[Federal Register Volume 90, Number 88 (Thursday, May 8, 2025)]
[Proposed Rules]
[Pages 19437-19447]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-08080]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R06-OAR-2025-0173; FRL-12753-01-R6]
Air Plan Approval; Louisiana; Nonattainment Plan for the
Evangeline Parish 2010 Sulfur Dioxide Primary National Ambient Air
Quality Standard Nonattainment Area
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
approve Louisiana's State Implementation Plan (SIP) revision submitted
to EPA on April 2, 2025, for the Evangeline Parish 2010 1-hour sulfur
dioxide (SO2) primary national ambient air quality standard
(NAAQS) nonattainment area. EPA is proposing approval of the following
Clean Air Act (CAA) SIP elements: The attainment demonstration for the
SO2 NAAQS, which includes an Agreed Order on Consent (AOC)
for the Cabot Corporation's Ville Platte Plant (Cabot) facility; the
reasonable further progress (RFP) plan; the reasonably available
control measures (RACM) and reasonably available control technology
(RACT) demonstration; the emission inventories; and the contingency
measures. The State has demonstrated that its current Nonattainment New
Source Review (NNSR) program covers this NAAQS; therefore, no revision
to the SIP is required for the NNSR element.
DATES: Comments must be received on or before June 9, 2025.
ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2025-0173, at https://www.regulations.gov. Follow the online
instructions for submitting comments. Once submitted, comments cannot
be edited or removed from Regulations.gov. The EPA may publish any
comment received to its public docket. Do not submit electronically any
information you consider to be Confidential Business Information (CBI)
or other information whose disclosure is restricted by statute.
Multimedia submissions (audio, video, etc.) must be accompanied by a
written comment. The written comment is considered the official comment
and should include discussion of all points you wish to make. The EPA
will generally not consider comments or comment contents located
outside of the primary submission (i.e., on the web, cloud, or other
file sharing system). For additional submission methods, please contact
Andrew Lee, 214-665-6750, [email protected]. For 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.
Docket: The index to the docket for this action is available
electronically at www.regulations.gov. While all documents in the
docket are listed in the index, some information may not be publicly
available due to docket file size restrictions or content (e.g., CBI).
FOR FURTHER INFORMATION CONTACT: Andrew Lee, EPA Region 6 Office, Ozone
and Infrastructure Section, 214-665-6750, [email protected]. We
encourage the public to submit comments via https://www.regulations.gov. Please call or email the contact listed above if
you need alternative access to material indexed but not provided in the
docket.
SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,''
``us,'' or ``our'' is used, we mean EPA.
Table of Contents
I. Background
A. Evangeline Parish SO2 Nonattainment Area
B. Requirements for SO2 Nonattainment Area Plans
C. Attainment Demonstration Requirements for SO2
Nonattainment Area Plans
II. Review of Modeled Attainment Plan
A. Model Selection and General Model Inputs
B. Meteorological Data
C. Emissions Data
D. Receptor Grid
E. Emission Limits
F. Background Concentrations
G. Summary of Results
III. Review of Other Plan Requirements
A. Emissions Inventory
B. RACM/RACT
C. New Source Review (NSR)
[[Page 19438]]
D. Reasonable Further Progress (RFP)
E. Contingency Measures
F. Conformity
IV. Proposed Action
V. Incorporation by Reference
VI. Statutory and Executive Order Reviews
I. Background
A. Evangeline Parish SO2 Nonattainment Area
On June 22, 2010, the EPA published a new 1-hour primary
SO2 NAAQS of 75 parts per billion (ppb), which is met at an
ambient air quality monitoring site (or in the case of dispersion
modeling, at an ambient air quality receptor location) when the 3-year
average of the annual 99th percentile of 1-hour daily maximum
concentrations does not exceed 75 ppb, as determined in accordance with
appendix T of 40 CFR part 50.\1\ On December 21, 2017, the EPA
designated a portion of Evangeline Parish, Louisiana as nonattainment
for the SO2 NAAQS, effective April 9, 2018.\2\ The EPA based
the nonattainment designation on modeling for the 2013-2015 period
submitted by the State, which demonstrated that the area violated the
NAAQS with a modeled design value of 106 ppb. The primary source of
SO2 emissions in the area is the Cabot facility which
manufactures various grades of carbon black for use in various
industrial applications such as the production of rubber products.
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\1\ See 75 Federal Register (FR) 35520. See also 40 Code of
Federal Regulations (CFR) 50.17(a) and (b).
\2\ See 83 FR 1098.
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Section 191 of the CAA directs Louisiana to submit a SIP for the
Evangeline Parish area within 18 months of the effective date of the
designation, i.e., by no later than October 9, 2019. Under CAA section
192, Louisiana's SIP must demonstrate that Evangeline Parish will
attain the NAAQS as expeditiously as practicable, but no later than 5
years from the effective date of designation, i.e., April 9, 2023. On
November 3, 2020, the EPA issued a final action of Finding of Failure
to Submit a SIP Required for Attainment of the 2010 1-Hour Primary
SO2 NAAQS for Evangeline Parish.\3\ This finding triggers
certain CAA deadlines for the EPA to impose mandatory emission offsets
and highway funding sanctions, unless and until the State submits a SIP
revision satisfying the CAA's completeness criteria. Additionally, this
finding triggered the CAA section 110(c) requirement for EPA to
promulgate a Federal implementation plan (FIP) within two years of the
finding unless the State submits and obtains EPA approval of a SIP
revision which corrects the deficiency before EPA promulgates a FIP.
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\3\ See 85 FR 69504, November 3, 2020.
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On December 16, 2024, the EPA published the finding that the
Evangeline Parish area failed to attain the 2010 SO2 NAAQS
by the April 9, 2023, CAA attainment date.\4\ The determination was
based upon evaluation of SO2 emissions data and prior
modeling for the area. EPA found that emissions increased when
comparing the 2020-2022 period to the prior modeled emissions (2013-
2015) underlying the EPA's nonattainment designation. Under section
179(d) of the CAA, following the finding of failure to attain by the
attainment date, Louisiana shall submit a SIP revision by December 16,
2025, that provides for attainment of the NAAQS as expeditiously as
practicable, but no later than December 16, 2029.
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\4\ See 89 FR 101475, April 9, 2023.
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On April 2, 2025, Louisiana submitted the Evangeline Parish
nonattainment SIP revision to the EPA. The SIP revision includes a
newly established Administrative Order on Consent (AOC) containing the
enforceable control strategy which is incorporated into the attainment
demonstration (AD) for Evangeline Parish. This SIP revision
contemplated in this proposed approval fulfills the SIP submittal
requirement imposed by both CAA sections 191(a) and 179(d).
B. Requirements for SO2 Nonattainment Area Plans
SO2 Nonattainment area SIPs must meet the applicable
requirements of CAA sections 110, 172, 191, and 192. The EPA's
regulations governing nonattainment area SIPs are set forth at 40 CFR
part 51, with specific procedural requirements and control strategy
requirements found at subparts F and G, respectively. Soon after
Congress enacted the 1990 Amendments to the CAA, the EPA issued
comprehensive guidance on SIPs, in a document entitled the ``General
Preamble for the Implementation of Title I of the Clean Air Act
amendments of 1990,'' published at 57 FR 13498 (April 16, 1992)
(General Preamble). Among other things, the General Preamble addressed
SO2 SIPs and fundamental principles for SIP control
strategies. Id., at 13545-49, 13567-68. On April 23, 2014, the EPA
issued additional guidance for meeting the statutory requirements in
SO2 SIPs in a document titled, ``Guidance for 1-Hour
SO2 Nonattainment Area SIP Submissions'' (April 2014
SO2 Guidance).\5\ In this guidance, the EPA describes how a
nonattainment area SIP can satisfy the following CAA requirements: an
accurate emissions inventory of current emissions for all sources of
SO2 within the nonattainment area, an AD, RFP, RACM,
(including RACT), NNSR program, enforceable emissions limitations and
control measures, and adequate contingency measures for the affected
area.\6\
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\5\ ``Guidance for 1-Hour SO2 Nonattainment Area SIP
Submissions'' available at: https://www.epa.gov/sites/production/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf.
\6\ See section V. of ``Guidance for 1-Hour SO2
Nonattainment Area SIP Submissions''.
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Under CAA sections 110(l) and 193, the EPA may not approve a SIP
revision that would interfere with any applicable requirement
concerning NAAQS attainment and RFP, or any other applicable
requirement under the Act.
C. Attainment Demonstration Requirements for SO2 Nonattainment Area
Plans
CAA section 172(c)(1) requires a SIP to provide for attainment of
the NAAQS. 40 CFR part 51, subpart G further delineates the control
strategy requirements that SIPs must meet. Generally, SO2
ADs consist of two components: (1) emission limits and other control
measures that assure implementation of permanent, enforceable, and
necessary emission controls and (2) a modeling analysis which
demonstrates that the emission limits and control measures provide for
attainment as expeditiously as practicable, but no later than the
attainment date, and meet the requirements of 40 CFR part 51, appendix
W (Guideline on Air Quality Models) and other EPA guidance.
In all cases, the emission limits and control measures must be
accompanied by appropriate methods and conditions to determine
compliance. As discussed in the General Preamble, the emission limits
and control measures should 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
[[Page 19439]]
assumptions used in the SIP demonstrations).\7\
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\7\ See published in the Federal Register at 57 FR 13498 (April
16,1992) at 13567-68.
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40 CFR 51.112(a)(1) states that all applications of air quality
modeling shall be based on the applicable models specified in the
Guideline on Air Quality Models (Modeling Guideline). Appendix A to the
Guideline on Air Quality Models delineates the EPA's preferred models
and other recommended techniques, as well as guidance for their use in
estimating ambient concentrations of air pollutants.8 9 In
2005, based on extensive developmental and performance evaluation, the
EPA promulgated AERMOD as the Agency's preferred near-field dispersion
modeling for a wide range of regulatory applications addressing
stationary sources (e.g., for estimating SO2 concentrations)
in all types of terrain.\10\
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\8\ See 80 FR 45340 (July 29, 2015).
\9\ The EPA published revisions to the Guideline on Air Quality
Models on January 17, 2017, (see 82 FR 5182) and on November 29,
2024 (see 89 FR 95034).
\10\ See 70 FR 68218 (November 9, 2005).
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The Modeling Guideline is periodically updated with the latest
recommended techniques and guidance for usage, with the applicable
requirements being those in effect at the time the modeling was
completed. The version of the Modeling Guideline in effect at the time
Louisiana developed its SIP was adopted in a Federal Register action on
January 17, 2017, effective May 22, 2017.\11\
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\11\ See 82 FR 5182 (January 17, 2017). The Modeling Guideline
has since been revised effective March 21, 2025. See 89 FR 95034
(November 29, 2024). See also https://www.epa.gov/scram/2024-appendix-w-final-rule.
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Based on and consistent with the Modeling Guideline's requirements,
EPA has issued supplemental guidance on modeling for purposes of
demonstrating attainment of the 2010 SO2 NAAQS in its April
2014 SO2 Guidance titled ``Appendix A. Modeling Guidance for
Nonattainment Areas'' (April 2014 SO2 Guidance Appendix A).
The April 2014 SO2 Guidance Appendix A provides specific
SO2 modeling guidance on the modeling domain, the source
inputs, assorted types of meteorological data, and background
concentrations.
As stated previously, ADs for the 2010 SO2 NAAQS should
demonstrate attainment of the NAAQS in the entire area designated as
nonattainment (i.e., not just at the violating monitor) by using air
quality dispersion modeling to show that the mix of sources, control
measures, and emission rates in an area will not lead to a violation of
the SO2 NAAQS.\12\ For a short-term (i.e., 1-hour) standard,
the EPA has stated that dispersion modeling, using allowable emissions
and addressing stationary sources in the 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 Dispersion modeling takes into
consideration combinations of meteorological and emission source
operating conditions that may contribute to peak ground-level
concentrations of SO2. Estimated concentrations should
include ambient background concentrations, should follow the form of
the standard, and should be calculated as described in section 2.6.1.2
of the August 23, 2010, clarification memo on ``Applicability of
Appendix W Modeling Guidance for the 1-hr SO2 National
Ambient Air Quality Standard.'' \13\
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\12\ April 2014 SO2 Guidance pages 11-12.
\13\ See https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/20100823_page_1-hr_so2_naaqs_psd_program.pdf.
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II. Review of Modeled Attainment Plan
This section discusses the EPA's review and analysis of the modeled
attainment plan, including model selection and general model inputs,
meteorological data, emissions data, receptor grid, emissions limits,
and background concentrations. A complete, detailed discussion of the
modeling requirements and our analysis is presented in the technical
support document (TSD) contained in the public docket for this proposed
action.
A. Model Selection and General Model Inputs
Louisiana's AD modeling conducted by Trinity Consultants, Inc.
(TCI), on behalf of Cabot, used EPA's regulatory dispersion model,
AERMOD, to determine the SO2 emission reductions needed to
bring the Evangeline Parish area into attainment. TCI relied upon
AERMOD Version 23132 and the companion AERMOD User Guide (EPA, October
2023) documentation in developing this AD, as it was the most recent
EPA approved version of AERMOD at the time the work was conducted.
Regulatory default options were specified in developing the AD that are
consistent with established practices for use of AERMOD in determining
NAAQS compliance for SIP revisions. Included among those default
options are stack tip downwash, buoyancy induced dispersion, default
wind profile coefficients, default vertical potential temperature
gradients, and final plume rise. EPA finds these selections
appropriate.
The most significant source, and only point source, addressed in
the modeling for the area is Cabot. This facility is the principal
cause of the modeled violations in the area. At the location of highest
concentrations modeled in the area, the Cabot facility contributed more
than 99% in total to the modeled violations. The modeling techniques
used for this source are discussed later in this section.
The selection of terrain data corresponds to the geographic area
represented by the Evangeline Parish nonattainment area, as well as the
locations of buildings and structures nearby the source that influence
concentrations in the area. TCI generated the necessary terrain inputs
for AERMAP using U.S. Geological Survey (USGS) National Elevation
Dataset (NED). Elevations from the NED data were determined for all
sources and structures, and both elevations and representative hill
heights were determined for receptors.
A detailed site characterization of the Cabot facility provided
dimensional and locational data for structures and stacks necessary for
addressing building-induced plume downwash. TCI used the EPA's Building
Profile Input Program with PRIME algorithm (BPIPPRM, dated 04274) to
generate direction-specific building parameters for modeling building
wake effects through the assistance of TCI's BREEZE[supreg] software
that fully incorporates the EPA sanctioned BPIPPRM. The location and
height of each stack to be evaluated and those of nearby structures
were processed in BPIPPRM to produce the building downwash parameters
required by AERMOD.
The Cabot facility has four main production units, VP-1 through VP-
4 (Units 1 through 4). During normal operations, all four units feed
into the MAIN stack which will be installed with a wet gas scrubber
pollution control device. When the MAIN stack and emission controls are
undergoing scheduled maintenance, the Cabot facility will rely on its
existing unit specific stacks that are monitored with the existing
Predictive Emissions Monitoring System (PEMS). VP-3 (Unit 3) has its
own flare stack (SFLR3) and dryer stack (SDRY3). VP-4 (Unit 4) has its
own flare stack (SFLR4) whereas VP-1 and VP-2 uses a combined flare
(SFLR12). VP-1, VP-2, and VP-4 use a combined dryer stack (SDRY124).
TCI used site specific building and stack data to model all stacks
in the Cabot facility at the lesser of actual stack height or Good
Engineering Practice
[[Page 19440]]
(GEP) stack height. For more details, analyses, and conclusions about
the sources modeled and how they were modeled, see our TSD. EPA finds
that LDEQ's model selection and selection of general inputs for its
model conform with EPA's modeling requirements.
B. Meteorological Data
In accordance with the Modeling Guideline and EPA's guidance cited
previously, meteorological data must be selected from a nearby and
representative source and adequately processed for use in AERMOD. The
State's modeling relied on the most recent five years (2016-2021) \14\
of surface meteorological and coincident upper air data that was
available at the time from the national weather service (NWS) Lake
Charles Regional Airport meteorological station (WBAN No. 03937) (Lake
Charles Station) to generate the necessary meteorological inputs for
use in AERMOD. The Lake Charles station is the closest station to Cabot
and was therefore selected as the most representative of meteorological
conditions within the area of analysis due to proximity, similar
terrain, and availability of recently collected data. TCI processed the
surface and upper air data using the appropriate versions of AERMINUTE,
AERSURFACE, and AERMET meteorological processing tools. AERMINUTE was
used to process NOAA's 1-minute ASOS data, AERSURFACE was used to
generate the surface characteristic values for the met station, and
then AERMET used those files to generate meteorological data files for
AERMOD.
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\14\ The 2020 meteorological data for Lake Charles Regional
Airport do not meet U.S. EPA's data requirement for 90% completeness
by quarter for wind direction, wind speed, and temperature. As such,
2020 was excluded from meteorological data calculations, leaving the
five years of 2016-19 and 2021. See Table 2-2 of TCI's Modeling
Report for a report of missing met data by year and quarter.
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The Lake Charles station meets the EPA's criteria as being nearby
and representative. The EPA also finds that TCI adequately processed
the upper air and surface air data from the Lake Charles station in
accordance with the Modeling Guideline and the EPA's AERMOD
Implementation Guide \15\ to generate the necessary meteorological data
to be used in the AERMOD model runs. Therefore, the EPA is proposing to
find the selection and processing of these data acceptable.
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\15\ See November 2024 AERMOD implementation guide. This
modeling project was completed prior to this version of the Guide,
but the updates do not affect how AERMOD or its preprocessors
function for this specific project. See https://gaftp.epa.gov/Air/aqmg/SCRAM/models/preferred/aermod/aermod_implementation_guide.pdf.
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C. Emissions Data
The primary source contributing to modeled violations in the
nonattainment area is the Cabot facility. This SIP revision includes an
emission inventory for SO2 sources that found that the Cabot
facility is the only point source located within the Evangeline Parish
nonattainment area and there are no major source SO2
facilities within 50 miles of Cabot. Furthermore, there are no nearby
sources outside the nonattainment area that could impact the
concentration gradient created by the Cabot facility. The impacts of
SO2 emissions from non-point sources, for example mobile
emissions, incineration, agricultural field burning, etc., were not
explicitly modeled in AERMOD but instead represented via monitored
background data.
The plant has four carbon black production units: VP-1 through VP-
4. VP-3 has its own flare stack (SFLR3) and dryer stack (SDRY3). VP-4
has its own flare stack (SFLR4) whereas VP-1 and VP-2 have a combined
flare stack (SFLR12). VP-1, VP-2, and VP-4 have a combined dryer stack
(SDRY124). As discussed elsewhere, during normal operations, emissions
from VP-1 through VP-4 will be routed through emission controls and the
MAIN stack. Hence, there are six major emissions points of
SO2 at the Cabot facility: MAIN stack, SFLR3 flare stack,
SDRY3 dryer stack, SFLR4 flare stack, SFLR12 flare stack, and SDRY124
dryer stack. Furthermore, there are several minor sources of
SO2 at the Cabot facility that were also accounted for in
the State's modeling: sampling units (EQT 0041), plant-wide fugitive
emissions (FUG 001), and unit process filters (EQT 0005, EQT 0007, EQT
0030, EQT 0032). LDEQ's previous modeling, submitted for EPA's
designation of the area, showed that Cabot was the principal
contributor to the highest modeled violations.\16\
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\16\ See https://www.epa.gov/sites/default/files/2017-08/documents/16_la_so2_rd3-final.pdf.
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The SIP's AD modeling covers operating scenarios with emissions
through the wet gas scrubber (WGS) and MAIN stack as well as a number
of operating scenarios for maintenance periods with emissions through
the flare and dryer stacks. This approach enabled the determination of
emission rates for each operating scenario that were shown through the
modeling to be consistent with attainment of the NAAQS. EPA's review
and analysis of the SIP revision's emissions limits and operating
parameters for the facility can be found in section II, E. Emission
Limits, of this document.
Additional details and evaluation of the emissions data utilized in
the AD are provided in our accompanying TSD and TCI's Modeling Report.
D. Receptor Grid
Within AERMOD, air quality concentration results are calculated at
discrete locations identified by the user; these locations are called
receptors. TCI's modeling domain for this demonstration consisted of
four nested receptor grids which increase in spacing as the receptors
increase in distance from Cabot. The inner most grid consists of a
circle approximately centered upon the location of Cabot's new MAIN
stack, extending outward to one kilometer from the facility center
filled with a gridded receptor array at 25-meter intervals. This 25-
meter spaced grid also includes receptors on the property fence line,
on the public road that bisects the plant, and the adjacent railway.
The second grid consists of 100-meter spaced receptors filling the
space between 1-kilometer and 2-kilometer circles. The third grid from
the center extends from 2 to 5 km with receptors spaced 200 meters
apart. The outermost rectangular grid (also trimmed to the shape of a
circle) extends from 5 kilometers from the Cabot facility to 10
kilometers with receptors placed every 500 meters. Receptors were
excluded within the boundary of the Cabot facility which is considered
non-ambient air relative to its own emissions. The modeling domain and
receptor network are sufficient to identify maximum impacts from the
modeled sources, and detect significant concentration gradients, and
are adequate for demonstrating attainment in the nonattainment area and
the surrounding area.
E. Emission Limits
An important aspect of a SIP is that the emission limits providing
for attainment be quantifiable, fully enforceable, replicable, and
accountable. See published in the Federal Register at 57 FR 13498
(April 16, 1992) at 13567-68. This SIP revision incorporates an
Administrative Order on Consent (AOC) between LDEQ and Cabot. The AOC
prescribes the emissions limits and operating parameters, among other
requirements, for the emissions stacks and small sources associated
with the four carbon black production units (VP-1 through VP-4) which
are reflected in the modeling demonstration. Cabot's operations fall
under two categories: Category 1--Series of operational scenarios for
planned turnaround (every fifth year) and yearly planned outages of
[[Page 19441]]
the WGS; and Category 2--Normal Operations where the WGS is operating
and emissions are routed through WGS before exiting the MAIN.
In 2013, EPA and Louisiana entered into consent decrees with select
carbon black facilities, including Cabot, in Louisiana for violations
of the Prevention of Significant Deteriorations provision of the
CAA.\17\ As part of the EPA's Carbon Black Consent Decrees (CD),
Cabot's Ville Platte plant in Evangeline Parish and others agreed (with
Louisiana as an intervenor) to the installation of a wet gas scrubber
pollution control system (WGS) that reduces SO2 emission by
at least 95 percent. Another requirement of the CD was to limit the use
of flares at these facilities to periods when the control device is
under maintenance, and to limit the hours of this planned maintenance.
These CD requirements are reflected in the emission limits submitted in
this SIP.
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\17\ See Appendix C: Cabot Corporation Consent Decree of LDEQ's
SIP submittal.
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Category 1: Planned turnaround (every fifth year) and yearly
planned outages: Planned turnaround includes scheduled downtime for
maintenance, repairs, and upgrades that can last up to 744 hours and
occur every five (5) years). Yearly planned outages occur in years when
turnarounds are not scheduled and can last up to 168 hours. During both
periods, the WGS and MAIN stack (through which the WGS exhausts to
atmosphere) are not operational. In lieu of being routed to the MAIN
stack, emissions from the VP-1 and VP-2 are routed through SFLR12 flare
and SDRY124 dryer stack, VP-3 emissions are routed through SFLR3 flare
and SDRY3 dryer stack, and VP-4 emissions are routed through SFLR4
flare and SDRY124 dryer stack.
In situations where a flare becomes inoperable, the facility must
cease feeding the carbon black feedstock to the associated carbon black
production unit. Under category 1, there are five different operating
scenarios allowed depending on the number of units operating, operating
capacity and the feedstock selected. During Category 1 operations, when
units VP-1 through VP-4 are transitioning from cold start to steady
state operations, startup of the emission units shall be conducted in
accordance with the sequence of operations in Table 1 of this document.
No two units will simultaneously undergo startup. Table 2 provides the
different operating scenarios that are allowed during Category 1
planned outage and turnaround periods along with the associated
operating units and maximum sulfur feedstock allowed during each such
scenario. Table 3 provides the maximum emission limit of each stack
associated with each operating scenario in Category 1. Table 3
establishes emission rates for the next-to-last-step (worst case hours)
and separate emission rates when all emission units are steady state.
The next-to-last-step emission rates are higher due to the transitional
state of the last unit in startup mode, where burners may be sputtering
or not staying lit in transitional state but are firing consistently
and uniformly in steady state.
Category 2: Normal Operations: Category 2 is defined as times when
the WGS is fully operational with emissions routed through the WGS
before being released to the atmosphere through the MAIN stack. During
periods of normal operations, emissions from units VP-1 through VP-4
must be routed through the WGS and then out of the MAIN stack. Table 2
provides the maximum sulfur feedstock allowed during Category 2 normal
operations, and Table 3 provides the allowable emission rate limits
during Category 2 operations.
Operating Scenarios and Associated Emissions Limits: the operating
parameters of the individual point sources of SO2 for the
crucial processes at the Cabot facility and the emission limitations
are detailed in Tables 1 through 3 and described briefly here. During
periods of planned outage/turnaround (in Category 1 operations) startup
of emission units VP-1 through VP-4 shall be conducted in accordance
with the sequence of operations in Table 1. Table 1 identifies the
specific steps that are followed to bring the units up to production
mode status. Each unit startup has two phases--transitional and steady-
state. See the Category 1 description above for further explanation of
transitional and steady state. Table 2 lists all allowable operating
scenarios, including Category 2 operations, with the sulfur feedstock
and capacity restrictions that the facility may operate under. The
combination of Tables 1 and 2 are provided in TCI's Modeling Report
(Tables 2-6 through 2-17) where each scenario with each step's
emissions is identified. For example, under Table 2, Scenario 4, all
dryers and flare stacks are emitting, but Scenario 1C of Table 2 has
only one flare and one dryer stack operating, consistent with operating
only VP-3. Table 3 was derived to identify the emission limits for each
stack by which the facility must abide under each operating category
and scenario. Continuing with our example, Table 3 lists the emission
limits for each dryer and flare stack operating under Scenario 4 and
Scenario 1C. For more details on these emissions allocations, see the
Scenario Specific Emission Rates section of the TCI's Modeling Report,
p2-11 through 2-20, especially Tables 2-6 through 2-17.
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\18\ Cabot will start the units in the following order only: VP-
4 will always be started first, followed by VP-1 and/or VP-2. VP-3
will always be started last. For scenarios that have fewer units
operational, the same order (after excluding non-operational units)
will be maintained.
Table 1--Sequence of Operation of Units During Planned Outage/Turnaround Period
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
Step Action
----------------------------------------------------------------------------------------------------------------
1............... Check emergency systems. All four process units (VP-1 through VP-4) are off.
2............... All units warm up.
3............... Purge gas header system.
4............... Light dryers, purge filters.
-----------------------------------------------------------------------------------------------
5............... First Unit Second Unit is off.... Third Unit is off..... Fourth Unit is off.
transitional i.e.,
any one of VP-1
through VP-4,
depending on scenario
\18\.
6............... First Unit Steady Second Unit is off.... Third Unit is off..... Fourth Unit is off.
State.
7............... First Unit Steady Second Unit Third Unit is off..... Fourth Unit is off.
State. Transitional.
8............... First Unit Steady Second Unit Steady Third Unit is off..... Fourth Unit is off.
State. State.
9............... First Unit Steady Second Unit Steady Third Unit Fourth Unit is off.
State. State. Transitional.
[[Page 19442]]
10.............. First Unit Steady Second Unit Steady Third Unit Steady Fourth Unit is off.
State. State. State.
11.............. First Unit Steady Second Unit Steady Third Unit Steady Fourth Unit
State. State. State. Transitional.
12.............. First Unit Steady Second Unit Steady Third Unit Steady Fourth Unit Steady
State. State. State. State.
----------------------------------------------------------------------------------------------------------------
Table 2--Operating Scenarios
------------------------------------------------------------------------
------------------------------------------------------------------------
Scenario Description......... Maximum
sulfur
feedstock
(%)
------------------------------------------------------------------------
Category 1.......... 1A............. 4.0% Sulfur 4.00
Feedstock with VP-1
(SFLR12 and
SDRY124)
Operational at
Normal Capacity.
Category 1.......... 1B............. 4.0% Sulfur 4.00
Feedstock with VP-2
(SFLR12 and
SDRY124)
Operational at
Normal Capacity.
Category 1.......... 1C............. 3.5% Sulfur 3.50
Feedstock with VP-3
(SFLR3 and SDRY3)
Operational at
Normal Capacity.
Category 1.......... 1D............. 4.0% Sulfur 4.00
Feedstock with VP-4
(SFLR4 and SDRY124)
Operational at
Normal Capacity.
Category 1.......... 2.............. 3.5% Sulfur 3.50
Feedstock with all
Flares and Dryers
Operational at
Normal Capacity
except for VP-3.
Category 1.......... 3A............. 2.5% Sulfur 2.50
Feedstock with VP-3
and VP-1
Operational at
Normal Capacity.
Category1........... 3B............. 2.5% Sulfur 2.50
Feedstock with VP-3
and VP-2
Operational at
Normal Capacity.
Category 1.......... 3C............. 2.5% Sulfur 2.50
Feedstock with VP-3
and VP-4
Operational at
Normal Capacity.
Category 1.......... 44............. 2.3% Sulfur 2.30
Feedstock with all
Units Operational
at Reduced Capacity.
Category 1.......... 55............. 2.00% Sulfur 2.00
Feedstock with all
Units Operational
at Normal Capacity.
Category 2.......... 66............. MAIN (WGS 4.00
Operational for all
hours).
------------------------------------------------------------------------
Table 3--Emission Limits
--------------------------------------------------------------------------------------------------------------------------------------------------------
Emission rates for Emission rates for
the next-to-last- the last step (all
Maximum % step (worst case units in steady
Category Source stack Scenario sulfur Capacity hour-transition) state)
-----------------------------------------
lb/hr lb/hr
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.............................. SDRY3............ 1C................ 3.5 Normal................ 409 192.2
3A................ 2.5 Normal................ 275 129.2
3B................ 2.5 Normal................ 275 129.2
3C................ 2.5 Normal................ 275 129.2
4................. 2.3 Reduced............... 168.9 79.3
5................. 2.0 Normal................ 210.4 98.8
SDRY124.......... 1A................ 4.0 Normal................ 501.3 387.1
1B................ 4.0 Normal................ 674.7 528.8
1D................ 4.0 Normal................ 500.3 316.2
2................. 3.5 Normal................ 1,058.5 910.3
3A................ 2.5 Normal................ 219.7 219.7
3B................ 2.5 Normal................ 301.8 301.8
3C................ 2.5 Normal................ 186.1 186.1
4................. 2.3 Reduced............... 413 413
5................. 2.0 Normal................ 467.8 467.8
SFLR12........... 1A................ 4.0 Normal................ 767.6 380.4
1B................ 4.0 Normal................ 1,015 486.3
2................. 3.5 Normal................ 1,215.3 883.5
3A................ 2.5 Normal................ 215.8 215.8
3B................ 2.5 Normal................ 277.5 277.5
4................. 2.3 Reduced............... 382.2 382.2
5................. 2.0 Normal................ 448.1 382.2
SFLR3............ 1C................ 3.5 Normal................ 884.6 722.9
3A................ 2.5 Normal................ 615.2 486
3B................ 2.5 Normal................ 615.2 486
3C................ 2.5 Normal................ 615.2 486
4................. 2.3 Reduced............... 377.8 298.5
5................. 2.0 Normal................ 470.7 371.8
SFLR4............ 1D................ 4.0 Normal................ 929.8 613.8
2................. 3.5 Normal................ 528.4 528.4
[[Page 19443]]
3C................ 2.5 Normal................ 361.4 361.2
4................. 2.3 Reduced............... 199.3 199.3
5................. 2.0 Normal................ 280 280
2.............................. MAIN (WGS)....... 6................. 4.0 Normal................ 151.1 151.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cabot may operate under any of these scenarios during any time of
the year with the restriction that Cabot is only allowed to operate the
flares and dryer stacks under Category 1 for up to 168 hours for yearly
planned outages and up to 744 hours during every fifth year for planned
turnaround. Cabot shall utilize the WGS and MAIN stack for all other
hours.
Small Sources at Cabot: In addition to the major sources of
emissions at the Cabot facility, there are several permitted small
sources of SO2 emissions at the facility that must operate
under the emission limits in Table 4 and Table 5. Furthermore, Small
Source Category 1 Sources in Table 4 shall not operate simultaneously
with VP-1 through VP-4 after step 4 of Table 1. Since these are only
used as vents during warm up (those first 4 steps) and fired with
natural gas only, when MAIN is not up to temperature yet, and those
first steps are not part of the worst-case transition scenarios, these
were not modeled in any scenario. Small Source Category 2 Sources in
Table 4 may be operated for readiness testing only (approximately 20
minutes each) under non-emergency conditions after step 4 of Table 1.
These five small sources were modeled at all times when MAIN was
emitting (when WGS was operational), but not during outage/turnaround
times when the units are transitioning. Small Source Category 3 Sources
of Table 5 will operate at reduced emission rates compared to current
permitted values after the installation of the WGS. The purge gas
filters will be heated with electric heaters instead of dryer gases, so
no emissions were modeled for these sources.
Table 4--Small Sources Categories 1 and 2
----------------------------------------------------------------------------------------------------------------
Small source categories 1 and 2
-----------------------------------------------------------------------------------------------------------------
Modeling Operating
Category Source ID scenario hours lb/hr Source description
----------------------------------------------------------------------------------------------------------------
1............................... EQT 0008........... ........... 627 0.02 VP-2 Main Filter.
EQT 0026........... ........... 200 0.03 VP-1 Reactor Warm-
up Vent.
EQT 0027........... ........... 200 0.03 VP-2 Reactor Warm-
up Vent.
EQT 0028........... ........... 200 0.03 VP-3 Reactor Warm-
up Vent.
EQT 0029........... ........... 200 0.03 VP-4 Reactor Warm-
up Vent.
EQT 0048........... ........... 477 0.04 VP-1 Main Filter.
2............................... EQT 0011........... 6 100 0.36 Emergency and Test
Only (ULSD)--
Standby Air
Blower Diesel
Engine.
EQT 0022........... 6 100 0.51 Emergency and Test
Only (ULSD)--
Standby Fire Pump
Diesel Engine.
EQT 0051........... 6 100 0.02 Emergency and Test
Only (NG)--Dryer
Drive Generator.
EQT 0052........... 6 100 0.01 Emergency and Test
Only (NG)--
Feedstock Area
Generator.
EQT 0053........... 6 100 0.01 Emergency and Test
Only (NG)--Lab
Area Generator.
----------------------------------------------------------------------------------------------------------------
Table 5--Small Source Category 3
----------------------------------------------------------------------------------------------------------------
Small Source Category 3
-----------------------------------------------------------------------------------------------------------------
Permitted max
Currently SO2 emission Post-WGS max SO2
Operating permitted max rate for dryer emission rate
Source ID hours SO2 emission purge gas for dryer purge Source description
rate (lb/hr) filters (lb/hr) gas filters (lb/
\19\ hr)
----------------------------------------------------------------------------------------------------------------
EQT 0014................. 8,760 1,335.85 51.23 (VP-1) 0 (VP-1) Units 1, 2, 4 Pellet
55.50 (VP-2) 0 (VP-2) Dryer and Oil
Heaters (combined
stack)--includes
VP1 And VP2 Purge
Gas Filter
emissions.
EQT 0034................. 8,760 51.23 51.23 (VP-4) 0 (VP-4) Unit 4 Pellet Dryer
Purge Gas Filter.
EQT 0038................. 8,760 412.37 46.96 (VP-3) 0 (VP-3) Unit 3 Pellet Dryers
(Combined Stack)--
includes VP3 Purge
Gas Filter
emissions.
[[Page 19444]]
EQT 0050................. 8,760 0.01 ................ ................ VP4 Supplemental
Feedstock Heater.
----------------------------------------------------------------------------------------------------------------
Monitoring and Recordkeeping: Under this Louisiana attainment SIP,
during Category 2 operations, the Cabot facility is required to monitor
its release of SO2 via continuous emissions monitoring
system (CEMS) at the MAIN stack to measure compliance at the source and
ensure that the facility does not exceed its SIP limits. The CEMS will
continuously monitor the SO2 emissions in accordance with
the requirements in 40 CFR 60.13, appendix B, Performance Specification
2 and 6, for SO2, and appendix F, quality assurance
procedures. To demonstrate compliance, emissions data will be collected
at least four times per hour and then those four data points will be
averaged to produce that hour's measured concentration.
---------------------------------------------------------------------------
\19\ These sources are already included in the Modeled Max
Emission Rate.
---------------------------------------------------------------------------
For Category 1 operations, emissions from the dryer stacks and
flares will be calculated via a Predictive Emission Monitoring System
(PEMS). To make the calculations, the system shall record: the weight
percent of sulfur in feedstock oil to all reactors, the total pounds of
feedstock oil processed in the reactors, the total pounds of sulfur
entering all reactors (feedstock oil sulfur content times amount
processed), and the amount of SO2 emitted from the process
(80 percent of the sulfur feed times 2). During startup and transition
periods, records must be kept of scenario and time information for each
step, identifying the corresponding step in Table 1, the operating
scenario in Table 2, and applicable emission limits in Table 3 until
steady state for all operating units is attained.
The owner or operator of the facility must maintain records for a
minimum of five years and must demonstrate compliance with all
applicable recordkeeping requirements. The owner or operator must
maintain records of the CEMS data for the exhaust gas sulfur content,
temperature, and velocity from the scrubber stack. The owner or
operator must maintain records of the PEMS data for the feed rate
monitoring and the sulfur content of the carbon black oil feed blend.
Additionally, records documenting any hourly period that exceeds the
emission limits or standards mandated by the Administrative Order on
Consent must be maintained. Finally, copies of each performance test
and relative accuracy audit and all associated records must be
maintained.
As required in LDEQ's SIP submittal, all exceedances of the
applicable emission limits or failure to meet other requirements must
be reported to LDEQ no later than April 30 of the subsequent year after
violation. The report must include an explanation of the exceedance or
failure; if the violation was due to a startup, shutdown, or
malfunction (SSM) event; and a description of any action taken to
rectify the issue.
The SIP revision requires the Cabot facility to complete
construction and commissioning of the WGS and CEMS on the MAIN stack
and comply with all requirements of the AOC by July 30, 2026.
If the EPA finalizes this proposed action, the emission limits and
source configuration requirements, as well as the monitoring,
recordkeeping and reporting requirements of the Administrative Order on
Consent will become federally enforceable as a source-specific revision
to the Louisiana SIP.
F. Background Concentrations
To satisfy the EPA modeling requirements, the SIP's AD must also
incorporate background concentrations into its modeling. The AD
estimates the combined impacts of facility-specific emission rates and
monitored background concentrations. Regional sources not explicitly
modeled in AERMOD, but that contribute to ambient SO2
concentrations within the nonattainment area, are represented via
background monitoring data. Louisiana identified three monitors that
were approximately equidistant from the Cabot facility, including: the
Lake Charles monitor (AQS ID: 22-019-0008), Port Allen monitor (AQS ID:
22-121-0001), and Baton Rouge monitor (AQS ID: 22-033-0009). Louisiana
stated that the Lake Charles monitor and the Port Allen monitor would
provide an unrepresentative and overly conservative background
concentration measurement for the Evangeline Parish area due to the
influence of industrial site emissions near those monitors. Louisiana
identified the Baton Rouge monitor as representative of background
concentrations due to its similar local emissions characteristics and
the stability of SO2 concentrations measured at this
monitor. The EPA has determined that Louisiana's selection of the Baton
Rouge monitor is appropriate.
Once a suitable monitor is selected, Appendix W prescribes tiered
approaches for incorporating that data as background concentration.
LDEQ selected the ``Tier 2'' approach recommended by the August 23,
2010, clarification memo on ``Applicability of Appendix W Modeling
Guidance for the 1-hour SO2 National Ambient Air Quality
Standard'' based on monitored design values. In accordance with EPA's
guidance on background concentrations, LDEQ's ``Tier 2'' approach
identified separate background values for each hour of the day for each
of the four seasons, totaling 96 background values. Each of these
values represents a three-year average (2020-2022) of the second
highest hourly concentration for the applicable hour of the day for the
applicable season. The seasonal, hourly-averaged 2020-2022
SO2 background values for the AD were developed from data
collected at the Baton Rouge monitor. The background values ranged from
0.300 ppb to 8.167 ppb. EPA concludes that the methodology used by LDEQ
to model background values is appropriate. This is also discussed in
TCI's Modeling Report and our TSD.
G. Summary of Results
The attainment plan establishes new emissions limits for the Cabot
facility needed to attain the 1-hour SO2 NAAQS. LDEQ
determined that the impact of these reduced maximum allowable emissions
limits and installation of a new scrubber stack at the facility yielded
a 5-year modeled
[[Page 19445]]
design value (DV)--the 5-year average (2016-2021, not including 2020)
of the predicted annual 99th percentile of 1-hour daily maximum
SO2 concentrations--of 194.5 ug/m3 (74.3 ppb) for the worst
case Category 1 scenario (Scenario 2) and 52.8 ug/m3 (20.2 ppb) for the
worst case Category 2 scenario (Scenario 6). Refer to Section 2.10 of
the Modeling Report \20\ or our TSD for a tabulation and discussion of
the modeled results.
---------------------------------------------------------------------------
\20\ Table 2-20 of TCI's Modeling Report was not updated for the
Category 2 final modeling results; yet TCI's Figures D-41 and D-42
do represent the final modeling for Category 2 with a max DV of
``5.28E+01'' (52.8 [micro]g/m3). EPA performed confirmatory modeling
using TCI's modeling files to confirm TCI's final modeling
representations for Category 2.
---------------------------------------------------------------------------
The EPA concludes that LDEQ's modeling is a suitable demonstration.
Based on our review of the SIP, EPA has determined that the SIP
submission satisfies the applicable CAA requirements and, if approved,
would provide for attainment of the SO2 NAAQS.
III. Review of Other Plan Requirements
A. Emissions Inventory
The emissions inventory and source emission rate data for an area
serve as the foundation for air quality modeling and other analyses
that enable states to: (1) estimate the degree to which different
sources within a nonattainment area contribute to violations within the
affected area; and (2) assess the expected improvement in air quality
within the nonattainment area due to the adoption and implementation of
control measures. A nonattainment SIP must include a comprehensive,
accurate, and current inventory of actual emissions from all sources of
SO2 in the nonattainment area as well as any sources located
outside the nonattainment area that may affect attainment in the area.
See CAA section 172(c)(3). In its submittal, LDEQ included a current
emissions inventory for the Evangeline Parish area covering the 2018-
2023 period. LDEQ did not specifically provide projected emissions for
the 2029 attainment year; however, the EPA has determined the projected
emissions based on the proposed SIP limits for the facility, the only
major source within the nonattainment area. The EPA identified three
possible projected 2029 attainment year scenarios to estimate projected
emissions: Cabot undergoes no period of turnaround during the year,
Cabot undergoes a planned outage not to exceed 168 hours during the
year, and Cabot undergoes a period of turnaround not to exceed 744
hours as allowed every fifth year. This information is provided in
Table 6.\21\
---------------------------------------------------------------------------
\21\ Presented in Table 6 is an estimation of the attainment
year projected worst-case emissions that can occur during operating
Scenario 2: 3.5% Sulfur Feedstock with all Flares and Dryers
Operational at Normal Capacity except for VP-3. During this period
each unit will be in steady state except for VP-3 which can be in
transitional state for up to three hours. During annual periods of
turnaround with less than 168 hours of outage, worst case scenarios
we assumed up to 5 separate periods of turnaround. For turnaround
periods occuring every fifth year, totaling less than 744 hours of
outage, worse case scenarios we assumed up to 10 separate periods of
turnaround.
---------------------------------------------------------------------------
The State of Louisiana compiled a statewide EI in accordance with
the CAA Amendments of 1990, LAC 33:III.918 and 919 (Recordkeeping and
Annual Reporting and Emissions Inventory). LDEQ chose the year 2018 as
the base year for its analyses as the most complete and representative
record of annual SO2 emissions because: (1) it was the most
recent periodic inventory year available; and (2) it was also the year
that the EPA designated the Evangeline Parish area as nonattainment for
the 2010 SO2 NAAQS. The 2018 baseline area source emissions
inventories were developed in accordance with the requirements of the
Air Emissions Reporting Requirements (AERR) rule.
A summary of the State's submitted emissions inventory is provided
in the following table:
Table 6--Evangeline Parish Nonattainment Area Emission Inventory--SO2 Point Source Emissions, Area, Mobile, and
Total SO2 Emissions
----------------------------------------------------------------------------------------------------------------
2018 Actual emissions 2029 Projected emissions
Category (tons/year) (tons/year)
----------------------------------------------------------------------------------------------------------------
Point--Cabot (no turnaround).............................. 11,069.91 662
Point--Cabot (annual <168 hours outage period)............ 11,069.91 848
Point--Cabot (every fifth year <744 hours turnaround 11,069.91 1,477
period)..................................................
----------------------------------------------------------------------------------------------------------------
The EPA agrees that the State's emissions inventories for point,
nonpoint, and mobile sources are appropriate because they have been
accumulated and reported in accordance with established methods and
criteria. The EPA proposes that the emissions inventory is
representative and satisfies the EI requirement.
B. RACM/RACT
CAA section 172(c)(1) requires states to adopt and submit all RACM,
including RACT, as needed to attain the standards as expeditiously as
practicable. Section 172(c)(6) requires the SIP to contain enforceable
emission limits and control measures necessary to provide for timely
attainment of the standard. The plan relies on ambient SO2
concentration reductions achieved by implementation of the limits
established in the AOC with the Cabot facility. The Cabot facility
plans to install post combustion controls to reduce SO2
emissions (lb/hr) from the facility as well as mandate explicit
operating parameters in order to ensure attainment in the area.
The control strategy at the Cabot facility incorporates post-
combustion flue gas desulfurization via controls for the MAIN stack by
requiring the installation of a wet gas scrubber (WGS). Furthermore,
the flares and dryer stacks (SDRY3, SDRY124, SFLR12, SFLR 3, and SFLR4)
shall only be operated in periods of planned outage of the WGS or
periods of turnaround while maintenance is being undertaken on the WGS
(MAIN stack), while maintaining compliance with specific parameters set
forth in the SIP.
The final emission limitations as included in the Administrative
Order on Consent are provided earlier in this document in section
II.E., Emission Limitations of this document. The Cabot facility is
required to complete construction and commissioning of the WGS and
comply with all requirements of the AOC by July 30, 2026. Furthermore,
the requirement to construct and operate a WGS is consistent with
requirements set forth in the 2013 carbon black consent decree entered
with Cabot. Louisiana provides in the SIP a discussion of the current
status of implementation and anticipated construction schedule to
[[Page 19446]]
support the compliance date. EPA concurs with the state that a July 30,
2026, compliance date is reasonable and consistent with the requirement
to attain the NAAQS as expeditiously as practicable but no later than
the December 16, 2029. Louisiana has provided modeling which
demonstrates that these measures for Cabot facility provide for timely
attainment and meet the RACM and RACT requirements. The EPA proposes
that the state has satisfied the requirements in section 172(c)(1) to
adopt and submit all RACM, including RACT, as needed to attain the
standard as expeditiously as practicable and in section 172(c)(6) to
include emission limits as necessary to attain the NAAQS.
C. New Source Review (NSR)
The EPA has approved both Louisiana's NNSR and Emission Reduction
Credits (ERC) banking programs. (LAC 33:111.504 was approved on
September 30, 2002; \22\ LAC 33:III.Chapter 6 was approved on September
27, 2002 (67 FR 60877)). Note that per a rule revision promulgated
November 20, 2012 (AQ 327), (See App. D to SIP), revisions to LDEQ's
ERC banking program (LAC 33:III.Chapter 6) were made such that
creditable SO2 reductions could be banked and traded as ERC.
No further revisions to LAC 33:III.504 or Chapter 6 are required to
implement the NNSR program in Evangeline Parish. These approved rules
provide for appropriate new source review for SO2 major
sources undergoing construction or major modification in Evangeline
Parish without need for modification of the approved rules. Therefore,
the EPA concludes that the SIP satisfies this CAA requirement.
---------------------------------------------------------------------------
\22\ See 67 FR 61270.
---------------------------------------------------------------------------
D. Reasonable Further Progress (RFP)
Section 171(1) of the CAA defines RFP as ``such annual incremental
reductions in emissions of the relevant air pollutant as are required
by [part D] or may reasonably be required by the [EPA] for the purpose
of ensuring attainment of the applicable [NAAQS] by the applicable
attainment date.'' For purposes of SO2, the EPA issued
guidance prescribing how states could satisfy this requirement when
developing their nonattainment SIPs.\23\ Since pollutants like
SO2 usually have a limited number of sources affecting areas
of air quality that are relatively well defined, and emissions control
measures for such sources generally provide significant and immediate
improvements in air quality, there is usually a single ``step'' between
pre-control nonattainment and post-control attainment. Therefore, due
to the discernible relationship between emissions and air quality, EPA
interprets RFP in the SO2 context as ``adherence to an
ambitious compliance schedule'' which ``ensures that affected sources
implement appropriate control measures as expeditiously as
practicable'' to ensure attainment by the applicable attainment
date.\24\
---------------------------------------------------------------------------
\23\ See ``Guidance for 1-Hour SO2 Nonattainment Area
SIP Submissions'', U.S. Environmental Protection Agency, Office of
Air Quality Planning and Standards, April 23, 2014, which can be
accessed at: https://www.epa.gov/sites/production/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf.
\24\ See General Preamble, 57 FR 13498, 13547 (April 16, 1992).
---------------------------------------------------------------------------
Section 172(c)(2) of the CAA requires the Evangeline Parish
Attainment Plan SIP provide for reasonable further progress towards
attainment. EPA has determined that once control requirements and
emissions limits have been implemented, these measures will provide for
attainment in the area. Cabot entered into an AOC that requires
compliance by July 30, 2026, and if finalized as a SIP revision, will
become federally enforceable. Louisiana provides in the SIP a
discussion of the current status of implementation and anticipated
construction schedule to support the compliance date. Therefore,
Louisiana concluded that its SIP submittal provides for RFP in
accordance with EPA's SO2 guidance and the Preamble. The EPA
finds that the SIP submittal satisfies the CAA requirements for RFP.
E. Contingency Measures
As discussed in our 2014 SO2 guidance, section 172(c)(9)
of the CAA defines contingency measures as specific measures to be
undertaken if the area fails to make RFP or fails to attain the NAAQS
by the applicable attainment date. Contingency measures are to become
effective without further action by the State or the EPA. These
contingency measures consist of other available control measures that
are not included in the control strategy for the nonattainment area
SIP. EPA guidance describes special features of SO2 planning
that influence the suitability of alternative means of addressing the
requirement in section 172(c)(9) for SO2 contingency
measures. Because SO2 control plans are based on what is
directly and quantifiably necessary emissions controls, any violations
of the NAAQS are likely related to source violations of a source's
permit or agreed order terms. Therefore, an appropriate means of
satisfying this requirement for SO2 is for the State to have
a comprehensive enforcement program that identifies sources of
violations of the SO2 NAAQS and undertakes an aggressive
follow-up for compliance and enforcement.
Louisiana's plan satisfies the contingency measure requirement with
this kind of comprehensive enforcement program and follow-up for
compliance. The EPA proposes to approve Louisiana's plan for meeting
the contingency measure requirement in this manner.
F. Conformity
Generally, as set forth in section 176(c) of the CAA, conformity
requires that actions by Federal agencies do not cause new air quality
violations, worsen existing violations, or delay timely attainment of
the relevant NAAQS. General conformity applies to Federal actions,
other than certain highway and transportation projects, if the action
takes place in a nonattainment area or maintenance area (i.e., an area
which submitted a maintenance plan that meets the requirements of
section 175A of the CAA and has been redesignated to attainment) for
ozone, particulate matter, nitrogen dioxide, carbon monoxide, lead, or
SO2. EPA's General Conformity Rule (40 CFR 93.150 to 93.165)
establishes the criteria and procedures for determining if a Federal
action conforms to the SIP. With respect to the 2010 SO2
NAAQS, Federal agencies are expected to continue to estimate emissions
for conformity analyses in the same manner as they estimated emissions
for conformity analyses under the previous NAAQS for SO2.
EPA's General Conformity Rule includes the basic requirement that a
Federal agency's general conformity analysis be based on the latest and
most accurate emission estimation techniques available (40 CFR
93.159(b)). When updated and improved emissions estimation techniques
become available, EPA expects the Federal agency to use these
techniques. EPA finds that the Evangeline Parish SO2
Attainment Plan SIP Revision submission would not interfere with
attainment of the NAAQS or worsen existing violations and therefore
meets these conformity requirements.
Transportation conformity determinations are not required in
SO2 nonattainment and maintenance areas. EPA concluded in
its 1993 transportation conformity rule that highway and transit
vehicles are not significant sources of SO2. Therefore,
transportation plans, transportation improvement programs and projects
are presumed to conform to applicable
[[Page 19447]]
implementation plans for SO2. (See 58 FR 3776, January 11,
1993.)
IV. Proposed Action
EPA is proposing to approve Louisiana's April 2, 2025, submission
as a SIP revision for attaining the 2010 1-hour SO2 NAAQS
for the Evangeline Parish nonattainment area. As part of this action,
EPA is also proposing to approve as a source-specific revision to the
SIP and incorporate by reference into the State's SIP, the
Administrative Order on Consent between LDEQ and Cabot, which provides
the enforceable control strategy for the Evangeline Parish area.
The SO2 nonattainment plan includes Louisiana's AD for
the Evangeline Parish SO2 nonattainment area. LDEQ
explicitly modeled air quality based on the Cabot facility's updated
emission limits; through that modeling, LDEQ provided sufficient
information that the revised limits at the Cabot facility would allow
the area to meet the standard. Therefore, EPA concludes that the
modeling in LDEQ' plan adequately demonstrates that the control
requirements that apply to relevant sources in the area, including the
one-hour SO2 emission limits for the Cabot facility, provide
for attainment in the area. This nonattainment plan also addresses
requirements for emission inventories, RACT/RACM, RFP, and contingency
measures. Louisiana has previously addressed requirements regarding
nonattainment area NSR. EPA has determined that Louisiana's
SO2 nonattainment plan meets the applicable requirements of
CAA sections 172, 179(d), 191, and 192. EPA is taking public comments
for thirty days following the publication of this proposed action in
the Federal Register. EPA will take these comments into consideration
in our final action.
V. Incorporation by Reference
In this action, we are proposing to include in a final rule
regulatory text that includes incorporation by reference. In accordance
with the requirements of 1 CFR 51.5, we are we are proposing to
incorporate by reference revisions to the Louisiana source-specific
requirements as described in section IV. of this document, Proposed
Action. We have made, and will continue to make, these documents
generally available electronically through www.regulations.gov (please
contact the person identified in the FOR FURTHER INFORMATION CONTACT
section of this preamble for more information).
VI. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the 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 proposes to approve 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 Order 12866 (58
FR 51735, October 4, 1993);
Is not subject to Executive Order 14192 (90 FR 9065,
February 6, 2025) because SIP actions are exempt from review 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 subject to Executive Order 13045 (62 FR 19885,
April 23, 1997) because it approves a state program;
Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001); and
Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the Clean Air Act.
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where the EPA or an Indian Tribe
has demonstrated that a Tribe has jurisdiction. In those areas of
Indian country, the proposed 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, Sulfur oxides.
Authority: 42 U.S.C. 7401 et seq.
Dated: April 30, 2025.
Walter Mason,
Regional Administrator, Region 6.
[FR Doc. 2025-08080 Filed 5-7-25; 8:45 am]
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