Proposed Rule2021-15464
Air Plan Approval; Wisconsin; Attainment Plan for the Rhinelander SO2 Nonattainment Area
Primary source
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Published
July 22, 2021
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing to approve the State Implementation Plan (SIP) revision submitted by Wisconsin on March 29, 2021, which amends a SIP submission previously submitted to EPA on January 22, 2016 and supplemented on July 18, 2016, and November 29, 2016, for attaining the 1-hour sulfur dioxide (SO<INF>2</INF>) primary national ambient air quality standard (NAAQS) for the Rhinelander SO<INF>2</INF> nonattainment area. This plan (herein referred to as Wisconsin's Rhinelander SO<INF>2</INF> plan or plan) includes Wisconsin's attainment demonstration and other elements required under the Clean Air Act (CAA). 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), and contingency measures. This action supplements a prior action which found that Wisconsin had satisfied emission inventory and new source review (NSR) requirements for this area, but had not met requirements for the elements proposed to be approved here. EPA is proposing to conclude that Wisconsin has appropriately demonstrated that the plan provisions provide for attainment of the 2010 1-hour primary SO<INF>2</INF> NAAQS in the Rhinelander SO<INF>2</INF> nonattainment area and that the plan meets the other applicable requirements under the CAA.
Full Text
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<title>Federal Register, Volume 86 Issue 138 (Thursday, July 22, 2021)</title>
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[Federal Register Volume 86, Number 138 (Thursday, July 22, 2021)]
[Proposed Rules]
[Pages 38643-38651]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-15464]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R05-OAR-2021-0256; FRL-8692-01-R5]
Air Plan Approval; Wisconsin; Attainment Plan for the Rhinelander
SO2 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 submitted by
Wisconsin on March 29, 2021, which amends a SIP submission previously
submitted to EPA on January 22, 2016 and supplemented on July 18, 2016,
and November 29, 2016, for attaining the 1-hour sulfur dioxide
(SO<INF>2</INF>) primary national ambient air quality standard (NAAQS)
for the Rhinelander SO<INF>2</INF> nonattainment area. This plan
(herein referred to as Wisconsin's Rhinelander SO<INF>2</INF> plan or
plan) includes Wisconsin's attainment demonstration and other elements
required under the Clean Air Act (CAA). 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), and contingency measures. This action
supplements a prior action which found that Wisconsin had satisfied
emission inventory and new source review (NSR) requirements for this
area, but had not met requirements for the elements proposed to be
approved here. EPA is proposing to conclude that Wisconsin has
appropriately demonstrated that the plan provisions provide for
attainment of the 2010 1-hour primary SO<INF>2</INF> NAAQS in the
Rhinelander SO<INF>2</INF> nonattainment area and that the plan meets
the other applicable requirements under the CAA.
DATES: Comments must be received on or before August 23, 2021.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R05-
OAR-2021-0256 at <a href="http://www.regulations.gov">http://www.regulations.gov</a>, or via email to
<a href="/cdn-cgi/l/email-protection#34585147585d511a595d575c555158745144551a535b42"><span class="__cf_email__" data-cfemail="4c20293f2025296221252f242d29200c293c2d622b233a">[email protected]</span></a>. For comments submitted at <a href="http://Regulations.gov">Regulations.gov</a>,
follow the online instructions for submitting comments. Once submitted,
comments cannot be edited or removed from <a href="http://Regulations.gov">Regulations.gov</a>. For either
manner of submission, EPA may publish any comment received to its
public docket. Do not submit electronically any information you
consider to be Confidential Business Information (CBI) or other
information whose disclosure is restricted by statute. Multimedia
submissions (audio, video, etc.) must be accompanied by a written
comment. The written comment is considered the official comment and
should include discussion of all points you wish to make. EPA will
generally not consider comments or comment contents located outside of
the primary submission (i.e., on the web, cloud, or other file sharing
system). For additional submission methods, please contact the person
identified in the FOR FURTHER INFORMATION CONTACT section. For the full
EPA public comment policy, information about CBI or multimedia
submissions, and general guidance on making effective comments, please
visit <a href="http://www2.epa.gov/dockets/commenting-epa-dockets">http://www2.epa.gov/dockets/commenting-epa-dockets</a>.
FOR FURTHER INFORMATION CONTACT: Abigail Teener, Environmental
Engineer, Attainment Planning and Maintenance Section, Air Programs
Branch (AR-18J), Environmental Protection Agency, Region 5, 77 West
Jackson Boulevard, Chicago, Illinois 60604, (312) 353-7314,
<a href="/cdn-cgi/l/email-protection#5f2b3a3a313a2d713e3d36383e36331f3a2f3e71383029"><span class="__cf_email__" data-cfemail="691d0c0c070c1b47080b000e080005290c1908470e061f">[email protected]</span></a>. The EPA Region 5 office is open from 8:30 a.m.
to 4:30 p.m., Monday through Friday, excluding Federal holidays and
facility closures due to COVID-19.
SUPPLEMENTARY INFORMATION: This SUPPLEMENTARY INFORMATION section is
arranged as follows:
I. Why was Wisconsin required to submit an SO<INF>2</INF> plan for
the Rhinelander area?
II. Requirements for SO<INF>2</INF> Nonattainment Area Plans
III. Attainment Demonstration and Longer Term Averaging
IV. Review of Modeled Attainment Plan
A. Model Selection
B. Simulation of Downwash
C. Meteorological Data
D. Emissions Data
E. Emission Limits
F. Background Concentrations
G. Summary of Results
V. Review of Other Plan Requirements
A. RACM/RACT
B. Reasonable Further Progress (RFP)
C. Contingency Measures
VI. What action is EPA taking?
VII. Incorporation by Reference
VIII. Statutory and Executive Order Reviews
I. Why was Wisconsin required to submit an SO2 plan for the Rhinelander
area?
On June 22, 2010, EPA promulgated a new 1-hour primary
SO<INF>2</INF> NAAQS of 75 parts per billion (ppb), which is met at an
ambient air quality monitoring site when the 3-year average of the
annual 99th percentile of daily maximum 1-
[[Page 38644]]
hour average concentrations does not exceed 75 ppb, as determined in
accordance with appendix T of 40 CFR part 50. See 75 FR 35520, codified
at 40 CFR 50.17(a)-(b). On August 5, 2013, EPA designated 29 areas of
the country as nonattainment for the 2010 SO<INF>2</INF> NAAQS,
including the Rhinelander area within the State of Wisconsin. 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
SO<INF>2</INF> NAAQS to EPA within 18 months of the effective date of
the designation, i.e., by no later than April 4, 2015 in this case.
These SIPs are required to demonstrate that their 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.
In response to the requirement for SO<INF>2</INF> nonattainment
plan submittals, Wisconsin submitted a nonattainment plan for the
Rhinelander area on January 22, 2016, and supplemented it on July 18,
2016, and November 29, 2016. On March 23, 2021,\1\ EPA partially
approved and partially disapproved Wisconsin's Rhinelander
SO<INF>2</INF> plan as submitted and supplemented in 2016. EPA approved
the base-year emissions inventory and affirmed that the new source
review requirements for the area had previously been met.\2\ EPA also
approved the SO<INF>2</INF> emission limit for Ahlstrom-Munksj[ouml]'s
Rhinelander facility (Ahlstrom-Munksj[ouml]) (formerly Expera Specialty
Solutions LLC (Expera)) as SIP-strengthening. At that time, EPA
disapproved the attainment demonstration, since the plan relied on
credit for more stack height than is creditable under the regulations
for good engineering practice (GEP) stack height. Additionally, EPA
disapproved the plan for failing to meet the requirements for meeting
RFP toward attainment of the NAAQS, RACM/RACT, emission limitations and
control measures as necessary to attain the NAAQS, and contingency
measures.
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\1\ 86 FR 15418 (March 23, 2021).
\2\ 79 FR 60064 (October 6, 2014).
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Under sections 110(c) and 179(a)-(b) of the CAA, a disapproval in
whole or in part of a state submittal initiates a Federal
Implementation Plan (FIP) clock and sanctions clocks, respectively,
which are terminated by an EPA rulemaking approving a revised plan. On
March 29, 2021, Wisconsin submitted a permit containing a revised
emission limit and supplemental information in order to remedy the
plan's deficiencies specified in EPA's March 23, 2021 rulemaking, along
with a request that EPA approve its revised plan for the Rhinelander
area.
The remainder of this action describes the requirements that
SO<INF>2</INF> nonattainment plans must meet in order to obtain EPA
approval, provides a review of Wisconsin's revised plan with respect to
these requirements, and describes 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. 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 SO<INF>2</INF> SIPs and
fundamental principles for SIP control strategies. Id., at 13545-49,
13567-68. On April 23, 2014, EPA issued recommended guidance for
meeting the statutory requirements in SO<INF>2</INF> SIPs, in a
document entitled, ``Guidance for 1-Hour SO<INF>2</INF> Nonattainment
Area SIP Submissions,'' available at <a href="https://www.epa.gov/sites/production/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf">https://www.epa.gov/sites/production/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf</a>. In this guidance EPA described
the statutory requirements for a complete nonattainment area SIP, which
includes: An accurate emissions inventory of current emissions for all
sources of SO<INF>2</INF> within the nonattainment area; an attainment
demonstration; demonstration of RFP; implementation of RACM (including
RACT); NSR; emissions limitations and control measures as necessary to
attain the NAAQS; and adequate contingency measures for the affected
area. EPA already concluded in its March 23, 2021 rulemaking that
Wisconsin has met the emissions inventory and NSR requirements.
In order for 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, EPA may not approve a SIP that
would interfere with any applicable requirement concerning NAAQS
attainment and RFP, or any other applicable requirement, and no
requirement in effect (or required to be adopted by an order,
settlement, agreement, or plan in effect before November 15, 1990) in
any area which is a nonattainment area for any air pollutant, may be
modified in any manner unless it ensures equivalent or 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. SO<INF>2</INF> attainment
plans must consist of two components: (1) Emission limits and other
control measures that ensure 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 SO<INF>2</INF> NAAQS as
expeditiously as practicable, but by no later than the attainment date
for the affected area. In all cases, the emission limits and control
measures must be accompanied by appropriate methods and conditions to
determine compliance with the respective emission limits and control
measures and must be quantifiable (i.e., a specific amount of emission
reduction can be ascribed to the measures), fully enforceable
(specifying clear, unambiguous and measurable requirements for which
compliance can be practicably determined), replicable (the procedures
for determining compliance are sufficiently specific and 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).
EPA's April 2014 guidance recommends that the emission limits be
expressed as short-term average limits (e.g., addressing emissions
averaged
[[Page 38645]]
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, 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 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 SO<INF>2</INF> NAAQS. In evaluating
this option, 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 SO<INF>2</INF>
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 ppb. 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 SO<INF>2</INF> 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
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 SO<INF>2</INF> plans 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'' \3\ which shows three 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 SO<INF>2</INF>, 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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\3\ 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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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. 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
SO<INF>2</INF> 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, EPA believes that the approach recommended in its guidance
document suitably addresses this concern. First, from a practical
perspective, 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. 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, EPA expects
either form of emission limit to yield comparable air quality.
Second, from a more theoretical perspective, 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 always emits 1,000 pounds of SO<INF>2</INF> per hour (lbs/hr),
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 lbs/hr. It is theoretically possible for a source
meeting this limit to have emissions that occasionally exceed 1,000
lbs/hr, but with a typical emissions profile emissions would much more
commonly be between 600 and 800 lbs/hr. In this simplified example,
assume a zero background concentration, which allows one to assume a
linear relationship between emissions and air quality. (A nonzero
[[Page 38646]]
background concentration would make the mathematics more difficult but
would give similar results.) Air quality will depend on what emissions
happen on what critical hours, but suppose that emissions at the
relevant times on these 5 days are 800 lbs/hr, 1,100 lbs/hr, 500 lbs/
hr, 900 lbs/hr, and 1,200 lbs/hr, respectively. (This is a conservative
example because the average of these emissions, 900 lbs/hr, 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 (84 ppb under the 30-
day average limit compared to 70 ppb under the 1-hour limit). However,
the third day would not have an exceedance that otherwise would have
occurred (40 ppb under the 30-day average limit compared to 80 ppb
under the 1-hour limit). The fourth day would have been below, rather
than at, 75 ppb (67.5 ppb under the 30-day average limit compared to 75
ppb under the 1-hour limit). 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 SO<INF>2</INF> nonattainment planning guidance, EPA found
that the requirement for lower average emissions is likely to yield as
good air quality as is required with a comparably stringent 1-hour
limit. Based on analyses described in appendix B of its 2014 guidance
and similar subsequent work, EPA expects that emission profiles with
maximum allowable emissions under an appropriately set comparably
stringent 30-day average limit are likely to have the net effect of no
more exceedances and as good air quality of an emission profile with
maximum allowable emissions under a 1-hour emission limit at the
critical emission value.\4\ 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.
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\4\ See also further analyses described in rulemaking on the
SO<INF>2</INF> nonattainment plan for Southwest Indiana. In response
to comments expressing concern that the emission profiles analyzed
for appendix B represented actual rather than allowable emissions,
EPA conducted additional work formulating sample allowable emission
profiles and analyzing the resulting air quality impact. This
analysis provided further support for the conclusion that an
appropriately set longer term average emission limit in appropriate
circumstances can suitably provide for attainment. The rulemaking
describing these further analyses was published on August 17, 2020,
at 85 FR 49967, available at <a href="https://www.govinfo.gov/content/pkg/FR-2020-08-17/pdf/2020-16044.pdf">https://www.govinfo.gov/content/pkg/FR-2020-08-17/pdf/2020-16044.pdf</a>. A more detailed description of these
analyses is available in the docket for that action, specifically at
<a href="https://www.regulations.gov/document?D=EPA-R05-OAR-2015-0700-0023">https://www.regulations.gov/document?D=EPA-R05-OAR-2015-0700-0023</a>.
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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
SO<INF>2</INF>, 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, 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 accommodating real
world emissions variability without significant risk of violations, are
also appropriate factors for 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, EPA believes that a
continuously enforceable limit averaged over as long as 30 days, if
determined in accordance with EPA's guidance, can reasonably be
considered to provide for attainment of the 2010 SO<INF>2</INF> 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), then
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 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.\5\ The 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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\5\ For example, if the critical emission value is 1,000 lbs/hr
of SO<INF>2</INF>, and a suitable adjustment factor is determined to
be 70 percent, the recommended longer term average limit would be
700 lbs/hr.
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Preferred air quality models for use in regulatory applications are
described in appendix A of EPA's Guideline on Air Quality Models (40
CFR part 51, appendix W). In 2005, EPA promulgated AERMOD as the
Agency's preferred near-field dispersion modeling for a wide range of
regulatory applications addressing stationary sources (for example in
estimating SO<INF>2</INF> concentrations) in all types of terrain based
on extensive developmental and performance evaluation. Supplemental
guidance on modeling for purposes of demonstrating attainment of the
SO<INF>2</INF> standard is provided in appendix A to the April 23, 2014
SO<INF>2</INF> nonattainment area SIP guidance document referenced
above. Appendix A provides extensive guidance on the modeling domain,
the source inputs, assorted types of meteorological data, and
background concentrations. Consistency with the recommendations in this
guidance is generally necessary for the attainment
[[Page 38647]]
demonstration to offer adequately reliable assurance that the plan
provides for attainment.
As stated previously, attainment demonstrations for the 2010 1-hour
primary SO<INF>2</INF> 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). This is demonstrated by
using air quality dispersion modeling (see appendix W to 40 CFR part
51) that shows that the mix of sources, enforceable control measures,
and emission rates in an identified area will not lead to a violation
of the SO<INF>2</INF> NAAQS. For a short-term (i.e., 1-hour) standard,
EPA believes that dispersion modeling, using allowable emissions and
addressing stationary sources in the affected area (and in some cases
those sources located outside the nonattainment area which may affect
attainment in the area) is technically appropriate, efficient and
effective in demonstrating attainment in nonattainment areas because it
takes into consideration combinations of meteorological and emission
source operating conditions that may contribute to peak ground-level
concentrations of SO<INF>2.</INF>
The meteorological data used in the analysis should generally be
processed with the most recent version of AERMET. Estimated
concentrations should include ambient background concentrations, should
follow the form of the standard, and should be calculated as described
in section 2.6.1.2 of the August 23, 2010 clarification memo on
``Applicability of appendix W Modeling Guidance for the 1-hr
SO<INF>2</INF> National Ambient Air Quality Standard'' (U.S. EPA,
2010a).
IV. Review of Modeled Attainment Plan
The following discussion evaluates various features of the modeling
that Wisconsin used in its attainment demonstration.
A. Model Selection
Wisconsin's attainment demonstration used AERMOD, the preferred
model for this application. Wisconsin's January 2016 submittal used
version 15181 of this model, which was the most recent version at that
time. However, the supplemental modeling that Wisconsin submitted in
March 2021 used version 19191, which is the current regulatory version
of AERMOD. EPA finds this selection appropriate.
Wisconsin's receptor grid and modeling domain for the Rhinelander
area followed the recommended approaches from EPA's Guideline on Air
Quality Models (40 CFR part 51, appendix W). Receptor spacing for each
modeled facility was every 25 meters out to a distance of 500 meters
from each source, then every 50 meters to 1,000 meters, every 100
meters out to 3 kilometers, every 250 meters out to 6 kilometers, and
every 500 meters out to 10 kilometers.
Wisconsin determined that the Rhinelander area should be modeled
with rural dispersion coefficients, as Ahlstrom-Munksj[ouml] is
surrounded by less than 50% of land classified as industrial,
commercial, or dense residential within 3 kilometers, as recommended by
EPA's Guideline on Air Quality Models. Therefore, EPA concurs with
Wisconsin's determination that this area warrants being modeled with
rural dispersion coefficients.
B. Simulation of Downwash
Modeling of emissions from Ahlstrom-Munksj[ouml] has historically
underpredicted concentrations measured at a nearby monitor. When winds
blow from this facility toward the monitor, the emissions traverse a
corner of the building. Under these circumstances, the building appears
to cause enhanced eddies in the air flow, known as corner vortices,
which in certain circumstances appear to result in a substantial
enhancement of downwash of emissions to ground level and substantially
greater concentrations than are modeled using the standard downwash
algorithm in AERMOD.
Recognizing these issues, the company contracted for a wind tunnel
study, carried out by Cermak Peterka Petersen (CPP), to assess the
magnitude of this effect and to support a more accurate assessment of
downwash at this facility. This study supported the conclusion that the
discrepancy between modeled and monitored SO<INF>2</INF> concentrations
were due to the corner vortex phenomenon, a phenomenon that is
described in EPA's ``Guideline for Determination of Good Engineering
Practice Stack Height (Technical Support Document for the Stack Height
Regulations).'' \6\ The wind tunnel study showed that as the wind
approaches the corner of the Ahlstrom-Munksj[ouml] building, vortices
are created that act to increase the SO<INF>2</INF> concentrations
downwind of the building. Analysis of these results suggested that the
influence of these corner vortices vary by wind speed. Ahlstrom-
Munksj[ouml]'s consultants, AECOM and CPP, developed an equation
estimating a multiplier, varying by wind speed, by which to estimate
the impact of downwash in this case, i.e., a multiplier by which to
multiply concentrations estimated in absence of downwash to estimate
concentrations reflecting the downwash induced by this facility. The
wind tunnel study focused on concentrations in the direction with the
most enhanced downwash but applied the same adjustment in all
directions. Since there is less downwash in directions less influenced
by corner vortices, EPA considers this approach conservative in
maximizing estimated downwash effects on concentrations.
---------------------------------------------------------------------------
\6\ EPA-450/4-80-023R, June 1985.
---------------------------------------------------------------------------
Wisconsin's 2016 SIP submittal relied on modeling Ahlstrom-
Munksj[ouml] using a stack height of 90 meters. For this facility, the
``formula good engineering practice (GEP) stack height'' computed
according to the formula in EPA's stack height regulations (defined at
40 CFR 51.100(ii)(2)(ii)) is 75 meters. EPA disapproved the 2016
submittal because EPA's stack height regulations prohibit credit for a
stack above formula GEP stack height unless the state meets
requirements specified in those regulations for the level of control at
the facility. Wisconsin's 2021 submittal meets EPA's stack height
regulations by applying a limit demonstrated to provide attainment with
a stack at the creditable height of 75 meters.
The wind tunnel studies primarily simulated a stack with a height
of 85 meters, with another run simulating a stack with a height of 90
meters. These runs indicated the following equation to estimate the
ratio of concentrations expected with the building as compared
concentrations without the building:
[GRAPHIC] [TIFF OMITTED] TP22JY21.023
[[Page 38648]]
The variable R is the ratio multiplier that is applied to the
hourly emission rate file used in AERMOD. The Uairport and Umax values
represent the actual hourly wind speed measured at the Rhinelander
airport and the maximum wind speed, i.e., wind speed exceeded less than
1% of the time, of 10.8 meters per second. The A and B parameters are
best-fit coefficients. The A parameter, plus 1, represents the maximum
multiplier that can be applied to the hourly emissions.
While this equation was originally derived to assess the wind-
speed-dependent influence of downwash with a 90-meter stack, the
influence of downwash for a 75-meter stack may be derived based on
these same 85-meter and 90-meter results by using a best-fit
coefficient (A) that is specific to a 75-meter stack. The best-fit
coefficient was originally developed using wind tunnel data at an 85-
meter stack height. This coefficient was then adjusted using observed
and predicted concentration ratios, from the wind tunnel information,
to determine the appropriate coefficient for a 75-meter stack height.
For a 75-meter stack, Wisconsin applied the above equation with a value
of A of 0.826 and B of 0.174.
Wisconsin did not modify any algorithms or computer code in AERMOD
to reflect this enhancement of the influence of downwash. Instead,
Wisconsin implemented this enhancement by using modified model inputs.
Wisconsin first examined hourly wind speeds. Wisconsin computed hourly
downwash multipliers based on the above equation. Ordinarily, Wisconsin
would run AERMOD using a fixed emission rate reflecting the allowable
emission rate, but in this case Wisconsin input an hourly varying
emission rate in which each hour's input value equaled the fixed
emission rate (reflecting the allowable emission rate) times that
hour's downwash multiplier. For example, for an hour with a wind speed
of 5 meters per second, for which the above equation gives a downwash
multiplier of 1.564, the modeled emission rate for that hour reflected
multiplication times 1.564. This multiplier gives the expected ratio of
concentrations with the magnitude of downwash at this facility as
compared to the concentrations expected if no downwash were occurring.
Therefore, Wisconsin estimated hourly concentrations with Ahlstrom-
Munksj[ouml]-specific downwash by modeling the facility without
downwash but incorporating the expected impact of downwash at this
facility by increasing the emission rate modeled for each hour
accordingly.
EPA views Wisconsin's modeling as applying an alternate model under
the terms of 40 CFR 51 appendix W section 3.2.2.b.2. Under the
alternative model criteria discussed in section 3.2.2.b.2, it must be
shown that the alternative model performs better for a given
application than the recommended model, using a statistical analysis.
The State of Wisconsin evaluated the performance of the alternative
model from both a theoretical and a performance perspective. This
information was included in the public notice which preceded Wisconsin
finalizing its submittal. The Wisconsin analysis showed that the
alternative model predicted a design value slightly above the monitored
design value using the recent three years of monitoring data, 2017-
2019. The most recent three years reflect the impact of emissions
exiting the 90-meter stack. Recent meteorological data, processed for
modeling purposes, was not available. Consequently, the comparison was
conducted using the full five years of meteorology applied for the
attainment demonstration.
Additional comparisons were conducted that examined, on a year-to-
year basis, how well the alternative model was performing compared to
the regulatory version of the model and compared to monitoring data.
That analysis only used emissions from boiler B26, which vents through
Stack S09, when the boiler was actually operating, essentially non-
summer months for the years 2017-2019. This supplemental modeling was
conducted using a grid focused on a 400-meter by 400-meter area around
the monitor to the north of Ahlstrom-Munskj[ouml]. Again, 5 years of
meteorological data (2011-2015) was used in the modeling.
The model to monitor comparison used High 1st High concentrations,
the average of the top 26 values, fractional bias, and 99th percentile
values. The results of the comparison showed that the alternative model
performed consistently better than the regulatory version, that is it
predicted higher concentrations than the standard version of AERMOD.
Additionally, the year-by-year comparisons to the monitored data showed
that the alternative model produced underestimates for one year,
overestimates for one year, and very similar estimates for the third
year. There was considerable year-to-year variability, as one would
expect. Consequently, the alternative model was viewed to be acceptable
based on the theoretical aspects of its development, the superior
performance compared to the recommended model, and the overall unbiased
nature of the alternative model's predictions.
Wisconsin's alternate model characterization was reviewed and
concurred with on May 28, 2021 by EPA's Model Clearinghouse under EPA's
Guideline on Air Quality Models criteria for alternate models. EPA
Region 5's request for concurrence and EPA's Model Clearinghouse
concurrence letters are included in the docket for this action.
C. Meteorological Data
Wisconsin used Rhinelander-Oneida County Airport (KRHI) surface
data and Green Bay, Wisconsin upper air data, years 2011-1015, for
modeling the Rhinelander area. The surface station is located less than
5 kilometers from Ahlstrom-Munksj[ouml] and is located in similar
rolling terrain. Given the close proximity of the surface station and
the similarity in surrounding terrain, EPA finds the use of the KRHI
airport data, combined with the Green Bay upper air data to be
appropriate, representative meteorological data sets for assessing
dispersion at the facility.
D. Emissions Data
Wisconsin included all point sources within 50 kilometers of
Rhinelander in its modeling analysis. These sources included boilers
B26 (sometimes coal fired) and B28 (natural gas and oil fired) at
Ahlstrom-Munksj[ouml], the Kerry Inc. facility (formerly Red Arrow
Foods), and the PCA facility. Wisconsin found that no other sources
were close enough to cause significant concentration gradients. Boilers
B20, B21, B22, and B23 at Ahlstrom-Munksj[ouml] were shut down in 2014,
and their decommissioning is included in a federally enforceable
permit, so they were not included in the modeling analysis. Wisconsin
determined that boiler B26, which vents through stack S09, was
primarily responsible for the Rhinelander area nonattainment
designation, as the modeling results show that boiler B26 accounts for
94-95 percent of the total SO<INF>2</INF> concentration in the area
depending on the boiler load. Therefore, boiler B26 was modeled at both
minimum and maximum loads. The Kerry Inc. and PCA sources, as well as
Ahlstrom-Munksj[ouml] boiler B28, were modeled at their current
permitted maximum allowable SO<INF>2</INF> emissions, as contained in
federally enforceable permits.
E. Emission Limits
An important prerequisite for approval of an attainment plan is
that
[[Page 38649]]
the emission limits that provide for attainment be quantifiable, fully
enforceable, replicable, and accountable. See General Preamble at
13567-68. The limit for Ahlstrom-Munksj[ouml] is expressed as a 24-hour
average limit. Therefore, part of the review of Wisconsin's attainment
plan must address the use of this limit, both with respect to the
general suitability of using such limits for this purpose and 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 particular the 24-
hour average limit.
1. Enforceability
In preparing its plan, Wisconsin adopted a revision to a previously
approved construction permit, Air Pollution Control Construction Permit
Revision 15-DMM-128-R1, governing the Ahlstrom-Munksj[ouml]
SO<INF>2</INF> emissions. These permit revisions were adopted by
Wisconsin following established, appropriate public review procedures.
The revised permit limits boiler B26 emission rates to 2.38 pounds per
million British Thermal Unit (lbs/MMBTU) on a 24-hour average basis.
This limit is more stringent than the previously approved limit of 3.0
lbs/MMBTU on a 24-hour average basis. The 3.0 lbs/MMBTU limit was
included as part of Wisconsin's 2016 attainment demonstration that EPA
disapproved in its March 23, 2021 rulemaking. In accordance with EPA
policy, the 24-hour 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. Additionally, the revised permit limits the maximum heat input
to boiler B26 to 260 MMBTU/hour and requires that stack SO9 be a
minimum of 75 meters (246 feet) above ground, as opposed to the
previous boiler B26 limit of 300 MMBTU/hour and requirement that stack
S09 be a minimum of 90 meters (296 feet) off the ground.\7\ The permit
compliance date for Ahlstrom-Munksj[ouml] is December 31, 2021. EPA
finds that this construction permit revision provides for permanent
enforceability.
---------------------------------------------------------------------------
\7\ For more discussion on stack height, see EPA's November 25,
2020 proposed partial approval and partial disapproval (85 FR
75273).
---------------------------------------------------------------------------
2. Longer Term Average Limits
Ahlstrom-Munksj[ouml] requested a limit expressed as a 24-hour
average limit in order to have a more robust limit, i.e., a limit based
on more values that would be less prone to indicate noncompliance based
on ordinary fluctuations in emissions. In accordance with EPA's April
2014 guidance for SO<INF>2</INF> nonattainment plans, Wisconsin
therefore adjusted its limit, reducing the limit for purposes of
assuring comparable stringency to the 1-hour limit that it otherwise
would have adopted.
Although compliance with this limit will be determined on the basis
of continuous emissions monitoring system (CEMS) data, the facility
does not have a sufficient historical record of CEMS data to be able to
evaluate source-specific emissions variability for purposes of
determining a source-specific factor by which to adjust the 1-hour
limit for this source. Instead, Wisconsin determined its 24-hour
average limit by applying one of the national average adjustment
factors listed in appendix D of EPA's guidance. In particular,
Wisconsin set its 24-hour average limit at 93 percent of the modeled
emission rate, reflecting the national average adjustment factor that
EPA found among facilities without emission control equipment. While
the facility operates dry sorbent injection equipment to control
hydrogen chloride (HCl) emissions so as to meet the maximum available
control technology requirements for industrial boilers, HCl is
generally much easier to control than SO<INF>2</INF>, and the
information about the facility's sorbent usage provided in Wisconsin's
submittal supports a conclusion that sorbent injection likely reduces
SO<INF>2</INF> emissions by less than one percent. Therefore, sorbent
usage may be presumed to have very little impact on the variability of
SO<INF>2</INF> emissions at this facility, and the national average
adjustment factor for facilities without control equipment is likely to
provide the best estimate of the appropriate degree of adjustment to
determine a 24-hour limit that is comparably stringent to the 1-hour
limit that otherwise would have been established.
Wisconsin set its limit at 2.38 lbs/MMBTU, corresponding to 93
percent of the 2.56 lbs/MMBTU emission rate that Wisconsin modeled.\8\
Although appendix D of EPA's guidance reports average adjustment
factors based on 99th percentile values among lbs/hr data rather than
among lbs/MMBTU data, EPA generally finds that lbs/hr data show greater
variability than lbs/MMBTU data, and so use of an adjustment factor
determined from analysis of lbs/hr data is likely to yield a
conservative (more stringent) result.
---------------------------------------------------------------------------
\8\ To be precise, the emission rates that Wisconsin modeled
reflected 2.56 lbs/MMBTU times the allowable operating rate of 260
MMBTU/hour times the hour-specific downwash multiplier discussed
above.
---------------------------------------------------------------------------
The Ahlstrom-Munksj[ouml] 24-hour average SO<INF>2</INF> emissions
will be calculated by summing the emissions rates of each 1-hour
operating period and dividing by the number of operating hours for that
calendar day. Although EPA recommends that the average values be
calculated by summing the total emissions and dividing by the total
heat input for each day, this approach is infeasible for Ahlstrom-
Munksj[ouml]. Because Ahlstrom-Munksj[ouml] is using Method 19,
calculating lbs/MMBTU SO<INF>2</INF> concentration without evaluating
either the mass or the heat input,\9\ the facility does not obtain the
hourly mass or heat input values to support a calculation of daily
total mass or daily total heat input. As the differences in results of
the two approaches are expected to be minimal, EPA concurs with
Wisconsin's approach.
---------------------------------------------------------------------------
\9\ ``Method 19--Determination of Sulfur Dioxide Removal
Efficiency and Particulate Matter, Sulfur Dioxide, and Nitrogen
Oxide Emission Rates'' (40 CFR part 60, appendix A).
---------------------------------------------------------------------------
Ahlstrom-Munksj[ouml] requested that Wisconsin specify compliance
determination procedures for days with fewer hours of data (generally,
days with fewer hours of operation) in order to ensure robust
compliance determinations, specifically to ensure that compliance is
determined on the basis of a minimum of 18 hours of data. For days with
fewer than 24 but at least 18 hours of data, compliance will be
determined by averaging the emissions rates from the hours of
operation. For operating days with fewer than 18 hours of data,
compliance will be determined by averaging all the values from that day
along with all the values from the most recent day with at least 18
hours of valid data. EPA supports the principle of ensuring that
compliance with a long-term average limit should be based on a robust
data set. Wisconsin's approach also is consistent with the principle
that the facility shall be accountable for emissions at all times,
i.e., that days with fewer hours of data shall not be disregarded but
rather shall be included in a suitably constructed compliance
determination. Therefore, EPA concludes that Wisconsin is using an
appropriate approach for addressing days with fewer hours of data.
Based on a review of the State's submittal, EPA believes that the
24-hour-average limit for Boiler B26 at Ahlstrom-Munksj[ouml] provides
a suitable alternative to establishing a 1-hour average emission limit
for this source.
[[Page 38650]]
EPA finds that Wisconsin used an appropriate adjustment factor,
yielding an emission limit 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 24-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 the reasons
described above and explained in more detail in EPA's April 2014
guidance for SO<INF>2</INF> nonattainment plans, 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 Wisconsin's plan, EPA finds that the 24-hour-average
limit for boiler B26 at Ahlstrom-Munksj[ouml] is a suitable alternative
to establishing a 1-hour limit on emissions from this boiler.
F. Background Concentrations
Wisconsin determined background concentrations for the Rhinelander
area using 2013-2015 data from the Horicon (Dodge County) monitor,
which is approximately 250 kilometers south of Rhinelander. The
background concentration values that Wisconsin used varied by month and
hour of the day and ranged from 1.40 micrograms per cubic meter ([mu]g/
m\3\) to 14.1 [mu]g/m\3\ with an average value of 4.87 [mu]g/m\3\. EPA
agrees that the values from the Horicon monitor are representative for
background concentration estimates.
G. Summary of Results
Modeling for the Rhinelander Area in Wisconsin's March 2021
submittal showed a design value of 74.8 ppb (195.8 [mu]g/m\3\). This
resulted from modeling the Ahlstrom-Munksj[ouml] boiler B26 at maximum
load, combined with all other area sources and including a background
concentration. The run was conducted with emissions at 2.56 lbs/MMBTU,
a level that corresponds in stringency to the 2.38 lbs/MMBTU 24-hour
average emission limit that Wisconsin adopted and submitted and is more
stringent than the previous 24-hour emission limit of 3.0 lbs/MMBTU.
Therefore, EPA concludes that Wisconsin's plan provides for attainment
in this area.
V. Review of Other Plan Requirements
A. RACM/RACT
CAA section 172(c)(1) states that nonattainment plans shall 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 national primary ambient air
quality standards. CAA section 172(c)(6) requires plans to include
enforceable emissions limitations, and such other control measures as
may be necessary or appropriate to provide for attainment of the NAAQS.
In its March 23, 2021 rulemaking, EPA disapproved Wisconsin's 2016
attainment plan because the Ahlstrom-Munksj[ouml] emissions limits (3.0
lbs/MMBTU 24-hour average SO<INF>2</INF> limit and 300 MMBTU/hr
operating limit) provided in the plan were not calculated in compliance
with the stack height regulations. Therefore, the plan could not be
considered to provide an appropriate attainment demonstration, and it
did not demonstrate RACM/RACT or meet the requirement for necessary
emissions limitations or control measures. Wisconsin's revised plan for
attaining the 1-hour SO<INF>2</INF> NAAQS in the Rhinelander area is
based on a variety of measures, including more stringent SO<INF>2</INF>
emissions and operating limits (2.38 lbs/MMBTU 24-hour average
SO<INF>2</INF> limit and 260 MMBTU/hr operating limit) for Ahlstrom-
Munksj[ouml], which were calculated in compliance with the stack height
regulations. Wisconsin's plan requires compliance with these measures
by December 31, 2021. Wisconsin has determined that these measures
suffice to provide for attainment. EPA concurs and proposes to conclude
that the State has satisfied the requirement in section 172(c)(1) and
(6) to adopt and submit all RACM/RACT and emissions limitations or
control measures as needed to attain the standards as expeditiously as
practicable.
B. Reasonable Further Progress (RFP)
In its March 23, 2021 rulemaking, EPA concluded that Wisconsin had
not satisfied the requirement in section 172(c)(2) to provide for RFP
toward attainment. Wisconsin's 2016 attainment plan did not demonstrate
that the implementation of the control measures required under the plan
were sufficient to provide for attainment of the NAAQS in the
Rhinelander SO<INF>2</INF> nonattainment area consistent with EPA
requirements (in particular consistent with EPA stack height
regulations). Therefore, a compliance schedule to implement those
controls was not sufficient to provide for RFP. Wisconsin's revised
plan requires compliance by December 31, 2021. Wisconsin concludes that
this is an ambitious compliance schedule, as described in April 2014
guidance for SO<INF>2</INF> nonattainment plans, and concludes that
this plan therefore provides for RFP in accordance with the approach to
RFP described in EPA's 2014 guidance. EPA concurs and proposes to
conclude that the plan provides for RFP.
C. Contingency Measures
As noted above, EPA guidance describes special features of
SO<INF>2</INF> planning that influence the suitability of alternative
means of addressing the requirement in section 172(c)(9) for
contingency measures for SO<INF>2</INF>, 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 SO<INF>2</INF> NAAQS and to undertake an aggressive
follow-up for compliance and enforcement. Wisconsin's plan provides for
satisfying the contingency measure requirement in this manner.\10\ EPA
concurs and proposes to approve Wisconsin's plan for meeting the
contingency measure requirement in this manner.
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\10\ Wisconsin Department of Natural Resources (WDNR) maintains
an enforcement program to ensure compliance with SIP requirements.
The Bureau of Air Management houses an active statewide compliance
and enforcement team that works in all geographic regions of the
State. WDNR refers actions as necessary to the Wisconsin Department
of Justice with the involvement of WDNR. Wis. Stats. 285.83 and Wis.
Stats. 285.87 provide WDNR with the authority to enforce violations
and assess penalties, to ensure that required measures are
ultimately implemented.
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VI. What action is EPA taking?
EPA is proposing to approve Wisconsin's SIP submission, which the
State submitted to EPA on March 29, 2021 to supplement the prior SIP it
had submitted on January 22, 2016 and supplemented on July 18, 2016,
and November 29, 2016, for attaining the 2010 1-hour SO<INF>2</INF>
NAAQS for the Rhinelander area and for meeting other nonattainment area
planning requirements. This SO<INF>2</INF> attainment plan includes
Wisconsin's attainment demonstration for the Rhinelander area. The plan
also addresses requirements for RFP, RACT/RACM, and contingency
measures. EPA has previously concluded that Wisconsin has addressed the
requirements for
[[Page 38651]]
emissions inventories for the Rhinelander area and nonattainment area
NSR. EPA has determined that Wisconsin's Rhinelander SO<INF>2</INF>
plan meets applicable requirements of section 172 of the CAA.
Wisconsin's Rhinelander SO<INF>2</INF> plan is based on the
emissions limits specified in Air Pollution Control Construction Permit
Revision 15-DMM-128-R1. Wisconsin seeks EPA to approve several elements
of the permit, including the permit cover sheet, emissions limitations
for Ahlstrom-Munksj[ouml] (Conditions A.3.a.(1)-(3)), compliance
demonstration (Conditions A.3.b.(1)-(3)), reference test methods,
recordkeeping and monitoring requirements (Conditions A.3.c.(1)-(5) and
A.3.c.(7)-(9)), and the effective date (Condition YYY.1.a.(1)).
Wisconsin did not seek approval of limits and test methods associated
with oil sulfur content. Wisconsin stated that limits on the portion of
emissions from oil are unnecessary to comply with the 24-hour
SO<INF>2</INF> emission limit and the boiler heat input limit, and
attainment is ensured by limits on total emissions from boiler B26. EPA
concurs with Wisconsin's rationale, and therefore EPA is proposing to
approve these elements of the permit.
Additionally, EPA is proposing to replace the previously approved
consent and administrative orders (AM-94-38 and AM-15-01) governing the
Ahlstrom-Munksj[ouml] emission limits \11\ with the elements of
Wisconsin's Air Pollution Control Construction Permit Revision 15-DMM-
128-R1 specified above. This replacement would not be effective until
December 31, 2021, which is the revised permit compliance date for
Ahlstrom-Munksj[ouml]. Section 110(l) of the CAA states that EPA
``shall not approve a revision of a plan if the revision would
interfere with any applicable requirement . . .'' Since Permit 15-DMM-
128-R1 contains a more stringent SO<INF>2</INF> limit for Ahlstrom-
Munksj[ouml] (2.38 lbs/MMBTU on a 24-hour average basis) than the
previous orders (3.0 lbs/MMBTU on a 24-hour average basis), and since
Wisconsin has demonstrated that the limit in Permit 15-DMM-128-R1
provides for attainment without need for the limits in the prior
orders, EPA concludes that Section 110(l) does not prohibit EPA from
replacing the prior orders with the newer permit, and EPA is proposing
to act in accordance with this Wisconsin request.
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\11\ Orders AM-94-38 and AM-15-01 were issued to the facility's
prior owner, Expera, but the orders continued to limit the
facility's emissions after it was acquired by Ahlstrom-Munksj[ouml].
---------------------------------------------------------------------------
EPA is taking public comments for thirty days following the
publication of this proposed action in the Federal Register. EPA will
take all comments into consideration in the final action. If this
approval is finalized, it would terminate the sanctions clock started
under CAA section 179 resulting from EPA's partial disapproval of the
prior SIP, as well as EPA's duty to promulgate a FIP for the area under
CAA section 110(c) that resulted from the previous partial disapproval.
VII. Incorporation by Reference
In this rule, EPA is proposing to include in a final EPA rule
regulatory text that includes incorporation by reference. In accordance
with requirements of 1 CFR 51.5, EPA is proposing to incorporate by
reference the specific portions of Wisconsin Air Pollution Control
Construction Permit Revision 15-DMM-128-R1, effective December 31,
2021, as described in section VI. above. EPA has made, and will
continue to make, these documents generally available through
<a href="http://www.regulations.gov">www.regulations.gov</a> and at the EPA Region 5 Office (please contact the
person identified in the FOR FURTHER INFORMATION CONTACT section of
this preamble for more information).
Also in this document, as described in section VI, EPA is proposing
to remove provisions of the EPA-Approved Wisconsin Source Specific
Requirements from the Wisconsin State Implementation Plan, which is
incorporated by reference in accordance with the requirements of 1 CFR
part 51.
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 CAA and applicable
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, EPA's role is to approve state choices,
provided that they meet the criteria of the CAA. Accordingly, this
action merely approves state law as meeting Federal requirements and
does not impose additional requirements beyond those imposed by state
law. For that reason, this action:
<bullet> 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);
<bullet> Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
<bullet> 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.);
<bullet> 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);
<bullet> Does not have federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
<bullet> Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
<bullet> Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
<bullet> 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
<bullet> Does not provide EPA with the discretionary authority to
address, as appropriate, disproportionate human health or environmental
effects, using practicable and legally permissible methods, under
Executive Order 12898 (59 FR 7629, February 16, 1994).
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where EPA or an Indian tribe has
demonstrated that a tribe has jurisdiction. In those areas of Indian
country, the rule does not have tribal implications and will not impose
substantial direct costs on tribal governments or preempt tribal law as
specified by Executive Order 13175 (65 FR 67249, November 9, 2000).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Reporting and recordkeeping
requirements, Sulfur oxides.
Dated: July 13, 2021.
Cheryl Newton,
Acting Regional Administrator, Region 5.
[FR Doc. 2021-15464 Filed 7-21-21; 8:45 am]
BILLING CODE 6560-50-P
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</html>Indexed from Federal Register on July 22, 2021.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.