Document ID: EPA-R07-OAR-2017-0416-0044
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: Iowa; Air Quality Implementation Plan-Muscatine Sulfur Dioxide Nonattainment Area and Start-up, Shutdown, Malfunction State Implementation Plan Call Withdrawal
Posted Date: 2020-06-22T04:00Z

[Federal Register Volume 85, Number 120 (Monday, June 22, 2020)]
[Proposed Rules]
[Pages 37405-37411]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-13380]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R07-OAR-2017-0416; FRL-10011-19-Region 7]

Air Plan Approval; Iowa; Air Quality Implementation Plan-
Muscatine Sulfur Dioxide Nonattainment Area and Start-Up, Shutdown, 
Malfunction SIP Call Withdrawal

AGENCY: Environmental Protection Agency (EPA).

ACTION: Supplemental notice of proposed rulemaking.

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SUMMARY: The Environmental Protection Agency's (EPA) Region 7 Office is 
publishing a second supplemental notice of proposed rulemaking (SNPRM) 
to propose approval of Iowa's State Implementation Plan (SIP) for the 
2010 1-hour Sulfur Dioxide (SO2) National Ambient Air 
Quality Standard (NAAQS) for the Muscatine nonattainment area, 
including the attainment plan control strategy. In this action, Region 
7 is including additional technical information in the docket. Region 7 
is also considering adoption of an alternative policy regarding 
startup, shutdown, and malfunction (SSM) exemption provisions in the 
Iowa SIP that departs from the policy detailed in EPA's 2015 SSM SIP 
Action, as well as proposing to withdraw the SIP call issued to Iowa as 
part of the 2015 SSM SIP Action and to approve the attainment plan 
control strategy.

DATES: Comments must be received on or before July 22, 2020.

ADDRESSES: You may send comments, identified by Docket ID No. EPA-R07-
OAR-2017-0416 to https://www.regulations.gov. Follow the online 
instructions for submitting comments.
    Instructions: All submissions received must include the Docket ID 
No. for this rulemaking. Comments received will be posted without 
change to https://www.regulations.gov/, including any personal 
information provided. For detailed instructions on sending comments and 
additional information on the rulemaking process, see the ``Written 
Comments'' section of this document.

FOR FURTHER INFORMATION CONTACT: Tracey Casburn, Environmental 
Protection Agency, Region 7 Office, Air Quality Planning Branch, 11201 
Renner Boulevard, Lenexa, Kansas 66219; telephone number (913) 551-
7016; email address casburn.tracey@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' and 
``our'' refer to EPA.

Table of Contents

I. Written Comments
II. Executive Summary
III. Background
    A. The EPA's SIP Policy for Treatment of Excess Emissions During 
Periods of Startup, Shutdown, or Malfunction (SSM)
    B. The SSM SIP Call for Iowa
    C. The Muscatine Attainment Plan
IV. What is Being Addressed in This Document?
V. Region 7's Evaluation of the Iowa SIP
VI. Additional Modeling Information
VII. What Action is EPA Region 7 Taking?
VIII. Statutory and Executive Order Reviews

I. Written Comments

    Submit your comments regarding the supplemental modeling 
information discussed in this document or the EPA's proposal to remove 
Iowa from the SSM SIP Call, identified by Docket ID No. EPA-R07-OAR-
2017-0416 at https://www.regulations.gov. Modeling files are provided 
in the docket to this rulemaking but can also be requested from the EPA 
by contacting the person identified in the FOR FURTHER INFORMATION 
CONTACT section of this document. 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://www.epa.gov/dockets/commenting-epa-dockets.

II. Executive Summary

    On August 24, 2017, the EPA's Region 7 published a notice of 
proposed rulemaking (NPRM) to propose approval of the Iowa SIP revision 
for attaining the 2010 1-hour SO2 primary NAAQS for the 
Muscatine nonattainment area.\1\ As a result of comments received on 
the NPRM, Region 7 published an SNPRM on January 9, 2018 to clarify the 
August 24, 2017 NPRM and to provide additional technical information in 
the docket.\2\ As a result of comments received on the NPRM and SNPRM, 
Region 7 is issuing a second SNPRM to provide additional detail 
regarding technical support for approving the attainment demonstration 
contained in Iowa's submitted SIP revision. In addition, Region 7 is 
considering in this document adoption of an alternative policy 
regarding SSM exemption provisions in the Iowa SIP that departs from 
the policy detailed in EPA's 2015 SSM SIP Action.\3\ Simultaneously, 
Region 7 is also proposing to withdraw the SIP call issued to Iowa as 
part of the 2015 SSM SIP Action and proposing to

[[Page 37406]]

approve the attainment plan control strategy.
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    \1\ 82 FR 40086.
    \2\ 83 FR 997.
    \3\ 80 FR 33840.
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III. Background

    Clean Air Act (CAA or Act) section 110 provides a framework for how 
states must adopt and periodically revise their SIPs with a goal of 
attaining and maintaining the NAAQS.\4\ State regulatory or statutory 
requirements are submitted by the state to the EPA for approval into 
the SIP. The CAA establishes the framework for EPA action on submitted 
SIP revisions, and the EPA must approve submitted SIP revisions that it 
determines meet the applicable requirements of the Act. Once approved 
by the EPA, the SIP provisions become federally enforceable.
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    \4\ See 40 CFR part 50.
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    There are times when a state will update or revise its SIP on its 
own initiative due to revisions to state law or the need to update its 
regulations. Additionally, certain events trigger requirements that a 
state revise or update its SIP. Examples of mandatory SIP revisions 
triggered by specific events include ``infrastructure'' SIP (iSIP) 
revisions, which are required 3 years after the promulgation of a new 
or revised NAAQS, and ``attainment plan'' SIP revisions, which are 
required after an area is designated or redesignated nonattainment for 
a NAAQS. A state may also be required to revise its SIP after the EPA 
revises its regulations to clarify certain requirements of the CAA.
    Another event that can result in a required SIP revision is if the 
EPA determines at any time that a state's SIP is substantially 
inadequate to meet certain requirements of the Act, including attaining 
or maintaining the relevant NAAQS or mitigating interstate pollutant 
transport. In such cases, the EPA will issue a ``SIP call'' pursuant to 
CAA section 110(k)(5) requiring the state to revise the SIP to address 
the inadequacy.

A. The EPA's SIP Policy for Treatment of Excess Emissions During 
Periods of Startup, Shutdown, or Malfunction (SSM)

    On June 30, 2011, Sierra Club (Petitioner) filed a petition for 
rulemaking (petition) asking the EPA to consider how air agency rules 
in the EPA-approved SIPs treated excess emissions during periods of 
startup, shutdown, or malfunction of industrial process or emission 
control equipment. On July 12, 2015, the EPA responded to the petition, 
restated and updated its national policy regarding SSM provisions in 
SIPs, and issued a SIP call pursuant to CAA section 110(k)(5) to 
certain states to amend those provisions. This action is referred to as 
the 2015 SSM SIP Action.
    In the 2015 SSM SIP Action, among other things, the EPA defined the 
following terms:
    Automatic exemption: A generally applicable provision in a SIP that 
would provide that if certain conditions existed during a period of 
excess emissions, then those exceedances would not be considered 
violations of the applicable emission limitations.\5\
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    \5\ See 80 FR 33839, page 33842.
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    Emission limitation: In the context of a SIP, a legally binding 
restriction on emissions from a source or source category, such as a 
numerical emission limitation, a numerical emission limitation with 
higher or lower levels applicable during specific modes of source 
operation, a specific technological control measure requirement, a work 
practice standard, or a combination of these things as components of a 
comprehensive and continuous emission limitation in a SIP provision. In 
this respect, the term emission limitation is defined as in section 
302(k) of the CAA. By definition, an emission limitation can take 
various forms or a combination of forms, but in order to be permissible 
in a SIP it must be applicable to the source continuously, i.e., cannot 
include periods during which emissions from the source are legally or 
functionally exempt from regulation. Regardless of its form, a fully 
approvable SIP emission limitation must also meet all substantive 
requirements of the CAA applicable to such a SIP provision, e.g., the 
statutory requirement of section 172(c)(1) for imposition of reasonably 
available control measures and reasonably available control technology 
(RACM and RACT) on sources located in designated nonattainment 
areas.\6\
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    \6\ See 80 FR 33839, page 33842.
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    The EPA used the D.C. Circuit's decision in Sierra Club v. Johnson, 
551 F.3d 1019 (D.C. Cir. 2008) (Sierra Club), to further support its 
position in the 2015 SSM SIP Action that SIPs may not contain SSM 
exemption provisions. In Sierra Club, the D.C. Circuit reviewed an EPA 
rule promulgated pursuant to CAA section 112 that contained an 
automatic SSM exemption and found that ``the SSM exemption violates the 
CAA's requirement that some section 112 standard apply continuously.'' 
\7\ In the 2015 SSM SIP Action, the EPA applied the Sierra Club court's 
interpretation of CAA section 302(k) definition of ``emission 
limitation'' in the CAA section 112 context to the requirements of CAA 
section 110. CAA section 110(a)(2)(A) provides that SIPs shall include 
``enforceable emission limitations and other control measures, means, 
or techniques . . . as may be necessary or appropriate to meet the 
applicable requirements of this chapter.'' The EPA's application of the 
Sierra Club decision to CAA section 110 SIP requirements rested on the 
Agency's premise that the D.C. Circuit's interpretation of the 
definition of ``emission limitation'' in CAA section 302(k) applied 
generally to the Act. The EPA thus determined that Sierra Club was 
consistent with the EPA's national policy, expressed through previously 
issued guidance documents and regulatory actions prohibiting exemption 
provisions for otherwise applicable emission limits in SIPs (such as 
automatic exemptions granted for startup, shutdown, and malfunction 
events). Based on this premise, the EPA interpreted the lack of 
continuous control as creating a substantial risk that exemptions could 
permit excess emissions that could ultimately result in a NAAQS 
violation.
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    \7\ 551 F.3d at 1027-1028.
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B. The SSM SIP Call for Iowa

    As part of the Agency's response to the 2011 petition from Sierra 
Club, the EPA evaluated dozens of existing SIP provisions in 36 state 
SIPs--including the Iowa SIP--related to automatic excess emission 
exemptions for consistency with EPA's policy. As a result, the EPA 
issued findings in its 2015 SSM SIP Action that certain SIP provisions 
for 36 states (including Iowa) were substantially inadequate to meet 
CAA requirements. In the 2015 SSM SIP Action, the EPA granted the 
Sierra Club's petition with respect to Iowa Administrative Code (IAC) 
subrule 567-24.1(1), finding that the provision was substantially 
inadequate and issuing a SIP call for that provision, and the EPA 
denied the petition with respect to IAC 567- 24.1(4).8 9
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    \8\ IAC 567-24.1(1) states that excess emissions during a period 
of startup, shutdown, or cleaning of control equipment is not a 
violation of the emission standard if the startup, shutdown or 
cleaning is accomplished expeditiously and in a way that is 
consistent with good practice for minimizing emissions.
    \9\ IAC 567-24.1(4) states that incidents of excess emissions 
(other than an incident during start-up, shutdown or cleaning of 
control equipment) are violations. If the source believes that the 
excess emissions are due to a malfunction the source must meet the 
burden of proof that the incident was not preventable by reasonable 
maintenance and control measures. Meeting the burden of proof does 
not guarantee that the excess emissions will not be enforced; the 
rule states that enforcement will be considered after review of the 
source's report.

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[[Page 37407]]

    In the 2015 SSM SIP Action, the EPA found IAC 567-24.1(1) to be 
substantially inadequate to meet the requirements of the Act on the 
basis that this provision automatically allows for exemptions from the 
otherwise applicable SIP emission limitations as required by CAA 
sections 110(a)(2)(A), 110(a)(2)(C), and 302(k).\10\ Specifically, IAC 
567-24.1(1) explicitly states that excess emissions during periods of 
startup, shutdown, and cleaning of control equipment are not violations 
of the emission standard. Iowa has not submitted a SIP revision 
addressing IAC 567.24.1(1).
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    \10\ See 80 FR 33969.
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C. The Muscatine Attainment Plan

    On May 26, 2016, the State of Iowa submitted a SIP revision for the 
purpose of attaining the 2010 1-hour sulfur dioxide (SO2) 
primary National Ambient Air Quality Standard (NAAQS) for the Muscatine 
nonattainment area (herein called an ``attainment plan''). As detailed 
in EPA's 2014 SO2 nonattainment area guidance, such 
attainment plans are to contain six CAA-required elements: an emissions 
inventory of current emissions for all sources of SO2 within 
the nonattainment area; a New Source Review (NSR) permit program; an 
attainment demonstration using an EPA-approved air dispersion model; 
contingency measures; Reasonable Further Progress; and implementation 
of a control strategy.\11\ The state noted that as part of its control 
strategy, 58 construction permits in the attainment plan relied on the 
SIP-called IAC 567-24.1(1) (``Condition 6'' of each permit). As such, 
the State's nonattainment area plan SIP submission requested that the 
EPA not act on Condition 6 of the included permits.
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    \11\ Guidance for 1-Hour SO2 Nonattainment Area SIP 
Submissions; April 23, 2014.
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    On August 24, 2017, the EPA published a notice of proposed 
rulemaking to approve the attainment plan.\12\ In that action, the EPA 
agreed with the State that it would not be appropriate to approve 
Condition 6 of each permit into the SIP and proposed to approve the 
permitted limits into the SIP without the condition. During the 30-day 
public comment period, the EPA received a comment that (1) because 
Condition 6 provides for an exemption for excess emissions during 
periods of SSM, and because Condition 6 refers to and implements IAC 
567-24.1(1), the construction permits do not ensure continuous 
compliance with the ``emission limitations'' therein; and (2) even if 
the EPA does not approve Condition 6 into the SIP, the continued 
existence of IAC 567-24.1(1) in Iowa's SIP means that Iowa cannot 
ensure continuous compliance with those ``emission limitations.'' \13\ 
Therefore, according to the comment, the EPA should not approve the 
attainment plan considering the policy and SIP call issued by the EPA 
in 2015 and the requirements of section 110(a)(2)(A) and 172(c)(6) of 
the CAA.\14\
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    \12\ See 82 FR 40086.
    \13\ As that term is defined in section 302(k) of the CAA.
    \14\ The requirements of CAA section 172(c)(6) parallel those in 
section 110(a)(2)(A), so Region 7 does not address them separately 
here.
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    On January 9, 2018, the EPA published a supplemental proposal 
document that: (1) Provided additional information in the docket and 
clarified that all information, including files that were too large to 
be provided in the docket, was available upon request; (2) provided an 
2018 projected emissions inventory that had been excluded from the 
Notice of Proposed Rulemaking; and, (3) re-opened the public comment 
period only on those specific aspects.\15\
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    \15\ See 83 FR 997.
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IV. What is being addressed in this proposal?

    In this second supplemental notice of proposed rulemaking related 
to Iowa's 2016 submission, EPA Region 7 is considering adopting an 
alternative policy to the national policy as stated in the 2015 SSM SIP 
Action specifically regarding exemptions for excess emissions in the 
State of Iowa, and is simultaneously proposing to withdraw the SIP call 
for Iowa if the alternative SSM policy for the State is adopted (see 
Section V).\16\ Additionally, after considering comments received to 
date on the Agency's proposed approval of all elements of the 
attainment plan for the Muscatine 2010 SO2 nonattainment 
area, EPA Region 7 is proposing to approve additional modeling that 
demonstrates attainment throughout the nonattainment area and at 
receptors on adjacent properties (see Section VI).
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    \16\ If the proposed policy is finalized and the SIP call 
withdrawn and Iowa requests that EPA act on Condition 6 of the 58 
construction permits submitted to the EPA as part of the control 
strategy for the attainment plan, EPA could propose to approve those 
provisions based on the rationale set forth in this document.
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    Region 7 is considering adopting an alternative policy for Iowa 
regarding the continuous application of emission limits in section 110 
SIPs. Specifically, although the Iowa SIP contains an exemption for 
SSM, the SIP is comprised of numerous overlapping planning 
requirements. Those overlapping planning requirements consist of an 
array of Federal and state requirements in the SIP that arise from the 
relationship between states and the Federal Government that underlies 
implementation of the CAA. Congress's primary goal in creating the SIP 
adoption and approval process was to ensure the NAAQS are attained and 
maintained.\17\ Region 7 is evaluating the overlapping requirements in 
the Iowa SIP to assess whether exemptions during SSM periods are 
allowable. On the basis of that evaluation, Region 7 is proposing to 
find that Iowa's SSM provision is allowable, because of the proposed 
finding that the SIP as a whole is protective of the NAAQS, 
accomplishing the task Congress set out for states and the EPA. If such 
an alternative policy is finalized, EPA would withdraw the SSM SIP call 
for Iowa because, under such circumstances, the SIP-called provision 
would not be substantially inadequate.
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    \17\ See, e.g., H.R. Rep. 91-1783 at 193-95 (1970).
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    As discussed above, the 2015 SSM SIP Action reiterated the EPA's 
policy that SIPs containing SSM exemptions were not allowable because 
they would create risk that excess emissions during SSM events could 
cause a state to fail to attain or maintain the NAAQS for one or more 
criteria pollutants. Region 7 is proposing to find that the inherent 
flexibilities in the SIP development process and the general 
requirements in CAA section 110 mean that a state like Iowa could 
ensure attainment and maintenance despite one or more SSM exemptions in 
the SIP.
    Although the Sierra Club decision did not allow sources to be 
exempt from complying with CAA section 112 emission limitations during 
periods of SSM, that finding is not binding on Region 7's consideration 
of SIPs under CAA section 110. In the Sierra Club decision, the court 
explained, ``[i]n requiring that sources regulated under section 112 
meet the strictest standards, Congress gave no indication that it 
intended the application of MACT standards to vary based on different 
time periods.'' \18\ That is, the court found that when the EPA 
promulgates standards pursuant to CAA section 112, CAA section 112-
compliant standards must apply continuously, but the court did not make 
any statement explicitly applying its finding beyond CAA section 112. 
The decision itself did not address whether the rationale articulated 
with respect to SSM exemptions in CAA section 112 rules applies to SIPs 
approved under CAA section 110.
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    \18\ Sierra Club, 551 F. 3d at 1028.

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[[Page 37408]]

    The EPA took the position in the 2015 SSM SIP Action that the legal 
reasoning in Sierra Club applied equally to CAA section 112 rules and 
section 110 approved SIPs, but further consideration of the Iowa SIP 
has shown that an alternative reading of the relevant statutory 
sections is possible and appropriate.\19\ More specifically, in the 
2015 SSM SIP Action the EPA interpreted CAA section 302(k)'s definition 
of ``continuous'' applied broadly to both sections 112 and 110.\20\ 
However, Region 7 believes that, given Iowa's particular factual 
situation, an alternative interpretation, that the court's reasoning in 
Sierra Club does not extend to CAA section 110, is warranted.
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    \19\ See 80 FR at 33839.
    \20\ See 80 FR at 33874.
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    Fundamentally, CAA sections 112 and 110 have different goals and 
establish different approaches for implementation by the state and the 
EPA. That is to say, the court in Sierra Club recognized that Congress 
intended ``that sources regulated under section 112 meet the strictest 
standards,'' a requirement without a similar analog in CAA section 
110.\21\ CAA section 112 sets forth specific standards for specific 
source categories once they are listed for regulation pursuant to CAA 
section 112(c). Once listed, the statute directs the EPA to use a 
specific and exacting process to establish nationally applicable, 
category-wide, technology-based emissions standards under section 
112(d), requiring the EPA to establish emission standards (known as 
``maximum achievable control technology'' or ``MACT'' standards) for 
major sources that ``require the maximum degree of reduction in 
emissions of the hazardous air pollutants subject to this section'' 
that EPA determines is achievable considering certain statutory 
factors.\22\
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    \21\ Sierra Club at 1028.
    \22\ EPA can also set work practice standards under CAA section 
112(h).
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    In contrast, the CAA sets out a different expectation for section 
110 SIPs, reflecting that SIP development and implementation rely on a 
federal-state partnership and are designed to be flexible for each 
state's circumstances. The CAA sets the minimum requirements to attain, 
maintain, and enforce ambient air quality standards, while allowing 
each state to customize its own approach for the sources and air 
quality challenges specific to each state. It is important to note that 
the EPA sets the NAAQS for each criteria pollutant to provide the 
requisite degree of protection for public health and welfare, but does 
not direct the states on how to achieve the NAAQS.\23\ The NAAQS, then, 
are fundamentally different in nature than the source-specific 
standards the EPA issues under section 112. As such, the D.C. Circuit's 
concern that 112 standards must apply ``continuously'' to regulate 
emissions from a particular source are not necessarily applicable in 
the context of section 110, where a state's plan may contain a broad 
range of measures, including limits on the emissions of multiple 
pollutants from multiple sources of various source categories--all 
targeted towards Congress's broad goal of attainment and maintenance of 
an air quality standard measured against emissions contributions from a 
variety of sources over a specific geographic area.
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    \23\ The exemption to this general rule is when EPA promulgates 
a Federal Implementation Plan (FIP) under CAA section 110(c)(1) 
because a state or tribe has failed to make a required SIP 
submission, or such submission does not comply with the NAAQS.
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    It is important to also note that the list of potential CAA section 
110(a)(2)(A) measures that a state must implement are required only 
``as may be necessary or appropriate to meet the applicable 
requirements of this chapter.'' This language suggests that Congress 
intended to give states the flexibility to craft a plan that makes the 
most sense for that state, so long as the set of emissions limitations, 
control measures, means and techniques, when taken as a whole, meet the 
requirements of attaining and maintaining the NAAQS under subpart A. As 
such, Region 7 is considering whether it may be appropriate to approve 
certain Iowa SIP submissions notwithstanding the existence of an 
exemption elsewhere in the Iowa SIP, so long as other provisions in the 
SIP remain in effect that would ensure protection of the NAAQS.
    The U.S. Supreme Court has recognized that the CAA gives a state 
``wide discretion'' to formulate its plan pursuant to CAA section 110 
and went so far as to say that ``the State has virtually absolute power 
in allocating emission limitations so long as the national standards 
are met.'' See, e.g., Union Elec. Co. v. EPA, 427 U.S. 246, 250 & 267 
(1976). See also id. at 269 (``Congress plainly left with the States, 
so long as the national standards were met, the power to determine 
which sources would be burdened by regulation and to what extent.''). 
The Court has also explained, ``so long as the ultimate effect of a 
State's choice of emission limitations is compliance with the national 
standards for ambient air, the State is at liberty to adopt whatever 
mix of emission limitations it deems best suited to its particular 
situation.'' See Train v. Natural Res. Def. Council, Inc., 421 U.S. 60, 
79 (1975). States are the best suited to determine how best to 
implement the NAAQS within their jurisdiction and are given primary 
responsibility under CAA section 110 to do so.
    Because the purposes of CAA sections 110 and 112 are different, it 
is reasonable to interpret the same term (emission limitation) to have 
different meanings in those sections; a singular interpretation may not 
necessarily apply statute-wide. The U.S. Supreme Court has recognized 
that principles of statutory construction are not so rigid as to 
necessarily require that the same terminology has the exact same 
meaning in different parts of the same statute. See Envtl. Defense v. 
Duke Energy Corp., 549 U.S. 561, 574 (2007). The Court explained that 
there is ``no effectively irrebuttable presumption that the same 
defined term in different provisions of the same statute must be 
interpreted identically.'' Id. at 575-6. ``Context counts,'' stated the 
Court; terms can have ``different shades of meaning'' reflecting 
``different implementation strategies'' even in the same statute. Id. 
at 574, 76 (citations omitted). See also Utility Air Regulatory Group 
v. EPA, 573 U.S. 302, 320 (2014) (``a statutory term--even one defined 
in the statute--may take on distinct characters from association with 
distinct statutory objects calling for different implementation 
strategies.'' (citations omitted)).
    The text of CAA section 110(a)(2)(A) reflects the increased 
flexibility built into section 110 as compared to section 112.\24\ The 
requirement that the ``emissions standards'' the EPA issues under 
section 112, see, e.g., section 112(c)(2), apply continuously may, as 
the D.C. Circuit held, prevent the EPA from providing SSM exemptions in 
those standards. However, at the same time, it is reasonable to 
interpret the concept of continuous ``emission limitations'' in a SIP 
to be focused not on implementation of each individual limit, but 
rather on whether the various components of the approved SIP operate 
together in a continuous manner to ensure attainment and maintenance of 
the NAAQS. Therefore, Region 7 believes it is reasonable to conclude 
that

[[Page 37409]]

the Sierra Club decision's disapproval of SSM provisions should not be 
extended to CAA section 110.
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    \24\ Under CAA section 110(a)(2)(A), each SIP shall include 
``enforceable emission limitations and control measures, means, or 
techniques (including economic incentives such as fees, marketable 
permits, and auctions of emissions rights), as well as schedules and 
timetables for compliance, as may be necessary or appropriate to 
meet the applicable requirements of this chapter.'' 42 U.S.C. 
7410(a)(2)(A).
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    If Region 7 adopts the policy outlined in this section based on the 
analysis contained in this document, we are proposing to change the 
finding of the SIP call issued to Iowa as part of the 2015 SSM SIP 
Action that a SIP provision contained in the Iowa SIP is substantially 
inadequate to meet CAA requirements. Specifically, if Region 7 adopts 
this alternative policy, we propose to find that the subject SIP 
provision is consistent with CAA requirements. If so adopted, the 
alternative SSM policy is a policy statement and would constitute 
guidance within Region 7 for Iowa. Such a guidance would not bind 
states, the EPA or other parties; it would only reflect Region 7's 
interpretation of the CAA requirements as applicable to the Iowa SIP. 
The evaluation of any SIP provision, and that provision's interaction 
with the SIP, must be done through a notice-and-comment process.

V. Region 7's Evaluation of the Iowa SIP

    In proposing to conclude that the Iowa SIP in its entirety is 
protective of the NAAQS, Region 7 has identified numerous provisions of 
the SIP that, when taken as a whole, establish such a basis. First, the 
Iowa SIP details a series of overlapping requirements that provide for 
robust testing, reporting, and accountability for sources during 
periods of excess emissions. Such overlapping requirements enable Iowa 
Department of Natural Resources (IDNR) to implement the NAAQS, allowing 
IDNR to maintain oversight, work with sources to maintain compliant 
operation, and, if necessary, enforce against sources.
    Although IAC 567-24.1(1) was SIP called in the EPA's 2015 SSM SIP 
Action, the provision contains limitations on whether SSM events are 
considered emission standard violations and requires that source owners 
or operators limit the duration and severity of SSM events. IAC 567-
24.1(1) states:

    24.1(1) Excess emission during a period of startup, shutdown, or 
cleaning of control equipment is not a violation of the emission 
standard if the startup, shutdown or cleaning is accomplished 
expeditiously and in a manner consistent with good practice for 
minimizing emissions. Cleaning of control equipment which does not 
require the shutdown of the process equipment shall be limited to 
one six-minute period per one-hour period.

    While the subrule does allow for an exemption for excess emissions, 
it also provides for two key backstops that protect air quality and 
ensure attainment and maintenance of the NAAQS: (1) Startup, shutdown 
and cleaning is to be accomplished expeditiously; and, (2) startup, 
shutdown, and cleaning is to be accomplished in a way that is 
consistent with good practice for minimizing emissions. IAC 567-24.1(4) 
clarifies that an ``expeditious manner'' is the time necessary to 
determine the cause of the excess emissions and to correct it within a 
reasonable period of time. IAC 567-24.1(4) also states that a 
``reasonable period of time'' is eight hours plus the period of time 
required to shut down the process without damaging the process or 
control equipment.
    As detailed in the EPA's technical support document for Iowa's 2010 
SO2 iSIP approval, the director of the IDNR has the duty to 
ensure that the NAAQS is attained and maintained in accordance with 
Federal laws and regulations, and is granted broad oversight, 
authority, and discretion with which to do so.\25\ Iowa has the 
requisite statutory authority that provides an adequate framework for 
attaining and maintaining the NAAQS.\26\
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    \25\ 83 FR 12486.
    \26\ 83 FR 12486.
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    Iowa Code 455B.132 designates IDNR as the Agency to prevent, abate, 
or control air pollution. The Environmental Protection Commission (EPC) 
governs the environmental services of IDNR and has the duty to develop 
emission limits and compliance schedules in order to abate, control, 
and prevent air pollution.\27\ The EPC adopts, amends, or repeals rules 
that are necessary to obtain approval of the State SIP under CAA 
section 110.\28\ The EPC is also charged with adopting, amending, or 
repealing ambient air quality standards necessary to protect public 
health and welfare.\29\ Furthermore, 455B.134(9) states that the 
director shall issue orders consistent with rules to cause the 
abatement or control of air pollution, or to secure compliance with 
permit conditions.
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    \27\ Iowa Code 455B.133.1 (``Duties''). The EPC is a panel of 
nine citizens who provide policy oversight over Iowa's environmental 
protection efforts. The EPC's members are appointed by the Governor 
and confirmed by vote of the Senate for four-year terms.
    \28\ Iowa Code 455B.133.2.
    \29\ Iowa Code 455B.133.4.
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    The IDNR director's duty to ensure the NAAQS is attained and 
maintained is reflected in specific provisions throughout Iowa's SIP, 
as detailed below. First, in adopting the NAAQS into its State 
regulations, IAC 567-28.1 requires that IDNR implement the NAAQS ``in a 
time frame and schedule consistent with implementation schedules in 
federal laws and regulations.'' For nonattainment areas, CAA section 
172(c), among other relevant statutory provisions, requires state plans 
to provide for attainment as expeditiously as practicable and for the 
implementation of reasonable available control measures (RACM) as 
expeditiously as practicable. As mentioned previously, Iowa has a fully 
approved 2010 SO2 infrastructure SIP, meaning that EPA has, 
through notice and comment rulemaking, found that the SIP provides for 
the implementation, maintenance, and enforcement of the NAAQS. Other 
than the Muscatine 2010 1-hr SO2 nonattainment area, 
previously mentioned, there are no other nonattainment areas, for any 
criteria pollutant, in the State.\30\ As can be seen via ambient air 
quality monitoring data for SO2, air quality in the 
Muscatine area is well below the NAAQS of 75 parts per billion (ppb). 
The current three-year (2016-2018) SO2 design value for the 
area is 34 ppb.\31\
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    \30\ The partial Pottawattamie County 2008 Lead NAAQS 
nonattainment area was redesignated to attainment in October 2018. 
See 83 FR 50024.
    \31\ At the time of this document, 2019 ambient air quality data 
had not been certified in the Air Quality System. Annual data 
certification is not required until May 1.
---------------------------------------------------------------------------

    Furthermore, the SIP provides for emergency powers comparable to 
that of the EPA Administrator under CAA section 303, and the State has 
a fully approved emergency episodes plan that meets the applicable 
requirements of 40 CFR part 51, subpart H, at IAC 567-26.1-4. IAC 567-
28.1, in concert with IAC 567-26.1-4 and the state's statutory 
provisions detailed further below, lay out IDNR's responsibility and 
authority for ensuring that air quality is protected, and the NAAQS are 
attained and maintained in the state of Iowa, notwithstanding an 
exemption for excess emissions in the SIP. The attainment status of 
areas in the State as well as monitored air quality demonstrate 
successful implementation on the part of the State.
    Third, the Iowa SIP provides IDNR with the specific discretion of 
whether to issue a construction permit for a source based solely on an 
analysis of that source's impact on attainment or maintenance of the 
NAAQS. Specifically, IAC 567-22.3(1) states:

    A construction permit shall be issued when the director 
concludes that (. . .) the expected emissions from the proposed 
source or modification in conjunction with all other emissions will 
not prevent the attainment or maintenance of the ambient air quality 
standards specified in 567--Chapter 28.

[[Page 37410]]

    Additionally, IAC 567-22.3(5) provides IDNR with the discretion to 
modify ``an existing permit for a major stationary source or an 
emission limit contained in an existing permit for a major stationary 
source if necessary to attain or maintain an ambient air quality 
standard.'' Accordingly, these provisions provide the State air agency 
with the authority to limit the issuance of construction permits and 
modify existing permits to ensure that the NAAQS is attained and 
maintained. This authority, when considered along with the enforcement, 
maintenance, and oversight provisions discussed herein, ensures 
accountability for sources and, when taken as a whole, protects air 
quality and provides for attainment and maintenance of the NAAQS, even 
though the Iowa SIP allows exemptions for excess emissions during 
periods of startup, shutdown, and cleaning. Of note, the State has been 
implementing its SIP-approved construction program, which includes 
issuing construction permits with Condition 6, and has not monitored a 
NAAQS violation resulting in the need to revise a permit due solely on 
emissions from SSM events.
    In addition to specific discretion afforded the IDNR director to 
ensure attainment and maintenance of the NAAQS, there are a number of 
direct requirements on sources in Iowa's approved SIP. IAC 567-24.1(2) 
details the initial report that a source owner or operator must submit 
when an emission limit is exceeded. Such incidences are to be reported 
to the appropriate IDNR regional office within eight hours of the onset 
of an incident. Reports are to be submitted via email, in person, or 
over the telephone. At a minimum, initial incident reports are to 
include the quantity, duration, cause and remedial steps taken for 
periods of excess emissions. IAC 567-24.1(3) requires that a written 
report is to be submitted as a follow-up to all required initial 
reports to the IDNR within seven days of the onset of the event. The 
written report is, at a minimum, to include the information required 
for initial reports under 24.1(2). In addition, written reports are to 
include, if the owner claims that the excess emission was due to 
malfunction, documentation to support such a claim.
    IAC 567-25.1(6), (7), and (8) detail the testing and sampling 
requirements for owners and operators of pollution control equipment. 
Specifically, any facility required to install a continuous monitoring 
system shall provide regular reports to IDNR, including periods of 
excess emissions. Furthermore, IDNR is granted the authority to require 
sources to conduct compliance demonstrations, including testing, which 
``may be required as necessary to determine actual emissions from a 
source where that source is believed to have a significant impact on 
the public health or ambient air quality of an area.'' IDNR may also 
conduct independent emission testing as deemed necessary. These 
provisions ensure that sources must report periods of excess emissions 
and could be required to conduct testing during such periods, thus 
ensuring that the State is aware of any such events and allowing the 
State to protect air quality and ensure attainment and maintenance of 
the NAAQS.
    Owners or operators of any control equipment are also required to 
maintain and repair equipment or control equipment in such a way that 
minimizes and remedies any causes of excess emissions. IAC 567-24.2(1) 
details the maintenance and repair that owners or operators are 
required to undertake, including maintaining operations that minimize 
emissions, undertaking scheduled routine maintenance, and remedying any 
cause of excess emissions in an expeditious manner (``expeditious 
manner,'' as discussed above, is defined in IAC 567-24.1(4)). 
Furthermore, IAC 567-24.2(1)(c) states that owners or operators shall:

    Minimize the amount and duration of any excess emission to the 
maximum extent possible during periods of such emissions. These 
measures may include but not be limited to the use of clean fuels, 
production cutbacks, or the use of alternate process units or, in 
the case of utilities, purchase of electrical power until repairs 
are completed.

    IAC 567 24.2(2) provides IDNR with the authority to require owners 
and operators to develop maintenance plans where, ``in the judgement of 
the executive director a continued pattern of excess emissions 
indicative of inadequate operation and maintenance is occurring.'' Such 
maintenance plans have been required of sources over time as 
appropriate and are to include numerous maintenance and inspection 
requirements. Most notably, these plans are to include a contingency 
plan intended to minimize the frequency, duration, and severity of 
excess emission events.
    Lastly, there are a number of Iowa-specific State regulations that 
help ensure attainment and maintenance of the NAAQS. Iowa Code 455B.139 
states that, if the director has evidence that any person is causing 
air pollution that creates a public health and safety emergency, the 
director may, without notice, issue an emergency order requiring the 
immediate discontinuation of emissions. While not SIP-approved, and 
therefore not federally enforceable, these codes provide supplemental 
support to the assertion that the State has considerable oversight and 
discretion to enforce against sources and ensure attainment and 
maintenance of the NAAQS.
    In light of the fact that Region 7 is considering an alternative 
policy relating to exemptions of excess emissions, and based on the 
above analysis of Iowa's SIP, Region 7 is simultaneously proposing to 
withdraw the SIP call issued as part of the 2015 SSM SIP Action and 
find that the subject SIP provision is not inconsistent with CAA 
requirements.
    EPA's CAA regulations allow EPA Regions to take actions that are 
inconsistent with national policy when the Region seeks and obtains 
concurrence from the relevant EPA Headquarters office. Pursuant to 
EPA's regional consistency regulations at 40 CFR 56.5(b), the Region 7 
Regional Administrator sought and obtained concurrence from the EPA's 
Office of Air and Radiation to propose an action that outlines an 
alternative policy that is inconsistent with the national EPA policy, 
most recently articulated in the 2015 SSM SIP Action, on provisions 
automatically exempting emissions exceeding otherwise applicable SIP 
limitations during periods of unit startup, shutdown, and malfunction 
and propose action consistent with that alternative policy. The 
concurrence request memorandum is included in the public docket for 
this action.

VI. Additional Modeling Information

    During the public comment period for the SNPRM, the EPA received 
comment that the modeling for the Muscatine nonattainment area did not 
include receptors with adjacent property boundaries. The commenter 
asserted that these areas could be considered ``ambient air'' and that 
they therefore should have been included in the attainment 
demonstration modeling. The EPA agrees with the commenter that these 
areas, as noted in the Code of Federal Regulations at 40 CFR part 51, 
appendix W, Guideline on Air Quality Models (hereafter referred to as 
``appendix W''), would be considered ambient air and should have model 
receptors included. To ensure a complete record for both the attainment 
plan approval action, and adherence to appendix W, the EPA performed 
modeling that evaluated the impacts on the properties of each of the 
modeled facilities-Grain Processing Corporation (GPC), Muscatine Power 
and Water (MPW), Monsanto, and Louisa Generating Station (LGS). The EPA 
used

[[Page 37411]]

the same model version (i.e., AERMOD version 14134) and modeling inputs 
(i.e., source characteristics and emissions rates, meteorological data, 
background value, etc.) that the State used in its attainment plan 
modeling demonstration. The only modification the EPA made for its 
evaluation was adding receptors at 50-meter spacing within each 
facility's boundary. The EPA modeled scenarios specific to each of the 
four facilities' property, which included receptors only on the 
property of the facility in question and has all emissions sources from 
that facility removed from the analysis. For example, a scenario to 
evaluate the impacts on GPC's facility property included receptors 
placed within GPC's facility fence line and with the emission sources 
from LGS, Monsanto, and MPW operating and GPC not operating.
    Table 1 provides the results of EPA's modeling analysis, which 
showed no violations within each of the four facilities' property when 
emissions from the other facilities were considered. The greatest 
impacts occurred within Grain Processing Corporation's property with a 
modeled highest 4th high of 164 micrograms per cubic meter ([micro]g/
m\3\).

   Table 1--The Highest-4th-High Predicted Impacts on Each Facility's
                                Property
                         [Including background]
------------------------------------------------------------------------
                                                                1-hour
                                                     Model     SO2 NAAQS
                Impacted facility                   impacts   ([micro]g/
                                                  ([micro]g/     m\3\)
                                                     m\3\)
------------------------------------------------------------------------
Grain Processing Corporation....................         164         196
Muscatine Power and Water.......................         110
Monsanto........................................          97
Louisa Generating Station.......................         110
------------------------------------------------------------------------

    The EPA proposes that the modeling submitted by Iowa with its 
nonattainment area plan, in addition to the supplemental modeling 
performed by the EPA and described above, demonstrates that the area is 
attaining the NAAQS.

VII. What action is EPA Region 7 taking?

    In this second supplemental notice of proposed rulemaking, the EPA 
is: (1) Considering adoption of an alternative policy regarding 
exemptions for excess emissions in the State of Iowa from the national 
policy detailed in the EPA's 2015 SSM SIP Action; (2) proposing 
simultaneously withdrawal of the SSM SIP call for Iowa if the 
alternative SSM policy for the State is adopted; and (3) proposing 
approval of Iowa's SIP for the 2010 1-hour SO2 NAAQS for the 
Muscatine nonattainment area, including the attainment plan control 
strategy.

VIII. 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, the EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely approves state law as meeting Federal requirements and 
does not impose additional requirements beyond those imposed by state 
law. For that reason, this action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Is not an Executive Order 13771 (82 FR 9339, February 2, 
2017) regulatory action because SIP approvals are exempted under 
Executive Order 12866.
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of the National Technology 
Transfer and Advancement Act (NTTA) because this rulemaking does not 
involve technical standards; 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, SSM policy, Start-up, shutdown and malfunction, Sulfur 
oxides.

    Dated: June 16, 2020.
James Gulliford,
Regional Administrator, Region 7.
[FR Doc. 2020-13380 Filed 6-19-20; 8:45 am]
BILLING CODE 6560-50-P