Air Plan Approval; Maryland; Determination of Attainment by the Attainment Date for the 2010 1-Hour Primary Sulfur Dioxide National Ambient Air Quality Standard, 72770-72775 [2024-19436]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 89, Number 173 (Friday, September 6, 2024)]
[Proposed Rules]
[Pages 72770-72775]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-19436]



[[Page 72770]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R03-OAR-2024-0152; FRL-11858-01-R3]


Air Plan Approval; Maryland; Determination of Attainment by the 
Attainment Date for the 2010 1-Hour Primary Sulfur Dioxide National 
Ambient Air Quality Standard

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
determine that the Anne Arundel County and Baltimore County, Maryland 
sulfur dioxide (SO2) nonattainment area attained the 2010 1-
hour primary SO2 national ambient air quality standard (2010 
SO2 NAAQS) by the applicable attainment date of September 
12, 2021. This determination is based on certified ambient air quality 
data from the 2018-2020 monitoring period, relevant modeling analysis, 
and additional emissions inventory information. This action, if 
finalized, will address the EPA's obligation under Clean Air Act (CAA) 
section 179(c) to determine whether the Anne Arundel and Baltimore 
County SO2 nonattainment area (referred to hereafter as the 
Anne Arundel-Baltimore County Area, or simply the Area) attained the 
2010 SO2 NAAQS by the September 12, 2021 attainment date.

DATES: Written comments must be received on or before October 7, 2024.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R03-
OAR-2024-0152 at www.regulations.gov, or via email to 
[email protected]. For comments submitted at Regulations.gov, follow 
the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from Regulations.gov. For either 
manner of submission, 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 www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Philip McGuire, Planning & 
Implementation Branch (3AD30), Air & Radiation Division, U.S. 
Environmental Protection Agency, Region III, 1600 John F Kennedy 
Boulevard, Philadelphia, Pennsylvania 19103. The telephone number is 
(215) 814-2251. Mr. McGuire can also be reached via electronic mail at 
[email protected].

SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we,'' 
``us,'' or ``our'' is used, we refer to 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. 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\
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    \1\ 36 FR 8186, April 30, 1971.
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    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\ This revised SO2 NAAQS provides 
increased protection of public health, and provided 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.
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    \2\ 75 FR 35520, June 22, 2010.
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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 this 2013 action, the EPA designated 29 areas in 16 states 
as nonattainment for the 2010 1-hour primary SO2 NAAQS. 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.\4\ Included in this second round of designations 
was the Anne Arundel-Baltimore County Area. This designation was based 
on the weight of evidence for the Area, including available air quality 
modeling and ambient air monitoring data from 2013-2015. Pursuant to 
section 192(a) of the CAA, the attainment date for the Anne Arundel-
Baltimore County Area was no later than five years after the effective 
date of initial designation, or September 12, 2021.
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    \3\ 78 FR 47191, August 5, 2013.
    \4\ 81 FR 45039, July 12, 2016.
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    CAA section 191(a) directs states containing 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. For SO2, the NAA SIP (also 
referred to as an attainment plan) must meet the requirements of 
subparts l and 5 of part D, of title 1 of the CAA, and provide for 
attainment of the NAAQS by the applicable statutory attainment date, or 
no later than five years from the effective date of designation. The 
Maryland Department of Environment (MDE) submitted an attainment plan 
SIP for the Anne Arundel-Baltimore County Area on January 31, 2020.
    When a nonattainment area is attaining the 2010 1-hour primary 
SO2 NAAQS based on the most recent available data, the EPA 
may issue a

[[Page 72771]]

Clean Data Determination (CDD), suspending certain NAA planning 
requirements. The EPA issued a CDD for the Anne Arundel-Baltimore 
County Area based on modeling and monitoring data for the period 2019-
2021 via a final rule published on November 2, 2022, and at the same 
time, approved certain elements of the submitted attainment plan that 
are not waived by the EPA's CDD policy.\5\ Notably, a CDD does not 
alter the Area's nonattainment designation. For the EPA to redesignate 
an area to attainment, the state must submit, and the EPA must approve 
a redesignation request for the Area that meets the requirements of CAA 
section 107(d)(3). To date, Maryland has not requested redesignation of 
the Area to attainment.
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    \5\ 87 FR 66086, November 2, 2022.
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C. EPA Determination of Attainment by the Attainment Date

    Section 179(c)(1) of the CAA requires the EPA to determine whether 
a nonattainment area attained an applicable standard by the applicable 
attainment date based on the area's air quality as of the attainment 
date. The EPA is required to issue this determination within six months 
of the attainment date. Thus, the EPA had a mandatory duty to determine 
by March 12, 2022, under CAA section 179(c) if the Area reached 
attainment. With this action, the EPA proposes to determine, in 
accordance with CAA section 179(c), that the Anne Arundel-Baltimore 
County Area attained the 2010 1-hour primary SO2 NAAQS by 
the September 12, 2021, 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.\6\ 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.\7\
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    \6\ 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 three-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 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.
    \7\ The memorandum of April 23, 2014, from Steve Page, Director, 
EPA Office of Air Quality Planning and Standards to the EPA Air 
Division Directors ``Guidance for 1-hr SO2 Nonattainment 
Area SIP Submissions'' provides guidance for determining attainment 
for the 2010 1-hr primary SO2 NAAQS. This document is 
available at www.epa.gov/sites/production/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf.
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    The attainment date for the Anne Arundel-Baltimore County Area was 
September 12, 2021. For an area where monitoring data alone is used in 
the determination of attainment, the three-year design value for the 
calendar years preceding the attainment date is typically used (e.g., 
the design value for January 2018 through December 2020 is the 
appropriate design value for an attainment date of September 12, 2021). 
In this case for the Anne Arundel-Baltimore County NAA however, the EPA 
is relying on both a combination of monitoring data and preexisting 
modeling from the November 2022 CDD to demonstrate attainment. The 
modeling for the CDD was for the period January 2019 through December 
2021, which includes approximately 3.5 months of data occurring after 
the attainment date. The use of modeling information from 2021 provides 
additional credible evidence to demonstrate attainment by the September 
12, 2021 attainment date because it is a more current representation of 
air quality in the area. Additionally, the EPA evaluated emissions from 
2018 (i.e., September 13, 2018 through December 31, 2018) as a 
crosscheck of the 3.5 months of data that was modeled after the 
attainment date (i.e., September 13, 2021 through December 31, 2021) to 
confirm that the modeling impacts would not have resulted in violations 
had other time periods been modeled which would have aligned more 
closely with the monitored design value from 2018-2020.

II. Proposed Determination

A. Area Characterization

    The Anne Arundel-Baltimore County Area is located in Maryland along 
the western banks of the Chesapeake Bay and encompasses portions of 
Anne Arundel County and Baltimore County within 26.8 kilometers of 
Herbert A. Wagner's Generating Station (Wagner) unit 3 stack, which is 
located at 39.17765 N latitude, 76.52752 W longitude. Any portion of 
Baltimore City that falls within this 26.8-kilometer radius is excluded 
from the nonattainment area. As noted, this area was designated as 
nonattainment by the EPA on July 12, 2016 for the 2010 1-hour primary 
SO2 NAAQS.\8\ A March 2, 2015 Consent Decree and enforceable 
order issued by the United States District Court for the Northern 
District of California mandated that the EPA issue designations within 
16 months (July 2, 2016) for areas that contained a stationary source 
that had not been announced for retirement and, according to the EPA's 
Air Markets Database, emitted either more than 16,000 tons of 
SO2 in 2012 or more than 2,600 tons of SO2 and 
had an annual average emission rate of at least 0.45 pounds of 
SO2 per one million British thermal units (lbs 
SO2/MMBTU) in 2012.\9\ In 2012, Wagner emitted 7,514 tons of 
SO2 and had an emissions rate of 1.105 lbs SO2/
MMBTU, and had not been announced for retirement as of March 2, 2015. 
As a result, the Consent Decree applied to the Anne Arundel-Baltimore 
County Area.
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    \8\ 81 FR 45039 (effective September 12, 2016).
    \9\ Consent Decree, Sierra Club v. McCarthy, No. 3:13-cv-3953-
SI, (N.D. Cal. March 2, 2015). This document is available at 
www.4cleanair.org/wp-content/uploads/resources/Litigation-SO2-Designations_Deadline_Suit-Final_CD-030215.pdf.
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    Including Wagner, the Anne Arundel-Baltimore County Area contains 
three facilities that emit or have historically emitted SO2 
for the timeframe of interest. Brandon Shores power plant, C.P. Crane 
(Crane) power plant, and Wagner possess or have possessed coal-fired 
electric generating units (EGUs). Brandon Shores and Wagner are located 
next to one another in northern Anne Arundel County near the City of 
Baltimore on a 456-acre site called the Fort Smallwood Complex. Crane 
is located approximately 22 kilometers northeast of the Fort Smallwood 
Complex in Baltimore County.\10\
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    \10\ The Wheelabrator-Baltimore waste-to-energy facility is the 
only other source that could produce model impacts in the NAA. 
However, Wheelabrator-Baltimore is excluded in this action as it is 
not located within the NAA and has a minimal contribution to the 
area of maximum concentration within the NAA, as described in the 
``EPA CDD TSD--Technical Support Document--Clean Data Determination 
for the Anne Arundel-Baltimore Counties SO2 Nonattainment 
Area__August 2022'' document.

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[[Page 72772]]

    To aid in assessing if an area is meeting attainment, SLAMS collect 
ambient air data. One such monitor, the Essex monitor (Air Quality 
System (AQS) Site ID 24-005-3001), is located in the Anne Arundel-
Baltimore County Area. The Essex monitor in Baltimore County is over 15 
kilometers northeast of the Fort Smallwood Complex (Brandon Shores and 
Wagner) and approximately 9 kilometers west of Crane--placing the 
monitor well away from any primary sources of SO2. The Essex 
monitor's 1-hour SO2 design values have not violated the 
2010 1-hour primary SO2 NAAQS of 75 ppb over the last 
decade. The last design value exceedance of the NAAQS for this site was 
during the 2007-2009 period. Additionally, there is a special purpose 
monitor in the Area--the Riviera Beach monitor (AQS ID 24-003-2002)--
which has only operated since January 2018. It is sited in Anne Arundel 
County, less than 5 kilometers away from the Fort Smallwood Complex, 
providing a better estimation of the actual maximum SO2 
concentration within the nonattainment area. While it has not measured 
any instances exceeding the 2010 1-hour SO2 NAAQS, it has 
experienced significant timeframes of invalid or missing measurements 
and was discontinued in 2022.
    As placement of the Essex SLAMS and Riviera Beach special purpose 
monitor does not capture the location of the maximum ambient 
SO2 concentration,\11\ modeling may supplement the 
monitoring data to assist in determining if the Anne Arundel-Baltimore 
County Area has timely reached attainment.\12\ This action utilizes the 
same modeling as the November 2022 CDD for the Anne Arundel-Baltimore 
County Area between 2019-2021. This modeling analysis followed much of 
the modeling procedures outlined in Maryland's SIP modeling protocol 
document \13\ and Maryland's original designation modeling analysis. As 
such, this modeling largely follows established model guidelines 
previously utilized in Maryland's analysis of the Anne Arundel-
Baltimore County Area.
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    \11\ See Page 43 of ``EPA CDD TSD--Technical Support Document--
Clean Data Determination for the Anne Arundel-Baltimore Counties 
SO2 Nonattainment Area__August 2022'' document.
    \12\ See supra Note 7, EPA ``Guidance for 1-hr SO2 
Nonattainment Area SIP Submissions'', available at www.epa.gov/sites/default/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf.
    \13\ See Maryland's Planning and Policy: State Implementation 
Plans (SIPs) web page: mde.maryland.gov/programs/air/airqualityplanning/pages/index.aspx and EPA Round 2 designation page 
for Maryland: www.epa.gov/sulfur-dioxide-designations/so2-designations-round-2-maryland-staterecommendation-and-epa-response.
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B. Evaluation of SO2 Emissions Data

    The EPA evaluated annual SO2 emissions trends for 
sources within the Anne Arundel-Baltimore County Area. The annual 
emissions from 2012-2021 from each major stationary source within the 
Area are provided in table 1 in this document, along with the total 
combined emissions from the listed stationary sources. By the end of 
2020, total SO2 emissions within the Area had declined 
approximately 90% from 2012 levels and approximately 89% from 2016 
levels--the year of nonattainment designation. The closure of Crane's 
coal units by 2018, the conversion of Wagner Unit 2 from coal to 
natural gas in 2020, and the installation of a dry sorbent injection 
emission control system for SO2 on Wagner Unit 3 in 2018 all 
contributed to this significant reduction. Additionally, the remaining 
Fort Smallwood Complex coal units have reduced their total annual 
operating hours under enforceable consent orders,\14\ further 
decreasing SO2 emissions within the Area.
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    \14\ See Appendix B of the January 30, 2020 attainment plan SIP 
Revision. Specifically, Appendix B1--Consent Order--Brandon Shores 
and Wagner Generating Stations, dated December 4, 2019; and Appendix 
B-2: Consent Order--C.P. Crane Generating Station, dated October 9, 
2019.
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    The reduction in emissions in the 2018-2020 timeframe compared to 
pre-2018 emissions provides evidence that the Anne Arundel-Baltimore 
County Area saw air quality improvements in SO2 levels and 
supports the finding that the Area attained the 2010 1-hour 
SO2 NAAQS by September 12, 2021.

            Table 1--Annual Emissions From Major Stationary SO2 Sources in the Anne Arundel-Baltimore County Nonattainment Area for 2012-2021
                                                                 [Tons of SO2 per year]
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                                                  Brandon Shores                        H.A. Wagner                         C.P. Crane
                    Year                     ------------------------------------------------------------------------------------------------    Total
                                                Unit 1      Unit 2      Unit 1      Unit 2      Unit 3      Unit 4      Unit 1      Unit 2
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2012........................................       1,547       1,301         0.2       2,513       4,964        41.1       1,214         962      12,542
2013........................................       1,389       1,482         0.2       1,555       8,557        72.7         719       2,143      15,918
2014........................................       1,670       1,475        72.6       1,940       7,277         323         574       1,316      14,648
2015........................................       1,311       1,643        65.0       1,188       8,754         185         382         946      14,474
2016........................................       1,450       1,270        26.5         163       7,575        74.8         412         638      11,609
2017........................................       1,098       1,418         2.5         117       1,245        60.8         379         449       4,769
2018........................................       1,747       1,785         6.1         230       2,733         197         392         475       7,565
2019........................................         547         954        15.3        88.8       1,124        39.9           0           0       2,769
2020........................................         420         267           0           0         605        13.5           0           0       1,306
2021........................................         759         720         5.7           0         645        17.4           0           0       2,147
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C. Evaluation of SO2 Monitoring Data

    The 3-year design values of 1-hour SO2 from 2014-2021 as 
well as the annual 99th percentile of 1-hour SO2 
concentrations for the Essex Monitor are shown in table 2 in this 
document. The Essex Monitor has been below the 2010 1-hour 
SO2 NAAQS design value since 2012 and has had no hourly 
SO2 values exceeding the 75 ppb 2010 1-hour SO2 
NAAQS in the same timeframe. From 2014 to 2020, the Essex Monitor 
design value has declined from 22 ppb to 9 ppb, representing a decrease 
of approximately 59%, which could be attributed to the significant 
decline in operations of the coal fired EGUs in the Area over the past 
decade. The 2018-2020 design value of 9 ppb represents 12% of the 2010 
1-hour SO2 NAAQS. Since 2014, the Essex Monitor has reliably 
reported data, collecting and logging data on approximately 95% of days 
since its installation. This

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represents complete data for monitoring purposes.\15\
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    \15\ See supra Note 6, for requirements of data completeness.

             Table 2--2014-2021 Essex Monitor SO2 Values for the Anne Arundel-Baltimore County Area
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                                       99th Percentile                       Number of hourly
                                         daily 1-hour       Design value     SO2 values above    Valid monitor
                Year                    maximum value         (ppb) *        75 ppb (by year)    days (by year)
                                            (ppb)
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2014................................               26.4                 22                  0                360
2015................................               17.7                 22                  0                357
2016................................               12.9                 19                  0                355
2017................................                8.5                 13                  0                323
2018................................               12.3                 11                  0                318
2019................................               10.5                 10                  0                351
2020................................                4.7                  9                  0                352
2021................................                5.4                  7                  0                354
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* The design value was calculated with the reported year as the final year of the three-year period used in
  determining the design value (e.g., 2014 was calculated from the years 2012-2014).

    The other monitor in the Area, the special purpose Riviera Beach 
Monitor, has a 2018-2020 1-hour SO2 design value of 24 ppb. 
This monitor was discontinued in mid-2022, precluding the use of a more 
recent design value. Furthermore, this monitor has experienced 
significant periods of invalid or missing measurements since its 
installation in January 2018 and as such, the incorporation of its data 
into this determination of attainment by the attainment date will be 
limited to segments of valid and recorded monitoring periods.
    The EPA finds the monitoring data from the Essex monitor in the 
Anne Arundel-Baltimore County Area supports the conclusion that the 
Area attained the 2010 1-hour SO2 NAAQS by the September 12, 
2021 attainment date.

D. Evaluation of Modeling Data

    The EPA conducted a modeling analysis for the CDD proposal \16\ in 
July 2022, and as both this action and the CDD largely pertain to the 
same timeframe, this determination of attainment by the attainment date 
will utilize the same modeling results. The modeling analysis was based 
on a combination of actual and allowable emissions for 2019-2021. 
Concurrent meteorological data for 2019-2021 and appropriate background 
concentrations were incorporated into the model, and inputs were 
overlaid into a model receptor grid covering the areas near the sources 
to adequately capture the maximum modeled concentration. As noted, this 
modeling analysis followed much of the modeling procedures outlined in 
Maryland's modeling protocol document and Maryland's original 
designation modeling analysis. Therefore, this modeling largely follows 
established model guidelines previously utilized in Maryland's analysis 
of the Anne Arundel-Baltimore County Area. Additional information on 
the model assumptions and development is available in the docket for 
this action.\17\
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    \16\ 87 FR 51006, August 19, 2022.
    \17\ See ``EPA CDD TSD--Technical Support Document--Clean Data 
Determination for the Anne Arundel-Baltimore Counties SO2 
Nonattainment Area__August 2022'' document.
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    The EPA's modeling analysis based on 2019-2021 SO2 
emissions demonstrate a peak design value of 53.1 ppb occurs within the 
Anne Arundel-Baltimore County Area. This modeled value is approximately 
71% of the 75 ppb 2010 SO2 NAAQS and occurred about one 
kilometer east of the Fort Smallwood Complex, near the southern 
shoreline of the Patapsco River. The peak model receptor design value 
and the 99th percentile model concentrations used in this calculation 
are summarized in table 3 in this document. It should be noted that the 
99th percentile values decline over this modeled period--aligning with 
the reduced SO2 emissions from the major stationary sources 
in the Area.

 Table 3--Summary of 2019-2021 Peak Modeled Receptor 1-Hour SO2 Design Values and 99th Percentile Values for the Anne Arundel-Baltimore County, MD Area
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                                                  Year 1                                  Year 2                                  Year 3
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       Design value (ppb)                                     SO2 99th                                SO2 99th                                SO2 99th
                                      Date        Hour of    percentile       Date        Hour of    percentile       Date        Hour of    percentile
                                                    day         (ppb)                       day         (ppb)                       day         (ppb)
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53.1............................   10-02-2019          14          69.3     7-27-2020          12          52.3     1-20-2021          09          37.9
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    As previously discussed, this CDD modeling data includes 
approximately 3.5 months of data occurring after the attainment date 
and does not include approximately 3.5 months of data from September 
2018 through December 2018. To ensure consideration of the 36-month 
period prior to the attainment date, the EPA has analyzed the emissions 
data of these 3.5 months at the end of 2018. While emissions between 
these two 36-month periods (September 2018 through September 2021 vs. 
January 2018 through December 2021) are relatively similar, the 
substitution of the September through December 2018 data for the 
September through December 2021 data does represent an approximately 
16% increase in the total emissions during the 36-month period utilized 
for

[[Page 72774]]

assessing timely attainment. This data, compiled from the EPA's Clean 
Air Markets Program Data,\18\ is available in table 4 in this document 
and can be compared to the totals for the 2019-2021 timeframe provided 
in table 1 in this document. The total tons of SO2 emissions 
for each of these 1-year (or 12-month) periods on a 2019-2021 calendar-
year basis vs. a September 2018 through September 2021 basis, 
respectively, are as follows: Period 1--2,769 vs. 3,396; Period 2--
1,306 vs. 1,764; and Period 3--2,147 vs. 2,083.
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    \18\ Available at campd.epa.gov/.

Table 4--Emissions From Major Stationary SO2 Sources in the Anne Arundel-Baltimore County Nonattainment Area for
                                      September 2018 Through September 2021
                                             [Tons of SO2 per year]
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                      Time period                          Brandon Shores         Wagner            Total *
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Sept. 12, 2018-Sept. 11, 2019..........................            1,976.1            1,419.4            3,395.5
Sept. 12, 2019-Sept. 11, 2020..........................              779.3              984.7            1,764.0
Sept. 12, 2020-Sept. 11, 2021..........................            1,608.2              474.5            2,082.7
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* C.P. Crane is excluded from this table as the facility had ceased operation by September 12, 2018.

    Two of these periods show higher emissions on the September-to-
September basis and thus suggest that the modeled 2019-2021 peak design 
value may underestimate the 36-month September 2018 through September 
2021 peak design value in the Area. However, the modeled peak design 
value of 53.1 ppb is substantially lower than the NAAQS of 75 ppb and 
even with the increase in emissions rates for this September 2018 
through September 2021 period, the EPA has determined that the 
increased emissions are insufficient to prevent the Area from having 
reached attainment by the attainment date.
    While emission increases are not necessarily proportional to 
increases in design values, if the 16% increase in the total emissions 
led to a 16% increase in the modeled design value of 53.1 ppb, the 
adjusted modeled design value would be 61.6 ppb--still well below the 
NAAQS of 75 ppb. Comparatively, the design value for September 2018 
through September 2021 would have to increase over 40% from the modeled 
design value of 53.1 ppb for January 2019 through December 2021 in 
order to violate the NAAQS.
    Additionally, the 2022 CDD Technical Support Document quantifies 
the annual 99th percentile of the daily maximum 1-hour average 
concentrations of SO2 for the 3 years used in computing the 
modeled peak design value.\19\ These values (available in table 3 in 
this document) are 69.3 ppb, 52.3 ppb, and 37.9 ppb for Years 2019, 
2020, and 2021, respectively, and the average of these values, 53.1 
ppb, is the modeled design value. In the event that the lowest of these 
values were to be substituted with an alternative annual 99th 
percentile of the daily maximum 1-hour average concentration of 
SO2 (which could have occurred during the September 2018 
through December 2018 time period), this theoretical value would need 
to measure in excess of 103.4 ppb for the design value to violate the 
NAAQS. For comparison, the highest SO2 concentration 
observed at the nearby Riviera Beach monitor during the entirety of its 
valid and recorded monitoring periods measured 63.9 ppb. While not 
positioned exactly in the area of maximum concentration, as noted 
above, this monitor was in close proximity to the Fort Smallwood 
Complex. Considering this monitoring data and the results of the CDD 
modeling, it is highly unlikely that the September 2018 through 
December 2018 period would result in an annual 99th percentile (i.e., 
4th highest observed) of the daily maximum 1-hour average 
concentrations exceeding 103.4 ppb and thus producing a design value in 
violation of the NAAQS.
---------------------------------------------------------------------------

    \19\ See Page 44 of ``EPA CDD TSD--Technical Support Document--
Clean Data Determination for the Anne Arundel-Baltimore Counties 
SO2 Nonattainment Area__August 2022'' document.
---------------------------------------------------------------------------

    The EPA finds that the modeling analysis conducted for Anne 
Arundel-Baltimore County for the January 2019 through December 2021 
period supports the conclusion that the Area attained the 2010 1-hour 
SO2 NAAQS by the September 12, 2021 attainment date, as the 
maximum modeled design value in the Area of 53.1 ppb is lower than the 
NAAQS of 75 ppb.\20\ Consideration of this 2019-2021 modeling analysis 
in concert with emissions data from September 2018 through December 
2018 indicates that the area was in attainment for the entire 36-month 
period prior to the attainment date.
---------------------------------------------------------------------------

    \20\ See Page 43 of ``EPA CDD TSD--Technical Support Document--
Clean Data Determination for the Anne Arundel-Baltimore Counties 
SO2 Nonattainment Area__August 2022'' document.
---------------------------------------------------------------------------

E. Conclusion

    The EPA proposes to determine that the Anne Arundel-Baltimore 
County nonattainment area attained the 2010 1-hour SO2 NAAQS 
by the September 12, 2021 attainment date. The supporting bases for our 
proposed determination of attainment include: emissions within the Area 
have been reduced by 90% between 2012 to 2020; ambient air quality 
monitoring has had no exceedances of the 2010 1-hour SO2 
NAAQS since 2012 and SO2 readings have declined 59% from 
2014 to 2020; and the EPA's modeling analysis (based on 2019-2021 
SO2 emissions) predicts a maximum design value within the 
Area of 53.1 ppm--71% of the 75 ppb 2010 SO2 NAAQS--and as 
explained above, the inclusion of 2018 emissions data would not result 
in a violating design value. Notably, MDE's report to the EPA, leading 
to the subsequent issuance of the CDD, shows that the area continues to 
attain the NAAQS. The EPA's 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 and Request for Public Comment

    Based on the EPA's review of all available evidence described in 
this proposed rulemaking, the EPA is proposing to determine that the 
Anne Arundel-Baltimore County nonattainment area attained the 2010 1-
hour primary SO2 NAAQS by the statutory attainment date of 
September 12, 2021.
    Finalizing this action would not constitute a redesignation of the 
Anne Arundel-Baltimore County nonattainment area to attainment of the 
2010 1-hour SO2 NAAQS under section 107(d)(3) of the CAA. If 
this action is finalized, the Anne Arundel-Baltimore

[[Page 72775]]

County Area will remain designated nonattainment for the 2010 1-hour 
SO2 NAAQS until such time as Maryland submits to the EPA a 
redesignation request and accompanying 10-year maintenance plan, and 
the EPA determines that the area meets the CAA requirements for 
redesignation to attainment and takes action to redesignate the area.
    If finalized, this action will address the EPA's obligation under 
CAA section 179(c) to determine if the Anne Arundel-Baltimore County 
Area attained the 2010 1-hour SO2 NAAQS by the September 12, 
2021 attainment date. The EPA is soliciting public comments on this 
proposed rulemaking. These comments will be considered before taking 
final action.

IV. Statutory and Executive Order Reviews

    This action proposes to determine an area has attained the NAAQS by 
the relevant 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 13563 (76 FR 3821, January 21, 2011);
     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. 
The 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.'' The 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.'' The EPA did not 
perform an EJ analysis and did not consider EJ in this action. Due to 
the nature of the action being taken here, this action is expected to 
have a neutral to positive impact on the air quality of the affected 
area. Consideration of EJ is not required as part of this action, which 
finds that a nonattainment area had 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 
determination of attainment by attainment date for the Anne Arundel-
Baltimore County SO2 nonattainment area, does not have 
tribal implications as specified by Executive Order 13175 (65 FR 67249, 
November 9, 2000), because this action is not approved 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.

List of Subjects in 40 CFR Part 52

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

Adam Ortiz,
Regional Administrator, Region III.
[FR Doc. 2024-19436 Filed 9-5-24; 8:45 am]
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