[Federal Register Volume 89, Number 170 (Tuesday, September 3, 2024)]
[Proposed Rules]
[Pages 71230-71237]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-19599]



[[Page 71230]]

=======================================================================
-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2020-0434; FRL-12215-01-R6]


Determination of Attainment by the Attainment Date for the 2010 
1-Hour Primary Sulfur Dioxide National Ambient Air Quality Standard; 
Texas; Freestone-Anderson and Titus Counties

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: Pursuant to the Federal Clean Air Act (CAA or the Act), the 
Environmental Protection Agency (EPA) is proposing to determine that 
the sulfur dioxide (SO2) nonattainment area (NAA) in 
Freestone and Anderson Counties and the SO2 NAA in Titus 
County have each attained the 2010 1-hour primary SO2 
national ambient air quality standard (NAAQS) by the applicable 
attainment date of January 12, 2022. This determination is based on 
primary source shutdowns, available ambient air quality monitoring data 
from the 2019-2021 monitoring period, relevant modeling analysis, and 
additional emissions inventory information. This action, if finalized, 
will address the EPA's obligation under CAA section 179(c) to determine 
whether the Freestone-Anderson and Titus SO2 NAAs attained 
the 2010 1-hour primary SO2 NAAQS by the statutory 
attainment date of January 12, 2022, for each area.

DATES: Written comments must be received on or before October 3, 2024.

ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2020-0434, at https://www.regulations.gov or via email to 
[email protected]. 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 James E. Grady, (214) 
665-6745, [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: James E. Grady, EPA Region 6 Office, 
Regional Haze and SO2 Section, 1201 Elm Street, Suite 500, 
Dallas, TX 72570, 214-665-6745; [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 ``we,'' ``us,'' or 
``our'' mean the EPA.

I. Background

A. The 2010 1-Hour Primary SO2 NAAQS

    Under section 109 of the CAA, 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 
that the EPA has determined are requisite to protect the public health, 
while the secondary NAAQS represent ambient air quality standards that 
the EPA has determined are requisite to protect the public welfare from 
any known or anticipated adverse effects associated with the presence 
of such an air pollutant in the ambient air.
    Under the CAA, the EPA must establish a NAAQS for SO2, 
which 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 burns 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 (fine particulate matter or PM2.5) that 
can penetrate deeply into the lungs and cause acute health problems 
and/or chronic diseases. The EPA first established primary 
SO2 standards in 1971 at 140 parts per billion (ppb) over a 
24-hour averaging period and at 30 ppb over an annual averaging 
period.\1\
---------------------------------------------------------------------------

    \1\ 36 FR 8186 (April 30, 1971).
---------------------------------------------------------------------------

    On June 22, 2010, the EPA published in the Federal Register a 
strengthened, primary 1-hour SO2 NAAQS, establishing a new 
standard at a level of 75 ppb, based on the 3-year average of the 
annual 99th percentile of daily maximum 1-hour average concentrations 
of SO2.\2\ The revised SO2 NAAQS provides 
increased protection of public health. Along with revision of the 
SO2 NAAQS, EPA revoked the 1971 primary annual and 24-hour 
SO2 standards for most areas of the country following area 
designations under the new NAAQS.
---------------------------------------------------------------------------

    \2\ 75 FR 35520.
---------------------------------------------------------------------------

B. Designations, Classifications, and Attainment Dates for the 2010 SO2 
NAAQS

    Following promulgation of a new or revised NAAQS, the EPA is 
required to designate all areas of the country as either 
``attainment,'' ``nonattainment,'' or ``unclassifiable,'' pursuant to 
CAA section 107(d)(1). On August 5, 2013, the EPA finalized its first 
round of designations for the 2010 1-hour primary SO2 
NAAQS.\3\ In that 2013 action, the EPA designated 29 areas in 16 states 
as nonattainment for the 2010 1-hour primary SO2 NAAQS based 
on air quality monitoring data. Following the first round of 
designations, EPA entered into a March 2, 2015, Consent Decree \4\ 
which required the EPA to complete the remaining area designations by 
three specific deadlines according to a court-ordered schedule. On July 
12, 2016, the EPA finalized its second round of initial designations 
under the 2010 1-hour primary SO2 NAAQS, designating an 
additional four areas as nonattainment, effective September 12, 
2016.\5\ On December 13, 2016 (effective January 12, 2017), EPA 
finalized a supplement to the July 12, 2016, second round final action, 
designating three more areas in Texas as nonattainment for the 2010 1-
hour primary SO2 NAAQS.\6\ Included in that

[[Page 71231]]

supplement to the second round of designations was one area in 
Freestone and Anderson Counties and one area in Titus County. These 
designations were based on consideration of the data available at the 
time of designations, including air quality modeling. Pursuant to 
section 192(a) of the CAA, the attainment dates for the Freestone-
Anderson and Titus NAAs were both no later than 5 years after the 
effective date of initial designation, or January 12, 2022.
---------------------------------------------------------------------------

    \3\ 78 FR 47191 (August 5, 2013).
    \4\ Mar. 02, 2015, Consent Decree; Sierra Club and Natural 
Resources Defense Council v. EPA, Case No. 3:13-cv-3953-SI (N.D. 
Cal.).
    \5\ 81 FR 45039 (July 12, 2016).
    \6\ 81 FR 89870 (December 13, 2016).
---------------------------------------------------------------------------

    CAA section 191(a) requires states that contain an area designated 
nonattainment for the 2010 1-hour primary SO2 NAAQS to 
develop and submit a nonattainment area (NAA) State Implementation Plan 
(SIP) to the EPA within 18 months of the effective date of an area's 
designation as nonattainment (i.e., by July 12, 2018). For 
SO2, a NAA SIP (also referred to as an attainment plan) must 
meet the requirements of CAA sections 110 and 172(c), and 191-192, and 
provide for attainment of the NAAQS by the applicable statutory 
attainment date, or no later than 5 years from the effective date of 
designation (i.e., by January 12, 2022).
    When a NAA is attaining the 2010 1-hour primary SO2 
NAAQS based on the most recent available data, the EPA may issue a 
Clean Data Determination (CDD), suspending certain NAA planning 
requirements. The EPA issued a CDD for the Freestone-Anderson and Titus 
NAAs based on available monitoring data, emissions data, and air 
quality modeling via a final rule published on May 14, 2021 (effective 
June 14, 2021).\7\ A CDD does not alter the nonattainment designations 
for these areas. For the EPA to redesignate these areas to attainment, 
the state must submit, and the EPA must approve, a redesignation 
request for these NAAs that meets the requirements of CAA section 
107(d)(3). On March 3, 2022, Texas submitted a request to EPA to 
redesignate the Freestone-Anderson and Titus NAAs to attainment for the 
2010 1-hour SO2 NAAQS, and accompanying maintenance plans 
for the two areas. EPA is currently reviewing Texas' redesignation 
submission.
---------------------------------------------------------------------------

    \7\ 86 FR 26401 (May 14, 2021).
---------------------------------------------------------------------------

C. EPA Determination of Attainment by the Attainment Date

    Section 179(c)(1) of the CAA requires the EPA to determine whether 
a NAA attained an applicable standard by the applicable statutory 
attainment date based on the area's air quality as of the attainment 
date. The EPA is to issue this determination within 6 months of the 
attainment date. Thus, the EPA had a mandatory duty under CAA section 
179(c) to determine by July 12, 2022, whether the NAAs attained the 
NAAQS by the statutory attainment date. With this action, the EPA 
proposes to determine, in accordance with CAA section 179(c), that the 
Freestone-Anderson and Titus NAAs attained the 2010 1-hour primary 
SO2 NAAQS by the January 12, 2022, statutory attainment 
date.
    A determination of whether an area's air quality meets applicable 
standards is generally based upon the most recent 3 years of complete, 
quality-assured data gathered at established state and local air 
monitoring stations (SLAMS) in a NAA and entered into the EPA's Air 
Quality System (AQS) database, along with other available 
information.\8\ Data from ambient air monitors operated by state and 
local agencies in compliance with the EPA monitoring requirements must 
be submitted to AQS. Monitoring agencies annually certify that these 
data are accurate to the best of their knowledge. All data are reviewed 
to determine the area's air quality status in accordance with 40 CFR 
part 50, appendix T (for SO2). In general, for 
SO2 the EPA does not rely exclusively on monitoring data to 
determine whether the NAAQS is met unless it has been demonstrated that 
the monitors were appropriately sited to record expected maximum 
ambient concentrations of SO2 in an area. As such, 
monitoring data can be supplemented with other relevant information, 
including dispersion modeling and emissions inventories, for 
determining attainment.\9\
---------------------------------------------------------------------------

    \8\ Under EPA regulations in 40 CFR 50.17 and in accordance with 
40 CFR part 50, appendix T, the 2010 1-hour annual SO2 
standard is met at an ambient air quality monitoring site when the 
design value is less than or equal to 75 ppb. Design values are 
calculated by computing the 3-year average of the annual 99th 
percentile daily maximum 1-hour average concentrations. An 
SO2 1-hour primary standard design value is valid if it 
encompasses 3 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.
    \9\ The memorandum dated April 23, 2014, from Steve Page, 
Director, EPA Office of Air Quality Planning and Standards to the 
EPA Air Division Directors and titled ``Guidance for 1-hour 
SO2 Nonattainment Area SIP Submissions'' provides 
guidance for determining attainment for the 2010 1-hour primary 
SO2 NAAQS. This document is available at https://www.epa.gov/sites/default/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf.
---------------------------------------------------------------------------

    The attainment date for the Freestone-Anderson and Titus NAAs was 
January 12, 2022. For an area where monitoring data alone is used in 
the determination of attainment, the 3-year design value for the 
calendar years preceding the attainment date is typically used (e.g., 
the design value for January 2019-December 2021 is the appropriate 
design value for an attainment date of January 12, 2022). In this case 
for the Freestone-Anderson and Titus NAAs, however, to demonstrate 
attainment EPA is relying on a combination of monitoring data, past 
modeling from the designation action and discussed in the May 2021 
CDD,\10\ primary source shutdowns, and recent emissions data.
---------------------------------------------------------------------------

    \10\ 86 FR 26401 (May 14, 2021). The background for this action 
is discussed in detail in our September 24, 2020, proposal (85 FR 
60407).
---------------------------------------------------------------------------

II. The EPA's Proposed Determination

A. Area Characterization

    The Freestone-Anderson NAA in Texas is bound by the following 
Universal Traverse Mercator (UTM) coordinates encompassed by the 
following rectangular area vertices in UTM zone 14 with datum NAD83:
    (1) vertices--UTM Easting (m) 766752.69, UTM Northing (m) 
3536333.0,
    (2) vertices--UTM Easting (m) 784752.69, UTM Northing (m) 
3536333.0,
    (3) vertices--UTM Easting (m) 784752.69, UTM Northing (m) 
3512333.0,
    (4) vertices--UTM Easting (m) 766752.69, UTM Northing (m) 
3512333.0.
    The Titus NAA in Texas is bound by the following UTM coordinates 
encompassed by the following rectangular area vertices in UTM zone 15 
with datum NAD83:
    (1) vertices--UTM Easting (m) 304329.030, UTM Northing (m) 
3666971.0,
    (2) vertices--UTM Easting (m) 311629.030, UTM Northing (m) 
3666971.0,
    (3) vertices--UTM Easting (m) 311629.03, UTM Northing (m) 
3661870.5,
    (4) vertices--UTM Easting (m) 304329.03, UTM Northing (m) 
3661870.5.
    At the time of these area designations, EPA relied on modeling that 
indicated that the Big Brown Steam Electric Station in Freestone County 
and the Monticello Steam Electric Station in Titus County were the key 
contributors to the modeled 2010 SO2 NAAQS violations in 
these rural areas. These two coal-fired power plants were responsible 
for contributing almost, if not equal to, 100 percent of the 
SO2

[[Page 71232]]

impacts on the maximum modeled concentrations in each respective area. 
Therefore, EPA only included these two principal sources within these 
area boundaries when designating these areas.\11\
---------------------------------------------------------------------------

    \11\ See final round two technical support document (TSD) titled 
``Final TSD for Supplemental SO2 NAAQS Designations for 
Four Areas in Texas.pdf'' (pages 16 and 38). Available in the docket 
for this action.
---------------------------------------------------------------------------

    Shortly after EPA published these nonattainment designation 
boundaries, Luminant announced plans to retire the Monticello Steam 
Electric Station (October 6, 2017) and the Big Brown Steam Electric 
Station (October 13, 2017), and to close both facilities at the 
beginning of 2018. Luminant permanently retired the Big Brown electric 
generating units 1 and 2 on February 12, 2018, and the TCEQ voided the 
operating permit for these units on August 3, 2018. The TCEQ voided 
most individual NSR permits for Big Brown units 1 and 2 on March 28, 
2018, and the remaining NSR authorizations were voided on June 30, 
2020. On April 18, 2021, the Big Brown facility was permanently 
demolished. Luminant permanently retired the Monticello electric 
generating units 1, 2, and 3 on December 31, 2017, and the TCEQ voided 
the operating permit for these units on August 29, 2018. The TCEQ 
voided most individual NSR permits for Monticello units 1, 2, and 3 on 
February 14, 2018, and the remaining NSR authorizations were voided on 
July 14, 2020. On July 1, 2021, the Monticello facility was permanently 
demolished. Thus, a key factor in our determination that these two 
areas attained the 2010 SO2 standard is the retirement of 
these two facilities since they were the only principal sources within 
these area boundaries when these areas were designated as 
nonattainment.

B. Evaluation of SO2 Monitoring Data

    On October 30, 2017, Texas deployed a special purpose 
SO2 monitor in Freestone County, Texas near the Big Brown 
Steam Electric facility at the Fairfield Farm to Market (FM) 2570 Ward 
Ranch site. This special purpose monitor (Air Quality System (AQS) ID 
48-161-1084) was specifically established to collect information about 
the SO2 ambient air concentrations impacted by emissions 
from the Big Brown Electric Station. Though the Big Brown Steam 
Electric Station shut down in February 2018, Texas continues to operate 
the monitor. In review of the available data at the time of the CDD 
request, data from the Big Brown monitor demonstrated a marked 
improvement in air quality in the NAA due to the permanent retirement 
of the source.\12\ CAA section 179(c) requires EPA's determination of 
whether the area attained by the attainment date to be based on the 
area's air quality as of the attainment date. Therefore, for the 
attainment date of January 12, 2022, the 3-year period of 2019 through 
2021 is the relevant time period for evaluation in fulfilling the 
Agency's obligation under CAA section 179(c). The 2019-2021 design 
value for the Big Brown monitor was 5 ppb (7 percent of the standard), 
compared to the standard of 75 ppb. The more recent 2020-2022 design 
value for the Big Brown monitor was 7 ppb (9 percent of the standard). 
The Freestone County monitor's 1-hour SO2 design values have 
never violated the 2010 1-hour primary SO2 NAAQS for the 
periods following the source shutdown. The EPA is proposing to find 
that this monitoring data supports the determination that the 
Freestone-Anderson NAA has been in attainment since the Big Brown Steam 
Electric Station retired in 2018.
---------------------------------------------------------------------------

    \12\ During the initial 107-day period from the start of 
monitoring on October 31, 2017, to the shutdown of Big Brown on 
February 14, 2018, the 99th percentile concentration (the 1st high 
value for this shorter-than-1-year period) was 77.5 ppb, slightly 
above the standard. Post-shutdown, 321 days were measured during 
2018; during this period the 99th percentile concentration (the 3rd 
high value) was 14 ppb, 19 percent of the standard. The 99th 
percentile concentration for 2019 (the 4th high value) was 5.8 ppb, 
8 percent of the standard.
---------------------------------------------------------------------------

    For the Titus County NAA, Texas did not install a monitor that had 
been planned near the Monticello Steam Electric Station once the 
retirement of the facility was announced for 2017. However, monitoring 
data from the Welsh monitor (AQS ID 48-449-1078), (the Cookville FM 
4855 monitor) also located in Titus County, Texas approximately 16 km 
to the east of the NAA surrounding the Monticello Steam Electric 
Station, was evaluated to provide corroborating evidence that the 
source shutdowns have resulted in attainment. The Welsh Monitor began 
operating in January 2017. The Welsh monitor was located at the 
Cookville FM 4855 site by Texas to characterize the SO2 
concentrations from the Welsh Power Plant. The Welsh plant was not 
included in the Titus NAA because it was not identified as a 
contributing source to the modeled SO2 NAAQS violation in 
the Titus NAA. Although the Welsh plant was not identified as a 
contributing source to the Titus NAA, it is the only other major 
SO2 producing plant in Titus County now that the Monticello 
Steam Electric Station has retired, and its SO2 emissions 
and resulting SO2 concentrations are accounted for with this 
monitor. And, moreover, the Welsh monitor which was sited to capture 
the impacts of this lone remaining source is recording SO2 
concentrations well below the level of the NAAQS. The 2019-2021 design 
value at the Welsh monitor is 19 ppb, 25 percent of the 1-hour 
SO2 NAAQS standard. The 2020-2022 design value is 14 ppb, 19 
percent of the standard. As explained in the CDD final action, these 
values represent an upper limit for the estimated design value for the 
Titus County NAA since the Welsh monitor includes the impacts from the 
nearby Welsh Power Plant. Concentrations within the Titus NAA, farther 
from the Welsh plant, would be expected to be lower since there are no 
other large sources nearby. The EPA is proposing to find that the 
monitoring data from the Welsh monitor in Titus County support the 
conclusion that the Titus NAA attained the 2010 1-hour SO2 
NAAQS by the January 12, 2022, statutory attainment date.

C. Evaluation of SO2 Modeling Data

    In 2016, Sierra Club and Vistra Energy submitted modeling data for 
the most recent 3 years (2013-2015) at that time. This modeling 
provided the basis for the two nonattainment designations as discussed 
earlier. In our CDD,\13\ we evaluated this modeling to determine if 
there was any possibility these areas would still be in nonattainment 
after the plant shutdowns. Our analysis of the maximum impacts around 
Big Brown and around Monticello found that these plants were 
responsible for almost 100 percent of the impacts on the maximum 
ambient SO2 concentration. EPA's boundaries for the NAAs 
encompassed the areas shown to be in violation of the standard based on 
the 2013-2015 emissions and the principal sources that contributed to 
the violation in each area (i.e., Big Brown and Monticello). Both 
facilities no longer emit any SO2 due to permanent 
shutdowns. Big Brown has emitted zero emissions since the second 
quarter of 2018 and Monticello has emitted zero emissions since the 
first quarter of 2018. The only emissions explicitly modeled were those 
from Big Brown and Monticello; the contributions from all other sources 
were represented in the model by an estimate of the background 
concentration. This is a technique in modeling to address smaller or 
more distant source contributions by examining monitoring data thought 
to be representative. In the modeling evaluated for designations, these 
contributions were estimated to be

[[Page 71233]]

small, 2 ppb for both areas (much less than the 75 ppb standard). 
Consistent with our analysis in the CDD, we do not believe that new 
modeling is required to determine attainment of the standard by the 
attainment date. Because the emissions from the Big Brown and 
Monticello facilities for the 2019-2021 period are zero and their 
modeled concentrations would also be zero, the total concentration 
within the nonattainment area would be modeled as equal to the 
contribution from all other sources, or background. In other words, the 
modeled design value, if remodeled, would be small and equal to the 
concentrations from all other sources as represented by the background 
concentration.
---------------------------------------------------------------------------

    \13\ 85 FR 60407, 60411 (September 25, 2020).
---------------------------------------------------------------------------

D. Evaluation of SO2 Emissions Data

    Although the initial designation modeling showed that Big Brown and 
Monticello Steam Electric Stations contributed nearly 100 percent of 
the point source emissions in their nonattainment areas, and those 
sources have shutdown, the EPA also evaluated total County-wide 
emissions to consider any point sources that are within the Counties. 
The EPA evaluated annual SO2 point source emission trends 
for sources within each County for 2012, and 2017 through 2022.\14\
---------------------------------------------------------------------------

    \14\ See spreadsheet titled, ``2010 to 2022 Texas Point Source 
Data.xlsx'' included in the docket of this action.
---------------------------------------------------------------------------

    Table 1 shows that Big Brown emitted nearly 100 percent of the 
total point source emissions within Freestone and Anderson Counties 
until after its retirement in 2018. The total SO2 point 
source emissions have been 100 tons per year (tpy) or less each year 
from 2019 to 2022. A flare from Mosbacher Energy Company is responsible 
for the majority of those remaining annual SO2 emissions 
(ranging from 28 to 86 tpy) with the rest coming from Freestone Energy 
Center (ranging from 12 to 16 tpy) and other various combined sources 
emitting less than 1 tpy each.

                                Table 1--Freestone and Anderson Counties Combined SO2 Point Source Emissions From Texas *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  SO2 emissions (tpy)
              Facility                      Description       ------------------------------------------------------------------------------------------
                                                                   2012         2017         2018         2019         2020         2021         2022
--------------------------------------------------------------------------------------------------------------------------------------------------------
Big Brown Steam Electric Station....  Boilers 10 and 11......       60,681       47,632        6,659            0            0            0            0
Freestone Energy Center.............  Turbines 1 to 4........         11.5         11.7           14           16         14.6         12.3         13.6
Mosbacher Energy Company............  Flare 3................          130         62.4           73         45.2           28           86           67
Teague Gas Plant....................  Incinerator 5 and              243.8            0            0            0            0            0            0
                                       unclassified unit 4.
Other...............................  Various (1 tpy or less           3.4          3.1          2.5          2.5          2.5            2          1.8
                                       each) **.
                                                              ------------------------------------------------------------------------------------------
    Total...........................  .......................       61,070       47,709        6,748         63.7         45.1        100.7         82.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Point source data obtained from the State of Texas Air Reporting System (STARS) reported on January 16, 2024.
** The Bethel Gas Plant Incinerator unit 32 was the only unit to exceed 1 tpy with 1.6 tpy in 2012.

    In Table 2, EPA provided categorized County-wide emissions, 
including point, non-point and mobile source emissions from 2017 and 
2020 National Emission Inventory (NEI) \15\ data to compare Big Brown's 
impact against the rest of the emissions inventory in Freestone and 
Anderson Counties. The total SO2 emissions in Freestone and 
Anderson Counties were significantly lower in 2020 after Big Brown's 
retirement, with 171 tpy total. The non-point source category made up 
the majority of these County-wide emissions at 122 tpy (71 percent) 
with fires (prescribed/agricultural burning, and wildfires) 
contributing the most at 108.5 tpy. Oil and gas, waste disposal, and 
combustion made up the remaining non-point emissions but were small at 
5.4, 4.1, and 3.5 tpy, respectively. On-road sources also contributed 
lightly with 3.6 tpy. These categorized County-wide emissions show that 
other source categories in and outside of the Freestone-Anderson NAA 
are very low. The NAA makes up a very small portion of the total areas 
in Freestone and Anderson Counties, so these County-wide non-point and 
mobile emissions, which are few, would make up an even smaller piece of 
the overall emissions in or near the Freestone-Anderson NAA. The 
retirement of the Big Brown Steam Electric Station in 2018 reduced the 
emissions in the Freestone-Anderson NAA by nearly 100 percent from 2012 
to 2020 and there are no other significant emission sources present. 
Therefore, this information supports a determination that the 
Freestone-Anderson NAA has attained the 2010 1-hour SO2 
NAAQS by the statutory attainment date.
---------------------------------------------------------------------------

    \15\ See spreadsheets titled ``NEI emissions by sector 2012, 
2017, 2020.xlsx'' and ``NEI emissions by unit 2012, 2017, 
2020.xlsx'' included in the docket of this action.

     Table 2--Freestone and Anderson Counties Combined 2017 and 2020
                   Categorized NEI SO2 Total Emissions
------------------------------------------------------------------------
                                                SO2 emissions (tpy)
                Category                 -------------------------------
                                               2017            2020
------------------------------------------------------------------------
Point...................................          47,710            45.1
Non-Point...............................             179             122
    Fires (prescribed/agricultural                 171.1           108.5
     burning, and wildfires)............
    Oil and gas production..............            3.03             5.4
    Waste Disposal......................             2.9             4.1
    Combustion (residential and                      2.4             3.5
     industrial)........................
On-Road Mobile..........................            12.2             3.6
Non-Road Mobile.........................             1.5             0.1
                                         -------------------------------

[[Page 71234]]

 
        Total...........................          47,903             171
------------------------------------------------------------------------

    Table 3 shows the SO2 total point source emissions 
within Titus County in 2012, and from 2017 to 2022. In 2018, after 
Monticello Steam Electric Station retired, the Welsh Power Plant 
emitted nearly 100 percent of the remaining SO2 emissions 
within Titus County. These results show that up until 2017 the 
Monticello and Welsh plants were the only primary SO2 point 
sources emitting in Titus County. During designations, EPA's 
nonattainment boundary did not include the Welsh Power Plant and was 
limited to the immediate area surrounding Monticello Steam Electric 
Station as the Welsh Power Plant was not identified as a contributing 
source to the modeled SO2 NAAQS violation. Therefore, since 
the Welsh Power Plant did not contribute to the NAAQS violation in the 
Titus NAA, and since there are no other point sources within Titus 
County, these County-wide emission results show that Monticello is the 
only point source that could contribute to nonattainment within the 
Titus NAA.

                                              Table 3--Titus County SO2 Point Source Emissions From Texas *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                  SO2 emissions (tpy)
              Facility                      Description       ------------------------------------------------------------------------------------------
                                                                   2012         2017         2018         2019         2020         2021         2022
--------------------------------------------------------------------------------------------------------------------------------------------------------
Monticello Steam Electric Station...  Boilers 7, 9, 10, 11,         31,450       29,412            0            0            0            0            0
                                       66.
Welsh Power Plant...................  Boilers 10, 11, and 12.       23,212       14,075       14,226       11,177      8,168.8        9,880       10,916
Other...............................  Flares and Fugitive                0         0.02          0.3          0.4          0.4          0.4          0.4
                                       Emissions.
                                                              ------------------------------------------------------------------------------------------
    Total...........................  .......................       54,662       43,487     14,226.3     11,177.4      8,169.2      9,880.4     10,916.4
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Point source data obtained from the State of Texas Air Reporting System (STARS) reported on January 16, 2024.

    In Table 4, EPA provided categorized County-wide emissions from 
2017 and 2020 NEI data to further compare Monticello's impact against 
the rest of the emission inventory in Titus County. The 2017 and 2020 
NEI data showed that the SO2 emissions from other categories 
in Titus County were small when compared to the point source emissions 
showing 44 tpy (0.1 percent) in 2017 and 51.7 tpy (0.6 percent) in 
2020. The non-point source category made up the majority of these low 
emissions with 38 tpy in 2017 and 50 tpy in 2020 coming mostly from 
fires (19 and 16.3 tpy, respectively, in 2017 and 2020) and combustion 
(18 and 29.6 tpy, respectively, in 2017 and 2020). Oil and gas and 
waste disposal made up the remaining of these low emissions with oil 
and gas showing 2.6 tpy or less and waste disposal 1.5 tpy or less for 
both years. On-road mobile sources also contributed very lightly as 
well (5.5 and 1.9 tpy for both years). These categorized County-wide 
emissions show that other source categories in and outside of the Titus 
NAA are very low. The Titus NAA makes up a very small portion of the 
total area in Titus County, so these County-wide non-point and mobile 
emissions, which are few, would make up an even smaller piece of those 
overall emissions in or near the Titus NAA. The retirement of 
Monticello Steam Electric Station reduced the emissions in the Titus 
NAA by nearly 100 percent from 2012 to 2020, and no other sources are 
contributing to that area from Titus County. This information supports 
a determination that the Titus NAA attained the 2010 1-hour 
SO2 NAAQS by the statutory attainment date.

 Table 4--Titus County 2017 and 2020 Categorized NEI SO2 Total Emissions
------------------------------------------------------------------------
                                                SO2 emissions (tpy)
                Category                 -------------------------------
                                               2017            2020
------------------------------------------------------------------------
Point (including the Welsh Power Plant).          43,487         8,169.3
Non-Point...............................              38              50
    Fires (prescribed/agricultural                    19            16.3
     burning, and wildfires)............
    Oil and gas production..............            0.01             2.6
    Waste Disposal......................             1.3             1.5
    Combustion (residential and                       18            29.6
     industrial)........................
On-Road Mobile..........................             5.5             1.9
Non-Road Mobile.........................             0.8            0.09
                                         -------------------------------
        Total...........................          43,531           8,221
------------------------------------------------------------------------


[[Page 71235]]

E. Conclusion

    We propose to determine that the Freestone-Anderson and Titus NAAs 
attained the 2010 1-hour SO2 NAAQS by the statutory 
attainment date of January 12, 2022. The supporting justification for 
our proposed determination of attainment by the attainment date 
includes the following: EPA's previous CDD; the permanent and 
enforceable shutdowns of the primary sources of SO2 
emissions in these areas; the available modeling analysis demonstrating 
that the Big Brown Steam Electric Station in Freestone County and the 
Monticello Steam Electric Station in Titus County were responsible for 
almost 100 percent of the SO2 impacts on the maximum modeled 
concentrations in each respective area; review of emissions data 
showing emissions within the Freestone-Anderson and Titus NAA's have 
been reduced by nearly 100 percent with the retirements of Big Brown 
and Monticello Steam Electric Stations in 2018 and that no other 
sources remain that are contributing to a violation of the 
SO2 NAAQS in those NAAs; and the Freestone County and Welsh 
monitors' reported 2019-2021 design values of 5 ppb (7 percent of the 
standard) and 19 ppb (25 percent of the standard) providing additional 
evidence that these areas are in attainment. The EPA's proposed 
determination that the area attained the 2010 1-hour SO2 
NAAQS by the attainment date is supported by all of the available 
aforementioned evidence.

III. Proposed Action

    Based on the EPA's review of all available evidence described in 
this notice, the EPA is proposing to determine that the Freestone-
Anderson and Titus NAA's attained the 2010 1-hour primary 
SO2 NAAQS by the statutory attainment date of January 12, 
2022.
    Finalizing this action would not constitute a redesignation of the 
Freestone-Anderson and Titus NAA's to attainment of the 2010 1-hour 
SO2 NAAQS under section 107(d)(3) of the CAA. If this action 
is finalized, the Freestone-Anderson and Titus NAA's will remain 
designated nonattainment for the 2010 1-hour SO2 NAAQS until 
EPA revises the area's designation under CAA section 107(d)(3).
    If finalized, this action will address the EPA's obligation under 
CAA section 179(c) to determine if the Freestone-Anderson and Titus 
NAAs attained the 2010 1-hour SO2 NAAQS by the statutory 
attainment date of January 12, 2022.
    The EPA is soliciting public comments on this notice. These 
comments will be considered before taking final action.

IV. Environmental Justice Considerations

    Information on Executive Order 12898 (Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations, 59 FR 7629, February 16, 1994) and how EPA defines 
environmental justice (EJ) can be found in the section, below, titled 
``V. Statutory and Executive Order Reviews.'' EPA is providing 
additional analysis of environmental justice associated with this 
action. We are doing so for the purpose of providing information to the 
public, not as a basis of our action.
    The EPA conducted screening analyses utilizing EJSCREEN, an 
environmental justice mapping and screening tool that combines various 
environmental and demographic indicators within the area.\16\ The 
EJSCREEN tool presents these indicators at a Census block group (CBG) 
level or a larger user-specified ``buffer'' area that covers multiple 
CBGs.\17\ An individual CBG is a cluster of contiguous blocks within 
the same census tract and generally contains between 600 and 3,000 
people. EJSCREEN is not a tool for performing in-depth risk analysis, 
but is instead a screening tool that provides an initial representation 
of indicators related to environmental justice and is subject to 
uncertainty in some underlying data (e.g., some environmental 
indicators are based on monitoring data which are not uniformly 
available; others are based on self-reported data).\18\ We present 
EJSCREEN environmental indicators to help screen for locations where 
residents may experience a higher overall pollution burden than would 
be expected for a block group with the same total population. These 
indicators of overall pollution burden include estimates of ambient 
PM2.5 and O3 concentration, air toxics cancer 
risk, air toxics respiratory health index, a score for traffic 
proximity and volume, percentage of pre-1960 housing units (lead paint 
indicator), and scores for proximity to Superfund sites, risk 
management plan (RMP) sites, and hazardous waste facilities.\19\ We 
note that the cancer risk and respiratory health indexes are based on 
2017 emissions data, when the sources in these areas were still 
operating. The EPA's EJSCREEN tool also provides information on 
demographic indicators for vulnerable populations in the area, 
including communities of color, percent low-income, linguistic 
isolation, and less than high school-level education. This action 
proposes a determination of NAAQS attainment by the attainment date for 
the Freestone-Anderson Counties and Titus County, Texas NAAs. The EPA 
prepared EJSCREEN reports covering buffer areas containing the 
designated boundaries for each nonattainment area. We selected a 15 km 
radius around the Big Brown Steam Electric Station in Freestone-
Anderson Counties and a 10 km radius around the Monticello Steam 
Electric Station in Titus County. These sources were responsible for 
almost 100 percent of the SO2 impacts on the maximum modeled 
concentrations in each respective area. Table 6 presents a summary of 
results from the EPA's screening-level analysis for the areas 
surrounding each nonattainment area compared to the U.S. as a whole 
(the detailed EJSCREEN reports are provided in the docket for this 
rulemaking).
---------------------------------------------------------------------------

    \16\ The EJSCREEN tool is available at https://www.epa.gov/ejscreen.
    \17\ See https://www.census.gov/programs-surveys/geography/about/glossary.html.
    \18\ In addition, EJSCREEN relies on the 5-year block group 
estimates from the U.S. Census American Community Survey. The 
advantage of using 5-year over 1-year estimates is increased 
statistical reliability of the data (i.e., lower sampling error), 
particularly for small geographic areas and population groups. For 
more information, see https://www.census.gov/content/dam/Census/library/publications/2020/acs/acs_general_handbook_2020.pdf.
    \19\ For additional information on environmental indicators and 
proximity scores in EJSCREEN, see ``EJSCREEN Environmental Justice 
Mapping and Screening Tool: EJSCREEN Technical Documentation,'' 
Chapter 3 and Appendix C (September 2019) at https://www.epa.gov/sites/default/files/2021-04/documents/ejscreen_technical_document.pdf.
---------------------------------------------------------------------------

    This action is proposing our determination of attainment by the 
attainment date for the 2010 1-hour primary SO2 NAAQS for 
the Freestone-Anderson and Titus County NAAs by January 12, 2022. 
Information on SO2 and its relationship to negative health 
impacts can be found at final Federal Register notice titled ``Primary 
National Ambient Air Quality Standard for Sulfur Dioxide'' (75 FR 
35520, June 22, 2010). We expect that this particular action will not 
have a detrimental effect on the populations in the NAAs, including 
people of color and low-income populations in the NAAs, as this action 
identifies that the areas attained the NAAQS by the attainment date.

[[Page 71236]]



                  Table 6--EJSCREEN Analysis Summary for Freestone-Anderson and Titus SO2 NAAs
----------------------------------------------------------------------------------------------------------------
                                           Values for buffer areas for each NAA and the U.S. (percentile within
                                                                  U.S. where indicated)
                                        ------------------------------------------------------------------------
           Selected variables                Big Brown Plant in
                                           Freestone-Anderson SO2   Monticello Plant in Titus
                                             NAA (15 km radius)       SO2 NAA (10 km radius)       U.S. (avg)
 
----------------------------------------------------------------------------------------------------------------
                                           Pollution Burden Indicators
----------------------------------------------------------------------------------------------------------------
Particulate matter (PM2.5), annual       9.12 (64th %ile).........  9.34 (70th %ile).........           8.74 (-)
 average ([micro]g/m\3\).
Cancer Risk (lifetime risk per million)  30 (80-90th %ile)........  38 (95-100th %tile)......             29 (-)
 **.
Respiratory Health Index **............  0.31 (<50th %tile).......  0.4 (80-90th %tile)......           0.36 (-)
Ozone (O3), summer seasonal average of   40.7 (36th %ile).........  40.7 (36th %ile).........           42.6 (-)
 daily 8-hour max (ppb).
Traffic proximity and volume score *...  11 (8th %ile)............  190 (46th %ile)..........            710 (-)
Lead paint (percent pre-1960 housing)..  0.11 (41st %ile).........  0.14 (45th %ile).........           0.28 (-)
Superfund proximity score *............  0.009 (3rd %ile).........  0.013 (9th %ile).........           0.13 (-)
RMP proximity score *..................  0.065 (7th %ile).........  2.8 (95th %ile)..........           0.75 (-)
Hazardous waste proximity score *......  0.022 (1st %ile).........  0.028 (3rd %ile).........            2.2 (-)
----------------------------------------------------------------------------------------------------------------
                                             Demographic Indicators
----------------------------------------------------------------------------------------------------------------
People of color population.............  43% (60th %ile)..........  61% (72nd %ile)..........            40% (-)
Low-income population..................  30% (53rd %ile)..........  51% (81st %ile)..........            31% (-)
Linguistically isolated population.....  1% (50th %ile)...........  8% (80th %ile)...........             5% (-)
Population with less than high school    23% (84th %ile)..........  22% (82nd %ile)..........            12% (-)
 education.
Population under 5 years of age........  3% (23rd %ile)...........  7% (64th %ile)...........             6% (-)
Population over 64 years of age........  12% (38th %ile)..........  14% (48th %ile)..........            16% (-)
----------------------------------------------------------------------------------------------------------------
* The traffic proximity and volume indicator is a score calculated by daily traffic count divided by distance in
  meters to the road. The Superfund proximity, RMP proximity, and hazardous waste proximity indicators are all
  scores calculated by site or facility counts divided by distance in kilometers.
** Air toxics cancer risk, and air toxics respiratory hazard index are from the EPA's 2017 Air Toxics Data
  Update, which is the Agency's ongoing, comprehensive evaluation of air toxics in the United States.

V. Statutory and Executive Order Reviews

    This action proposes to find that areas attained the NAAQS by the 
relevant statutory attainment date and does not impose additional or 
modify existing requirements. For that reason, this action:
     Is not a significant regulatory action subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 14094 (88 FR 21879, April 11, 2023);
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001); 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.
    Executive Order 12898 (Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations, 59 FR 7629, 
February 16, 1994) directs Federal agencies to identify and address 
``disproportionately high and adverse human health or environmental 
effects'' of their actions on minority populations and low-income 
populations to the greatest extent practicable and permitted by law. 
EPA defines environmental justice (EJ) as ``the fair treatment and 
meaningful involvement of all people regardless of race, color, 
national origin, or income with respect to the development, 
implementation, and enforcement of environmental laws, regulations, and 
policies.'' EPA further defines the term fair treatment to mean that 
``no group of people should bear a disproportionate burden of 
environmental harms and risks, including those resulting from the 
negative environmental consequences of industrial, governmental, and 
commercial operations or programs and policies.'' As noted in Section 
IV, the EPA performed an EJ analysis, but we did not consider EJ as a 
basis for this action. Due to the nature of the action being taken 
here, this action is expected to have no impact on the air quality of 
the affected area. Consideration of EJ is not required as part of this 
action, which finds that NAAs attained the 2010 SO2 NAAQS by 
the applicable attainment date, and there is no information in the 
record inconsistent with the stated goal of E.O. 12898 of achieving 
environmental justice for people of color, low-income populations, and 
Indigenous peoples.
    In addition, this proposed rulemaking, the finding of attainment by 
the attainment date for the Freestone-Anderson and Titus SO2 
NAAs, does not have tribal implications as specified by Executive Order 
13175 (65 FR 67249, November 9, 2000), because this action is not 
intended to apply in Indian country located in the State, and the EPA 
notes that it will not impose substantial direct costs on tribal 
governments or preempt tribal law.

[[Page 71237]]

List of Subjects in 40 CFR Part 52

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


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

    Dated: August 27, 2024.
Earthea Nance,
Regional Administrator, Region 6.
[FR Doc. 2024-19599 Filed 8-30-24; 8:45 am]
BILLING CODE 6560-50-P