Document ID: EPA-R06-OAR-2017-0558-0043
Agency: epa
Document Type: Proposed Rule
Title: LA060.043 Air Quality State Implementation Plans; Approvals and Promulgations; Louisiana; Finding of Failure to Attain the Primary 2010 One-Hour Sulfur Dioxide Standard for the St. Bernard Parish, Louisiana, Nonattainment Area, Proposed rule, 6 pages
Posted Date: 2021-12-07T05:00Z

[Federal Register Volume 86, Number 232 (Tuesday, December 7, 2021)]
[Proposed Rules]
[Pages 69210-69215]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-26433]

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2017-0558; FRL-9308-01-R6]

Finding of Failure To Attain the Primary 2010 One-Hour Sulfur 
Dioxide Standard for the St. Bernard Parish, Louisiana Nonattainment 
Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
determine that the St. Bernard Parish sulfur dioxide (SO2) 
nonattainment area (``St. Bernard area'' or ``area'') failed to attain 
the primary 2010 one-hour SO2 national ambient air quality 
standard (NAAQS) under the Clean Air Act (CAA or the Act) by the 
applicable attainment date of October 4, 2018. This proposed 
determination is based upon review of compliance records for the area's 
primary SO2 source, the Rain CII Carbon, LLC (Rain) 
facility, in addition to dispersion modeling based on the allowable 
limits showing design values close to the SO2 NAAQS. If the 
EPA finalizes this determination as proposed, the State of Louisiana 
will be required to submit revisions to the Louisiana State 
Implementation Plan (SIP) that, among other elements, provide for 
expeditious attainment of the 2010 SO2 standard.

DATES: Comments must be received on or before January 6, 2022.

ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2017-0558, at https://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed. 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 the person 
identified in the FOR FURTHER INFORMATION CONTACT section. For the full 
EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit https://www.epa.gov/dockets/commenting-epa-dockets.
    Docket: The index to the docket for this action is available 
electronically at https://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). Publicly available docket materials are available 
electronically through https://www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Ms. Karolina Ruan Lei, EPA Region 6 
Office, SO2 and Regional Haze Section (R6-ARSH), 214-665-
7346, [email protected]. Out of an abundance of caution for 
members of the public and our staff, the EPA Region 6 office will be 
closed to the public to reduce the risk of transmitting COVID-19. We 
encourage the public to submit comments via https://www.regulations.gov, as there will be a delay in processing mail and no 
courier or hand deliveries will be accepted. Please call or email the 
contact listed above if you need alternative access to material indexed 
but not provided in the docket.

[[Page 69211]]

SUPPLEMENTARY INFORMATION: Throughout this document ``we,'' ``us,'' or 
``our'' means EPA.

Table of Contents

I. Background
    A. The 2010 SO2 NAAQS
    B. Designations and Attainment Dates for the 2010 SO2 
NAAQS
    C. Louisiana's Nonattainment SIP Revision
II. Proposed Determination
    A. Applicable Statutory and Regulatory Provisions
    B. Monitoring Network Considerations
    C. Data Considerations and Proposed Determination
    a. Monitor Data
    b. Modeling Data
    c. Record of Compliance
    d. EPA's Proposed Determination
III. Proposed Action
IV. Statutory and Executive Order Reviews

I. Background

A. The 2010 SO2 NAAQS

    Under section 109 of the Act, the EPA has established primary and 
secondary NAAQS for certain pervasive air pollutants (referred to as 
``criteria pollutants'') and conducts periodic reviews of the NAAQS to 
determine whether they should be revised or whether new NAAQS should be 
established. The primary NAAQS represent ambient air quality standards 
the attainment and maintenance of which the EPA has determined, 
including a margin of safety, are requisite to protect the public 
health. The secondary NAAQS represent ambient air quality standards the 
attainment and maintenance of which the EPA has determined are 
requisite to protect the public welfare from any known or anticipated 
adverse effects associated with the presence of such air pollutant in 
the ambient air.
    Under the CAA, the EPA must establish NAAQS for criteria 
pollutants, including SO2. SO2 is primarily 
released to the atmosphere through the burning of fossil fuels by power 
plants and other industrial facilities. SO2 is also emitted 
from industrial processes including metal extraction from ore and heavy 
equipment that burn fuel with a high sulfur content. Short-term 
exposure to SO2 can damage the human respiratory system and 
increase breathing difficulties. Small children and people with 
respiratory conditions, such as asthma, are more sensitive to the 
effects of SO2. Sulfur oxides at high concentrations in 
ambient air can also react with compounds to form small particulates 
that can penetrate deeply into the lungs and cause health problems.
    The EPA first established primary SO2 standards in 1971 
at 0.14 parts per million (ppm) over a 24-hour averaging period and 0.3 
ppm over an annual averaging period.\1\ In June 2010, the EPA revised 
the NAAQS for SO2 to provide increased protection of public 
health, providing for revocation of the 1971 primary annual and 24-hour 
SO2 standards for most areas of the country following area 
designations under the new NAAQS.\2\ The primary 2010 SO2 
NAAQS is 75 parts per billion (ppb), or 0.075 ppm, over a one-hour 
averaging period.\3\ A violation of the 2010 one-hour SO2 
NAAQS occurs when the annual 99th percentile of ambient daily maximum 
one-hour average SO2 concentrations, averaged over a 3-year 
period, exceeds 75 ppb.\4\
---------------------------------------------------------------------------

    \1\ See 36 FR 8186 (April 30, 1971).
    \2\ See 40 CFR 50.4(e).
    \3\ See 75 FR 35520 (June 22, 2010).
    \4\ See 40 CFR 50.17.
---------------------------------------------------------------------------

B. Designations and Attainment Dates for the 2010 SO2 NAAQS

    Following promulgation of any new or revised NAAQS, the EPA is 
required by CAA section 107(d) to designate areas throughout the nation 
as attaining or not attaining the NAAQS. On August 5, 2013, the EPA 
finalized its first round of designations for the 2010 primary 
SO2 NAAQS.\5\ In this 2013 action, the EPA designated 29 
areas in 16 states as nonattainment for the 2010 SO2 NAAQS, 
including the St. Bernard area in Louisiana. The EPA designated the St. 
Bernard area nonattainment based on certified monitoring data for years 
2009 through 2011.\6\ The EPA's initial round of designations for the 
2010 SO2 NAAQS including the St. Bernard area became 
effective on October 4, 2013. Pursuant to CAA section 192(a), the 
maximum attainment date for the St. Bernard area was October 4, 2018, 
five years after the effective date of the final action designating the 
area as nonattainment for the 2010 SO2 NAAQS.
---------------------------------------------------------------------------

    \5\ See 78 FR 47191 (August 5, 2013).
    \6\ See 78 FR 47191, codified at 40 CFR part 81, subpart C.
---------------------------------------------------------------------------

C. Louisiana's Nonattainment SIP Revision

    Section 172(c) of the CAA lists the required components of a 
nonattainment plan submittal. In addition to an attainment 
demonstration, the nonattainment plan addresses the requirements for 
meeting reasonable further progress (RFP) toward attainment of the 
NAAQS, implementation of reasonably available control measures and 
reasonably available control technology (RACM/RACT), base-year and 
projection-year emission inventories, a new source review permit 
program, enforceable emissions limitations and control measures, and 
contingency measures. The attainment demonstration includes a modeling 
analysis showing that the enforceable emissions limitations and other 
control measures taken by the state will provide for RFP and 
expeditious attainment of the NAAQS (section 172(c)(2), (4), (6), and 
(7)).
    On November 9, 2017, the Louisiana Department of Environmental 
Quality (LDEQ) submitted a nonattainment area SIP for the St. Bernard 
Parish area. On February 8, 2018, LDEQ submitted a letter to the EPA, 
accompanied by an Administrative Order on Consent (AOC), dated February 
2, 2018, executed between LDEQ and the Rain CII Carbon, LLC (Rain) 
facility, that included new emissions limits for the Rain facility's 
cold stack and hot stack/pyroscrubber, as well as monitoring, testing 
and recordkeeping requirements. LDEQ submitted this as a source 
specific SIP revision and supplement to the 2017 nonattainment area 
SIP. Rain is a coke calcining operation that includes a waste heat 
recovery boiler. During normal operations, the exhaust from the 
calcining operation is routed through the recovery boiler and then 
through a scrubber and finally to the atmosphere through what is termed 
the ``cold stack.'' During start up and times when the recovery boiler 
is down, emissions are routed to the atmosphere through what is known 
as the ``hot stack.'' The modeling covers three operation scenarios: 
Cold stack only operation, hot stack only operation, and a transitional 
period with emissions through both stacks. The transition period from 
hot stack to cold stack occurs in a phased approach, gradually routing 
more and more exhaust to the cold stack from the hot stack until all 
exhaust is routed to the cold stack. The emission limits in the AOC 
included all operation regimes at the facility, with differing emission 
limits depending on the stage of operation defined by a minimum or 
range of flowrates and stack temperatures of the cold and hot stacks. 
On April 19, 2018, we published a proposed rulemaking action to approve 
the 2010 SO2 Primary NAAQS Nonattainment Area SIP revision 
for St. Bernard Parish.\7\ The April 19, 2018 action proposed approval 
of the following CAA SIP elements: The attainment demonstration for the 
SO2 NAAQS; enforceable emissions limits including the AOC 
dated February 2, 2018, for the Rain facility; RFP plan; RACM and RACT 
demonstrations; emission inventories; and contingency

[[Page 69212]]

measures. We also proposed to find that the State had demonstrated that 
its current nonattainment new source review (NNSR) program covered the 
2010 one-hour SO2 NAAQS; therefore, no revision to the SIP 
was required for the NNSR element.
---------------------------------------------------------------------------

    \7\ See 83 FR 17349 (April 19, 2018).
---------------------------------------------------------------------------

    After the close of the public comment period to the April 19, 2018 
proposal, the LDEQ submitted additional information to EPA on August 
24, 2018.\8\ The additional information was submitted to EPA partly in 
response to a public comment that expressed concern that Rain would 
need to modify the February 2018 AOC entered between Rain and LDEQ as 
Rain did not believe that it could meet the limits set forth in the AOC 
without an additional extension to the compliance dates.\9\ In response 
to the comment, and in order to determine feasible emission limits for 
operations during transitions from exhaust flow through the hot stack 
to the cold stack, LDEQ granted an extension of the deadline of the 
February 2018 AOC on April 27, 2018.\10\
---------------------------------------------------------------------------

    \8\ See letter from Secretary Chuck Carr Brown to Anne Idsal, 
August 24, 2018, St. Bernard 2008 Sulfur Dioxide State 
Implementation Plan Supplemental Information and Executed 
Administrative Order on Consent (AOC) included in the docket for 
this action.
    \9\ See the April 24, 2018 letter (in the docket to this action) 
from Senator Cassidy to EPA that referred to Rain's need to modify 
the February 2, 2018 AOC.
    \10\ See April 27, 2018 Letter from Secretary Chuck Carr Brown 
to Rain in the docket for this action.
---------------------------------------------------------------------------

    On August 2, 2018, Rain and LDEQ revised their existing AOC. On 
August 24, 2018, LDEQ supplemented their SIP submittal with the revised 
AOC and additional modeling analysis. On October 9, 2018, LDEQ again 
supplemented their SIP with an updated modeling analysis. The revised 
AOC \11\ and the October 9, 2018 modeling files served as a supplement 
to the November 9, 2017 and February 8, 2018 SIP submittals and 
incorporated certain additional AOC revisions (dated August 2, 2018) 
and supporting modeling into the 2010 SO2 NAAQS 
Nonattainment Area SIP revision for St. Bernard Parish. On February 8, 
2019, EPA proposed to approve LDEQ's August 24, 2018 and October 9, 
2018 submittals as a supplement to the prior SIP submittals (84 FR 
2801). Please refer to EPA's April 19, 2018 proposed approval and 
February 8, 2019 supplemental notice of proposed rulemaking.
---------------------------------------------------------------------------

    \11\ AOC signed by LDEQ and Rain on August 2, 2018, and 
submitted to EPA on August 24, 2018.
---------------------------------------------------------------------------

    In a May 29, 2019 final action, EPA approved the nonattainment SIP 
for the St. Bernard area (84 FR 24712). For additional information 
concerning the St. Bernard Parish, Louisiana nonattainment SIP revision 
see docket ID No. EPA-R06-OAR-2017-0558 available at https://www.regulations.gov.

II. Proposed Determination

A. Applicable Statutory and Regulatory Provisions

    Section 179(c)(1) of the Act requires the EPA to determine whether 
a nonattainment area has achieved an applicable attainment date based 
on the area's air quality as of the attainment date. A determination of 
whether an area's air quality meets applicable standards is generally 
based upon the most recent three years of complete, quality-assured 
data gathered at established state and local air monitoring stations 
(SLAMS) in a nonattainment area and entered into the EPA's Air Quality 
System (AQS) database.\12\ Data from ambient air monitors operated by 
state and local agencies in compliance with the EPA monitoring 
requirements must be submitted to AQS.\13\ Monitoring agencies annually 
certify that these data are accurate to the best of their 
knowledge.\14\ All SO2 data are reviewed to determine the 
area's air quality status in accordance with 40 CFR part 50, Appendix 
T.
---------------------------------------------------------------------------

    \12\ AQS is the EPA's repository of ambient air quality data.
    \13\ See 40 CFR 58.16.
    \14\ See 40 CFR 58.15.
---------------------------------------------------------------------------

    Under EPA regulations in 40 CFR 50.17 and in accordance with 40 CFR 
part 50 Appendix T, the 2010 one-hour annual SO2 standard is 
met when the design value is less than or equal to 75 ppb. Design 
values are calculated by computing the three-year average of the annual 
99th percentile daily maximum one-hour average concentrations.\15\ An 
SO2 one-hour primary standard design value is valid if it 
encompasses three consecutive calendar years of complete data. A year 
is considered complete when all four quarters are complete, and a 
quarter is complete when at least 75 percent of the sampling days are 
complete. A sampling day is considered complete if 75 percent of the 
hourly concentration values are reported; this includes data affected 
by exceptional events that have been approved for exclusion by the 
Administrator.\16\
---------------------------------------------------------------------------

    \15\ As defined in 40 CFR part 50, Appendix T section 1(c), 
daily maximum 1-hour values refer to the maximum one-hour 
SO2 concentration values measured from midnight to 
midnight that are used in the NAAQS computations.
    \16\ See 40 CFR part 50, Appendix T sections 1(c), 3(b), 4(c), 
and 5(a).
---------------------------------------------------------------------------

    We note that when determining the attainment status of 
SO2 nonattainment areas, including when making 
determinations of attainment by the attainment date, in addition to 
ambient monitoring data, the EPA may also consider air quality 
dispersion modeling and/or a demonstration that the control strategy in 
the SIP has been fully implemented.\17\ With regard to the use of 
monitoring data for such determinations, the EPA's SO2 
Nonattainment Area Guidance specifically notes that ``[i]f the EPA 
determines that the air quality monitors located in the affected area 
are located in the area of maximum concentration, the EPA may be able 
to use the data from these monitors to make the determination of 
attainment without the use of air quality modeling data.'' If there are 
no air quality monitors located in the affected area, or there are air 
quality monitors located in the area, but analyses show that none of 
the monitors are located in the area of maximum concentration,\18\ then 
air quality dispersion modeling will generally be needed to estimate 
SO2 concentrations in the area. In this case, as discussed 
in our proposed actions on the St. Bernard nonattainment plan and 
Technical Support Documents (TSDs),\19\ the monitors are not located in 
the area of expected maximum concentration, meaning we-must also 
consider the available modeling data in determining whether the area 
attained by the attainment date. When relying on a modeling 
demonstration based on allowable emissions for purposes of determining 
attainment by the attainment date, the EPA looks to whether the 
emission limit or limits were adopted and whether the relevant source 
or sources were complying with those modeled limits prior to the 
attainment date. That is, when determining attainment by the attainment 
date using air quality modeling of allowable emissions, EPA looks to 
whether the state has demonstrated that the control strategy in the SIP 
has been fully implemented (compliance records demonstrating that the 
control measures have been implemented as required by the approved 
SIP). This is necessary because a modeling demonstration based on 
allowable emissions is not itself sufficient since, without the 
supporting emissions information

[[Page 69213]]

reflected in the control strategy, there would be no way to confirm 
that the actual emissions were below the modeled limits within the 
period under review.
---------------------------------------------------------------------------

    \17\ EPA, April 23, 2014 Guidance for 1-Hour SO2 
Nonattainment Area SIP Submissions (``SO2 Nonattainment 
Area Guidance''), page 49.
    \18\ See section VIII.A of the SO2 Nonattainment Area 
Guidance
    \19\ See EPA's April 19, 2018 proposed approval (83 FR 17349), 
February 8, 2019 supplemental notice of proposed rulemaking (84 FR 
2801) and EPA's Technical Support Documents, available in the docket 
for this action.
---------------------------------------------------------------------------

B. Monitoring Network Considerations

    Section 110(a)(2)(B)(i) of the CAA requires states to establish and 
operate air monitoring networks to compile data on ambient air quality 
for all criteria pollutants. The EPA's monitoring requirements are 
specified by regulation in 40 CFR part 58. These requirements are 
applicable to state, and where delegated, local air monitoring agencies 
that operate criteria pollutant monitors. In section 4.5 of Appendix D 
to 40 CFR part 58, the EPA specifies the minimum requirements for 
SO2 monitoring sites to be classified as state or local air 
monitoring stations (SLAMS). SLAMS produce data that are eligible for 
comparison with the NAAQS, and therefore, the monitor must be an 
approved federal reference method (FRM) or federal equivalent method 
(FEM), per section 2 of Appendix C to 40 CFR part 58. In St. Bernard 
Parish, LDEQ operates a SLAMS monitor at Chalmette-Vista (EPA Site ID 
22-087-0007, 24 E Chalmette Circle). In addition, LDEQ operates a 
special purpose monitor (SPM) at Meraux (EPA Site ID 22-087-0004, 4101 
Mistrot Drive).

C. Data Considerations and Proposed Determination

a. Monitor Data
    Under 40 CFR 58.15, monitoring agencies must certify, on an annual 
basis, data collected at all SLAMS by FRM, FEM, and special purpose 
monitors (SPMs) that meet EPA quality assurance requirements. In doing 
so, monitoring agencies must certify that the previous year of ambient 
concentration and quality assurance data are completely submitted to 
AQS and that the ambient concentration data are accurate to the best of 
their knowledge.
    The one-hour SO2 design values at Chalmette Vista and 
Meraux monitoring sites within the St. Bernard area for the 2013-2020 
period are shown below.

   Table 1--2013-2020 One-Hour Design Values for the St. Bernard Area
------------------------------------------------------------------------
                                                      Chalmette
                                                        vista     Meraux
                       Years                           design     design
                                                        value     value
                                                        (ppb)     (ppb)
------------------------------------------------------------------------
2013-2015..........................................         114       19
2014-2016..........................................          82       16
2015-2017..........................................          73       13
2016-2018..........................................          59       10
2017-2019..........................................          44        7
2018-2020..........................................          42        8
------------------------------------------------------------------------

    The attainment date for the area was October 4, 2018. In order for 
the EPA to determine that the area attained by the October 4, 2018 
attainment date based solely on air quality monitoring data, the design 
value based upon complete, quality-assured monitored air quality data 
from three consecutive years (2015-2017) at each eligible monitoring 
site must be equal to or less than 75 ppb for the one-hour standard, 
and air quality modeling would need to show that there was an air 
quality monitor located in the area of maximum concentration.
    Although the one-hour SO2 design values at the Chalmette 
Vista monitoring site located within the St. Bernard area show a 
downward trend of SO2 concentrations less than 75 ppb for 
the one-hour standard beginning with the 2015-2017 design value, this 
monitor is not located in the area of maximum predicted concentration, 
and therefore cannot be used, on its own, to determine that the St. 
Bernard Parish area attained by the attainment date.
b. Modeling Data
    LDEQ and Rain developed the one-hour SO2 emission limits 
contained in the August 2, 2018 AOC to ensure compliance with the 
SO2 NAAQS. The emission limits in the AOC were effective 
August 2, 2018. The LDEQ undertook an additional modeling analysis 
which also incorporated the amended stack parameters and utilized more 
recent allowable emission rates from other contributing sources, an 
expanded receptor grid, and covered all operating scenarios. The 
additional modeling used the most recent version of AERMOD and followed 
EPA's guidance for SIP modeling for SO2.\20\ The analysis 
included modeling allowable emissions and stack parameters for 
different operational stages at the Rain facility, including stand-
alone operations for the waste heat boiler and the pyroscrubber as well 
as transition stages between the two modes of operation; a summary of 
the results is given in Table 2. The modeling demonstration approved in 
the nonattainment SIP demonstrates that compliance with the emission 
limits and required stack parameters in the AOC provide for attainment, 
with predicted SO2 concentrations near (just below) the 
NAAQS if the emission limits and stack parameters are met.\21\ 
Additional, more detailed discussion of the State's modeling is 
contained in the TSD for the EPA's proposed Approval and Promulgation 
of Implementation Plans; Louisiana Attainment Demonstration for the St. 
Bernard Parish 2010 SO2 Primary National Ambient Air Quality 
Standard Nonattainment Area published on February 8, 2019 (84 FR 2801).
---------------------------------------------------------------------------

    \20\ See Appendix A, page A-1 of the SO2 
Nonattainment Area Guidance.
    \21\ See Table 2.

 Table 2--Summary of LDEQ Supplemental Modeling Results for the St. Bernard Parish SIP Using the Emission Limits
                                        and Stack Parameters From the AOC
----------------------------------------------------------------------------------------------------------------
                     Operational stage                                       Model design value
----------------------------------------------------------------------------------------------------------------
Waste Heat Boiler Stack Alone.............................  190.8 [micro]g/m\3\ (72.9 ppb).
Pyroscrubber Stack Alone..................................  176.6 [micro]g/m\3\ (67.4 ppb).
Transition between Pyroscrubber Stack to the Waste Heat     185.6 [micro]g/m\3\ (70.9 ppb).
 Boiler Stack (transitional stage with maximum design
 value).
----------------------------------------------------------------------------------------------------------------

c. Record of Compliance
    As noted, when relying on modeling of allowable emissions to 
support a determination of whether an area has attained by its 
attainment date, the EPA must also look at whether the control strategy 
in the SIP has been fully implemented and whether the relevant sources 
in an area are complying with the emission limits and stack parameters 
required in the SIP. As discussed above, the modeling, based on the 
August 2, 2018 AOC limits, shows attainment of the NAAQS with maximum 
modeled concentrations just below the 75 ppb standard. Emissions higher 
than modeled limits and/or

[[Page 69214]]

actual stack parameters (flowrate or temperature) below the modeled 
stack parameters can result in downwind concentrations higher than 
those modeled. We note that Rain's compliance records, Title V 
deviation reports, and annual stack tests since August 2, 2018 (the 
effective date of AOC) demonstrate a pattern of difficulty complying 
with the SIP emission limits at all times and difficulty in estimating 
emissions and flowrates from the pyroscrubber to demonstrate 
compliance.\22\ During the 9-week period between when the AOC limits 
became effective (August 2, 2018) and the attainment date (October 4, 
2018), Rain reported that deviations occurred on 7 separate days for a 
total duration of 27.2 hours (25.2 hours due to calculated pyroscrubber 
flowrates less than the AOC requirements, and 2 hours when cold stack 
emissions exceeded the AOC emission limits).\23\ Rain has since 
identified the need to revise the limits and potentially adjust the 
methodology used to estimate emissions and flowrates in the 
pyroscrubber that are contained in the AOC. In March of 2019, Rain 
conducted the first annual stack test as required by the August 2, 2018 
AOC.\24\ The 2019 stack test report found that ``the AOC hot stack 
equation underestimates hot stack emissions during most of the 
transition from hot stack to cold stack'' and ``[d]uring no hour did 
the combined flue gas flow and temperature meet the description of any 
transition stage.'' The report then states ``the AOC limits and 
conditions do not reflect actual emissions conditions and it is 
difficult to identify the appropriate transition stage,'' before 
recommending that the August 2018 AOC's flue gas flow rates, 
temperatures, and emissions limits for transitions stages 1, 2, and 3 
be replaced with new conditions. Generally, one stack test may not be 
determinative, but the EPA believes that it is reasonable to conclude 
that the problems identified in the 2019 stack test were significant 
and, in conjunction with the 2018 semiannual monitoring report 
violations, indicative that the facility not only failed to meet the 
AOC requirements during the two days of the stack test, but likely 
failed to meet the 2018 AOC's transition stage operational requirements 
during the period between the effective date of the AOC and the 
attainment date.
---------------------------------------------------------------------------

    \22\ See deviations listed in semiannual monitoring reports for 
2018. We also note as dicta that the source continued to experience 
deviations in 2019 and 2020. The semiannual monitoring reports for 
2018, 2019, and 2020 as well as the 2019 and 2020 stack test reports 
are available in the docket for this action.
    \23\ See deviations listed in semiannual monitoring report for 
July 1-December 31, 2018.
    \24\ Annual stack tests are a requirement of the August 2, 2018 
AOC. The 2019 stack test was the first annual stack test performed 
pursuant to this requirement.
---------------------------------------------------------------------------

    The EPA also notes that the semiannual monitoring report for 
January through June 2020, while not the basis or rational for our 
decision making, includes additional deviations indicating that the 
facility continued to have difficulty complying with the limits in the 
SIP after the attainment date had passed. The report further states 
that: ``Rain continues to analyze this and similar deviations to 
identify a corrective action. The permit requirements do not match 
actual start-up conditions. Rain is in negotiations with EPA and LDEQ 
to revise the permit requirements to reflect actual start-up 
conditions.''
    From the available information, EPA cannot determine with certainty 
that the area attained the NAAQS as the emissions and stack parameters 
at times fall outside the limits and conditions modeled in the approved 
attainment demonstration. The noted violations of the permit limits or 
underestimated emissions may have resulted in violations of the one-
hour SO2 NAAQS in areas other than the monitored location. 
Furthermore, the data demonstrates a clear need for development of a 
new attainment SIP with revised limits that better align with the 
source's operations and modeling to demonstrate attainment.

d. EPA's Proposed Determination

    Based on our review of the monitor, modeling and compliance data, 
EPA proposes to find that the St. Bernard area did not attain the 2010 
one-hour SO2 NAAQS by the October 4, 2018 attainment date. 
The modeling data demonstrates that the emission limits and stack 
parameters in the AOC required of the Rain facility were necessary for 
the St. Bernard area to attain the standard. However, review of Rain's 
compliance record demonstrates that emissions have exceeded those 
limits, and stack temperatures and flowrates have not met the necessary 
parameters to demonstrate attainment in the St. Bernard area. As 
described in the previous section, Rain reported deviations during the 
period between the effective date of the limits and the attainment 
date. Rain has also reported underestimation of emissions from the hot 
stack when comparing estimated emissions to the measured emissions 
during the 2019 stack test indicative that Rain has failed to meet the 
AOC limits since the effective date. We also note, without relying 
upon, that Rain continued to report deviations in additional stack 
tests and deviation reports from 2018, 2019, and 2020. Under CAA 
section 179(d)(2), if the EPA determines that an area did not attain 
the NAAQS by the applicable deadline, the responsible air agency has up 
to 12 months from the effective date of the determination to submit a 
revised SIP for the area demonstrating attainment and containing any 
additional measures that the EPA may reasonably prescribe that can be 
feasibly implemented in the area in light of technological 
achievability, costs, and any non-air quality and other air quality-
related health and environmental impacts as required. According to CAA 
section 179(d)(3), this revised SIP is to achieve attainment of the 
one-hour SO2 NAAQS as expeditiously as practicable, but no 
later than 5 years from the effective date of the area's failure to 
attain (i.e., 5 years after the EPA publishes a final action in the 
Federal Register determining that the nonattainment area failed to 
attain the SO2 NAAQS). In addition to triggering 
requirements for a new SIP submittal, a final determination that a 
nonattainment area failed to attain the NAAQS by the attainment date 
would trigger the implementation of contingency measures adopted under 
172(c)(9).

III. Proposed Action

    Under CAA section 179(d)(2), the EPA proposes to determine that the 
St. Bernard Parish SO2 nonattainment area has failed to 
attain the 2010 one-hour SO2 standard of 75 ppb by the 
applicable attainment date of October 4, 2018. This determination is 
based upon review of (1) the state's air quality modeling 
demonstration, which showed the emission limits and stack parameters 
required at Rain, the primary source of SO2 emission in the 
area, that were necessary to provide for the area's attainment and (2) 
Rain's available compliance records. The state's dispersion modeling, 
which was based on the allowable limits in the AOC, showed that with 
compliance with the limits, modeled design values were close to the 
SO2 NAAQS. Rain has demonstrated a pattern of difficulty 
meeting its federally enforceable applicable SO2 emission 
limits and stack parameters (memorialized in its Title V permit and the 
AOC). Emissions have exceeded those limits, and stack temperatures and 
flowrates have not met the necessary parameters to demonstrate 
attainment in the St. Bernard area, including the deviations noted 
above during the period between the effective date of the limits and 
the attainment date and reported underestimation of emissions from the

[[Page 69215]]

hot stack. If finalized as proposed, the State of Louisiana would be 
required under CAA section 179(d) to submit revisions to the SIP for 
the St. Bernard area. The required SIP revision for the area must, 
among other elements, demonstrate expeditious attainment of the 
SO2 standard within the time period prescribed by CAA 
section 179(d) and such additional measures as the Administrator may 
reasonably prescribe that can be feasibly implemented in the area in 
light of technological achievability, costs, and any non-air quality 
and other air quality-related health and environmental impacts. If 
finalized as proposed, the SIP revisions required under CAA section 
179(d) would be due for submittal to the EPA no later than one year 
after the publication date of the final action.

IV. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders 
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review, and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and therefore 
was not submitted to the Office of Management and Budget (OMB) for 
review.

B. Paperwork Reduction Act (PRA)

    This action does not impose an information collection burden under 
the provisions of the PRA because it does not contain any information 
collection activities.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. This 
proposed action, if finalized, would require the state to adopt and 
submit SIP revisions to satisfy CAA requirements and would not itself 
directly regulate any small entities.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandate of $100 million 
or more, as described in UMRA (2 U.S.C. 1531-1538) and does not 
significantly or uniquely affect small governments. This action itself 
imposes no enforceable duty on any state, local, or tribal governments, 
or the private sector. This action proposes to determine that the St. 
Bernard Parish SO2 nonattainment area failed to attain the 
SO2 NAAQS by the applicable attainment dates. If finalized, 
this determination would trigger existing statutory timeframes for the 
State to submit SIP revisions. Such a determination in and of itself 
does not impose any federal intergovernmental mandate.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

F. Executive Order 13175, Consultation and Coordination With Indian 
Tribal Governments

    This action does not have tribal implications as specified in 
Executive Order 13175. The proposed finding of failure to attain the 
SO2 NAAQS does not apply to tribal areas, and the proposed 
rule would not impose a burden on Indian reservation lands or other 
areas where the EPA or an Indian tribe has demonstrated that a tribe 
has jurisdiction within the St. Bernard Parish SO2 
nonattainment area. Thus, this 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.

G. Executive Order 13045, Protection of Children From Environmental 
Health Risks and Safety Risks

    The EPA interprets Executive Order 13045 as applying only to those 
regulatory actions that concern environmental health or safety risks 
that the EPA has reason to believe may disproportionately affect 
children, per the definition of ``covered regulatory action'' in 
section 2-202 of the Executive Order. This proposed action is not 
subject to Executive Order 13045 because the effect of this proposed 
action, if finalized, would be to trigger additional planning 
requirements under the CAA. This proposed action does not establish an 
environmental standard intended to mitigate health or safety risks.

H. Executive Order 13211, Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This proposed rule is not subject to Executive Order 13211, because 
it is not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act (NTTAA)

    This rulemaking does not involve technical standards.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    The EPA believes that this action does not have disproportionately 
high and adverse human health or environmental effects on minority 
populations, low-income populations and/or indigenous peoples, as 
specified in Executive Order 12898 (59 FR 7629, February 16, 1994). The 
effect of this proposed action, if finalized, would be to trigger 
additional planning requirements under the CAA.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Pollution, Reporting and 
recordkeeping requirements, Sulfur dioxide.

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

    Dated: December 1, 2021.
David Gray,
Acting Regional Administrator, Region 6.
[FR Doc. 2021-26433 Filed 12-6-21; 8:45 am]
BILLING CODE 6560-50-P