for the 2010 1-hr 
SO2 Muscatine SIP.
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C. Emissions Data

    The state utilized information from the technical support document 
(TSD) it submitted to EPA during the nonattainment boundary 
recommendations to inform which sources needed to be included in its 
nonattainment SIP modeling.\7\ The nonattainment boundary analysis 
demonstrated that industrial sources along the Mississippi River have a 
role in causing or contributing to monitored exceedances at the Musser 
Park monitor. Based on this analysis, all major sources of 
SO2 emissions within the nonattainment area- Grain 
Processing Corporation (GPC), Muscatine Power and Water (MPW), and 
Monsanto- were included in the nonattainment SIP control strategy 
analysis.
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    \7\ https://www.epa.gov/sulfur-dioxide-designations/so2-designations-round-1-iowa-state-recommendation-and-epa-response and 
provided in the docket of this rulemaking.
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    As described in the state's nonattainment SIP, GPC is the largest 
source of SO2 within the nonattainment area. GPC is a corn 
wet milling facility that processes grain into industrial, beverage, 
and fuel-grade ethanol, as well as a variety of grain based food 
products, industrial products, and animal feeds. Early in the corn wet 
milling process the grain is soaked (steeped) in large tanks where 
sulfur containing compounds are added to the steep water to reduce 
bacterial growth and help break down the kernels. The sulfur content in 
the steep water is generally low but does lead to SO2 
emissions from a variety of downstream processes. The state asserts 
that 96 percent of the SO2 emissions at GPC is generated by 
six coal-fired boilers.
    MPW is a municipal electric generating station. MPW produces steam 
through the combustion of fossil fuels, generally coal, and uses the 
steam to produce electricity. The largest sources of SO2 
operated at MPW are three coal-fired boilers, Units 7, 8, and 9, 
serving generators with nameplate capacities of 25, 937, and 175.5 
megawatts (MW), respectively. An auxiliary boiler operated at MPW is 
not capable of burning coal but has the potential to emit 
SO2 when firing on distillate fuel oil.
    Monsanto is a manufacturer and formulator of herbicides for 
agricultural use and also produces intermediates for herbicide 
manufacturing and formulation. A coal-fired boiler (Boiler #8) used for 
the production of on-site heat and power is the largest SO2 
source at Monsanto.
    The state excluded four facilities located within the nonattainment 
area from the its nonattainment SIP modeling analysis: HNI 
Corporation--North Campus (HNI North); H.J. Heinz, L.P. (H.J. Heinz); 
Union Tank Car Co. (Union Tank); and HNI Corporation--Central Campus 
(HNI Central). As shown in the state's nonattainment SIP, the 
cumulative actual emissions from these sources is relatively low; the 
sources emitted a combined 0.14 tons of SO2 per year (tpy) 
in 2011. See section V.A. Emissions Inventory in this

[[Page 40091]]

preamble for the 2011 emissions data from these sources. Additionally, 
if the state were to consider the maximum fuel capacity of a source 
like Heinz that has two boilers that burn natural gas, it is unlikely 
that the SO2 emissions would be sufficient enough to cause a 
significant concentration gradient. The TAD indicates that ``other'' 
sources in the area not causing significant concentration gradients in 
the vicinity of the source(s) of interest, should be included in the 
modeling via monitored background concentrations. The EPA agrees with 
the state's recommendation that these facilities do not need to be 
explicitly modeled and that they are adequately characterized in the 
background SO2 concentrations. See section IV.E. Background 
Concentrations in this preamble for more detailed information regarding 
the determination of the background concentration.
    The state also evaluated several major sources of SO2 
emissions located outside of the nonattainment area boundary- 
MidAmerican Energy Louisa Generating Station (LGS), Gerdau Ameristeel 
(Gerdau), SSAB and Linwood and Lafarge. Linwood and Lafarge, located in 
Scott County, are approximately 20 km away from the nonattainment area. 
The selection of the Davenport monitor to represent background likely 
accounts for the emissions from Linwood and Lafarge.\8\ As such, 
Linwood and Lafarge were excluded from further consideration. See 
section IV.E. Background Concentrations in this preamble for additional 
information.
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    \8\ According to information provided by the state in its 
nonattainment SIP, the Davenport monitor is located in Scott County, 
approximately 11 km from Linwood and Lafarge, and likely accounts 
for the emissions from Lafarge and Linwood.
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    All included emission units were modeled using their actual stack 
parameters and site layout. There were no stacks above formula GEP 
(good engineering practice) height. There were stacks greater than 65 
meters at GPC, MPW, and LGS and each of those stacks were adjacent to 
tall buildings making the formula height taller than the actual stack 
height. Therefore, each of those stacks were modeled at their actual 
stack heights.
    Per EPA's April 2014 guidance, the use of allowable emissions and 
the modeling of intermittent emissions (for sources such as emergency 
generators and startup/shutdown emissions), for the purpose of modeling 
for SO2 attainment demonstrations, should follow the 
recommendations in EPA's March 2011 1-hour NO2 clarification 
memo (even though it was specific to NO2). The state's 
nonattainment SIP indicates that it addressed modeling intermittent 
sources in according with EPA's March 2011 1-hour NO2 
clarification memo, and as such all emission units that operate 
intermittently (e.g., emergency engines and fire pumps) were excluded 
from the analysis. Additionally, emission units that were limited to 
burning a specific fuel occasionally were modeled at emission rates 
that represent the fuel that is burned during normal operations. For 
example, the two auxiliary boilers (EP2 and EP3) operated by LGS are 
limited to burning fuel oil for no more than 48 hours per year. EP2 and 
EP3 burn natural gas during normal operations therefore, EP2 and EP3 
were modeled at emission rates associated with burning natural gas. EPA 
agrees with the state that it is appropriate to exclude these 
intermittent emissions (e.g., emergency engines and fire pumps) in the 
analysis and modeling the fuel burned during normal operations, as it 
is consistent with appendix W and the TAD.
    The state's nonattainment SIP acknowledges that, although 
SO2 emissions in and near the nonattainment area are 
principally attributable to point sources, a comprehensive emissions 
inventory should include an assessment of the other source sectors. The 
state asserted that it accomplished this by using estimates of air 
emissions for the onroad, nonroad, and nonpoint (area) sources from 
EPA's 2011 National Emissions Inventory (NEI) datasets. According to 
the state's sector summary analyses using EPA's SCC (source 
classification code) full detail data files from the 2011 NEI (version 
2, dated March 4, 2015), approximately 2.64 tons of SO2 were 
emitted by onroad mobile sources in all of Muscatine County (this 
includes areas within and outside of the nonattainment area). Nonroad 
mobile sources (which include non-road equipment, locomotives, 
commercial marine vessels, and aircraft) contributed approximately 1.99 
tpy of SO2. Again, that estimate includes nonroad mobile 
sources across all of Muscatine County.
    The state asserts that nonpoint (area) SO2 emissions 
were also relatively low, at approximately 18.73 tpy. Of that total, 
roughly half (8.92 tons) was associated with emissions mostly from 
prescribed fires. As with the mobile sectors, the nonpoint totals also 
represent sums across all of Muscatine County. The EPA agrees with the 
state's proposal that onroad, nonroad, and nonpoint sources in and near 
the Muscatine nonattainment area are adequately represented by 
background concentrations included in modeling analysis and that 
further consideration of these sectors is unnecessary. See section 
IV.E. Background Concentrations and section V. A. Emissions Inventory 
in this preamble for more detailed information.

D. Emission Limits

    Section 172(c)(6) of the CAA requires that the state's 
nonattainment plan include enforceable emission limitations, and such 
other control measures, means or techniques (including economic 
incentives such as fees, marketable permits, and auctions of emission 
rights), as well as schedules and timetables for compliance, as may be 
necessary or appropriate to provide for attainment of such standard in 
such area by the applicable attainment date. See General Preamble at 
13567-68.
    Part of the review of state's attainment plan must address the use 
of these limits, both with respect to the general suitability of using 
such limits for the purpose of meeting the requirements of CAA Sec.  
172(c)(6) with respect to whether the particular limits included in the 
plan have been suitably demonstrated to provide for attainment. The 
first subsection that follows addresses the enforceability of the 
limits in the plan, and the second subsection that follows addresses in 
the limits in particular the longer term average limits (i.e., the 21-
day average limit for MPW).
1. Enforceability
    As specified in section 172(c)(6) and section 110(a)(2)(A) of the 
CAA and 75 FR 35520, emission limitations, control measures and other 
elements in the SIP must be enforceable by the state and EPA. Working 
with GPC, MPW, and Monsanto the state developed an implementable 
control strategy designed to ensure expeditious attainment of the 1-hr 
SO2 NAAQS. The control strategy establishes source-specific 
control measures that include more stringent SO2 emissions 
limits, new control devices, and process changes. The state's 
nonattainment SIP includes these control measures with specific 
timetables for implementation, establishes minimum performance 
criteria, and provides schedules for completing verification processes. 
See section V. B. RACM/RACT in this preamble for additional 
information. New air construction permits issued to GPC, MPW, and 
Monsanto include emissions limits, timetables for compliance, and 
enforcement criteria and are the enforceable documents included in the 
state's nonattainment SIP that EPA is proposing to approve. As noted in 
the nonattainment SIP, the

[[Page 40092]]

state has the authority to implement each of the permits. Each permit 
includes notification, reporting, and recordkeeping requirements. The 
facilities must, for example, notify the state when they initiate and 
when they complete construction. Each permit also contains performance 
testing (emissions testing) obligations with specific schedules, 
methods, and frequencies for compliance. Each performance test must be 
approved by the state and a testing protocol must be submitted to the 
state in advance of the compliance demonstration. Results of the tests 
must be submitted in writing to the state in the form of a 
comprehensive report within six weeks of the completion of any testing. 
Additionally, GPC, MPW, and Monsanto are major sources under the Title 
V operating permit program and must submit semi-annual monitoring 
reports by September 30 and March 31, and an annual compliance 
certification by March 31, of each year. The state also inspects Title 
V sources at a minimum of every two years. In summary, the state has a 
comprehensive program to identify sources of violations and to 
undertake follow-up for compliance and enforcement.
    As noted in the state's May 26, 2016, submittal letter, Iowa was 
included in the agency's Response to Petition for Rulemaking; 
Restatement and Update of EPA's SSM Policy Applicable to SIPs; Findings 
of Substantial Inadequacy; and SIP Calls To Amend Provisions Applying 
to Excess Emissions During Periods of Startup, Shutdown and Malfunction 
(SSM SIP call) published June 12, 2015, (80 FR 33839). In the SSM SIP 
call, subrule 567--Iowa Administrate Code (IAC) 24.1(1) was found to be 
``substantially inadequate'' because it provides that excess emissions 
during periods of startup and shutdown are not a violation of an 
emission standard if good practices for minimizing emissions are 
followed. Each construction permit the state requested be included in 
the SIP apart if its control strategy contains SSM language from the 
subrule that is subject to the SIP call (Condition 6 of each permit). 
As such the state is requested that EPA not act on permit Condition 6 
of the included permits. EPA agrees that it would not be appropriate to 
approve Condition 6 of each permit into the SIP and propose the 
condition's exclusion.
    EPA is proposing to determine that these control measures, and the 
permits that contain them, satisfy CAA Sec.  110(a)(2)(A) and 172(c)(6) 
requirements and 75 FR 35520. It should be noted that the emission 
limit established for MPW in the control strategy of the state's 
nonattainment plan relies on a pound/hour (lb/hr) limit expressed an 
averaging time (e.g. as 21-day average) across multiple units.\9\ In 
accordance with EPA policy, the 21-day average limit is set at a lower 
level than the emission rate used in the attainment demonstration; the 
relationship between these two values is discussed in more detail in 
the following section.
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    \9\ The MPW permit included as appendix C to the nonattainment 
SIP specifies that compliance with the emission standard of 1153 lb/
hr of SO2 shall be demonstrated through the use a 
Continuous Emissions Monitoring System (CEMS) and shall be 
determined on a 21-day rolling average bases. The limit includes 
startup, shutdown and malfunction emissions. Compliance with the 
emission limit shall be demonstrated using the formula found in 
Permit Condition 15.8. The emission limit became effective January 
1, 2017.
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2. Longer Term Averaging
    As discussed in the April 2014 guidance, and in section III. 
Attainment Demonstration and Longer Term Averaging in this preamble, 
EPA has recommended that averaging times in SIP emission limits should 
not exceed the applicable NAAQS averaging time, in this case 1-hour, 
however, EPA has acknowledged that a 1-hr emission rate limit may be 
difficult to achieve at some facilities. As such EPA provided guidance 
for establishing longer term averaging limits based on a supportable 
downward adjustment of the critical emissions value. The critical 
emissions value is the 1-hr averaged emission rate that dispersion 
modeling predicts would attain the NAAQS.
    The control strategy included in the state's nonattainment SIP 
allows MPW to meet a compliance formula based on a 21-day averaging 
period across multiple units running alone or in combination. The 
formula incorporates a weighting function derived from the modeling 
results of the individual units (Units 7, 8 and 9), and downward 
adjustments of the critical emissions values. A separate downward 
adjustment was calculated for each unit using five years of unit-
specific CEMS data, 2010-2014; the state considered this data to be 
representative of the boilers' operations into the future, and reflect 
the fact that each unit is emitting from a separate stack. The 1-hour 
emissions value of 1,153 lbs/hr used in the formula incorporates the 
adjustment to a longer term limit according to the ratio of the 99th 
percentile 21-day average emission rate to the 99th percentile 1-hr 
emission rates from the CEMS data. Because the 1,153 lbs/hr value was 
derived from all 3 units operating together additional model runs were 
needed to ensure the formula was protective under other operating 
scenarios, with combinations of one or two units operating. The formula 
provides flexibility for MPW to run their three coal units alone or in 
combination in such a way that the NAAQS will be protected at all 
times. Because the units have different dispersion characteristics, the 
formula weighs each unit's individual emissions such that the critical 
modeled value in the formula is always protected.
    To determine the longer term average limit, the state determined 
the individual variability of each unit from the 2010-2014 CEMS data as 
described above. The variability value ratios of the 99th percentile 
21-day average and 99th percentile hourly values were 0.71, 0.90, 0.63 
for the three units respectively. The state determined a critical value 
for each of these units individually using their respective variability 
and stack characteristics. In the first modeling scenario (the ``All'' 
run) the state determined the hourly critical values for Units 7,8,9 as 
250 lbs/hr, 1000 lbs/hr, and 120 lbs/hr respectively, so 1,370 lbs/hr 
total from the 3 units. Applying the individual unit variability, the 
equivalent 21 day limits would be 177.5 lbs/hr, 900.0 lbs/hr, and 75.6 
lbs/hr respectively which when added together is 1,153 lbs/hr, the 
value that becomes the basis of the compliance formula. The state then 
modeled 7 combinations of emissions scenarios using the individual unit 
stack characteristics that all demonstrated compliance with the NAAQS 
and accounted for individual variability of each unit. These scenarios 
consisted of 3 model runs where the individual units were operating 
alone and 4 model runs with various combinations of units operating. 
Each run had its own hourly critical modeled value demonstrating 
compliance and these 7 runs formed the basis for the weights in the 
formula to ensure 1,153 lbs/hr was always protective of all the 
individual critical values modeled. This provided modeled emission 
rates such that a weighted formula could be derived such that any 
combination of emissions from the three individual units would always 
be at or below the value of 1,153 lbs/hr as expressed in the formula. 
Because the stacks have different dispersion characteristics and the 
modeled scenarios have different critical emission values, the formula 
derived contains different weights or multipliers for each unit's 
actual hourly emissions, but the weights are such that no individual 
unit operating alone or a combination of units will cause a NAAQS 
violation as long as the formula criteria as expressed in the permit 
are

[[Page 40093]]

met.\10\ Table 1 shows that during each operational scenario at MPW, 
combined with the control strategies for GPC and Monsanto, the current 
maximum allowable permitted emission rates from LGS, and background 
concentrations, will result in attainment of the 1-hour SO2 
NAAQS.
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    \10\ The formula for MPW, as specified in their permit is as 
follows:
    ``The owner or operator shall maintain a file of computations to 
show the total hourly emission level for SO2. The owner 
or operator shall use the total hourly SO2 emission rates 
to calculate and record the average SO2 emission rate for 
each calendar day. Effective January 1, 2017, the owner or operator 
shall use the daily average SO2 emission rates to 
demonstrate compliance with the 21-day rolling average as calculated 
below: SO2 = 2.03*(Unit 7) + 0.84*(Unit 8) + 1.22*(Unit 
9) Where, SO2 = total emissions, in pounds per hour, of 
sulfur dioxide from Unit 7, Unit 8 and Unit 9
    Unit 7 = 24-hour average sulfur dioxide emission rate, lb/hr, 
for Unit 7
    Unit 8 = 24-hour average sulfur dioxide emission rate, lb/hr, 
for Unit 8
    Unit 9 = 24-hour average sulfur dioxide emission rate, lb/hr, 
for Unit 9.

  Table 1--Cumulative Modeling Results With Each MPW Operating Scenario
------------------------------------------------------------------------
                                            Cumulative      1-hour SO2
         MPW operating scenario            model result    NAAQS ([mu]g/
                                            ([mu]g/m3)          m3)
------------------------------------------------------------------------
All.....................................          182.76             196
U9 Off..................................          182.71  ..............
U8 Off..................................          183.66  ..............
U7 Off..................................          182.88  ..............
U7 Only.................................          183.96  ..............
U8 Only.................................          181.86  ..............
U9 Only.................................          187.78  ..............
------------------------------------------------------------------------

    Based on a review of the state's submittal, the EPA believes that 
the 21-day average limit for MPW provides a suitable alternative to 
establishing a 1-hour average emission limit for this source. The state 
has used a suitable data base in an appropriate manner and has thereby 
applied an appropriate adjustment, yielding an emission limit formula 
that has comparable stringency to the 1-hour average limit that the 
state determined would otherwise have been necessary to provide for 
attainment. While the 21-day average limit allows occasions in which 
emissions may be higher than the level that would be allowed with the 
1-hour limit, the state's limit compensates by requiring average 
emissions to be lower than the level that would otherwise have been 
required by a 1-hour average limit. For reasons described above and 
explained in more detail in EPA's April 2014 guidance, EPA finds that 
appropriately set longer term average limits provide a reasonable basis 
by which nonattainment plans may provide for attainment. Based on its 
review of this general information as well as the particular 
information in state's plan, the EPA finds that the 21-day average 
limit formula for MPW in combination with other limitations in the 
state's plan, will provide for attainment of the NAAQS.

E. Background Concentrations

    The state reviewed its statewide SO2 monitoring network 
to determine an appropriate background monitoring location- the 
Davenport SO2 monitoring site. As noted by the state, the 
ideal background location chosen represents the contributions from all 
sources not explicitly modeled. Because the monitoring locations in 
Muscatine, IA are impacted significantly by sources that were included 
in the modeling analysis, those monitors were eliminated as an option 
to represent the background concentrations in the area. Of the 
remaining monitor locations, two are situated adjacent to 
industrialized areas (Cedar Rapids and Clinton), and, as such, would 
likely be an overestimate of the concentrations caused by background 
sources. The state determined that the Des Moines and Lake Sugema 
monitors were impacted by less SO2 emissions than what would 
be represented by the background for the Muscatine nonattainment area--
and, as such, would likely be an underestimation of the concentrations 
of SO2 caused by background sources.\11\
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    \11\ The Des Moines monitor is approximately 5 km from the 
nearest SO2 source. The county emissions are 
approximately 163 tpy. The Lake Sugema monitor is more than 10 km 
away from the nearest SO2 source. The state's 
nonattainment SIP indicates that are no reported major or minor 
sources of SO2 emissions in the county.
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    The state determined that the Davenport SO2 monitoring 
location was appropriate for estimating background concentrations for 
the following reasons: (1) The Davenport monitor is the nearest 
location to the nonattainment area (other than those monitors located 
in Muscatine already excluded); (2) the Davenport monitor is near a 
moderately industrialized area, but is not situated adjacent to those 
sources of emissions; (3) the Davenport monitor is in a county with a 
moderate amount of SO2 emissions; and (4) using the 
Davenport monitor is consistent with the meteorological data used for 
the analysis. For these reasons the state believed that the Davenport 
monitoring location could account for the sources screened out of the 
control strategy such as emissions from natural sources, major and 
minor point sources not included in the analysis, mobile (onroad and 
nonroad) sources, and nonpoint sources.
    The state utilized temporally varying background concentrations by 
hour and season from the Davenport SO2 monitoring location 
to account for contributions to the predicted impacts from background 
SO2 sources. To account for seasonal and diurnal variations 
in the background levels, the state based the background concentration 
on the average diurnal and seasonal concentration pattern observed at 
the Davenport monitor during the years 2011-2013. For the years 2011-
2013, the 99th percentile monitor concentration was calculated for each 
hour of the day by season and then averaged across the three years.\12\
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    \12\ The EPA's SO2 National Ambient Air Quality 
Standards Designations Modeling TAD describes an appropriate 
methodology of calculating temporally varying background monitored 
concentrations by hour of day and season (excluding periods when the 
source in question is expected to impact the monitored 
concentration). The methodology is to use the 99th percentile 
concentration for each hour of the day by season and average across 
3 years, excluding periods when the dominant source(s) are 
influencing the monitored concentration (i.e., 99th percel1tile, or 
4th highest, concentrations for hour l for January or winter, 99th 
percentile concentrations for hour 2 for January or winter, etc.).
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    The state also averaged the 2011-2013 design values for Cedar 
Rapids, Davenport, Des Moines, and Lake Sugema to determine if that 
number,

[[Page 40094]]

10.5 ppb, would be appropriate as background. The state called this the 
Tier 1 value. The Tier 1 value of 10.5 ppb is higher than all but one 
of the seasonal/diurnal concentrations. This shows that the use of the 
Tier 1 value for all hours and seasons would have been too high to 
represent the variable background concentrations. The EPA agrees with 
the state's proposal that the method of using temporally varying 
background monitor concentrations by hour and season from the Davenport 
monitoring location, as it is calculated from the 99th percentile, is 
appropriate.

F. Summary of Results

    The modeling analysis was conducted in two phases. The first phase 
(Phase 1) of the analysis was a screening analysis to determine the 
sources that needed to be included in the control strategy analysis. 
The second phase (Phase 2) of the analysis was used to develop the 
control strategy and included all significant sources identified in 
Phase 1.
1. Phase 1--Preliminary Analysis
    This phase was accomplished by modeling actual emissions from GPC, 
MPW, Monsanto, and LGS and allowable emissions from SSAB and Gerdau and 
then determining the percentage of predicted NAAQS exceedances within 
the nonattainment area to which each facility significantly 
contributed. In this way, the state determined that GPC contributed to 
100 percent of the NAAQS exceedances, MPW contributed to approximately 
25 percent of the NAAQS exceedances, Monsanto contributed to 
approximately 1 percent of the NAAQS exceedances, and LGS contributed 
to approximately 5 percent of the NAAQS exceedances. Both SSAB and 
Gerdau each modeled less than a 1 percent contribution to the NAAQS 
exceedance days within the nonattainment area. Therefore, only GPC, 
MPW, Monsanto and LGS were determined to have enough potential 
contribution to NAAQS exceedances to be evaluated further.\13\
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    \13\ The LGS facility is located immediately south of the 
nonattainment area. During the designations process, this source was 
shown to be insignificant during predicted exceedances at the Musser 
Park monitor, but as it was possible that the source could cause a 
concentration gradient in the vicinity of the southern portion of 
the nonattainment area, it was included in the analysis.
---------------------------------------------------------------------------

    The state then further subdivided the sources by classifying the 
significant contributors as either a primary or a secondary 
contributor. If the facility's significant contribution to the 
predicted NAAQS exceedance was greater than or equal to half of the 
total concentration (minus background) it was considered a primary 
contributor. If the facility's contribution was less than half of the 
total concentration, but still more than the Significant Impact Level 
(SIL) it was considered a secondary contributor.\14\
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    \14\ Per EPA's August 23, 2010, ``Guidance Concerning the 
Implementation of the 1-hour SO2 NAAQS for the Prevention 
of Significant Deterioration Program'', the SIL is 3 ppb. The EPA 
plans ``to undertake rulemaking to adopt a 1-hour SO2 SIL 
value. However, until such time as a 1-hour SO2 SIL is 
defined in the PSD regulations, we are providing an interim SIL of 3 
ppb, which we intend to use as a screening tool for completing the 
required air quality analyses for the new 1-hour SO2 SIL 
NAAQS under the federal PSD program at 40 CFR 52.21. We are also 
making the interim SIL available to States with EPA-approved 
implementation plans containing a PSD program to use at their 
discretion.'' The SIL remains an interim SIL until rulemaking is 
complete.
---------------------------------------------------------------------------

    GPC was identified as a primary contributor to all predicted NAAQS 
exceedances within the nonattainment area. GPC's max potential 
contribution was estimated as 3,180 [micro]g/m\3\ (or approximately 
1,223 ppb).\15\ GPC's contribution to the predicted NAAQS exceedance 
was greater than or equal to half of the total concentration (minus 
background) 100 percent of the time.
---------------------------------------------------------------------------

    \15\ To convert from [micro]g/m\3\ to ppb, the [micro]g/m\3\ 
value was divided by 2.6.
---------------------------------------------------------------------------

    MPW, Monsanto and LGS were identified as secondary contributors. 
MPW's max potential contribution was estimated as 107 [micro]g/m\3\ (or 
approximately 41 ppb). MPW's contribution to the predicted NAAQS 
exceedance was less than half of the total concentration, but still 
more than SIL (minus background) 26 percent of the time. Monsanto's max 
potential contribution was estimated as 28 [micro]g/m\3\ (or 
approximately 11 ppb). Monsanto's contribution to the predicted NAAQS 
exceedance was less than half of the total concentration, but still 
more than SIL (minus background) less than 1 percent of the time. LGS's 
maximum potential contribution was estimated as 59 [micro]g/m\3\ (or 
approximately 22.7 ppb). LGS's contribution to the predicted NAAQS 
exceedance was less than half of the total concentration, but still 
more than SIL (minus background) 2 percent of the time. As such, only 
GPC, MPW, Monsanto and LGS were included in the second phase of the 
analysis.
2. Phase 2--Control Strategy Development
    Sources identified in Phase 1 (GPC, MPW, Monsanto, and LGS) as 
being significant contributors were modeled at their maximum permitted 
allowable emission rates. Using the process summarized below, more 
restrictive maximum permitted emission rates were developed where 
necessary to ensure modeled attainment.
    To start its Phase 2 analysis, the state provided GPC with a model 
input file that included its emission units as well as the exceedance 
receptors to which it contributed. The state's nonattainment SIP 
submittal indicates that GPC reviewed the input data for accuracy and 
then mitigated all modeled exceedances caused by the GPC facility 
alone.
    The remaining facilities (MPW, Monsanto, and LGS) were then added 
to the analysis with their maximum permitted allowable emission rates 
and the cumulative impacts were determined across the entire 
nonattainment area. According to the state's nonattainment SIP 
submittal, the remaining predicted exceedances were then discussed with 
Monsanto and MPW. As a result of those discussions, additional control 
measures were developed for those facilities and are incorporated in 
construction permits submitted as part of the SIP revision. See section 
V.B. in this preamble for more information regarding the control 
measures.
    Monsanto proposed to decrease the emission rate for Boiler 8 at its 
facility to mitigate exceedances just north of its property. MPW 
proposed multiple model scenarios with combined operation of Units 7, 
8, and 9. Regardless of the operational scenario, the unit/units were 
modeled at an equation cap of 1,153 lb/hr SO2. The model 
results varied depending on which combination of boilers was running. 
Each of the modeling scenarios (with background included) resulted in 
concentrations below the 1-hour SO2 NAAQS. The highest 
modeled SO2 concentration was 187.87 ug/m\3\ which included 
the operation of just Unit 9 at MPW. See section IV.D.2. Longer Term 
Averaging limits, in this preamble, for more discussion of the equation 
used to determine compliance with the NAAQS for each MPW modeling 
scenario.
    These results indicate that the controls established in the 
construction permits for MPW, GPC and Monsanto result in attainment of 
the NAAQS, and as such, additional controls were not necessary for LGS 
in order for the area to attain. EPA agrees with the state's 
determination that its control strategy analysis results in modeled 
concentrations throughout the nonattainment area that are at or below 
75 ppb/196.4 ug/m\3\. Based upon monitoring data discussed in section 
V.B. RACM/RACT in this preamble, EPA expects that the Muscatine area 
will attain by the attainment date, August 5, 2018.

[[Page 40095]]

V. Review of Other Plan Requirements

A. Emissions Inventory and the Quantification of Emissions

    Section 172(c)(3) of the CAA requires that the state's 
nonattainment plan include a comprehensive, accurate, current inventory 
of actual emissions from all sources of the relevant pollutant or 
pollutants in such area, including such periodic revisions as the 
Administrator may determine necessary to assure that the requirements 
of this part are met. Section 172(c)(4) of the CAA requires that the 
state's nonattainment plan expressly identify and quantify the 
emissions, if any, of any such pollutant or pollutants which will be 
allowed, in accordance with section 703(a)(1)(B) of the CAA, from the 
construction and operation of major new or modified stationary sources 
in each such area. The plan shall demonstrate to the satisfaction of 
the Administrator that the emissions quantified for this purpose will 
be consistent with the achievement of reasonable further progress and 
will not interfere with attainment of the applicable National Ambient 
Air Quality Standard by the applicable attainment date.
    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 the April 2014 guidance. 
Additional emission inventory information was discussed in section IV.C 
Emissions Data in this preamble. A brief summary is provided later in 
this action.
    The base year inventory establishes a baseline that is used to 
evaluate emissions reductions achieved by the control strategy and to 
assess reasonable further progress requirements. The state's 
nonattainment SIP noted that, at the time, the most recent and 
available triennial inventory year was 2011 and the stated found that 
it served as a suitable base year. Table 2 provides the 2011 
SO2 emissions inventory data for sources within and outside 
of the nonattainment the area (data have been rounded to the nearest 
whole number).

       Table 2--Base Line Emission Inventory for the Muscatine, IA
                           Nonattainment Area
------------------------------------------------------------------------
                                                             2011 SO2
                                         Facility            emissions
                                                               (tpy)
------------------------------------------------------------------------
           Base Line Emissions Inventory for the Muscatine NAA
------------------------------------------------------------------------
Inside of the NAA..............  Grain Processing                 10,810
                                  Corporation.
                                 Muscatine Power and               2,374
                                  Water.
                                 Monsanto...............             537
                                 HNI Corp.--North Campus              <1
                                 HNI Corp.--Central                   <1
                                  Campus.
                                 H.J. Heinz L.P.........              <1
                                 Union Tank Car Co......              <1
Outside of the NAA.............  Louisa Generating                 7,304
                                  Station.
All of Muscatine County........  Onroad Mobile..........               3
                                 Nonroad Mobile.........               2
                                 Area Sources...........              10
                                 Fires..................               9
                                                         ---------------
    Total......................  .......................          21,049
------------------------------------------------------------------------

    Although not part of the state's discussion of its 2011 baseline 
emissions inventory, the state's nonattainment SIP also provides 2013 
SO2 data for Gerdau and SSAB in Muscatine County and Linwood 
and Lafarge in Scott County. However, the state provided this as a sum 
for the sources by county (e.g., the sum of Gerdau and SSAB was 254 tpy 
and the sum of Linwood and Lafarge was 1,539 tpy). Gerdau and SSAB are 
approximately 8-9 km away from the nonattainment boundary and Linwood 
and Lafarge are approximately 20 km away from the nonattainment area 
boundary.
    As already noted, the state's nonattainment SIP must identify and 
quantify the emissions which will be allowed from the construction and 
operation of major new or modified stationary sources in the area (see 
CAA Sec.  172(c)(4)). The state must demonstrate that such emissions 
will be consistent with RFP requirements and will not interfere with 
attainment of the 1-hr SO2 NAAQS. These requirements are met 
by the states preconstruction permitting program and implementation of 
the Nonattainment New Source Review Rules (NNSR). See section C. 
Nonattainment New Source Review in this preamble for more information.
    According to EPA's April 2014 SO2 guidance, the SIP 
should also include a projected attainment year inventory that includes 
estimated emissions for all emission sources of SO2 that 
were determined to have an impact on the affected nonattainment area 
for the year in which the area is expected to attain the standard, 
consistent with the attainment demonstration. The inventory should 
reflect projected emissions for the attainment year for all 
SO2 sources in the nonattainment area. The state's 
nonattainment SIP provided a projected inventory only for the 
controlled sources, as provided in table 3. The inventory was developed 
assuming each SO2 source operates 8,760 hours per year at 
its permitted maximum allowable emission rate.\16\
---------------------------------------------------------------------------

    \16\ The projections don't consider operational, physical, 
supply/demand, or other factors that typically curb actual emissions 
to values below the maximum permitted allowable rate. There is 
potential for the actual attainment-year emissions to be lower than 
those in Table 2.

[[Page 40096]]



 Table 3--Projected Allowable Annual SO2 Emissions From Control Strategy
                                 Sources
------------------------------------------------------------------------
                                                               2018 SO2
                                                               emissions
                          Facility                               (tpy)
 
------------------------------------------------------------------------
           Projected 2018 Emissions for the Controlled Sources
------------------------------------------------------------------------
Grain Processing Corporation................................         167
Muscatine Power and Water...................................       5,051
Monsanto....................................................       1,196
------------------------------------------------------------------------

    The EPA is proposing to determine that the state has met the 
requirements of CAA Sec.  172(c)(3) and 172(c)(4).

B. RACM/RACT

    CAA Sec.  172(c)(1) requires that the state's nonattainment plan 
provide for the implementation of all RACM as expeditiously as 
practicable (including such reductions in emissions from existing 
sources in the area as may be obtained through the adoption, at a 
minimum, of RACT) and shall provide for attainment of the NAAQS. The 
state's plan for attaining the 1-hour SO2 NAAQS in the 
Muscatine nonattainment area is based on a variety of control measures 
at GPC, MPW and Monsanto. Those measures were included in the state's 
nonattainment SIP as construction permits.\17\
---------------------------------------------------------------------------

    \17\ Appendix B, C and D of the state's nonattainment SIP 
contain the Federally enforceable air construction permits that 
define RACM/RACT requirements. The RACM/RACT limits taken to comply 
with the NAAQS are specifically noted in each permit via footnotes 
in the permits.
---------------------------------------------------------------------------

    To ensure the SO2 NAAQS is attained, GPC must install 
additional scrubbers, comply with new and more stringent SO2 
emission limits, and implement process modifications designed to ), 
andreduce SO2 emissions across numerous downstream sources. 
Table 4-1 of the state's nonattainment SIP lists all the sources 
included in the control strategy, contains descriptions of the control 
measures, and provides effective dates. Source specific permitted 
allowable emission rates, compliance and monitoring obligations, 
reporting and recordkeeping requirements, and implementation deadlines 
(where not immediately effectively upon permit issuance) are detailed 
in each construction permit included with the SIP submittal (appendix B 
of the state's nonattainment plan). The GPC control strategy includes 
measures at 52 emission points (EP) at the facility. In summary, those 
measures include EP0001.0 (Power House Boilers 1-4 and 6-7) is subject 
to a more stringent SO2 emission limit based on natural gas 
combustion; EP546.0 is subject to a more stringent, source-specific 
SO2 limit of .0034 lb/hr; a requirement to continue to add 
sodium bisulfate to the steep water instead of sulfur dioxide in order 
to reduce SO2 emissions from the steeping operations and 
downstream processes; the establishment of source specific 
SO2 emission limits at 43 EPs and the required installation 
of scrubbers on EP015.0 (Germ Drier Nos. 1 and 2), EP097.0 (Germ Drier 
No. 3), EP126.0 (Germ Drier No. 4), EP200N (Corn Steep Tank Nos. 1-30 
and the North Wet Corn Drag), EP200S (Corn Steep Tank Nos. 31-62 and 
the South Wet Corn Drag), and EP279.0 (Wet Milling Nos. 1-6). The state 
expects the installation of the scrubbers to reduce SO2 
emissions by up to 90 percent from those units.\18\
---------------------------------------------------------------------------

    \18\ The state's estimation of a 90 percent reduction in 
SO2 emissions is based off of the control efficiency 
readily achieved by the types of scrubbers being installed.
---------------------------------------------------------------------------

    While the scrubber installations will not be completed by January 
1, 2017, the desired target date discussed in EPA's April 2014 
guidance, the scrubbers will be operational as expeditiously as 
practicable. Based on permitted requirements, three of the six new 
scrubbers must be in operation no later than August 30, 2017, with the 
final scrubber operational by March 31, 2018. The installation 
timetable accommodates factors such as demolition and construction 
schedules, structural modifications, ductwork design, and the addition 
of scrubber water treatment capacity. The state asserts in its 
nonattainment plan that the scrubber installation timeline will not 
delay or prevent timely attainment of the 1-hr SO2 NAAQS.
    It should also be noted that, on July 14, 2015, GPC converted all 
of its coal-fired boilers to natural gas. The state estimates that the 
fuel switch will result in a 96 percent reduction in the facility's 
total SO2 emissions. In terms of 2011 data, this fuel switch 
eliminated 10,374 tons of SO2 emissions. The state believes, 
and the EPA agrees, that the fuel conversion from coal to natural gas 
in GPC's boilers has significantly reduced measured ambient 
SO2 concentrations in Muscatine, as noted in Table 4. Based 
on existing air quality improvements the state projects that monitored 
attainment will be achieved by the attainment date. Appendix B of the 
state's nonattainment SIP contains the Federally enforceable air 
construction permits that define GPC's RACM/RACT requirements.

                                                                    Table 4--Air Monitoring Data From the Musser Park Monitor
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                Design values (ppb)                     99th Percentile daily max 1-hr SO2 concentrations (ppb)
-------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                     -----------------------------------------------------------
              Monitor location                     1-hr SO2 NAAQS (ppb)         2011-2013     2012-2014     2013-2015     2014-2016     2011      2012      2013      2014      2015      2016
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Musser Park.................................  75............................          217           194           158           113       248       224       179       180       116        45
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    MPW is subject to several Federal programs that directly or 
indirectly affect SO2 emissions, including the Acid Rain 
provisions of title IV of the CAA, the Cross State Air Pollution Rule 
(CSAPR), and the CAA section 112 Maximum Achievable Control Technology 
regulations more commonly known as the Mercury and Air Toxics 
Standards. However, the state did not rely on these Federal programs 
alone to address SO2 emissions. Instead, as per the states 
control strategy, MPW will comply with new SO2 emission 
limits that provide for attainment of the NAAQS. The control measures, 
described in table 4-2 of the state's nonattainment SIP, account for 
seven possible operating scenarios involving the three coal-fired 
boilers (Units 7, 8, and 9). Permit No. 74-A-175-S3, issued to the 
facility in 2013, shows the SO2 emission limit for Units 7 
and 8 was a combined maximum of 2,772 lb/hr. Permit No. 80-A-191-P2, 
issued to the facility in 2013, shows the SO2 emission limit 
for Unit 9 was 0.56 lb/MMBtu (a maximum daily average). Permit No. 80-
A-191-P4, issued to the facility in 2016 as part of the control 
strategy of

[[Page 40097]]

the state's nonattainment SIP, shows the combined SO2 
emissions from Units 7-9 must be less than 1,153 lbs/hr.
    The control strategy for MPW also addresses emission reductions 
from EP60 (Auxiliary Boiler). A permit issued to the facility in 2013, 
Permit No. 13-A-152, for the Auxiliary Boiler required that 
SO2 emissions be limited to limited 0.44 lbs/MMBtu 
(expressed as the average of 3 runs) when burning fuel oil, and to 500 
ppm by volume when burning natural gas or propane.\19 20\ The permit 
issued to the facility in 2016, as part of the control strategy, Permit 
No. 13-A-152-S1, requires that the SO2 emissions be limited 
to 0.45 lb/hr and that the sulfur content of the distillate fuel oil 
combusted in the unit not exceed 15 ppm. Appendix C of the state's 
nonattainment SIP contains the Federally enforceable air construction 
permits that define MPW's RACM/RACT requirements. These permits are 
effective January 1, 2017.
---------------------------------------------------------------------------

    \19\ The unit's 0.44 lbs/MMBtu emission rate is a Lowest 
Achievable Emission Rate (LAER).
    \20\ The limit of 500 ppm by volume is from state rule.
---------------------------------------------------------------------------

    The control measures developed for Monsanto, described in table 4-3 
of the state's nonattainment SIP, establish lower emission limits on 
two sources--EP-195 (Boiler #8) and EP-234 (CAC Process Flare). The 
Boiler #8 control strategy includes a more stringent SO2 
emission limit. A 2007 permit issued to the facility Permit No. 82-A-
092-P9, limited the unit's SO2 emissions to 292.5 lb/hr. The 
permit issued to the facility in 2015, Permit No. 82-A-092-P11, as part 
of the control strategy, limits the unit's SO2 emissions to 
273 lb/hr.\21\
---------------------------------------------------------------------------

    \21\ The unit also has a 1.95 lbs/MMBtu based on a 3-hr rolling 
average limit is a Best Available Control Technology limit.
---------------------------------------------------------------------------

    The control strategy for the CAC Process Flare includes new 
SO2 emission limit that restricts the unit's fuel use to 
natural gas only. A 2012 permit issued to the facility, Permit No. 88-
A-001-S2, limited the unit's SO2 emissions to 500 ppm by 
volume. The permit issued to the facility in 2015, Permit No. 88-A-001-
S3, as part of the control strategy, limits the unit to burning only 
natural gas and the unit's SO2 emissions to 0.02 lb/hr. 
Appendix D of the state's nonattainment SIP contains the Federally 
enforceable air construction permits that define Monsanto's RACM/RACT 
requirements. These permits are effective May 13, 2015.
    The state has determined that these measures suffice to provide for 
attainment the attainment date, August 5, 2018. EPA concurs and 
proposes to conclude that the state has satisfied the requirement in 
CAA Sec.  172(c)(1) to adopt and submit all RACM as needed to attain 
the standards as expeditiously as practicable.

C. Nonattainment New Source Review (NNSR)

    Section 172(c)(5) requires that the state's nonattainment plan 
provisions shall require permits for the construction and operation of 
new or modified major stationary sources anywhere in the nonattainment 
area, in accordance with section CAA Sec.  173. EPA approved the 
state's nonattainment new source review rules on May 15, 2014 (79 FR 
27763). These rules provide for appropriate new source review for 
SO2 sources undergoing construction or major modification in 
the Muscatine nonattainment area without need for modification of the 
approved rules. Therefore, EPA concludes that the requirements of CAA 
Sec.  172(c)(5) have been met.

D. Reasonable Further Progress (RFP)

    Section 172(c)(2) requires that nonattainment plans include 
provisions addressing reasonable further progress (RFP). Reasonable 
further progress is defined in CAA Sec.  171(1) as: ``. . . such annual 
incremental reductions in emissions of the relevant air pollutant as 
are required by this part [part D] or may reasonably be required by the 
Administrator for the purpose of ensuring attainment of the applicable 
national ambient air quality standard by the applicable date.''
    As discussed in EPA's April 2014 guidance, this definition is most 
appropriate for pollutants that are emitted by numerous and diverse 
sources, where the relationship between any individual source and 
overall air quality is not explicitly quantified, and where NAAQS 
attainment requires inventory-wide emissions reductions. The 
SO2 NAAQS presents special circumstances because there are 
usually a limited number of well-defined sources affecting the area's 
air quality and any emission control measures commonly result in swift 
improvements that typically occur in one step. As noted in the state's 
nonattainment SIP, the EPA has interpreted that RFP is best construed 
as ``adherence to an ambitious compliance schedule'' in previous 
rulemaking.\22\
---------------------------------------------------------------------------

    \22\ See 74 FR 13547 (April 16, 1992).
---------------------------------------------------------------------------

    As previously noted in section V.B. RACT/RACM, in this preamble, 
the SO2 emission limits and application of control 
technologies established for Monsanto (effective on May 13, 2015), MPW 
(effective January 1, 2017) and for GPC occur on reasonable timelines.
    The state asserts 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. The state concluded that its 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 as required by CAA Sec.  172(c)(2).

E. Contingency Measures

    Section 172(c)(9) of the CAA requires that the state's 
nonattainment plan provide for the implementation of specific measures 
to be undertaken if the area fails to make reasonable further progress, 
or to attain the national primary ambient air quality standard by the 
attainment date applicable under this part. Such measures shall be 
included in the plan revision as contingency measures to take effect in 
any such case without further action by the State or the Administrator.
    EPA's April 2014 guidance describes special features of 
SO2 planning that influence the suitability of alternative 
means of addressing the requirement in section 172(c)(9) for 
contingency measures for SO2, such that in particular an 
appropriate means of satisfying this requirement is for the state to 
have a comprehensive enforcement program that identifies sources of 
violations of the SO2 NAAQS and to undertake an aggressive 
follow-up for compliance and enforcement.
    The state's nonattainment SIP provides that, after full 
implementation of the control strategy, contingency measures will be 
triggered if monitored ambient air quality records 1-hr SO2 
NAAQS violation in the nonattainment area, or if the nonattainment area 
fails to meet RFP. If triggered, the state will evaluate culpabilities 
for the violation and will plan to complete the investigation within 3 
months of the trigger. Where the investigation concludes unequivocally 
that SO2 emissions from one of the three sources in the 
control strategy is the cause of the recorded 1-hr SO2 NAAQS 
violation or failure to achieve RFP, the state will conduct a 
compliance evaluation and establish orders for the abatement or control 
of air pollution or make changes to the GPC, MPW, or Monsanto 
construction permits. Orders or construction permits will be issued 
within approximately 9 months of completion of the investigation and 
could include fuel switches, addition of

[[Page 40098]]

controls, curtailment of production, reducing boiler operating loads, 
or other appropriate measures necessary to mitigate the violation.
    EPA proposes to approve the state's plan for meeting the 
contingency measure requirement of CAA Sec.  172(c)(9).

VI. Additional Elements of the State's Submittal

A. Compliance With Section 110(a)(2) of the CAA

    Section 172(c)(7) of the CAA requires nonattainment SIPs to meet 
the applicable provisions of CAA Sec.  110(a)(2). While the provisions 
of 110(a)(2) address various topics, EPA's past determinations suggest 
that only the Sec.  110(a)(2) criteria which are linked with a 
particular area's designation and classification are relevant to Sec.  
172(c)(7). This nonattainment SIP submittal satisfies all applicable 
CAA Sec.  110(a)(2) criteria, as evidenced by the state's nonattainment 
new source review program which addresses 110(a)(2)(I), the included 
control strategy, and the associated emissions limits which are 
relevant to 110(a)(2)(A). In addition, on July 26, 2013, Iowa submitted 
to EPA an infrastructure SIP to demonstrate that the state has the 
necessary plans, programs, and statutory authority to implement the 
requirements of section 110 of the CAA as they pertain to the 2010 1-hr 
SO2 NAAQS. EPA will take action on the state's 
SO2 infrastructure SIP in a separate rulemaking. The EPA is 
proposing to conclude that the state has meet the requirements of CAA 
Sec.  172(c)(7).

B. Equivalent Techniques

    Section 172(c)(8) of the CAA states that upon application by any 
state, the Administrator may allow the use of equivalent modeling, 
emission inventory, and planning procedures, unless the Administrator 
determines that the proposed techniques are, in the aggregate, less 
effective than the methods specified by the Administrator.
    The state's nonattainment SIP indicates that it followed existing 
regulations, guidance, and standard practices when conducting modeling, 
preparing the emissions inventories, and implementing its planning 
procedures. Therefore, the state did not use or request approval of 
alternative or equivalent techniques as allowed under of the CAA and 
the EPA is proposing to conclude that the state's nonattainment SIP 
meets the requirements of CAA Sec.  172(c)(8).

VII. EPA's Proposed Action

    The EPA is proposing to approve the nonattainment SIP submission, 
which the state submitted to EPA on May 26, 2016, for attaining the 
2010 1-hour SO2 NAAQS for the Muscatine nonattainment area 
and for meeting other nonattainment area planning requirements. This 
SO2 attainment plan includes the state's attainment 
demonstration for the Muscatine nonattainment area. The nonattainment 
area plan also addresses requirements for RFP, RACT/RACM, base-year and 
projection-year emission inventories, and contingency measures.
    The EPA has determined that the state's nonattainment plan meets 
applicable requirements of the section 172 of the CAA (107(c)(1) 
through (9). EPA's analysis is discussed in this proposed rulemaking.
    The EPA is taking public comments for thirty days following the 
publication of this proposed action in the Federal Register. We will 
take all comments into consideration in our final action.

VIII. 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 the Iowa Regulations described in the amendments to 40 CFR 
part 52 set forth below. EPA has made, and will continue to make, these 
materials generally available through https://www.regulations.gov and/
or at the EPA Region 7 Office (please contact the person identified in 
the For Further Information Contact section of this preamble for more 
information).
    Therefore, these materials have been approved by EPA for inclusion 
in the State implementation plan, have been incorporated by reference 
by EPA into that plan, are fully Federally enforceable under sections 
110 and 113 of the CAA as of the effective date of the final rulemaking 
of EPA's approval, and will be incorporated by reference by the 
Director of the Federal Register in the next update to the SIP 
compilation.\23\
---------------------------------------------------------------------------

    \23\ 62 FR 27968 (May 22, 1997).
---------------------------------------------------------------------------

IX. Statutory and Executive Order Reviews

    Under the CAA, 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 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);
     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).
    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.


[[Page 40099]]


    Dated: August 9, 2017.
Edward H. Chu,
Acting Regional Administrator, Region 7.
    For the reasons stated in the preamble, EPA proposes to amend 40 
CFR part 52 as set forth below:

Part 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

0
1. The authority citation for part 52 continues to read as follows:

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

Subpart Q--Iowa

0
2. Amend Sec.  52.820 by:
0
a. In the table in paragraph (d), adding entries ``(112)'' through 
``(169)'' in numerical order; and
0
b. In the table in paragraph (e), adding an entry ``(47)'' in numerical 
order.
    The additions read as follows:


Sec.  52.820  Identification of plan.

* * * * *
    (d)* * *

                                EPA-Approved Iowa Source-Specific Orders/Permits
----------------------------------------------------------------------------------------------------------------
                                                          State
         Name of source           Order/permit No.   effective date   EPA approval date        Explanation
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
(112) Grain Processing           Permit No. 95-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     374-S4.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(113) Grain Processing           Permit No. 15-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     078.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(114) Grain Processing           Permit No. 79-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     194-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(115) Grain Processing           Permit No. 71-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     067-S4.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(116) Grain Processing           Permit No. 75-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     087-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(117) Grain Processing           Permit No. 72-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     199-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(118) Grain Processing           Permit No. 74-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     014-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(119) Grain Processing           Permit No. 74-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     015-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(120) Grain Processing           Permit No. 75-A-            7/6/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     353-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(121) Grain Processing           Permit No. 79-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     195-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(122) Grain Processing           Permit No. 80-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     149-S5.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].

[[Page 40100]]

 
(123) Grain Processing           Permit No. 80-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     150-S5.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(124) Grain Processing           Permit No. 85-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     031-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(125) Grain Processing           Permit No. 85-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     032-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(126) Grain Processing           Permit No. 85-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     038-P1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(127) Grain Processing           Permit No. 85-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     135-P1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(128) Grain Processing           Permit No. 90-A-            7/6/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     111-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(129) Grain Processing           Permit No. 91-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     068-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(130) Grain Processing           Permit No. 93-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     110-P1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(131) Grain Processing           Permit No. 92-A-            7/6/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     383-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(132) Grain Processing           Permit No. 92-A-            7/6/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     385-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(133) Grain Processing           Permit No. 94-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     055-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(134) Grain Processing           Permit No. 94-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     061-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(135) Grain Processing           Permit No. 02-A-            7/6/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     781-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(136) Grain Processing           Permit No. 02-A-            7/6/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     782-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].

[[Page 40101]]

 
(137) Grain Processing           Permit No. 09-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     482-S2.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(138) Grain Processing           Permit No. 10-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     563-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(139) Grain Processing           Permit No. 15-A-           3/25/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     200.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(140) Grain Processing           Permit No. 15-A-           3/25/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     201.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(141) Grain Processing           Permit No. 15-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     202.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(142) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     203.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(143) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     204.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(144) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     205.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(145) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     206.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(146) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     207.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(147) Grain Processing           Permit No. 15-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     208.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(148) Grain Processing           Permit No. 15-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     209.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(149) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     480.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(150) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     481.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].

[[Page 40102]]

 
(151) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     482.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(152) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     483.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(153) Grain Processing           Permit No. 15-A-           1/26/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     213.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(154) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     484.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(155) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     485.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(156) Grain Processing           Permit No. 15-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     486.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(157) Grain Processing           Permit No. 15-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     326.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(158) Grain Processing           Permit No. 03-A-            7/6/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     471-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(159) Grain Processing           Permit No. 05-A-           2/15/16  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     926-S4.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(160) Grain Processing           Permit No. 06-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     1261-S1.                            publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(161) Grain Processing           Permit No. 11-A-            7/6/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     338-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(162) Grain Processing           Permit No. 15-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     354.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(163) Grain Processing           Permit No. 15-A-          12/10/15  [date of final      2010 1-hr SO2 NAAQ
 Corporation.                     199.                                publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(164) Muscatine Power and Water  Permit No. 13-A-            3/2/16  [date of final      2010 1-hr SO2 NAAQ
                                  152-S1.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].

[[Page 40103]]

 
(165) Muscatine Power and Water  Permit No. 74-A-            3/2/16  [date of final      2010 1-hr SO2 NAAQ
                                  175-S4.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(166) Muscatine Power and Water  Permit No. 95-A-            3/2/16  [date of final      2010 1-hr SO2 NAAQ
                                  373-P3.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(167) Muscatine Power and Water  Permit No. 80-A-            3/2/16  [date of final      2010 1-hr SO2 NAAQ
                                  191-P3.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(168) Monsanto.................  Permit No. 82-A-           5/13/15  [date of final      2010 1-hr SO2 NAAQ
                                  092-P11.                            publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
(169) Monsanto.................  Permit No. 88-A-           5/13/15  [date of final      2010 1-hr SO2 NAAQ
                                  001-S3.                             publication in      Nonattainment Plan;
                                                                      the Federal         Condition 6 of the
                                                                      Register] and       permit is not part of
                                                                      [Federal Register   the SIP; EPA-R07-OAR-
                                                                      citation].          2017-0416; FRL-XXXX-
                                                                                          Region 7].
----------------------------------------------------------------------------------------------------------------

    (e)* * *

                                   EPA-Approved Iowa Nonregulatory Provisions
----------------------------------------------------------------------------------------------------------------
                                     Applicable
   Name of nonregulatory SIP        geographic or         State       EPA approval date        Explanation
           provision             nonattainment area  submittal date
----------------------------------------------------------------------------------------------------------------
 
                                                  * * * * * * *
(47) 2010 1-hr SO2 National      A portion of               5/26/16  [date of final      EPA-R07-OAR-2017-0416;
 Ambient Air Quality Standard     Muscatine County.                   publication in      FRL-XXXX-Region 7].
 Nonattainment Plan.                                                  the Federal
                                                                      Register] and
                                                                      [Federal Register
                                                                      citation].
----------------------------------------------------------------------------------------------------------------

* * * * *

[FR Doc. 2017-17736 Filed 8-23-17; 8:45 am]
 BILLING CODE 6560-50-P



                                                    40086                 Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                    Environmental Management (ADEM),                        rule and incorporated herein by                       DATES:   Comments must be received on
                                                    on May 7, 2012. The portion of the                      reference. If no adverse comments are                 or before September 25, 2017.
                                                    revision that EPA is proposing to                       received in response to this rule, no                 ADDRESSES: Submit your comments,
                                                    approve relates to the State’s Prevention               further activity is contemplated. If EPA              identified by Docket ID No. EPA–R07–
                                                    of Significant Deterioration (PSD)                      receives adverse comments, the direct                 OAR–2017–0416 to https://
                                                    permitting regulations. In particular, the              final rule will be withdrawn and all                  www.regulations.gov. Follow the online
                                                    revision adds a definition of                           adverse comments received will be                     instructions for submitting comments.
                                                    ‘‘replacement unit’’ and provides that a                addressed in a subsequent final rule                  Once submitted, comments cannot be
                                                    replacement unit is a type of existing                  based on this proposed rule. EPA will                 edited or removed from Regulations.gov.
                                                    emissions unit under the definition of                  not institute a second comment period                 The EPA may publish any comment
                                                    ‘‘emissions unit.’’ This action is being                on this document. Any parties                         received to its public docket. Do not
                                                    taken pursuant to the Clean Air Act                     interested in commenting on this                      submit electronically any information
                                                    (CAA or Act).                                           document should do so at this time.                   you consider to be Confidential
                                                    DATES: Written comments must be                           Dated: August 7, 2017.                              Business Information (CBI) or other
                                                    received on or before September 25,                     V. Anne Heard,                                        information whose disclosure is
                                                    2017.                                                                                                         restricted by statute. Multimedia
                                                                                                            Acting Regional Administrator, Region 4.
                                                    ADDRESSES: Submit your comments,                                                                              submissions (audio, video, etc.) must be
                                                                                                            [FR Doc. 2017–17343 Filed 8–23–17; 8:45 am]
                                                    identified by Docket ID No. EPA–R04–                                                                          accompanied by a written comment.
                                                                                                            BILLING CODE 6560–50–P
                                                    OAR–2017–0371 at http://                                                                                      The written comment is considered the
                                                    www.regulations.gov. Follow the online                                                                        official comment and should include
                                                    instructions for submitting comments.                   ENVIRONMENTAL PROTECTION                              discussion of all points you wish to
                                                    Once submitted, comments cannot be                      AGENCY                                                make. The EPA will generally not
                                                    edited or removed from Regulations.gov.                                                                       consider comments or comment
                                                    EPA may publish any comment received                    40 CFR Part 52                                        contents located outside of the primary
                                                    to its public docket. Do not submit                                                                           submission (i.e., on the web, cloud, or
                                                    electronically any information you                                                                            other file sharing system). For
                                                                                                            [EPA–R07–OAR–2017–0416; FRL–9966–60–
                                                    consider to be Confidential Business                    Region 7]                                             additional submission methods, the full
                                                    Information (CBI) or other information                                                                        EPA public comment policy,
                                                    whose disclosure is restricted by statute.              Approval of Iowa’s Air Quality                        information about CBI or multimedia
                                                    Multimedia submissions (audio, video,                   Implementation Plan; Muscatine Sulfur                 submissions, and general guidance on
                                                    etc.) must be accompanied by a written                  Dioxide Nonattainment Area                            making effective comments, please visit
                                                    comment. The written comment is                                                                               https://www2.epa.gov/dockets/
                                                    considered the official comment and                     AGENCY:  Environmental Protection                     commenting-epa-dockets.
                                                    should include discussion of all points                 Agency (EPA).                                         FOR FURTHER INFORMATION CONTACT:
                                                    you wish to make. EPA will generally                    ACTION: Proposed rule.                                Tracey Casburn, Environmental
                                                    not consider comments or comment                                                                              Protection Agency, Air Planning and
                                                    contents located outside of the primary                 SUMMARY:   The Environmental Protection               Development Branch, 11201 Renner
                                                    submission (i.e., on the web, cloud, or                 Agency (EPA) is proposing to approve                  Boulevard, Lenexa, Kansas 66219 at
                                                    other file sharing system). For                         the State Implementation Plan (SIP)                   (913) 551–7016, or by email at
                                                    additional submission methods, the full                 revision, which the State of Iowa (the                casburn.tracey@epa.gov.
                                                    EPA public comment policy,                              state) submitted to the EPA on May 26,                SUPPLEMENTARY INFORMATION:
                                                    information about CBI or multimedia                     2016, for attaining the 1-hour sulfur                 Throughout this document whenever
                                                    submissions, and general guidance on                    dioxide (SO2) primary National Ambient                ‘‘we,’’ ‘‘us,’’ and ‘‘our’’ is used, we mean
                                                    making effective comments, please visit                 Air Quality Standard (NAAQS) for the                  the EPA.
                                                    http://www2.epa.gov/dockets/                            Muscatine nonattainment area. This                       Organization of this document. The
                                                    commenting-epa-dockets.                                 plan (herein called a ‘‘nonattainment                 following outline is provided to aid in
                                                    FOR FURTHER INFORMATION CONTACT:                        plan’’) includes the state’s attainment               locating information in this preamble.
                                                    Andres Febres of the Air Regulatory                     demonstration and other elements
                                                    Management Section, Air Planning and                    required under Clean Air Act (CAA)                    Table of Contents
                                                    Implementation Branch, Air, Pesticides                  sections 172, 191, and 192. In addition               I. Why was Iowa required to submit an SO2
                                                    and Toxics Management Division, U.S.                    to an attainment demonstration, the                         plan for the Muscatine area?
                                                    Environmental Protection Agency,                        plan addresses the requirement for                    II. Requirements for SO2 Nonattainment Area
                                                    Region 4, 61 Forsyth Street SW.,                        meeting reasonable further progress                         Plans
                                                    Atlanta, Georgia 30303–8960. Mr.                        (RFP) toward attainment of the NAAQS,                 III. Attainment Demonstration and Longer
                                                                                                                                                                        Term Averaging
                                                    Febres can be reached via telephone at                  reasonably available control measures                 IV. Review of Modeled Attainment Plan
                                                    (404) 562–8966 or via electronic mail at                and reasonably available control                         A. Model Selection
                                                    febres-martinez.andres@epa.gov.                         technology (RACM/RACT), base-year                        B. Meteorological Data
                                                    SUPPLEMENTARY INFORMATION:                              and projection-year emission                             C. Emissions Data
                                                       In the Final Rules Section of this                   inventories, and contingency measures.                   D. Emission Limits
                                                    Federal Register, EPA is approving the                  The EPA proposes to conclude that the                    1. Enforceability
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                                                    portion of Alabama’s May 7, 2012, SIP                   state has appropriately demonstrated                     2. Longer Term Averaging
                                                    revision addressing the State’s PSD                     that the plan provisions provide for                     E. Background Concentrations
                                                    program as a direct final rule without                  attainment of the 2010 1-hour primary                    F. Summary of Results
                                                                                                                                                                     1. Phase 1—Preliminary Analysis
                                                    prior proposal because the Agency                       SO2 NAAQS in the Muscatine                               2. Phase 2—Control Strategy Development
                                                    views this as a noncontroversial                        nonattainment area by the applicable                  V. Review of Other Plan Requirements
                                                    submittal and anticipates no adverse                    attainment date and that the plan meets                  A. Emissions Inventory and the
                                                    comments. A detailed rationale for the                  the other applicable requirements under                     Quantification of Emissions
                                                    approval is set forth in the direct final               CAA sections 172, 191, and 192.                          B. RACM/RACT



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                                                                          Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                         40087

                                                      C. Nonattainment New Source Review                      The remainder of this preamble                      November 15, 1990) in any area which
                                                         (NNSR)                                             describes the requirements that                       is a nonattainment area for any air
                                                      D. Reasonable Further Progress (RFP)                  nonattainment SIPs must meet in order                 pollutant, may be modified in any
                                                      E. Contingency Measures
                                                                                                            to obtain EPA approval, provides a                    manner unless it insures equivalent or
                                                    VI. Additional Elements of the State’s
                                                         Submittal                                          review of the state’s plan with respect               greater emission reductions of such air
                                                      A. Compliance With Section 110(a)(2) of               to these requirements, and describes the              pollutant.
                                                         the CAA                                            EPA’s proposed action on the plan.
                                                                                                                                                                  III. Attainment Demonstration and
                                                      B. Equivalent Techniques
                                                    VII. EPA’s Proposed Action
                                                                                                            II. Requirements for SO2                              Longer Term Averaging
                                                    VIII. Incorporation by Reference                        Nonattainment Area Plans                                 CAA section 172(c)(1) directs states
                                                    IX. Statutory and Executive Order Reviews                  Nonattainment SIPs must meet the                   with areas designated as nonattainment
                                                    I. Why was Iowa required to submit an                   applicable requirements of the CAA,                   to demonstrate that the submitted plan
                                                    SO2 plan for the Muscatine area?                        and specifically CAA sections 172, 191                provides for attainment of the NAAQS.
                                                                                                            and 192. The EPA’s regulations                        40 CFR part 51, subpart G further
                                                       On June 22, 2010, the EPA                            governing nonattainment SIPs are set                  delineates the control strategy
                                                    promulgated a new 1-hour primary SO2                    forth at 40 CFR part 51, with specific                requirements that SIPs must meet, and
                                                    NAAQS of 75 parts per billion (ppb),                    procedural requirements and control                   EPA has long required that all SIPs and
                                                    which is met at an ambient air quality                  strategy requirements residing at                     control strategies reflect four
                                                    monitoring site when the 3-year average                 subparts F and G, respectively. Soon                  fundamental principles of
                                                    of the annual 99th percentile of 1-hour                 after Congress enacted the 1990                       quantification, enforceability,
                                                    daily maximum concentrations does not                   Amendments to the CAA, EPA issued                     replicability, and accountability.
                                                    exceed 75 ppb, as determined in                         comprehensive guidance on SIPs, in a                  General Preamble, at 13567–68. SO2
                                                    accordance with appendix T of 40 CFR                    document entitled the ‘‘General                       attainment plans must consist of two
                                                    part 50. See 75 FR 35520, codified at 40                Preamble for the Implementation of                    components: (1) Emission limits and
                                                    CFR 50.17(a)–(b). On August 5, 2013,                    Title I of the Clean Air Act Amendments               other control measures that assure
                                                    the EPA designated 29 areas of the                      of 1990,’’ published at 57 FR 13498                   implementation of permanent,
                                                    country as nonattainment for the 2010                   (April 16, 1992) (General Preamble).                  enforceable and necessary emission
                                                    SO2 NAAQS, including the Muscatine                      Among other things, the General                       controls, and (2) a modeling analysis
                                                    area in the State of Iowa. See 78 FR                    Preamble addressed SO2 SIPs and                       which meets the requirements of 40 CFR
                                                    47191, codified at 40 CFR part 81,                      fundamental principles for SIP control                part 51, appendix W which
                                                    subpart C. These area designations were                 strategies. Id., at 13545–49, 13567–68.               demonstrates that these emission limits
                                                    effective October 4, 2013. Section 191 of               On April 23, 2014, the EPA issued                     and control measures provide for timely
                                                    the CAA directs states to submit SIPs for               recommended guidance for meeting the                  attainment of the primary SO2 NAAQS
                                                    areas designated as nonattainment for                   statutory requirements in SO2 SIPs, in a              as expeditiously as practicable, but by
                                                    the SO2 NAAQS to the EPA within 18                      document entitled, ‘‘Guidance for 1-                  no later than the attainment date for the
                                                    months of the effective date of the                     Hour SO2 Nonattainment Area SIP                       affected area. In all cases, the emission
                                                    designation, i.e., by no later than April               Submissions,’’ (April 2014 guidance)                  limits and control measures must be
                                                    4, 2015. These SIPs must demonstrate                    available at https://www.epa.gov/sites/               accompanied by appropriate methods
                                                    that the respective areas will attain the               production/files/2016-06/documents/                   and conditions to determine compliance
                                                    NAAQS as expeditiously as practicable,                  20140423guidance_nonattainment_                       with the respective emission limits and
                                                    but no later than 5 years from the                      sip.pdf. In this guidance the EPA                     control measures and must be
                                                    effective date of designation, which is                 described the statutory requirements for              quantifiable (i.e., a specific amount of
                                                    October 4, 2018.                                        a complete nonattainment area SIP,                    emission reduction can be ascribed to
                                                       On March 18, 2016, the EPA                           which includes: An accurate emissions                 the measures), fully enforceable
                                                    published an action that the State of                   inventory of current emissions for all                (specifying clear, unambiguous and
                                                    Iowa failed to submit the required SO2                  sources of SO2 within the                             measureable requirements for which
                                                    nonattainment plan for the Muscatine                    nonattainment area; an attainment                     compliance can be practicably
                                                    area by the SIP submittal deadline. See                 demonstration; demonstration of RFP;                  determined), replicable (the procedures
                                                    81 FR 14736. This finding initiated a                   implementation of RACM (including                     for determining compliance are
                                                    deadline under CAA section 179(a) for                   RACT); new source review (NSR) and,                   sufficiently specific and non-subjective
                                                    the potential imposition of new source                  adequate contingency measures for the                 so that two independent entities
                                                    and highway funding sanctions.                          affected area.                                        applying the procedures would obtain
                                                    However, pursuant to Iowa’s submittal                      In order for the EPA to fully approve              the same result), and accountable
                                                    of May 26, 2016, and the SIP becoming                   a SIP as meeting the requirements of                  (source specific limits must be
                                                    complete by operation of law on                         CAA sections 110, 172 and 191–192 and                 permanent and must reflect the
                                                    November 26, 2016, the sanctions under                  EPA’s regulations at 40 CFR part 51, the              assumptions used in the SIP
                                                    section 179(a) will not be imposed.                     SIP for the affected area needs to                    demonstrations).
                                                    Additionally, under CAA section 110(c),                 demonstrate to EPA’s satisfaction that                   The EPA’s April 2014 guidance
                                                    the finding triggers a requirement that                 each of the aforementioned                            recommends that the emission limits be
                                                    the EPA promulgate a Federal                            requirements have been met. Under                     expressed as short-term average limits
                                                    Implementation Plan (FIP) within two                    CAA sections 110(l) and 193, the EPA                  (e.g., addressing emissions averaged
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                                                    years of the finding unless, by that time               may not approve a SIP that would                      over one or three hours), but also
                                                    (a) the state has made the necessary                    interfere with any applicable                         describes the option to utilize emission
                                                    complete submittal and (b) EPA has                      requirement concerning NAAQS                          limits with longer averaging times of up
                                                    approved the submittal as meeting                       attainment and RFP, or any other                      to 30 days so long as the state meets
                                                    applicable requirements. This FIP                       applicable requirement, and no                        various suggested criteria. See 2014
                                                    obligation will not apply if EPA makes                  requirement in effect (or required to be              guidance, pp. 22 to 39. The guidance
                                                    final the approval action proposed here                 adopted by an order, settlement,                      recommends that—should states and
                                                    by March 18, 2018.                                      agreement, or plan in effect before                   sources utilize longer averaging times—


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                                                    40088                 Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                    the longer term average limit should be                 attainment (i.e., in an ‘‘average year’’ 1              maximum allowable emissions under an
                                                    set at an adjusted level that reflects a                shows three, not four days with                         appropriately set longer term limit, as
                                                    stringency comparable to the 1-hour                     maximum hourly levels exceeding 75                      compared to the likely air quality with
                                                    average limit at the critical emission                  ppb) is labeled the ‘‘critical emission                 the source having maximum allowable
                                                    value shown to provide for attainment                   value.’’ The modeling process for                       emissions under the comparable 1-hour
                                                    that the plan otherwise would have set.                 identifying this critical emissions value               limit. In this comparison, in the 1-hour
                                                       The April 2014 guidance provides an                  inherently considers the numerous                       average limit scenario, the source is
                                                    extensive discussion of the EPA’s                       variables that affect ambient                           presumed at all times to emit at the
                                                    rationale for concluding that                           concentrations of SO2, such as                          critical emission level, and in the longer
                                                    appropriately set comparably stringent                  meteorological data, background                         term average limit scenario, the source
                                                                                                            concentrations, and topography. In the                  is presumed occasionally to emit more
                                                    limitations based on averaging times as
                                                                                                            standard approach, the state would then                 than the critical emission value but on
                                                    long as 30 days can be found to provide
                                                                                                            provide for attainment by setting a                     average, and presumably at most times,
                                                    for attainment of the 2010 SO2 NAAQS.
                                                                                                            continuously applicable 1-hour                          to emit well below the critical emission
                                                    In evaluating this option, the EPA
                                                                                                            emission limit at this critical emission                value. In an ‘‘average year,’’ compliance
                                                    considered the nature of the standard,
                                                                                                            value.                                                  with the 1-hour limit is expected to
                                                    conducted detailed analyses of the                         The EPA recognizes that some sources
                                                    impact of use of 30-day average limits                                                                          result in three exceedance days (i.e.,
                                                                                                            have highly variable emissions, for                     three days with hourly values above 75
                                                    on the prospects for attaining the                      example due to variations in fuel sulfur
                                                    standard, and carefully reviewed how                                                                            ppb) and a fourth day with a maximum
                                                                                                            content and operating rate, that can                    hourly value at 75 ppb. By comparison,
                                                    best to achieve an appropriate balance                  make it extremely difficult, even with a
                                                    among the various factors that warrant                                                                          with the source complying with a longer
                                                                                                            well-designed control strategy, to ensure               term limit, it is possible that additional
                                                    consideration in judging whether a                      in practice that emissions for any given
                                                    state’s plan provides for attainment. Id.                                                                       exceedances would occur that would
                                                                                                            hour do not exceed the critical emission                not occur in the 1-hour limit scenario (if
                                                    at pp. 22 to 39. See also id. at                        value. The EPA also acknowledges the
                                                    Appendices B, C, and D.                                                                                         emissions exceed the critical emission
                                                                                                            concern that longer term emission limits                value at times when meteorology is
                                                       As specified in 40 CFR 50.17(b), the                 can allow short periods with emissions                  conducive to poor air quality). However,
                                                    1-hour primary SO2 NAAQS is met at an                   above the ‘‘critical emissions value,’’                 this comparison must also factor in the
                                                    ambient air quality monitoring site                     which, if coincident with                               likelihood that exceedances that would
                                                    when the 3-year average of the annual                   meteorological conditions conducive to                  be expected in the 1-hour limit scenario
                                                    99th percentile of daily maximum 1-                     high SO2 concentrations, could in turn                  would not occur in the longer term limit
                                                    hour concentrations is less than or equal               create the possibility of a NAAQS                       scenario. This result arises because the
                                                    to 75 parts per billion. In a year with                 exceedance occurring on a day when an                   longer term limit requires lower
                                                    365 days of valid monitoring data, the                  exceedance would not have occurred if                   emissions most of the time (because the
                                                    99th percentile would be the fourth                     emissions were continuously controlled                  limit is set well below the critical
                                                    highest daily maximum 1-hour value.                     at the level corresponding to the critical              emission value), so a source complying
                                                    The 2010 SO2 NAAQS, including this                      emission value. However, for several                    with an appropriately set longer term
                                                    form of determining compliance with                     reasons, the EPA believes that the                      limit is likely to have lower emissions
                                                    the standard, was upheld by the U.S.                    approach recommended in its April                       at critical times than would be the case
                                                    Court of Appeals for the District of                    2014 guidance document suitably                         if the source were emitting as allowed
                                                    Columbia Circuit in Nat’l Envt’l Dev.                   addresses this concern. First, from a                   with a 1-hour limit.
                                                    Ass’n’s Clean Air Project v. EPA, 686                   practical perspective, the EPA expects
                                                                                                                                                                       As a hypothetical example to
                                                    F.3d 803 (D.C. Cir. 2012). Because the                  the actual emission profile of a source
                                                                                                                                                                    illustrate these points, suppose a source
                                                    standard has this form, a single                        subject to an appropriately set longer
                                                                                                                                                                    that always emits 1000 pounds of SO2
                                                    exceedance does not create a violation                  term average limit to be similar to the
                                                                                                                                                                    per hour, which results in air quality at
                                                    of the standard. Instead, at issue is                   emission profile of a source subject to
                                                                                                                                                                    the level of the NAAQS (i.e., results in
                                                    whether a source operating in                           an analogous 1-hour average limit. The
                                                                                                                                                                    a design value of 75 ppb). Suppose
                                                    compliance with a properly set longer                   EPA expects this similarity because it
                                                                                                                                                                    further that in an ‘‘average year,’’ these
                                                    term average could cause exceedances,                   has recommended that the longer term
                                                                                                                                                                    emissions cause the 5 highest maximum
                                                    and if so the resulting frequency and                   average limit be set at a level that is
                                                                                                                                                                    daily average 1-hour concentrations to
                                                    magnitude of such exceedances, and in                   comparably stringent to the otherwise
                                                                                                                                                                    be 100 ppb, 90 ppb, 80 ppb, 75 ppb, and
                                                    particular whether the EPA can have                     applicable 1-hour limit (reflecting a
                                                                                                                                                                    70 ppb. Then suppose that the source
                                                    reasonable confidence that a properly                   downward adjustment from the critical
                                                                                                                                                                    becomes subject to a 30-day average
                                                    set longer term average limit will                      emissions value) and that takes the
                                                                                                                                                                    emission limit of 700 pounds per hour.
                                                    provide that the average fourth highest                 source’s emissions profile into account.
                                                                                                                                                                    It is theoretically possible for a source
                                                    daily maximum value will be at or                       As a result, the EPA expects either form
                                                                                                                                                                    meeting this limit to have emissions that
                                                    below 75 ppb. A synopsis of how EPA                     of emission limit to yield comparable air
                                                                                                                                                                    occasionally exceed 1000 pounds per
                                                    judges whether such plans ‘‘provide for                 quality.
                                                                                                               Second, from a more theoretical                      hour, but with a typical emissions
                                                    attainment,’’ based on modeling of
                                                                                                            perspective, the EPA has compared the                   profile emissions would much more
                                                    projected allowable emissions and in
                                                                                                                                                                    commonly be between 600 and 800
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                                                    light of the NAAQS’ form for                            likely air quality with a source having
                                                                                                                                                                    pounds per hour. In this simplified
                                                    determining attainment at monitoring
                                                                                                                                                                    example, assume a zero background
                                                    sites, follows.                                           1 An ‘‘average year’’ is used to mean a year with

                                                                                                            average air quality. While 40 CFR 50 appendix T         concentration, which allows one to
                                                       For plans for SO2 based on 1-hour                    provides for averaging three years of 99th percentile   assume a linear relationship between
                                                    emission limits, the standard approach                  daily maximum values (e.g., the fourth highest          emissions and air quality. (A nonzero
                                                    is to conduct modeling using fixed                      maximum daily concentration in a year with 365
                                                                                                            days with valid data), this discussion and an
                                                                                                                                                                    background concentration would make
                                                    emission rates. The maximum emission                    example below uses a single ‘‘average year’’ in order   the mathematics more difficult but
                                                    rate that would be modeled to result in                 to simplify the illustration of relevant principles.    would give similar results.) Air quality


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                                                                          Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                                  40089

                                                    will depend on what emissions happen                    than was anticipated in the plan.                     emission limitation. In this
                                                    on what critical hours, but suppose that                Therefore, in determining whether a                   recommended method, the ratio of the
                                                    emissions at the relevant times on these                plan meets the requirement to provide                 99th percentile among these long term
                                                    5 days are 800 pounds/hour, 1100                        for attainment, the EPA’s task is                     averages to the 99th percentile of the 1-
                                                    pounds per hour, 500 pounds per hour,                   commonly to judge not whether the                     hour values represents an adjustment
                                                    900 pounds per hour, and 1200 pounds                    plan provides absolute certainty that                 factor that may be multiplied by the
                                                    per hour, respectively. (This is a                      attainment will in fact occur, but rather             candidate 1-hour emission limit to
                                                    conservative example because the                        whether the plan provides an adequate                 determine a longer term average
                                                    average of these emissions, 900 pounds                  level of confidence of prospective                    emission limit that may be considered
                                                    per hour, is well over the 30-day average               NAAQS attainment. From this                           comparably stringent.2 The April 2014
                                                    emission limit.) These emissions would                  perspective, in evaluating use of a 30-               guidance also addresses a variety of
                                                    result in daily maximum 1-hour                          day average limit, EPA must weigh the                 related topics, such as the potential
                                                    concentrations of 80 ppb, 99 ppb, 40                    likely net effect on air quality. Such an             utility of setting supplemental emission
                                                    ppb, 67.5 ppb, and 84 ppb. In this                      evaluation must consider the risk that                limits, such as mass-based limits, to
                                                    example, the fifth day would have an                    occasions with meteorology conducive                  reduce the likelihood and/or magnitude
                                                    exceedance that would not otherwise                     to high concentrations will have                      of elevated emission levels that might
                                                    have occurred, but the third and fourth                 elevated emissions leading to                         occur under the longer term emission
                                                    days would not have exceedances that                    exceedances that would not otherwise                  rate limit.
                                                    otherwise would have occurred. In this                  have occurred, and must also weigh the                  Preferred air quality models for use in
                                                    example, the fourth highest maximum                     likelihood that the requirement for                   regulatory applications are described in
                                                    daily concentration under the 30-day                    lower emissions on average will result                appendix A of the EPA’s Guideline on
                                                    average would be 67.5 ppb.                              in days not having exceedances that                   Air Quality Models (40 CFR part 51,
                                                       This simplified example illustrates                  would have been expected with                         appendix W (appendix W)). In 2005, the
                                                    the findings of a more complicated                      emissions at the critical emissions                   EPA promulgated the American
                                                    statistical analysis that EPA conducted                 value. Additional policy considerations,              Meteorological Society/Environmental
                                                    using a range of scenarios using actual                 such as in this case the desirability of              Protection Agency Regulatory Model
                                                    plant data. As described in appendix B                  accommodating real world emissions                    (AERMOD) as the Agency’s preferred
                                                    of EPA’s April 2014 SO2 nonattainment                   variability without significant risk of               near-field dispersion modeling for a
                                                    planning guidance, the EPA found that                   violations, are also appropriate factors              wide range of regulatory applications
                                                    the requirement for lower average                       for the EPA to weigh in judging whether               addressing stationary sources (for
                                                    emissions is highly likely to yield better              a plan provides a reasonable degree of                example in estimating SO2
                                                    air quality than is required with a                     confidence that the plan will lead to                 concentrations) in all types of terrain
                                                    comparably stringent 1-hour limit.                      attainment. Based on these                            based on extensive developmental and
                                                    Based on analyses described in                          considerations, especially given the                  performance evaluation. Supplemental
                                                    appendix B of its April 2014 guidance,                  high likelihood that a continuously                   guidance on modeling for purposes of
                                                    the EPA expects that an emission profile                enforceable limit averaged over as long               demonstrating attainment of the SO2
                                                    with maximum allowable emissions                        as 30 days, determined in accordance                  standard is provided in appendix A to
                                                    under an appropriately set comparably                   with the EPA’s April 2014 guidance,                   the April 2014 guidance. Appendix A
                                                    stringent 30-day average limit is likely                will result in attainment, the EPA                    provides extensive guidance on the
                                                    to have the net effect of having a lower                                                                      modeling domain, the source inputs,
                                                                                                            believes as a general matter that such
                                                    number of exceedances and better air                                                                          assorted types of meteorological data,
                                                                                                            limits, if appropriately determined, can
                                                    quality than an emission profile with                                                                         and background concentrations.
                                                                                                            reasonably be considered to provide for
                                                    maximum allowable emissions under a                                                                           Consistency with the recommendations
                                                                                                            attainment of the 2010 SO2 NAAQS.
                                                    1-hour emission limit at the critical                                                                         in this guidance is generally necessary
                                                    emission value. This result provides a                     The April 2014 guidance offers                     for the attainment demonstration to
                                                    compelling policy rationale for allowing                specific recommendations for                          offer adequately reliable assurance that
                                                    the use of a longer averaging period, in                determining an appropriate longer term                the plan provides for attainment.
                                                    appropriate circumstances where the                     average limit. The recommended                          As stated previously, attainment
                                                    facts indicate this result can be expected              method starts with determination of the               demonstrations for the 2010 1-hour
                                                    to occur.                                               1-hour emission limit that would                      primary SO2 NAAQS must demonstrate
                                                       The question then becomes whether                    provide for attainment (i.e., the critical            future attainment and maintenance of
                                                    this approach—which is likely to                        emission value), and applies an                       the NAAQS in the entire area
                                                    produce a lower number of overall                       adjustment factor to determine the                    designated as nonattainment (i.e., not
                                                    exceedances even though it may                          (lower) level of the longer term average              just at the violating monitor) by using
                                                    produce some unexpected exceedances                     emission limit that would be estimated                air quality dispersion modeling (see
                                                    above the critical emission value—                      to have a stringency comparable to the                appendix W to 40 CFR part 51) to show
                                                    meets the requirement in section                        otherwise necessary 1-hour emission                   that the mix of sources and enforceable
                                                    110(a)(1) and 172(c)(1) for state                       limit. This method uses a database of                 control measures and emission rates in
                                                    implementation plans to ‘‘provide for                   continuous emission data reflecting the               an identified area will not lead to a
                                                    attainment’’ of the NAAQS. For SO2, as                  type of control that the source will be               violation of the SO2 NAAQS. For a
                                                    for other pollutants, it is generally                   using to comply with the SIP emission                 short-term (i.e., 1-hour) standard, the
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                                                    impossible to design a nonattainment                    limits, which (if compliance requires                 EPA believes that dispersion modeling,
                                                    plan in the present that will guarantee                 new controls) may require use of an                   using allowable emissions and
                                                    that attainment will occur in the future.               emission database from another source.                addressing stationary sources in the
                                                    A variety of factors can cause a well-                  The recommended method involves
                                                    designed attainment plan to fail and                    using these data to compute a complete                  2 For example, if the critical emission value is

                                                                                                            set of emission averages, computed                    1000 pounds of SO2 per hour, and a suitable
                                                    unexpectedly not result in attainment,                                                                        adjustment factor is determined to be 70 percent,
                                                    for example if meteorology occurs that                  according to the averaging time and                   the recommended longer term average limit would
                                                    is more conducive to poor air quality                   averaging procedures of the prospective               be 700 pounds per hour.



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                                                    40090                 Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                    affected area (and in some cases those                  spacing of 50 meters was used to resolve              nonattainment boundary analysis
                                                    sources located outside the                             modeled impacts around other nearby                   demonstrated that industrial sources
                                                    nonattainment area which may affect                     individual facilities included in the                 along the Mississippi River have a role
                                                    attainment in the area) is technically                  analyses, but finer grid spacing was                  in causing or contributing to monitored
                                                    appropriate, efficient and effective in                 applied only around sources within the                exceedances at the Musser Park
                                                    demonstrating attainment in                             confines of the nonattainment area.                   monitor. Based on this analysis, all
                                                    nonattainment areas because it takes                    Receptors were excluded from areas                    major sources of SO2 emissions within
                                                    into consideration combinations of                      within the property boundaries of each                the nonattainment area- Grain
                                                    meteorological and emission source                      facility in the analysis. The most recent             Processing Corporation (GPC),
                                                    operating conditions that may                           version of AERMAP (11103) was used to                 Muscatine Power and Water (MPW),
                                                    contribute to peak ground-level                         import terrain and source elevations                  and Monsanto- were included in the
                                                    concentrations of SO2.                                  from the National Elevation Dataset                   nonattainment SIP control strategy
                                                       The meteorological data used in the                  (NED). All building downwash analyses                 analysis.
                                                    analysis should generally be processed                  were conducted using the most recent                     As described in the state’s
                                                    with the most recent version of                         version (04274) of EPA’s Building                     nonattainment SIP, GPC is the largest
                                                    AERMET. Estimated concentrations                        Profile Input Program with Plume Rise                 source of SO2 within the nonattainment
                                                    should include ambient background                       Enhancements (BPIP-Prime). EPA finds                  area. GPC is a corn wet milling facility
                                                    concentrations, should follow the form                  the selection and use of these inputs to              that processes grain into industrial,
                                                    of the standard, and should be                          AERMOD, AERMAP and BPIP-Prime to                      beverage, and fuel-grade ethanol, as well
                                                    calculated as described in section                      be appropriate and in accordance with                 as a variety of grain based food
                                                    2.6.1.2 of the August 23, 2010                          appendix W and applicable EPA                         products, industrial products, and
                                                    clarification memo ‘‘Applicability of                   guidance, such as the TAD.5                           animal feeds. Early in the corn wet
                                                    Appendix W Modeling Guidance for the                                                                          milling process the grain is soaked
                                                                                                            B. Meteorological Data                                (steeped) in large tanks where sulfur
                                                    1-hr SO2 National Ambient Air Quality
                                                    Standard’’ (U. S. EPA, 2010a) (August                     Modeling for the Muscatine 1-hr SO2                 containing compounds are added to the
                                                    2010 1-hour SO2 clarification memo).                    nonattainment SIP was conducted using                 steep water to reduce bacterial growth
                                                                                                            the surface station and upper air data                and help break down the kernels. The
                                                    IV. Review of Modeled Attainment Plan                   from the Davenport airport, and used                  sulfur content in the steep water is
                                                      The following discussion evaluates                    consecutive years from 2008–2012.6                    generally low but does lead to SO2
                                                    various features of the modeling that                   This represents the most recent, readily              emissions from a variety of downstream
                                                    Iowa used in its attainment                             available 5-year period at the time of the            processes. The state asserts that 96
                                                    demonstration.                                          initial analysis per section 8.3.1.2 of 40            percent of the SO2 emissions at GPC is
                                                                                                            CFR part 51 appendix W. The most                      generated by six coal-fired boilers.
                                                    A. Model Selection                                      current version of AERMET available                      MPW is a municipal electric
                                                       Iowa’s attainment demonstration used                 during each phase of the analysis was                 generating station. MPW produces
                                                    the most current version of AERMOD                      used. The final control strategy analysis             steam through the combustion of fossil
                                                    available during each phase of its                      utilized data processed with AERMET                   fuels, generally coal, and uses the steam
                                                    analysis (i.e., the determining sources                 version 14134. The state utilized                     to produce electricity. The largest
                                                    culpable to nonattainment phase and                     AERMINUTE to process 1-minute ASOS                    sources of SO2 operated at MPW are
                                                    the control strategy phase). As                         wind data to generate hourly average                  three coal-fired boilers, Units 7, 8, and
                                                    previously stated, AERMOD is the                        winds for input to AERMET. EPA finds                  9, serving generators with nameplate
                                                    preferred model for this application.                   the selection and use of these inputs to              capacities of 25, 937, and 175.5
                                                    The final control strategy modeling                     AERMET to be appropriate and in                       megawatts (MW), respectively. An
                                                    analysis utilized version 15181. The                    accordance with appendix W and                        auxiliary boiler operated at MPW is not
                                                    state asserts that all analyses were                    applicable EPA guidance, such as the                  capable of burning coal but has the
                                                    conducted with EPA’s regulatory default                 TAD.                                                  potential to emit SO2 when firing on
                                                    options and considering EPA’s guidance                                                                        distillate fuel oil.
                                                                                                            C. Emissions Data
                                                                                                                                                                     Monsanto is a manufacturer and
                                                    documents including the August 2010                       The state utilized information from                 formulator of herbicides for agricultural
                                                    1-hour SO2 clarification memo; the                      the technical support document (TSD) it               use and also produces intermediates for
                                                    ‘‘Additional Clarification Regarding                    submitted to EPA during the                           herbicide manufacturing and
                                                    Application of Appendix W Modeling                      nonattainment boundary                                formulation. A coal-fired boiler (Boiler
                                                    Guidance for the 1-hour NO2 National                    recommendations to inform which                       #8) used for the production of on-site
                                                    Ambient Air Quality Standard’’ memo                     sources needed to be included in its                  heat and power is the largest SO2 source
                                                    (March 2011 1-hour NO2 clarification                    nonattainment SIP modeling.7 The                      at Monsanto.
                                                    memo); and the December 2013 SO2                                                                                 The state excluded four facilities
                                                    Modeling Technical Assistance                             5 The state utilized the December 2013 version of
                                                                                                                                                                  located within the nonattainment area
                                                    Document (TAD).3 The receptor grid                      the modeling TAD when completing its technical        from the its nonattainment SIP
                                                    was centered on the Musser Park                         analysis. The modeling TAD has been revised since
                                                                                                            then; the TAD was revised in February 2016 and        modeling analysis: HNI Corporation—
                                                    monitor, and extended out to the edges                  then again in August 2016.                            North Campus (HNI North); H.J. Heinz,
                                                    of the nonattainment area.4 Those                         6 A detailed analysis to support the use of the
                                                                                                                                                                  L.P. (H.J. Heinz); Union Tank Car Co.
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                                                    portions of the fence lines of the                      Davenport meteorological data from the Davenport      (Union Tank); and HNI Corporation—
                                                    facilities being evaluated that fell                    airport was previously approved by EPA for use in
                                                                                                                                                                  Central Campus (HNI Central). As
                                                    outside of the nonattainment area were                  the PM2.5 Muscatine SIP analysis. See 79 FR 46742.
                                                                                                            EPA finds use of the Davenport airport site           shown in the state’s nonattainment SIP,
                                                    omitted from the analysis. Finer grid                   meteorological data to be appropriate for the 2010    the cumulative actual emissions from
                                                                                                            1-hr SO2 Muscatine SIP.                               these sources is relatively low; the
                                                      3 SO NAAQS Designations Modeling Technical              7 https://www.epa.gov/sulfur-dioxide-
                                                          2
                                                    Assistance Document, December 2013.                     designations/so2-designations-round-1-iowa-state-
                                                                                                                                                                  sources emitted a combined 0.14 tons of
                                                      4 The Musser Park monitor was the violating           recommendation-and-epa-response and provided in       SO2 per year (tpy) in 2011. See section
                                                    monitor utilized during the designations process.       the docket of this rulemaking.                        V.A. Emissions Inventory in this


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                                                                          Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                           40091

                                                    preamble for the 2011 emissions data                    NO2). The state’s nonattainment SIP                   concentrations included in modeling
                                                    from these sources. Additionally, if the                indicates that it addressed modeling                  analysis and that further consideration
                                                    state were to consider the maximum                      intermittent sources in according with                of these sectors is unnecessary. See
                                                    fuel capacity of a source like Heinz that               EPA’s March 2011 1-hour NO2                           section IV.E. Background
                                                    has two boilers that burn natural gas, it               clarification memo, and as such all                   Concentrations and section V. A.
                                                    is unlikely that the SO2 emissions                      emission units that operate                           Emissions Inventory in this preamble
                                                    would be sufficient enough to cause a                   intermittently (e.g., emergency engines               for more detailed information.
                                                    significant concentration gradient. The                 and fire pumps) were excluded from the
                                                                                                                                                                  D. Emission Limits
                                                    TAD indicates that ‘‘other’’ sources in                 analysis. Additionally, emission units
                                                    the area not causing significant                        that were limited to burning a specific                  Section 172(c)(6) of the CAA requires
                                                    concentration gradients in the vicinity                 fuel occasionally were modeled at                     that the state’s nonattainment plan
                                                    of the source(s) of interest, should be                 emission rates that represent the fuel                include enforceable emission
                                                    included in the modeling via monitored                  that is burned during normal operations.              limitations, and such other control
                                                    background concentrations. The EPA                      For example, the two auxiliary boilers                measures, means or techniques
                                                    agrees with the state’s recommendation                  (EP2 and EP3) operated by LGS are                     (including economic incentives such as
                                                    that these facilities do not need to be                 limited to burning fuel oil for no more               fees, marketable permits, and auctions
                                                    explicitly modeled and that they are                    than 48 hours per year. EP2 and EP3                   of emission rights), as well as schedules
                                                    adequately characterized in the                         burn natural gas during normal                        and timetables for compliance, as may
                                                    background SO2 concentrations. See                      operations therefore, EP2 and EP3 were                be necessary or appropriate to provide
                                                    section IV.E. Background                                modeled at emission rates associated                  for attainment of such standard in such
                                                    Concentrations in this preamble for                     with burning natural gas. EPA agrees                  area by the applicable attainment date.
                                                    more detailed information regarding the                 with the state that it is appropriate to              See General Preamble at 13567–68.
                                                    determination of the background                         exclude these intermittent emissions                     Part of the review of state’s attainment
                                                    concentration.                                          (e.g., emergency engines and fire                     plan must address the use of these
                                                       The state also evaluated several major               pumps) in the analysis and modeling                   limits, both with respect to the general
                                                    sources of SO2 emissions located                        the fuel burned during normal                         suitability of using such limits for the
                                                    outside of the nonattainment area                       operations, as it is consistent with                  purpose of meeting the requirements of
                                                    boundary- MidAmerican Energy Louisa                     appendix W and the TAD.                               CAA § 172(c)(6) with respect to whether
                                                    Generating Station (LGS), Gerdau                           The state’s nonattainment SIP                      the particular limits included in the
                                                    Ameristeel (Gerdau), SSAB and                           acknowledges that, although SO2                       plan have been suitably demonstrated to
                                                    Linwood and Lafarge. Linwood and                        emissions in and near the                             provide for attainment. The first
                                                    Lafarge, located in Scott County, are                   nonattainment area are principally                    subsection that follows addresses the
                                                    approximately 20 km away from the                       attributable to point sources, a                      enforceability of the limits in the plan,
                                                    nonattainment area. The selection of the                comprehensive emissions inventory                     and the second subsection that follows
                                                    Davenport monitor to represent                          should include an assessment of the                   addresses in the limits in particular the
                                                    background likely accounts for the                      other source sectors. The state asserted              longer term average limits (i.e., the 21-
                                                    emissions from Linwood and Lafarge.8                    that it accomplished this by using                    day average limit for MPW).
                                                    As such, Linwood and Lafarge were                       estimates of air emissions for the                    1. Enforceability
                                                    excluded from further consideration.                    onroad, nonroad, and nonpoint (area)
                                                    See section IV.E. Background                            sources from EPA’s 2011 National                         As specified in section 172(c)(6) and
                                                    Concentrations in this preamble for                     Emissions Inventory (NEI) datasets.                   section 110(a)(2)(A) of the CAA and 75
                                                    additional information.                                 According to the state’s sector summary               FR 35520, emission limitations, control
                                                       All included emission units were                     analyses using EPA’s SCC (source                      measures and other elements in the SIP
                                                    modeled using their actual stack                        classification code) full detail data files           must be enforceable by the state and
                                                    parameters and site layout. There were                  from the 2011 NEI (version 2, dated                   EPA. Working with GPC, MPW, and
                                                    no stacks above formula GEP (good                       March 4, 2015), approximately 2.64 tons               Monsanto the state developed an
                                                    engineering practice) height. There were                of SO2 were emitted by onroad mobile                  implementable control strategy designed
                                                    stacks greater than 65 meters at GPC,                   sources in all of Muscatine County (this              to ensure expeditious attainment of the
                                                    MPW, and LGS and each of those stacks                   includes areas within and outside of the              1-hr SO2 NAAQS. The control strategy
                                                    were adjacent to tall buildings making                  nonattainment area). Nonroad mobile                   establishes source-specific control
                                                    the formula height taller than the actual               sources (which include non-road                       measures that include more stringent
                                                    stack height. Therefore, each of those                  equipment, locomotives, commercial                    SO2 emissions limits, new control
                                                    stacks were modeled at their actual                     marine vessels, and aircraft) contributed             devices, and process changes. The
                                                    stack heights.                                          approximately 1.99 tpy of SO2. Again,                 state’s nonattainment SIP includes these
                                                       Per EPA’s April 2014 guidance, the                   that estimate includes nonroad mobile                 control measures with specific
                                                    use of allowable emissions and the                      sources across all of Muscatine County.               timetables for implementation,
                                                    modeling of intermittent emissions (for                    The state asserts that nonpoint (area)             establishes minimum performance
                                                    sources such as emergency generators                    SO2 emissions were also relatively low,               criteria, and provides schedules for
                                                    and startup/shutdown emissions), for                    at approximately 18.73 tpy. Of that total,            completing verification processes. See
                                                    the purpose of modeling for SO2                         roughly half (8.92 tons) was associated               section V. B. RACM/RACT in this
                                                    attainment demonstrations, should                       with emissions mostly from prescribed                 preamble for additional information.
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                                                    follow the recommendations in EPA’s                     fires. As with the mobile sectors, the                New air construction permits issued to
                                                    March 2011 1-hour NO2 clarification                     nonpoint totals also represent sums                   GPC, MPW, and Monsanto include
                                                    memo (even though it was specific to                    across all of Muscatine County. The                   emissions limits, timetables for
                                                                                                            EPA agrees with the state’s proposal that             compliance, and enforcement criteria
                                                      8 According to information provided by the state
                                                                                                            onroad, nonroad, and nonpoint sources                 and are the enforceable documents
                                                    in its nonattainment SIP, the Davenport monitor is                                                            included in the state’s nonattainment
                                                    located in Scott County, approximately 11 km from
                                                                                                            in and near the Muscatine
                                                    Linwood and Lafarge, and likely accounts for the        nonattainment area are adequately                     SIP that EPA is proposing to approve.
                                                    emissions from Lafarge and Linwood.                     represented by background                             As noted in the nonattainment SIP, the


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                                                    40092                 Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                    state has the authority to implement                    plan relies on a pound/hour (lb/hr) limit             two units operating. The formula
                                                    each of the permits. Each permit                        expressed an averaging time (e.g. as 21-              provides flexibility for MPW to run their
                                                    includes notification, reporting, and                   day average) across multiple units.9 In               three coal units alone or in combination
                                                    recordkeeping requirements. The                         accordance with EPA policy, the 21-day                in such a way that the NAAQS will be
                                                    facilities must, for example, notify the                average limit is set at a lower level than            protected at all times. Because the units
                                                    state when they initiate and when they                  the emission rate used in the attainment              have different dispersion characteristics,
                                                    complete construction. Each permit also                 demonstration; the relationship between               the formula weighs each unit’s
                                                    contains performance testing (emissions                 these two values is discussed in more                 individual emissions such that the
                                                    testing) obligations with specific                      detail in the following section.                      critical modeled value in the formula is
                                                    schedules, methods, and frequencies for                                                                       always protected.
                                                                                                            2. Longer Term Averaging
                                                    compliance. Each performance test must
                                                    be approved by the state and a testing                     As discussed in the April 2014                        To determine the longer term average
                                                    protocol must be submitted to the state                 guidance, and in section III. Attainment              limit, the state determined the
                                                    in advance of the compliance                            Demonstration and Longer Term                         individual variability of each unit from
                                                    demonstration. Results of the tests must                Averaging in this preamble, EPA has                   the 2010–2014 CEMS data as described
                                                    be submitted in writing to the state in                 recommended that averaging times in                   above. The variability value ratios of the
                                                    the form of a comprehensive report                      SIP emission limits should not exceed                 99th percentile 21-day average and 99th
                                                    within six weeks of the completion of                   the applicable NAAQS averaging time,                  percentile hourly values were 0.71, 0.90,
                                                    any testing. Additionally, GPC, MPW,                    in this case 1-hour, however, EPA has                 0.63 for the three units respectively. The
                                                    and Monsanto are major sources under                    acknowledged that a 1-hr emission rate                state determined a critical value for each
                                                    the Title V operating permit program                    limit may be difficult to achieve at some             of these units individually using their
                                                    and must submit semi-annual                             facilities. As such EPA provided                      respective variability and stack
                                                    monitoring reports by September 30 and                  guidance for establishing longer term                 characteristics. In the first modeling
                                                    March 31, and an annual compliance                      averaging limits based on a supportable               scenario (the ‘‘All’’ run) the state
                                                    certification by March 31, of each year.                downward adjustment of the critical                   determined the hourly critical values for
                                                    The state also inspects Title V sources                 emissions value. The critical emissions               Units 7,8,9 as 250 lbs/hr, 1000 lbs/hr,
                                                    at a minimum of every two years. In                     value is the 1-hr averaged emission rate
                                                                                                                                                                  and 120 lbs/hr respectively, so 1,370
                                                    summary, the state has a comprehensive                  that dispersion modeling predicts
                                                                                                                                                                  lbs/hr total from the 3 units. Applying
                                                    program to identify sources of violations               would attain the NAAQS.
                                                                                                               The control strategy included in the               the individual unit variability, the
                                                    and to undertake follow-up for                                                                                equivalent 21 day limits would be 177.5
                                                    compliance and enforcement.                             state’s nonattainment SIP allows MPW
                                                                                                            to meet a compliance formula based on                 lbs/hr, 900.0 lbs/hr, and 75.6 lbs/hr
                                                       As noted in the state’s May 26, 2016,
                                                    submittal letter, Iowa was included in                  a 21-day averaging period across                      respectively which when added together
                                                    the agency’s Response to Petition for                   multiple units running alone or in                    is 1,153 lbs/hr, the value that becomes
                                                    Rulemaking; Restatement and Update of                   combination. The formula incorporates                 the basis of the compliance formula.
                                                    EPA’s SSM Policy Applicable to SIPs;                    a weighting function derived from the                 The state then modeled 7 combinations
                                                    Findings of Substantial Inadequacy; and                 modeling results of the individual units              of emissions scenarios using the
                                                    SIP Calls To Amend Provisions                           (Units 7, 8 and 9), and downward                      individual unit stack characteristics that
                                                    Applying to Excess Emissions During                     adjustments of the critical emissions                 all demonstrated compliance with the
                                                    Periods of Startup, Shutdown and                        values. A separate downward                           NAAQS and accounted for individual
                                                    Malfunction (SSM SIP call) published                    adjustment was calculated for each unit               variability of each unit. These scenarios
                                                    June 12, 2015, (80 FR 33839). In the                    using five years of unit-specific CEMS                consisted of 3 model runs where the
                                                    SSM SIP call, subrule 567—Iowa                          data, 2010–2014; the state considered                 individual units were operating alone
                                                    Administrate Code (IAC) 24.1(1) was                     this data to be representative of the                 and 4 model runs with various
                                                    found to be ‘‘substantially inadequate’’                boilers’ operations into the future, and              combinations of units operating. Each
                                                    because it provides that excess                         reflect the fact that each unit is emitting           run had its own hourly critical modeled
                                                    emissions during periods of startup and                 from a separate stack. The 1-hour                     value demonstrating compliance and
                                                    shutdown are not a violation of an                      emissions value of 1,153 lbs/hr used in               these 7 runs formed the basis for the
                                                    emission standard if good practices for                 the formula incorporates the adjustment               weights in the formula to ensure 1,153
                                                    minimizing emissions are followed.                      to a longer term limit according to the               lbs/hr was always protective of all the
                                                    Each construction permit the state                      ratio of the 99th percentile 21-day                   individual critical values modeled. This
                                                    requested be included in the SIP apart                  average emission rate to the 99th                     provided modeled emission rates such
                                                    if its control strategy contains SSM                    percentile 1-hr emission rates from the               that a weighted formula could be
                                                    language from the subrule that is subject               CEMS data. Because the 1,153 lbs/hr
                                                                                                                                                                  derived such that any combination of
                                                    to the SIP call (Condition 6 of each                    value was derived from all 3 units
                                                                                                                                                                  emissions from the three individual
                                                    permit). As such the state is requested                 operating together additional model
                                                                                                                                                                  units would always be at or below the
                                                    that EPA not act on permit Condition 6                  runs were needed to ensure the formula
                                                                                                                                                                  value of 1,153 lbs/hr as expressed in the
                                                    of the included permits. EPA agrees that                was protective under other operating
                                                                                                                                                                  formula. Because the stacks have
                                                    it would not be appropriate to approve                  scenarios, with combinations of one or
                                                                                                                                                                  different dispersion characteristics and
                                                    Condition 6 of each permit into the SIP
                                                                                                                                                                  the modeled scenarios have different
                                                    and propose the condition’s exclusion.                     9 The MPW permit included as appendix C to the
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                                                       EPA is proposing to determine that                   nonattainment SIP specifies that compliance with      critical emission values, the formula
                                                    these control measures, and the permits                 the emission standard of 1153 lb/hr of SO2 shall be   derived contains different weights or
                                                                                                            demonstrated through the use a Continuous             multipliers for each unit’s actual hourly
                                                    that contain them, satisfy CAA                          Emissions Monitoring System (CEMS) and shall be
                                                    § 110(a)(2)(A) and 172(c)(6)                            determined on a 21-day rolling average bases. The     emissions, but the weights are such that
                                                    requirements and 75 FR 35520. It                        limit includes startup, shutdown and malfunction      no individual unit operating alone or a
                                                    should be noted that the emission limit                 emissions. Compliance with the emission limit         combination of units will cause a
                                                                                                            shall be demonstrated using the formula found in
                                                    established for MPW in the control                      Permit Condition 15.8. The emission limit became
                                                                                                                                                                  NAAQS violation as long as the formula
                                                    strategy of the state’s nonattainment                   effective January 1, 2017.                            criteria as expressed in the permit are


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                                                                                    Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                                                                             40093

                                                    met.10 Table 1 shows that during each                                         Monsanto, the current maximum                                                  will result in attainment of the 1-hour
                                                    operational scenario at MPW, combined                                         allowable permitted emission rates from                                        SO2 NAAQS.
                                                    with the control strategies for GPC and                                       LGS, and background concentrations,

                                                                                      TABLE 1—CUMULATIVE MODELING RESULTS WITH EACH MPW OPERATING SCENARIO
                                                                                                                                                                                                                                        Cumulative       1-hour SO2
                                                                                                                        MPW operating scenario                                                                                          model result       NAAQS
                                                                                                                                                                                                                                         (μg/m3)           (μg/m3)

                                                    All .............................................................................................................................................................................         182.76                     196
                                                    U9 Off ......................................................................................................................................................................             182.71   ........................
                                                    U8 Off ......................................................................................................................................................................             183.66   ........................
                                                    U7 Off ......................................................................................................................................................................             182.88   ........................
                                                    U7 Only ....................................................................................................................................................................              183.96   ........................
                                                    U8 Only ....................................................................................................................................................................              181.86   ........................
                                                    U9 Only ....................................................................................................................................................................              187.78   ........................



                                                       Based on a review of the state’s                                           E. Background Concentrations                                                   excluded); (2) the Davenport monitor is
                                                    submittal, the EPA believes that the 21-                                         The state reviewed its statewide SO2                                        near a moderately industrialized area,
                                                    day average limit for MPW provides a                                          monitoring network to determine an                                             but is not situated adjacent to those
                                                    suitable alternative to establishing a 1-                                     appropriate background monitoring                                              sources of emissions; (3) the Davenport
                                                    hour average emission limit for this                                          location- the Davenport SO2 monitoring                                         monitor is in a county with a moderate
                                                    source. The state has used a suitable                                         site. As noted by the state, the ideal                                         amount of SO2 emissions; and (4) using
                                                    data base in an appropriate manner and                                        background location chosen represents                                          the Davenport monitor is consistent
                                                    has thereby applied an appropriate                                            the contributions from all sources not                                         with the meteorological data used for
                                                    adjustment, yielding an emission limit                                        explicitly modeled. Because the                                                the analysis. For these reasons the state
                                                    formula that has comparable stringency                                        monitoring locations in Muscatine, IA                                          believed that the Davenport monitoring
                                                    to the 1-hour average limit that the state                                    are impacted significantly by sources                                          location could account for the sources
                                                    determined would otherwise have been                                          that were included in the modeling                                             screened out of the control strategy such
                                                                                                                                  analysis, those monitors were                                                  as emissions from natural sources, major
                                                    necessary to provide for attainment.
                                                                                                                                  eliminated as an option to represent the                                       and minor point sources not included in
                                                    While the 21-day average limit allows
                                                                                                                                  background concentrations in the area.                                         the analysis, mobile (onroad and
                                                    occasions in which emissions may be                                                                                                                          nonroad) sources, and nonpoint sources.
                                                    higher than the level that would be                                           Of the remaining monitor locations, two
                                                                                                                                  are situated adjacent to industrialized                                           The state utilized temporally varying
                                                    allowed with the 1-hour limit, the
                                                                                                                                  areas (Cedar Rapids and Clinton), and,                                         background concentrations by hour and
                                                    state’s limit compensates by requiring
                                                                                                                                  as such, would likely be an overestimate                                       season from the Davenport SO2
                                                    average emissions to be lower than the
                                                                                                                                  of the concentrations caused by                                                monitoring location to account for
                                                    level that would otherwise have been                                                                                                                         contributions to the predicted impacts
                                                    required by a 1-hour average limit. For                                       background sources. The state
                                                                                                                                  determined that the Des Moines and                                             from background SO2 sources. To
                                                    reasons described above and explained                                                                                                                        account for seasonal and diurnal
                                                                                                                                  Lake Sugema monitors were impacted
                                                    in more detail in EPA’s April 2014                                                                                                                           variations in the background levels, the
                                                                                                                                  by less SO2 emissions than what would
                                                    guidance, EPA finds that appropriately                                                                                                                       state based the background
                                                                                                                                  be represented by the background for
                                                    set longer term average limits provide a                                      the Muscatine nonattainment area—and,                                          concentration on the average diurnal
                                                    reasonable basis by which                                                     as such, would likely be an                                                    and seasonal concentration pattern
                                                    nonattainment plans may provide for                                           underestimation of the concentrations of                                       observed at the Davenport monitor
                                                    attainment. Based on its review of this                                       SO2 caused by background sources.11                                            during the years 2011–2013. For the
                                                    general information as well as the                                               The state determined that the                                               years 2011–2013, the 99th percentile
                                                    particular information in state’s plan,                                       Davenport SO2 monitoring location was                                          monitor concentration was calculated
                                                    the EPA finds that the 21-day average                                         appropriate for estimating background                                          for each hour of the day by season and
                                                    limit formula for MPW in combination                                          concentrations for the following                                               then averaged across the three years.12
                                                    with other limitations in the state’s                                         reasons: (1) The Davenport monitor is                                            The state also averaged the 2011–2013
                                                    plan, will provide for attainment of the                                      the nearest location to the                                                    design values for Cedar Rapids,
                                                    NAAQS.                                                                        nonattainment area (other than those                                           Davenport, Des Moines, and Lake
                                                                                                                                  monitors located in Muscatine already                                          Sugema to determine if that number,
                                                      10 The formula for MPW, as specified in their                                  Unit 7 = 24-hour average sulfur dioxide emission                               12 The EPA’s SO National Ambient Air Quality
                                                                                                                                                                                                                                     2
                                                    permit is as follows:                                                         rate, lb/hr, for Unit 7                                                        Standards Designations Modeling TAD describes an
                                                      ‘‘The owner or operator shall maintain a file of                               Unit 8 = 24-hour average sulfur dioxide emission                            appropriate methodology of calculating temporally
                                                    computations to show the total hourly emission                                rate, lb/hr, for Unit 8                                                        varying background monitored concentrations by
                                                                                                                                                                                                                 hour of day and season (excluding periods when
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                                                    level for SO2. The owner or operator shall use the                               Unit 9 = 24-hour average sulfur dioxide emission                            the source in question is expected to impact the
                                                    total hourly SO2 emission rates to calculate and                              rate, lb/hr, for Unit 9.                                                       monitored concentration). The methodology is to
                                                    record the average SO2 emission rate for each                                    11 The Des Moines monitor is approximately 5 km                             use the 99th percentile concentration for each hour
                                                    calendar day. Effective January 1, 2017, the owner                                                                                                           of the day by season and average across 3 years,
                                                                                                                                  from the nearest SO2 source. The county emissions
                                                    or operator shall use the daily average SO2 emission                                                                                                         excluding periods when the dominant source(s) are
                                                                                                                                  are approximately 163 tpy. The Lake Sugema
                                                    rates to demonstrate compliance with the 21-day                                                                                                              influencing the monitored concentration (i.e., 99th
                                                                                                                                  monitor is more than 10 km away from the nearest
                                                    rolling average as calculated below: SO2 =                                                                                                                   percel1tile, or 4th highest, concentrations for hour
                                                                                                                                  SO2 source. The state’s nonattainment SIP indicates
                                                    2.03*(Unit 7) + 0.84*(Unit 8) + 1.22*(Unit 9)                                                                                                                l for January or winter, 99th percentile
                                                                                                                                  that are no reported major or minor sources of SO2
                                                    Where, SO2 = total emissions, in pounds per hour,                                                                                                            concentrations for hour 2 for January or winter,
                                                    of sulfur dioxide from Unit 7, Unit 8 and Unit 9                              emissions in the county.
                                                                                                                                                                                                                 etc.).



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                                                    40094                 Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                    10.5 ppb, would be appropriate as                       primary contributor. If the facility’s                    To start its Phase 2 analysis, the state
                                                    background. The state called this the                   contribution was less than half of the                  provided GPC with a model input file
                                                    Tier 1 value. The Tier 1 value of 10.5                  total concentration, but still more than                that included its emission units as well
                                                    ppb is higher than all but one of the                   the Significant Impact Level (SIL) it was               as the exceedance receptors to which it
                                                    seasonal/diurnal concentrations. This                   considered a secondary contributor.14                   contributed. The state’s nonattainment
                                                    shows that the use of the Tier 1 value                    GPC was identified as a primary                       SIP submittal indicates that GPC
                                                    for all hours and seasons would have                    contributor to all predicted NAAQS                      reviewed the input data for accuracy
                                                    been too high to represent the variable                 exceedances within the nonattainment                    and then mitigated all modeled
                                                    background concentrations. The EPA                      area. GPC’s max potential contribution                  exceedances caused by the GPC facility
                                                    agrees with the state’s proposal that the               was estimated as 3,180 mg/m3 (or                        alone.
                                                    method of using temporally varying                      approximately 1,223 ppb).15 GPC’s
                                                                                                            contribution to the predicted NAAQS                       The remaining facilities (MPW,
                                                    background monitor concentrations by                                                                            Monsanto, and LGS) were then added to
                                                    hour and season from the Davenport                      exceedance was greater than or equal to
                                                                                                            half of the total concentration (minus                  the analysis with their maximum
                                                    monitoring location, as it is calculated                                                                        permitted allowable emission rates and
                                                    from the 99th percentile, is appropriate.               background) 100 percent of the time.
                                                                                                              MPW, Monsanto and LGS were                            the cumulative impacts were
                                                    F. Summary of Results                                   identified as secondary contributors.                   determined across the entire
                                                      The modeling analysis was conducted                   MPW’s max potential contribution was                    nonattainment area. According to the
                                                    in two phases. The first phase (Phase 1)                estimated as 107 mg/m3 (or                              state’s nonattainment SIP submittal, the
                                                    of the analysis was a screening analysis                approximately 41 ppb). MPW’s                            remaining predicted exceedances were
                                                    to determine the sources that needed to                 contribution to the predicted NAAQS                     then discussed with Monsanto and
                                                    be included in the control strategy                     exceedance was less than half of the                    MPW. As a result of those discussions,
                                                    analysis. The second phase (Phase 2) of                 total concentration, but still more than                additional control measures were
                                                    the analysis was used to develop the                    SIL (minus background) 26 percent of                    developed for those facilities and are
                                                    control strategy and included all                       the time. Monsanto’s max potential                      incorporated in construction permits
                                                    significant sources identified in Phase 1.              contribution was estimated as 28 mg/m3                  submitted as part of the SIP revision.
                                                                                                            (or approximately 11 ppb). Monsanto’s                   See section V.B. in this preamble for
                                                    1. Phase 1—Preliminary Analysis                         contribution to the predicted NAAQS                     more information regarding the control
                                                       This phase was accomplished by                       exceedance was less than half of the                    measures.
                                                    modeling actual emissions from GPC,                     total concentration, but still more than                  Monsanto proposed to decrease the
                                                    MPW, Monsanto, and LGS and                              SIL (minus background) less than 1                      emission rate for Boiler 8 at its facility
                                                    allowable emissions from SSAB and                       percent of the time. LGS’s maximum                      to mitigate exceedances just north of its
                                                    Gerdau and then determining the                         potential contribution was estimated as                 property. MPW proposed multiple
                                                    percentage of predicted NAAQS                           59 mg/m3 (or approximately 22.7 ppb).                   model scenarios with combined
                                                    exceedances within the nonattainment                    LGS’s contribution to the predicted                     operation of Units 7, 8, and 9.
                                                    area to which each facility significantly               NAAQS exceedance was less than half                     Regardless of the operational scenario,
                                                    contributed. In this way, the state                     of the total concentration, but still more              the unit/units were modeled at an
                                                    determined that GPC contributed to 100                  than SIL (minus background) 2 percent                   equation cap of 1,153 lb/hr SO2. The
                                                    percent of the NAAQS exceedances,                       of the time. As such, only GPC, MPW,                    model results varied depending on
                                                    MPW contributed to approximately 25                     Monsanto and LGS were included in the                   which combination of boilers was
                                                    percent of the NAAQS exceedances,                       second phase of the analysis.                           running. Each of the modeling scenarios
                                                    Monsanto contributed to approximately                                                                           (with background included) resulted in
                                                                                                            2. Phase 2—Control Strategy
                                                    1 percent of the NAAQS exceedances,                                                                             concentrations below the 1-hour SO2
                                                                                                            Development
                                                    and LGS contributed to approximately 5                                                                          NAAQS. The highest modeled SO2
                                                    percent of the NAAQS exceedances.                          Sources identified in Phase 1 (GPC,                  concentration was 187.87 ug/m3 which
                                                    Both SSAB and Gerdau each modeled                       MPW, Monsanto, and LGS) as being                        included the operation of just Unit 9 at
                                                    less than a 1 percent contribution to the               significant contributors were modeled at                MPW. See section IV.D.2. Longer Term
                                                    NAAQS exceedance days within the                        their maximum permitted allowable                       Averaging limits, in this preamble, for
                                                    nonattainment area. Therefore, only                     emission rates. Using the process                       more discussion of the equation used to
                                                    GPC, MPW, Monsanto and LGS were                         summarized below, more restrictive                      determine compliance with the NAAQS
                                                    determined to have enough potential                     maximum permitted emission rates                        for each MPW modeling scenario.
                                                    contribution to NAAQS exceedances to                    were developed where necessary to
                                                                                                            ensure modeled attainment.                                These results indicate that the
                                                    be evaluated further.13
                                                                                                                                                                    controls established in the construction
                                                       The state then further subdivided the
                                                                                                              14 Per EPA’s August 23, 2010, ‘‘Guidance              permits for MPW, GPC and Monsanto
                                                    sources by classifying the significant
                                                                                                            Concerning the Implementation of the 1-hour SO2         result in attainment of the NAAQS, and
                                                    contributors as either a primary or a                   NAAQS for the Prevention of Significant                 as such, additional controls were not
                                                    secondary contributor. If the facility’s                Deterioration Program’’, the SIL is 3 ppb. The EPA      necessary for LGS in order for the area
                                                    significant contribution to the predicted               plans ‘‘to undertake rulemaking to adopt a 1-hour
                                                                                                            SO2 SIL value. However, until such time as a 1-hour     to attain. EPA agrees with the state’s
                                                    NAAQS exceedance was greater than or
                                                                                                            SO2 SIL is defined in the PSD regulations, we are       determination that its control strategy
                                                    equal to half of the total concentration                providing an interim SIL of 3 ppb, which we intend      analysis results in modeled
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                                                    (minus background) it was considered a                  to use as a screening tool for completing the           concentrations throughout the
                                                                                                            required air quality analyses for the new 1-hour SO2
                                                      13 The LGS facility is located immediately south      SIL NAAQS under the federal PSD program at 40           nonattainment area that are at or below
                                                    of the nonattainment area. During the designations      CFR 52.21. We are also making the interim SIL           75 ppb/196.4 ug/m3. Based upon
                                                    process, this source was shown to be insignificant      available to States with EPA-approved                   monitoring data discussed in section
                                                    during predicted exceedances at the Musser Park         implementation plans containing a PSD program to        V.B. RACM/RACT in this preamble,
                                                    monitor, but as it was possible that the source could   use at their discretion.’’ The SIL remains an interim
                                                    cause a concentration gradient in the vicinity of the   SIL until rulemaking is complete.                       EPA expects that the Muscatine area
                                                    southern portion of the nonattainment area, it was        15 To convert from mg/m3 to ppb, the mg/m3 value      will attain by the attainment date,
                                                    included in the analysis.                               was divided by 2.6.                                     August 5, 2018.


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                                                                                  Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                                                                                 40095

                                                    V. Review of Other Plan Requirements                                       Administrator that the emissions                                              emissions in each nonattainment area,
                                                                                                                               quantified for this purpose will be                                           as well as any sources located outside
                                                    A. Emissions Inventory and the
                                                                                                                               consistent with the achievement of                                            the nonattainment area which may
                                                    Quantification of Emissions
                                                                                                                               reasonable further progress and will not                                      affect attainment in the area. See the
                                                       Section 172(c)(3) of the CAA requires                                   interfere with attainment of the                                              April 2014 guidance. Additional
                                                    that the state’s nonattainment plan                                        applicable National Ambient Air                                               emission inventory information was
                                                    include a comprehensive, accurate,                                         Quality Standard by the applicable                                            discussed in section IV.C Emissions
                                                    current inventory of actual emissions                                      attainment date.                                                              Data in this preamble. A brief summary
                                                    from all sources of the relevant                                              The emissions inventory and source                                         is provided later in this action.
                                                    pollutant or pollutants in such area,                                      emission rate data for an area serve as
                                                    including such periodic revisions as the                                   the foundation for air quality modeling                                          The base year inventory establishes a
                                                    Administrator may determine necessary                                      and other analyses that enable states to:                                     baseline that is used to evaluate
                                                    to assure that the requirements of this                                    (1) estimate the degree to which                                              emissions reductions achieved by the
                                                    part are met. Section 172(c)(4) of the                                     different sources within a                                                    control strategy and to assess reasonable
                                                    CAA requires that the state’s                                              nonattainment area contribute to                                              further progress requirements. The
                                                    nonattainment plan expressly identify                                      violations within the affected area; and                                      state’s nonattainment SIP noted that, at
                                                    and quantify the emissions, if any, of                                     (2) assess the expected improvement in                                        the time, the most recent and available
                                                    any such pollutant or pollutants which                                     air quality within the nonattainment                                          triennial inventory year was 2011 and
                                                    will be allowed, in accordance with                                        area due to the adoption and                                                  the stated found that it served as a
                                                    section 703(a)(1)(B) of the CAA, from                                      implementation of control measures. As                                        suitable base year. Table 2 provides the
                                                    the construction and operation of major                                    noted above, the state must develop and                                       2011 SO2 emissions inventory data for
                                                    new or modified stationary sources in                                      submit to EPA a comprehensive,                                                sources within and outside of the
                                                    each such area. The plan shall                                             accurate and current inventory of actual                                      nonattainment the area (data have been
                                                    demonstrate to the satisfaction of the                                     emissions from all sources of SO2                                             rounded to the nearest whole number).

                                                                               TABLE 2—BASE LINE EMISSION INVENTORY FOR THE MUSCATINE, IA NONATTAINMENT AREA
                                                                                                                                                                                                                                                                2011 SO2
                                                                                                                                                                                                    Facility                                                    emissions
                                                                                                                                                                                                                                                                  (tpy)

                                                                                                                      Base Line Emissions Inventory for the Muscatine NAA

                                                    Inside of the NAA ........................................................................          Grain Processing Corporation ...................................................                             10,810
                                                                                                                                                        Muscatine Power and Water .....................................................                               2,374
                                                                                                                                                        Monsanto ...................................................................................                    537
                                                                                                                                                        HNI Corp.—North Campus ........................................................                                  <1
                                                                                                                                                        HNI Corp.—Central Campus .....................................................                                   <1
                                                                                                                                                        H.J. Heinz L.P. ...........................................................................                      <1
                                                                                                                                                        Union Tank Car Co. ...................................................................                           <1
                                                    Outside of the NAA .....................................................................            Louisa Generating Station .........................................................                           7,304
                                                    All of Muscatine County ..............................................................              Onroad Mobile ...........................................................................                         3
                                                                                                                                                        Nonroad Mobile ..........................................................................                         2
                                                                                                                                                        Area Sources .............................................................................                       10
                                                                                                                                                        Fires ...........................................................................................                 9

                                                          Total .....................................................................................    ....................................................................................................        21,049



                                                       Although not part of the state’s                                        operation of major new or modified                                            the standard, consistent with the
                                                    discussion of its 2011 baseline                                            stationary sources in the area (see CAA                                       attainment demonstration. The
                                                    emissions inventory, the state’s                                           § 172(c)(4)). The state must demonstrate                                      inventory should reflect projected
                                                    nonattainment SIP also provides 2013                                       that such emissions will be consistent                                        emissions for the attainment year for all
                                                    SO2 data for Gerdau and SSAB in                                            with RFP requirements and will not                                            SO2 sources in the nonattainment area.
                                                    Muscatine County and Linwood and                                           interfere with attainment of the 1-hr SO2                                     The state’s nonattainment SIP provided
                                                    Lafarge in Scott County. However, the                                      NAAQS. These requirements are met by                                          a projected inventory only for the
                                                    state provided this as a sum for the                                       the states preconstruction permitting                                         controlled sources, as provided in table
                                                    sources by county (e.g., the sum of                                        program and implementation of the                                             3. The inventory was developed
                                                    Gerdau and SSAB was 254 tpy and the                                        Nonattainment New Source Review                                               assuming each SO2 source operates
                                                    sum of Linwood and Lafarge was 1,539                                       Rules (NNSR). See section C.                                                  8,760 hours per year at its permitted
                                                    tpy). Gerdau and SSAB are                                                  Nonattainment New Source Review in                                            maximum allowable emission rate.16
                                                    approximately 8–9 km away from the                                         this preamble for more information.
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                                                    nonattainment boundary and Linwood                                            According to EPA’s April 2014 SO2
                                                    and Lafarge are approximately 20 km                                        guidance, the SIP should also include a
                                                    away from the nonattainment area                                           projected attainment year inventory that
                                                    boundary.                                                                  includes estimated emissions for all
                                                                                                                                                                                                               16 The projections don’t consider operational,

                                                                                                                                                                                                             physical, supply/demand, or other factors that
                                                       As already noted, the state’s                                           emission sources of SO2 that were                                             typically curb actual emissions to values below the
                                                    nonattainment SIP must identify and                                        determined to have an impact on the                                           maximum permitted allowable rate. There is
                                                    quantify the emissions which will be                                       affected nonattainment area for the year                                      potential for the actual attainment-year emissions to
                                                    allowed from the construction and                                          in which the area is expected to attain                                       be lower than those in Table 2.



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                                                    40096                    Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                     TABLE 3—PROJECTED ALLOWABLE AN- 4–1 of the state’s nonattainment SIP lists   While the scrubber installations will
                                                      NUAL SO2 EMISSIONS FROM CON- all the sources included in the control      not be completed by January 1, 2017,
                                                      TROL STRATEGY SOURCES          strategy, contains descriptions of the     the desired target date discussed in
                                                                                                        control measures, and provides effective                     EPA’s April 2014 guidance, the
                                                                                               2018 SO2 dates. Source specific permitted                             scrubbers will be operational as
                                                                 Facility                      emissionsallowable emission rates, compliance                         expeditiously as practicable. Based on
                                                                                                 (tpy)  and monitoring obligations, reporting                        permitted requirements, three of the six
                                                                                                        and recordkeeping requirements, and                          new scrubbers must be in operation no
                                                          Projected 2018 Emissions for the
                                                                 Controlled Sources                     implementation deadlines (where not                          later than August 30, 2017, with the
                                                                                                        immediately effectively upon permit                          final scrubber operational by March 31,
                                                    Grain Processing Corporation ....               167 issuance) are detailed in each                               2018. The installation timetable
                                                    Muscatine Power and Water ......              5,051 construction permit included with the                        accommodates factors such as
                                                    Monsanto .................................... 1,196 SIP submittal (appendix B of the state’s                     demolition and construction schedules,
                                                                                                        nonattainment plan). The GPC control                         structural modifications, ductwork
                                                      The EPA is proposing to determine                 strategy includes measures at 52                             design, and the addition of scrubber
                                                    that the state has met the requirements             emission points (EP) at the facility. In                     water treatment capacity. The state
                                                    of CAA § 172(c)(3) and 172(c)(4).                   summary, those measures include                              asserts in its nonattainment plan that
                                                    B. RACM/RACT                                        EP0001.0 (Power House Boilers 1–4 and                        the scrubber installation timeline will
                                                                                                        6–7) is subject to a more stringent SO2                      not delay or prevent timely attainment
                                                      CAA § 172(c)(1) requires that the
                                                                                                        emission limit based on natural gas                          of the 1-hr SO2 NAAQS.
                                                    state’s nonattainment plan provide for
                                                    the implementation of all RACM as                   combustion; EP546.0 is subject to a                             It should also be noted that, on July
                                                    expeditiously as practicable (including             more stringent, source-specific SO2 limit                    14, 2015, GPC converted all of its coal-
                                                    such reductions in emissions from                   of .0034 lb/hr; a requirement to continue                    fired boilers to natural gas. The state
                                                    existing sources in the area as may be              to add sodium bisulfate to the steep                         estimates that the fuel switch will result
                                                    obtained through the adoption, at a                 water instead of sulfur dioxide in order                     in a 96 percent reduction in the
                                                    minimum, of RACT) and shall provide                 to reduce SO2 emissions from the                             facility’s total SO2 emissions. In terms of
                                                    for attainment of the NAAQS. The                    steeping operations and downstream                           2011 data, this fuel switch eliminated
                                                    state’s plan for attaining the 1-hour SO2           processes; the establishment of source                       10,374 tons of SO2 emissions. The state
                                                    NAAQS in the Muscatine                              specific SO2 emission limits at 43 EPs                       believes, and the EPA agrees, that the
                                                    nonattainment area is based on a variety and the required installation of                                        fuel conversion from coal to natural gas
                                                    of control measures at GPC, MPW and                 scrubbers on EP015.0 (Germ Drier Nos.                        in GPC’s boilers has significantly
                                                    Monsanto. Those measures were                       1 and 2), EP097.0 (Germ Drier No. 3),                        reduced measured ambient SO2
                                                    included in the state’s nonattainment               EP126.0 (Germ Drier No. 4), EP200N                           concentrations in Muscatine, as noted in
                                                    SIP as construction permits.17                      (Corn Steep Tank Nos. 1–30 and the                           Table 4. Based on existing air quality
                                                      To ensure the SO2 NAAQS is attained, North Wet Corn Drag), EP200S (Corn                                        improvements the state projects that
                                                    GPC must install additional scrubbers,              Steep Tank Nos. 31–62 and the South                          monitored attainment will be achieved
                                                    comply with new and more stringent                  Wet Corn Drag), and EP279.0 (Wet                             by the attainment date. Appendix B of
                                                    SO2 emission limits, and implement                  Milling Nos. 1–6). The state expects the                     the state’s nonattainment SIP contains
                                                    process modifications designed to ),                installation of the scrubbers to reduce                      the Federally enforceable air
                                                    andreduce SO2 emissions across                      SO2 emissions by up to 90 percent from                       construction permits that define GPC’s
                                                    numerous downstream sources. Table                  those units.18                                               RACM/RACT requirements.

                                                                                           TABLE 4—AIR MONITORING DATA FROM THE MUSSER PARK MONITOR
                                                                                                            Design values (ppb)                               99th Percentile daily max 1-hr SO2 concentrations
                                                                                                                                                                                     (ppb)
                                                                       1-hr SO2
                                                      Monitor          NAAQS              2011–2013      2012–2014       2013–2015          2014–2016
                                                      location           (ppb)                                                                              2011      2012       2013        2014       2015        2016

                                                    Musser           75 ...............     217              194                158            113           248       224        179        180         116         45
                                                     Park.



                                                       MPW is subject to several Federal                      rely on these Federal programs alone to                and 9). Permit No. 74–A–175–S3, issued
                                                    programs that directly or indirectly                      address SO2 emissions. Instead, as per                 to the facility in 2013, shows the SO2
                                                    affect SO2 emissions, including the Acid                  the states control strategy, MPW will                  emission limit for Units 7 and 8 was a
                                                    Rain provisions of title IV of the CAA,                   comply with new SO2 emission limits                    combined maximum of 2,772 lb/hr.
                                                    the Cross State Air Pollution Rule                        that provide for attainment of the                     Permit No. 80–A–191–P2, issued to the
                                                    (CSAPR), and the CAA section 112                          NAAQS. The control measures,                           facility in 2013, shows the SO2 emission
                                                    Maximum Achievable Control                                described in table 4–2 of the state’s                  limit for Unit 9 was 0.56 lb/MMBtu (a
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                                                    Technology regulations more commonly                      nonattainment SIP, account for seven                   maximum daily average). Permit No.
                                                    known as the Mercury and Air Toxics                       possible operating scenarios involving                 80–A–191–P4, issued to the facility in
                                                    Standards. However, the state did not                     the three coal-fired boilers (Units 7, 8,              2016 as part of the control strategy of

                                                      17 Appendix B, C and D of the state’s                   limits taken to comply with the NAAQS are                 18 The state’s estimation of a 90 percent reduction

                                                    nonattainment SIP contain the Federally                   specifically noted in each permit via footnotes in     in SO2 emissions is based off of the control
                                                    enforceable air construction permits that define          the permits.                                           efficiency readily achieved by the types of
                                                    RACM/RACT requirements. The RACM/RACT                                                                            scrubbers being installed.



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                                                                          Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                             40097

                                                    the state’s nonattainment SIP, shows the                5, 2018. EPA concurs and proposes to                    Monsanto (effective on May 13, 2015),
                                                    combined SO2 emissions from Units 7–                    conclude that the state has satisfied the               MPW (effective January 1, 2017) and for
                                                    9 must be less than 1,153 lbs/hr.                       requirement in CAA § 172(c)(1) to adopt                 GPC occur on reasonable timelines.
                                                       The control strategy for MPW also                    and submit all RACM as needed to                          The state asserts that this plan
                                                    addresses emission reductions from                      attain the standards as expeditiously as                requires that affected sources implement
                                                    EP60 (Auxiliary Boiler). A permit issued                practicable.                                            appropriate control measures as
                                                    to the facility in 2013, Permit No. 13–                                                                         expeditiously as practicable in order to
                                                    A–152, for the Auxiliary Boiler required                C. Nonattainment New Source Review                      ensure attainment of the standard by the
                                                    that SO2 emissions be limited to limited                (NNSR)                                                  applicable attainment date. The state
                                                    0.44 lbs/MMBtu (expressed as the                          Section 172(c)(5) requires that the                   concluded that its plan therefore
                                                    average of 3 runs) when burning fuel oil,               state’s nonattainment plan provisions                   provides for RFP in accordance with the
                                                    and to 500 ppm by volume when                           shall require permits for the                           approach to RFP described in EPA’s
                                                    burning natural gas or                                  construction and operation of new or                    guidance. EPA concurs and proposes to
                                                    propane.19 thnsp;20 The permit issued                   modified major stationary sources                       conclude that the plan provides for RFP
                                                    to the facility in 2016, as part of the                 anywhere in the nonattainment area, in                  as required by CAA § 172(c)(2).
                                                    control strategy, Permit No. 13–A–152–                  accordance with section CAA § 173.
                                                                                                            EPA approved the state’s nonattainment                  E. Contingency Measures
                                                    S1, requires that the SO2 emissions be
                                                    limited to 0.45 lb/hr and that the sulfur               new source review rules on May 15,                         Section 172(c)(9) of the CAA requires
                                                    content of the distillate fuel oil                      2014 (79 FR 27763). These rules provide                 that the state’s nonattainment plan
                                                    combusted in the unit not exceed 15                     for appropriate new source review for                   provide for the implementation of
                                                    ppm. Appendix C of the state’s                          SO2 sources undergoing construction or                  specific measures to be undertaken if
                                                    nonattainment SIP contains the                          major modification in the Muscatine                     the area fails to make reasonable further
                                                    Federally enforceable air construction                  nonattainment area without need for                     progress, or to attain the national
                                                    permits that define MPW’s RACM/                         modification of the approved rules.                     primary ambient air quality standard by
                                                    RACT requirements. These permits are                    Therefore, EPA concludes that the                       the attainment date applicable under
                                                    effective January 1, 2017.                              requirements of CAA § 172(c)(5) have                    this part. Such measures shall be
                                                       The control measures developed for                   been met.                                               included in the plan revision as
                                                    Monsanto, described in table 4–3 of the                                                                         contingency measures to take effect in
                                                                                                            D. Reasonable Further Progress (RFP)                    any such case without further action by
                                                    state’s nonattainment SIP, establish
                                                    lower emission limits on two sources—                      Section 172(c)(2) requires that                      the State or the Administrator.
                                                    EP–195 (Boiler #8) and EP–234 (CAC                      nonattainment plans include provisions                     EPA’s April 2014 guidance describes
                                                    Process Flare). The Boiler #8 control                   addressing reasonable further progress                  special features of SO2 planning that
                                                    strategy includes a more stringent SO2                  (RFP). Reasonable further progress is                   influence the suitability of alternative
                                                    emission limit. A 2007 permit issued to                 defined in CAA § 171(1) as: ‘‘. . . such                means of addressing the requirement in
                                                    the facility Permit No. 82–A–092–P9,                    annual incremental reductions in                        section 172(c)(9) for contingency
                                                    limited the unit’s SO2 emissions to                     emissions of the relevant air pollutant                 measures for SO2, such that in particular
                                                    292.5 lb/hr. The permit issued to the                   as are required by this part [part D] or                an appropriate means of satisfying this
                                                    facility in 2015, Permit No. 82–A–092–                  may reasonably be required by the                       requirement is for the state to have a
                                                    P11, as part of the control strategy,                   Administrator for the purpose of                        comprehensive enforcement program
                                                    limits the unit’s SO2 emissions to 273                  ensuring attainment of the applicable                   that identifies sources of violations of
                                                    lb/hr.21                                                national ambient air quality standard by                the SO2 NAAQS and to undertake an
                                                       The control strategy for the CAC                     the applicable date.’’                                  aggressive follow-up for compliance and
                                                    Process Flare includes new SO2                             As discussed in EPA’s April 2014                     enforcement.
                                                    emission limit that restricts the unit’s                guidance, this definition is most                          The state’s nonattainment SIP
                                                    fuel use to natural gas only. A 2012                    appropriate for pollutants that are                     provides that, after full implementation
                                                    permit issued to the facility, Permit No.               emitted by numerous and diverse                         of the control strategy, contingency
                                                    88–A–001–S2, limited the unit’s SO2                     sources, where the relationship between                 measures will be triggered if monitored
                                                    emissions to 500 ppm by volume. The                     any individual source and overall air                   ambient air quality records 1-hr SO2
                                                    permit issued to the facility in 2015,                  quality is not explicitly quantified, and               NAAQS violation in the nonattainment
                                                    Permit No. 88–A–001–S3, as part of the                  where NAAQS attainment requires                         area, or if the nonattainment area fails
                                                    control strategy, limits the unit to                    inventory-wide emissions reductions.                    to meet RFP. If triggered, the state will
                                                    burning only natural gas and the unit’s                 The SO2 NAAQS presents special                          evaluate culpabilities for the violation
                                                    SO2 emissions to 0.02 lb/hr. Appendix                   circumstances because there are usually                 and will plan to complete the
                                                    D of the state’s nonattainment SIP                      a limited number of well-defined                        investigation within 3 months of the
                                                    contains the Federally enforceable air                  sources affecting the area’s air quality                trigger. Where the investigation
                                                    construction permits that define                        and any emission control measures                       concludes unequivocally that SO2
                                                    Monsanto’s RACM/RACT requirements.                      commonly result in swift improvements                   emissions from one of the three sources
                                                    These permits are effective May 13,                     that typically occur in one step. As                    in the control strategy is the cause of the
                                                    2015.                                                   noted in the state’s nonattainment SIP,                 recorded 1-hr SO2 NAAQS violation or
                                                       The state has determined that these                  the EPA has interpreted that RFP is best                failure to achieve RFP, the state will
                                                    measures suffice to provide for                         construed as ‘‘adherence to an                          conduct a compliance evaluation and
mstockstill on DSK30JT082PROD with PROPOSALS




                                                    attainment the attainment date, August                  ambitious compliance schedule’’ in                      establish orders for the abatement or
                                                                                                            previous rulemaking.22                                  control of air pollution or make changes
                                                      19 The unit’s 0.44 lbs/MMBtu emission rate is a
                                                                                                               As previously noted in section V.B.                  to the GPC, MPW, or Monsanto
                                                    Lowest Achievable Emission Rate (LAER).                 RACT/RACM, in this preamble, the SO2                    construction permits. Orders or
                                                      20 The limit of 500 ppm by volume is from state
                                                                                                            emission limits and application of                      construction permits will be issued
                                                    rule.
                                                      21 The unit also has a 1.95 lbs/MMBtu based on        control technologies established for                    within approximately 9 months of
                                                    a 3-hr rolling average limit is a Best Available                                                                completion of the investigation and
                                                    Control Technology limit.                                 22 See   74 FR 13547 (April 16, 1992).                could include fuel switches, addition of


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                                                    40098                 Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                    controls, curtailment of production,                    VII. EPA’s Proposed Action                             the CAA. Accordingly, this proposed
                                                    reducing boiler operating loads, or other                 The EPA is proposing to approve the                  action merely approves state law as
                                                    appropriate measures necessary to                       nonattainment SIP submission, which                    meeting Federal requirements and does
                                                    mitigate the violation.                                 the state submitted to EPA on May 26,                  not impose additional requirements
                                                      EPA proposes to approve the state’s                   2016, for attaining the 2010 1-hour SO2                beyond those imposed by state law. For
                                                    plan for meeting the contingency                        NAAQS for the Muscatine                                that reason, this proposed action:
                                                    measure requirement of CAA                              nonattainment area and for meeting                        • Is not a significant regulatory action
                                                    § 172(c)(9).                                            other nonattainment area planning                      subject to review by the Office of
                                                                                                            requirements. This SO2 attainment plan                 Management and Budget under
                                                    VI. Additional Elements of the State’s                  includes the state’s attainment                        Executive Orders 12866 (58 FR 51735,
                                                    Submittal                                               demonstration for the Muscatine                        October 4, 1993) and 13563 (76 FR 3821,
                                                                                                            nonattainment area. The nonattainment                  January 21, 2011);
                                                    A. Compliance With Section 110(a)(2) of
                                                                                                            area plan also addresses requirements                     • Does not impose an information
                                                    the CAA
                                                                                                            for RFP, RACT/RACM, base-year and                      collection burden under the provisions
                                                       Section 172(c)(7) of the CAA requires                projection-year emission inventories,                  of the Paperwork Reduction Act (44
                                                    nonattainment SIPs to meet the                          and contingency measures.                              U.S.C. 3501 et seq.);
                                                    applicable provisions of CAA                              The EPA has determined that the                         • Is certified as not having a
                                                    § 110(a)(2). While the provisions of                    state’s nonattainment plan meets                       significant economic impact on a
                                                    110(a)(2) address various topics, EPA’s                 applicable requirements of the section                 substantial number of small entities
                                                    past determinations suggest that only                   172 of the CAA (107(c)(1) through (9).                 under the Regulatory Flexibility Act (5
                                                    the § 110(a)(2) criteria which are linked               EPA’s analysis is discussed in this                    U.S.C. 601 et seq.);
                                                    with a particular area’s designation and                proposed rulemaking.                                      • Does not contain any unfunded
                                                    classification are relevant to § 172(c)(7).               The EPA is taking public comments                    mandate or significantly or uniquely
                                                    This nonattainment SIP submittal                        for thirty days following the publication              affect small governments, as described
                                                    satisfies all applicable CAA § 110(a)(2)                of this proposed action in the Federal                 in the Unfunded Mandates Reform Act
                                                    criteria, as evidenced by the state’s                   Register. We will take all comments into               of 1995 (Pub. L. 104–4);
                                                    nonattainment new source review
                                                                                                            consideration in our final action.                        • Does not have Federalism
                                                    program which addresses 110(a)(2)(I),                   VIII. Incorporation by Reference                       implications as specified in Executive
                                                    the included control strategy, and the                                                                         Order 13132 (64 FR 43255, August 10,
                                                                                                              In this rule, EPA is proposing to                    1999);
                                                    associated emissions limits which are                   include in a final EPA rule regulatory
                                                    relevant to 110(a)(2)(A). In addition, on                                                                         • Is not an economically significant
                                                                                                            text that includes incorporation by
                                                    July 26, 2013, Iowa submitted to EPA an                                                                        regulatory action based on health or
                                                                                                            reference. In accordance with
                                                    infrastructure SIP to demonstrate that                                                                         safety risks subject to Executive Order
                                                                                                            requirements of 1 CFR 51.5, EPA is
                                                    the state has the necessary plans,                                                                             13045 (62 FR 19885, April 23, 1997);
                                                                                                            proposing to incorporate by reference
                                                    programs, and statutory authority to                                                                              • Is not a significant regulatory action
                                                                                                            the Iowa Regulations described in the
                                                    implement the requirements of section                                                                          subject to Executive Order 13211 (66 FR
                                                                                                            amendments to 40 CFR part 52 set forth
                                                    110 of the CAA as they pertain to the                   below. EPA has made, and will continue                 28355, May 22, 2001);
                                                    2010 1-hr SO2 NAAQS. EPA will take                      to make, these materials generally                        • Is not subject to requirements of
                                                    action on the state’s SO2 infrastructure                available through https://                             Section 12(d) of the National
                                                    SIP in a separate rulemaking. The EPA                   www.regulations.gov and/or at the EPA                  Technology Transfer and Advancement
                                                    is proposing to conclude that the state                 Region 7 Office (please contact the                    Act of 1995 (15 U.S.C. 272 note) because
                                                    has meet the requirements of CAA                        person identified in the FOR FURTHER                   application of those requirements would
                                                    § 172(c)(7).                                            INFORMATION CONTACT section of this                    be inconsistent with the CAA; and
                                                                                                            preamble for more information).                           • Does not provide EPA with the
                                                    B. Equivalent Techniques                                  Therefore, these materials have been                 discretionary authority to address, as
                                                                                                            approved by EPA for inclusion in the                   appropriate, disproportionate human
                                                      Section 172(c)(8) of the CAA states                                                                          health or environmental effects, using
                                                    that upon application by any state, the                 State implementation plan, have been
                                                                                                            incorporated by reference by EPA into                  practicable and legally permissible
                                                    Administrator may allow the use of                                                                             methods, under Executive Order 12898
                                                    equivalent modeling, emission                           that plan, are fully Federally enforceable
                                                                                                            under sections 110 and 113 of the CAA                  (59 FR 7629, February 16, 1994).
                                                    inventory, and planning procedures,                                                                               The SIP is not approved to apply on
                                                    unless the Administrator determines                     as of the effective date of the final
                                                                                                            rulemaking of EPA’s approval, and will                 any Indian reservation land or in any
                                                    that the proposed techniques are, in the                                                                       other area where EPA or an Indian tribe
                                                    aggregate, less effective than the                      be incorporated by reference by the
                                                                                                            Director of the Federal Register in the                has demonstrated that a tribe has
                                                    methods specified by the Administrator.                                                                        jurisdiction. In those areas of Indian
                                                                                                            next update to the SIP compilation.23
                                                      The state’s nonattainment SIP                                                                                country, the rule does not have tribal
                                                    indicates that it followed existing                     IX. Statutory and Executive Order                      implications and will not impose
                                                    regulations, guidance, and standard                     Reviews                                                substantial direct costs on tribal
                                                    practices when conducting modeling,                       Under the CAA, the Administrator is                  governments or preempt tribal law as
                                                    preparing the emissions inventories,                    required to approve a SIP submission                   specified by Executive Order 13175 (65
mstockstill on DSK30JT082PROD with PROPOSALS




                                                    and implementing its planning                           that complies with the provisions of the               FR 67249, November 9, 2000).
                                                    procedures. Therefore, the state did not                Act and applicable Federal regulations.
                                                    use or request approval of alternative or                                                                      List of Subjects in 40 CFR Part 52
                                                                                                            42 U.S.C. 7410(k); 40 CFR 52.02(a).
                                                    equivalent techniques as allowed under                  Thus, in reviewing SIP submissions,                      Environmental protection, Air
                                                    of the CAA and the EPA is proposing to                  EPA’s role is to approve state choices,                pollution control, Incorporation by
                                                    conclude that the state’s nonattainment                 provided that they meet the criteria of                reference, Intergovernmental relations,
                                                    SIP meets the requirements of CAA                                                                              Reporting and recordkeeping
                                                    § 172(c)(8).                                              23 62   FR 27968 (May 22, 1997).                     requirements, Sulfur oxides.


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                                                                          Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                                 40099

                                                      Dated: August 9, 2017.                                 Part 52—APPROVAL AND                                   ■ a. In the table in paragraph (d), adding
                                                    Edward H. Chu,                                           PROMULGATION OF                                        entries ‘‘(112)’’ through ‘‘(169)’’ in
                                                    Acting Regional Administrator, Region 7.                 IMPLEMENTATION PLANS                                   numerical order; and
                                                                                                                                                                    ■ b. In the table in paragraph (e), adding
                                                      For the reasons stated in the                          ■ 1. The authority citation for part 52                an entry ‘‘(47)’’ in numerical order.
                                                    preamble, EPA proposes to amend 40                       continues to read as follows:
                                                    CFR part 52 as set forth below:                                                                                   The additions read as follows:
                                                                                                                 Authority: 42 U.S.C. 7401 et seq.
                                                                                                                                                                    § 52.820    Identification of plan.
                                                                                                             Subpart Q—Iowa                                         *      *     *      *      *
                                                                                                             ■   2. Amend § 52.820 by:                                  (d)* * *
                                                                                                EPA-APPROVED IOWA SOURCE-SPECIFIC ORDERS/PERMITS
                                                                                                                           State effective
                                                           Name of source                      Order/permit No.                                       EPA approval date                     Explanation
                                                                                                                                date


                                                             *                  *                 *                                   *                       *                      *                   *
                                                    (112) Grain Processing Cor- Permit No. 95–A–374–S4 ..                         12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (113) Grain Processing Cor-           Permit No. 15–A–078 ........            12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (114) Grain Processing Cor-           Permit No. 79–A–194–S2 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (115) Grain Processing Cor-           Permit No. 71–A–067–S4 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (116) Grain Processing Cor-           Permit No. 75–A–087–S1 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (117) Grain Processing Cor-           Permit No. 72–A–199–S2 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (118) Grain Processing Cor-           Permit No. 74–A–014–S1 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (119) Grain Processing Cor-           Permit No. 74–A–015–S2 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (120) Grain Processing Cor-           Permit No. 75–A–353–S2 ..                 7/6/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (121) Grain Processing Cor-           Permit No. 79–A–195–S2 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
mstockstill on DSK30JT082PROD with PROPOSALS




                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (122) Grain Processing Cor-           Permit No. 80–A–149–S5 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].



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                                                    40100                 Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                                                     EPA-APPROVED IOWA SOURCE-SPECIFIC ORDERS/PERMITS—Continued
                                                                                                                          State effective
                                                           Name of source                      Order/permit No.                                       EPA approval date                     Explanation
                                                                                                                               date

                                                    (123) Grain Processing Cor-           Permit No. 80–A–150–S5 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (124) Grain Processing Cor-           Permit No. 85–A–031–S2 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (125) Grain Processing Cor-           Permit No. 85–A–032–S2 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (126) Grain Processing Cor-           Permit No. 85–A–038–P1 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (127) Grain Processing Cor-           Permit No. 85–A–135–P1 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (128) Grain Processing Cor-           Permit No. 90–A–111–S1 ..                 7/6/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (129) Grain Processing Cor-           Permit No. 91–A–068–S2 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (130) Grain Processing Cor-           Permit No. 93–A–110–P1 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (131) Grain Processing Cor-           Permit No. 92–A–383–S2 ..                 7/6/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (132) Grain Processing Cor-           Permit No. 92–A–385–S1 ..                 7/6/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (133) Grain Processing Cor-           Permit No. 94–A–055–S1 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (134) Grain Processing Cor-           Permit No. 94–A–061–S1 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (135) Grain Processing Cor-           Permit No. 02–A–781–S2 ..                 7/6/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
mstockstill on DSK30JT082PROD with PROPOSALS




                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (136) Grain Processing Cor-           Permit No. 02–A–782–S2 ..                 7/6/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].



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                                                                          Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                                 40101

                                                                                     EPA-APPROVED IOWA SOURCE-SPECIFIC ORDERS/PERMITS—Continued
                                                                                                                          State effective
                                                           Name of source                      Order/permit No.                                       EPA approval date                     Explanation
                                                                                                                               date

                                                    (137) Grain Processing Cor-           Permit No. 09–A–482–S2 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (138) Grain Processing Cor-           Permit No. 10–A–563–S1 ..               12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (139) Grain Processing Cor-           Permit No. 15–A–200 ........             3/25/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (140) Grain Processing Cor-           Permit No. 15–A–201 ........             3/25/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (141) Grain Processing Cor-           Permit No. 15–A–202 ........            12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (142) Grain Processing Cor-           Permit No. 15–A–203 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (143) Grain Processing Cor-           Permit No. 15–A–204 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (144) Grain Processing Cor-           Permit No. 15–A–205 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (145) Grain Processing Cor-           Permit No. 15–A–206 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (146) Grain Processing Cor-           Permit No. 15–A–207 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (147) Grain Processing Cor-           Permit No. 15–A–208 ........            12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (148) Grain Processing Cor-           Permit No. 15–A–209 ........            12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (149) Grain Processing Cor-           Permit No. 15–A–480 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
mstockstill on DSK30JT082PROD with PROPOSALS




                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (150) Grain Processing Cor-           Permit No. 15–A–481 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].



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                                                    40102                 Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules

                                                                                     EPA-APPROVED IOWA SOURCE-SPECIFIC ORDERS/PERMITS—Continued
                                                                                                                          State effective
                                                           Name of source                      Order/permit No.                                       EPA approval date                     Explanation
                                                                                                                               date

                                                    (151) Grain Processing Cor-           Permit No. 15–A–482 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (152) Grain Processing Cor-           Permit No. 15–A–483 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (153) Grain Processing Cor-           Permit No. 15–A–213 ........             1/26/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (154) Grain Processing Cor-           Permit No. 15–A–484 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (155) Grain Processing Cor-           Permit No. 15–A–485 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (156) Grain Processing Cor-           Permit No. 15–A–486 ........             2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (157) Grain Processing Cor-           Permit No. 15–A–326 ........            12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (158) Grain Processing Cor-           Permit No. 03–A–471–S1 ..                 7/6/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (159) Grain Processing Cor-           Permit No. 05–A–926–S4 ..                2/15/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (160) Grain Processing Cor-           Permit No. 06–A–1261–S1                 12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (161) Grain Processing Cor-           Permit No. 11–A–338–S1 ..                 7/6/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (162) Grain Processing Cor-           Permit No. 15–A–354 ........            12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (163) Grain Processing Cor-           Permit No. 15–A–199 ........            12/10/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
mstockstill on DSK30JT082PROD with PROPOSALS




                                                      poration.                                                                                 the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].
                                                    (164) Muscatine Power and             Permit No. 13–A–152–S1 ..                 3/2/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      Water.                                                                                    the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                  XXXX–Region 7].



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                                                                            Federal Register / Vol. 82, No. 163 / Thursday, August 24, 2017 / Proposed Rules                                                 40103

                                                                                          EPA-APPROVED IOWA SOURCE-SPECIFIC ORDERS/PERMITS—Continued
                                                                                                                            State effective
                                                           Name of source                        Order/permit No.                                       EPA approval date                     Explanation
                                                                                                                                 date

                                                    (165) Muscatine Power and               Permit No. 74–A–175–S4 ..                 3/2/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      Water.                                                                                      the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                  and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                  citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                    XXXX–Region 7].
                                                    (166) Muscatine Power and               Permit No. 95–A–373–P3 ..                 3/2/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      Water.                                                                                      the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                  and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                  citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                    XXXX–Region 7].
                                                    (167) Muscatine Power and               Permit No. 80–A–191–P3 ..                 3/2/16    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                      Water.                                                                                      the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                  and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                  citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                    XXXX–Region 7].
                                                    (168) Monsanto ....................     Permit No. 82–A–092–P11                  5/13/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                                                                                                                  the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                  and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                  citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                    XXXX–Region 7].
                                                    (169) Monsanto ....................     Permit No. 88–A–001–S3 ..                5/13/15    [date of final publication in     2010 1-hr SO2 NAAQ Nonattain-
                                                                                                                                                  the Federal Register]             ment Plan; Condition 6 of the per-
                                                                                                                                                  and [Federal Register             mit is not part of the SIP; EPA–
                                                                                                                                                  citation].                        R07–OAR–2017–0416;          FRL–
                                                                                                                                                                                    XXXX–Region 7].



                                                        (e)* * *

                                                                                                      EPA-APPROVED IOWA NONREGULATORY PROVISIONS
                                                     Name of nonregulatory SIP               Applicable geographic or       State submittal             EPA approval date                     Explanation
                                                             provision                         nonattainment area                date


                                                             *                   *                  *                                   *                       *                     *               *
                                                    (47) 2010 1-hr SO2 National A portion of Muscatine                               5/26/16    [date of final publication in     EPA–R07–OAR–2017–0416;        FRL–
                                                      Ambient Air Quality Stand-   County.                                                        the Federal Register]            XXXX–Region 7].
                                                      ard Nonattainment Plan.                                                                     and [Federal Register
                                                                                                                                                  citation].



                                                    *      *       *       *      *                            Pollutants (NESHAP) for the                            sources during periods when an
                                                    [FR Doc. 2017–17736 Filed 8–23–17; 8:45 am]                Manufacture of Amino/Phenolic Resins                   emission control system used to control
                                                    BILLING CODE 6560–50–P
                                                                                                               (APR). Subsequently, the EPA received                  vents on fixed roof tanks is undergoing
                                                                                                               three petitions for reconsideration of the             planned routine maintenance. The EPA
                                                                                                               final rule. The EPA is reconsidering and               is seeking comments only on the four
                                                    ENVIRONMENTAL PROTECTION                                   requesting public comment on issues                    issues specifically addressed in this
                                                    AGENCY                                                     related to the maximum achievable                      notice: proposed revised back-end CPV
                                                                                                               control technology (MACT) standards                    MACT standards for existing sources,
                                                    40 CFR Part 63                                             for continuous process vents (CPVs) at                 whether the EPA should modify the
                                                    [EPA–HQ–OAR–2012–0133, FRL–9966–26–
                                                                                                               existing affected sources. The EPA is                  front-end CPV MACT standards for
                                                    OAR]                                                       proposing to revise the MACT standard                  existing sources, whether the EPA
                                                                                                               for back-end CPVs at existing affected                 should extend the compliance date for
                                                    RIN 2060–AS79                                              sources based on hazardous air                         the proposed revised back-end CPV
                                                                                                               pollutant (HAP) emissions test data for                MACT standards for existing sources,
                                                    National Emission Standards for                            back-end CPVs at existing sources for                  and the proposed work practice
                                                    Hazardous Air Pollutants: Manufacture                      this source category submitted by                      standards for storage vessels during
                                                    of Amino/Phenolic Resins                                   petitioners. The EPA is also soliciting                planned routine maintenance of
mstockstill on DSK30JT082PROD with PROPOSALS




                                                    AGENCY:  Environmental Protection                          comments regarding the need to revise                  emission control systems. In this
                                                    Agency (EPA).                                              the standard for front-end CPVs at                     rulemaking, the EPA is not reopening or
                                                    ACTION: Proposed rule.                                     existing sources, and to extend the                    requesting comment on any other
                                                                                                               compliance date for the proposed                       aspects of the 2014 final amendments to
                                                    SUMMARY:   On October 8, 2014, the                         revised emission limit for back-end                    the NESHAP for the Manufacture of
                                                    Environmental Protection Agency (EPA)                      CPVs at existing sources. Additionally,                APR, including other issues raised in
                                                    finalized amendments to the National                       the EPA is proposing requirements for                  petitions for reconsideration of the 2014
                                                    Emission Standards for Hazardous Air                       storage vessels at new and existing                    rule. The EPA estimates this proposal, if


                                               VerDate Sep<11>2014     16:24 Aug 23, 2017    Jkt 241001   PO 00000   Frm 00027   Fmt 4702   Sfmt 4702    E:\FR\FM\24AUP1.SGM    24AUP1



Document Created: 2018-10-24 12:37:11
Document Modified: 2018-10-24 12:37:11
CategoryRegulatory Information
CollectionFederal Register
sudoc ClassAE 2.7:
GS 4.107:
AE 2.106:
PublisherOffice of the Federal Register, National Archives and Records Administration
SectionProposed Rules
ActionProposed rule.
DatesComments must be received on or before September 25, 2017.
ContactTracey Casburn, Environmental Protection Agency, Air Planning and Development Branch, 11201 Renner Boulevard, Lenexa, Kansas 66219 at (913) 551-7016, or by email at [email protected]
FR Citation82 FR 40086 
CFR AssociatedEnvironmental Protection; Air Pollution Control; Incorporation by Reference; Intergovernmental Relations; Reporting and Recordkeeping Requirements and Sulfur Oxides

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