Proposed Rule2024-22466
Finding of Failure To Attain the Primary 2010 1-Hour Sulfur Dioxide Standard for the San Juan and Guayama-Salinas Nonattainment Areas; Approval and Conditional Approval of Air Quality State Implementation Plans; Puerto Rico; Attainment Plan for the 2010 1-Hour Sulfur Dioxide Standard for the San Juan and Guayama-Salinas Nonattainment Areas
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
October 1, 2024
Issuing agencies
Environmental Protection Agency
Abstract
The Environmental Protection Agency (EPA) is proposing two actions related to attainment of the 2010 primary 1-hour sulfur dioxide (SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS or "standard"). First, the EPA is proposing to determine that the San Juan and Guayama-Salinas SO<INF>2</INF> Nonattainment Areas (NAAs) failed to attain the 2010 primary 1-hour SO<INF>2</INF> NAAQS by the applicable attainment date of April 9, 2023, based upon a technical analysis of various evidence available (i.e., weight-of-evidence analysis). If the EPA finalizes this determination as proposed, within one year, Puerto Rico will be required to submit revisions to the Puerto Rico State Implementation Plan (SIP) that, among other elements, provide for expeditious attainment of the 2010 SO<INF>2</INF> standard no later than five years from the publication date of the final rule. Second, the EPA is proposing to approve certain elements of Puerto Rico's November 22, 2022, SIP revision (hereinafter referred to as the "plan"), which was submitted to demonstrate attainment of the 2010 primary 1-hour SO<INF>2</INF> standard in the San Juan and Guayama-Salinas NAAs. Elements being proposed for approval include Puerto Rico's nonattainment new source review (NNSR) program and the base year emissions inventory. Finally, the EPA is proposing to approve in part, and conditionally approve in part, for SIP-strengthening purposes, other remaining elements of the plan, including amendments to Puerto Rico's Regulation for the Control of Atmospheric Pollution (or RCAP), which include control measures, emissions limitations, and reporting requirements for sources in the NAAs.
Full Text
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<title>Federal Register, Volume 89 Issue 190 (Tuesday, October 1, 2024)</title>
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[Federal Register Volume 89, Number 190 (Tuesday, October 1, 2024)]
[Proposed Rules]
[Pages 79828-79850]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-22466]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R02-OAR-2024-0083; FRL-11767-01-R2]
Finding of Failure To Attain the Primary 2010 1-Hour Sulfur
Dioxide Standard for the San Juan and Guayama-Salinas Nonattainment
Areas; Approval and Conditional Approval of Air Quality State
Implementation Plans; Puerto Rico; Attainment Plan for the 2010 1-Hour
Sulfur Dioxide Standard for the San Juan and Guayama-Salinas
Nonattainment Areas
AGENCY: Environmental Protection Agency (EPA).
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing two
actions related to attainment of the 2010 primary 1-hour sulfur dioxide
(SO<INF>2</INF>) National Ambient Air Quality Standard (NAAQS or
``standard''). First, the EPA is proposing to determine that the San
Juan and Guayama-Salinas SO<INF>2</INF> Nonattainment Areas (NAAs)
failed to attain the 2010 primary 1-hour SO<INF>2</INF> NAAQS by the
applicable attainment date of April 9, 2023, based upon a technical
analysis of various evidence
[[Page 79829]]
available (i.e., weight-of-evidence analysis). If the EPA finalizes
this determination as proposed, within one year, Puerto Rico will be
required to submit revisions to the Puerto Rico State Implementation
Plan (SIP) that, among other elements, provide for expeditious
attainment of the 2010 SO<INF>2</INF> standard no later than five years
from the publication date of the final rule. Second, the EPA is
proposing to approve certain elements of Puerto Rico's November 22,
2022, SIP revision (hereinafter referred to as the ``plan''), which was
submitted to demonstrate attainment of the 2010 primary 1-hour
SO<INF>2</INF> standard in the San Juan and Guayama-Salinas NAAs.
Elements being proposed for approval include Puerto Rico's
nonattainment new source review (NNSR) program and the base year
emissions inventory. Finally, the EPA is proposing to approve in part,
and conditionally approve in part, for SIP-strengthening purposes,
other remaining elements of the plan, including amendments to Puerto
Rico's Regulation for the Control of Atmospheric Pollution (or RCAP),
which include control measures, emissions limitations, and reporting
requirements for sources in the NAAs.
DATES:
Comments: Written comments must be received on or before December
2, 2024.
Public Information Sessions: The EPA will hold two public
information sessions on this proposed rulemaking in Puerto Rico on
dates and locations to be determined and announced at a later date.
For more information on the public information sessions, see
SUPPLEMENTARY INFORMATION.
ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R02-
OAR-2024-0083 at <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Although listed in the
index, some information is not publicly available, e.g., Controlled
Unclassified Information (CUI) (formally referred to as Confidential
Business Information (CBI)) or other information whose disclosure is
restricted by statute. Certain other material, such as copyrighted
material, is not placed on the internet and will be publicly available
only in hard copy form. Publicly available docket materials are
available electronically through <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow
the online instructions for submitting comments. Once submitted,
comments cannot be edited or removed from <a href="http://Regulations.gov">Regulations.gov</a>. The EPA may
publish any comment received to its public docket. Do not submit
electronically any information you consider to be CUI 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, the full EPA public comment
policy, information about CUI or multimedia submissions, and general
guidance on making effective comments, please visit <a href="https://www.epa.gov/dockets/commenting-epa-dockets">https://www.epa.gov/dockets/commenting-epa-dockets</a>.
Docket: All documents in the electronic docket are listed in the
<a href="http://www.regulations.gov">www.regulations.gov</a> index. Although listed in the index, some
information is not publicly available, i.e., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, is not placed on the internet and will be
publicly available only in hard copy form. The files will also be made
available by appointment for public inspection between the hours of
9:00 a.m. and 4:30 p.m. weekdays except for legal holidays. Contact the
person(s) listed in the FOR FURTHER INFORMATION CONTACT paragraph below
to make an appointment. If possible, please make the appointment at
least two working days in advance of your visit. We may charge you a
reasonable fee for copying parts of the docket.
FOR FURTHER INFORMATION CONTACT: Nicholas Ferreira, Environmental
Protection Agency, Region 2, Air Programs Branch, 290 Broadway, New
York, New York 10007-1866, at (212) 637-3127, or by email at
<a href="/cdn-cgi/l/email-protection#d5b3b0a7a7b0bca7b4fbbbbcb6bdbab9b4a695b0a5b4fbb2baa3"><span class="__cf_email__" data-cfemail="82e4e7f0f0e7ebf0e3acecebe1eaedeee3f1c2e7f2e3ace5edf4">[email protected]</span></a>, and/or Andres Febres, Environmental
Protection Agency, Region 2, Caribbean Environmental Protection
Division Office, City View Plaza II, #48 RD. 165 km 1.2, Guaynabo,
Puerto Rico, 00968-8069, at (787) 977-5801, or by email at <a href="/cdn-cgi/l/email-protection#7d1b181f0f180e50101c0f0914131807531c13190f180e3d180d1c531a120b"><span class="__cf_email__" data-cfemail="412724233324326c2c203335282f243b6f202f25332432012431206f262e37">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Public Information Session
The EPA intends to provide two public information sessions
concerning this proposed rule. The EPA will announce the date, time,
and location for each session on its website. These public information
sessions will provide informal opportunities for members of the public
to learn about this proposed action. The EPA anticipates these sessions
will allow the public to be better informed when submitting formal
comments during the 60-day comment period for this proposed action.
A translator will be present at the public engagement sessions to
ensure participants are able to understand the information provided by
the EPA. There will be no recording or transcript of these public
information sessions since these sessions are not considered to be
formal public hearings. Statements made and/or questions asked at these
sessions will not be considered formal comments on the proposed rule
and will not be included in the EPA's response to comments, unless
submitted as a formal comment on the record.
Members of the public who wish to formally comment should do so
during the 60-day public comment period provided following the
publication of this proposed rule.
This notice is organized as follows:
Table of Contents
I. Background
A. The 2010 SO<INF>2</INF> NAAQS
B. Designations and Attainment Date Requirements for the 2010
SO<INF>2</INF> NAAQS
C. Finding of Failure To Submit and SIP Submittal
D. Puerto Rico's Integrated Resource Plan
II. What is the EPA proposing?
III. Proposed Determination of Failure To Attain and the Associated
Consequences
A. Applicable Statutory and Regulatory Provisions
B. San Juan and Guayama-Salinas SO<INF>2</INF> Monitoring
Networks and Considerations
C. SO<INF>2</INF> Data Considerations and the EPA's Proposed
Determination
1. SO<INF>2</INF> Monitor Data
2. Modeling Data and Control Strategy Timeline
3. Failure To Implement the Control Strategy
4. SO<INF>2</INF> Emissions Data
5. Weight-of-Evidence Analysis Conclusions and the EPA's
Proposed Determination
D. Consequences for SO<INF>2</INF> NAAs Failing To Attain
Standards by Attainment Dates
IV. Requirements for SO<INF>2</INF> Nonattainment Area Plans
V. Review of Modeled Attainment Demonstration
A. Modeling Approach
B. Area of Analysis
C. Receptor Grid
D. Meteorological Data
E. Source Characterization
F. Emissions Data
G. Retirements and Emission Limits
H. Background Concentrations
I. Summary of Results
VI. Review of Other Plan Requirements
A. Emissions Inventory
B. RACM and RACT and Enforceable Emission Limitations and
Control Measures
C. New Source Review
D. Reasonable Further Progress
[[Page 79830]]
E. Contingency Measures
F. Conformity
VII. Puerto Rico's New Source Review Program
VIII. The EPA's Evaluation of Rule 425
IX. Environmental Justice Considerations
X. The EPA's Proposed Action
XI. Incorporation by Reference
XII. Statutory and Executive Order Reviews
I. Background
A. The 2010 SO2 NAAQS
Under section 109 of the Clean Air Act (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 the attainment and maintenance
of which the EPA has determined, including a margin of safety, are
requisite to protect the public health. The secondary NAAQS represent
ambient air quality standards the attainment and maintenance of which
the EPA has determined are requisite to protect the public welfare from
any known or anticipated adverse effects associated with the presence
of such air pollutant in the ambient air.
Under the CAA, the EPA must establish NAAQS for criteria
pollutants, including SO<INF>2</INF>. SO<INF>2</INF> is primarily
released to the atmosphere through the burning of fossil fuels by power
plants and other industrial facilities. Short-term exposure to
SO<INF>2</INF> 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
SO<INF>2</INF>. Sulfur oxides at high concentrations in ambient air can
also react with compounds to form small particulates that can penetrate
deeply into the lungs and cause health problems.
The EPA first established primary SO<INF>2</INF> standards in 1971
at 0.14 parts per million (ppm) over a 24-hour averaging period and 0.3
ppm over an annual averaging period.\1\ On June 22, 2010, the EPA
revised the primary NAAQS for SO<INF>2</INF> and published a new 1-hour
primary SO<INF>2</INF> NAAQS of 75 parts per billion (ppb).\2\ The
intent of this revision is to provide increased protection of public
health, providing for revocation of the 1971 primary annual and 24-hour
SO<INF>2</INF> standards for most areas of the country following area
designations under the new NAAQS.
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\1\ See 36 FR 8186 (April 30, 1971).
\2\ See 75 FR 35520 (June 22, 2010), codified at 40 CFR
50.17(a)-(b).
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The 2010 standard is met at an ambient air quality monitoring site
when the 3-year average of the annual 99th percentile of daily maximum
1-hour average concentrations does not exceed 75 ppb, or 0.075 ppm, as
determined in accordance with Appendix T of 40 CFR part 50.17. The EPA
established the SO<INF>2</INF> NAAQS based on significant evidence and
numerous studies demonstrating that serious health effects are
associated with short-term exposures to SO<INF>2</INF> emissions
ranging from five minutes to 24 hours, including an array of adverse
respiratory effects such as narrowing of the airways, which can cause
difficulty breathing (bronchoconstriction) and increased asthma
symptoms. For more information regarding the health impacts of
SO<INF>2,</INF> please refer to the June 22, 2010 final rulemaking. See
75 FR 35520, codified at 40 CFR 50.17.
B. Designations and Attainment Date Requirements for the 2010 SO2 NAAQS
Following promulgation of a new or revised NAAQS, the EPA is
required by the CAA to designate areas throughout the United States as
attaining or not attaining the NAAQS; this designation process is
described in section 107(d)(1)-(2) of the CAA. For the 2010
SO<INF>2</INF> NAAQS, the EPA defined a nonattainment area (NAA) as an
area that the EPA determined violates the 2010 1-hour primary
SO<INF>2</INF> NAAQS and/or contributes to a violation in a nearby
area, based on the most recent 3 years of air quality monitoring data,
appropriate dispersion modeling analysis, and any other relevant
information.\3\
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\3\ See 83 FR 1101 (Jan. 9, 2018).
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On January 9, 2018, the EPA, as part of the third round \4\ of area
designations for the 2010 1-hour primary SO<INF>2</INF> NAAQS,
designated six areas of the country as nonattainment, including the San
Juan and Guayama-Salinas NAAs.\5\ These area designations had an
effective date of April 9, 2018.
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\4\ 83 FR 1098 (Jan. 9, 2018), codified at 40 CFR part 81,
subpart C.
\5\ The EPA completed its first round of initial area
designations for the 2010 1-hour primary SO<INF>2</INF> NAAQS
effective October 4, 2013. See 78 FR 47191 (Aug. 5, 2013). A second
round of designations was effective September 12, 2016, with a
supplement effective January 17, 2017. See 81 FR 45039 (July 12,
2016) and 81 FR 89870 (Dec. 13, 2016), respectively. A fourth round
of designations was effective April 30, 2021. See 86 FR 16055 (Mar.
26, 2021).
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Areas designated nonattainment for the SO<INF>2</INF> NAAQS are
subject to the general NAA planning requirements of CAA section 172 and
to the SO<INF>2</INF>-specific planning requirements of subpart 5 of
part D of Title I of the CAA (sections 191 and 192). All components of
the SO<INF>2</INF> part D nonattainment area SIP, including the
emissions inventory, attainment demonstration, reasonably available
control measures (RACM) and reasonably available control technology
(RACT), enforceable emissions limitations and control measures,
Reasonable Further Progress (RFP) plan, nonattainment New Source Review
(NNSR) program, and contingency measures, are due to the EPA within 18
months of the effective date of designation of a nonattainment area
under CAA section 191.
Therefore, the nonattainment area SIPs for areas designated
effective April 9, 2018, were due on October 9, 2019. These SIPs are
required to demonstrate that their respective areas will attain the
2010 1-hour primary SO<INF>2</INF> NAAQS as expeditiously as
practicable, but no later than five years from the effective date of
designation, or by April 9, 2023, for the San Juan and Guayama-Salinas
NAAs.
C. Finding of Failure To Submit and SIP Submittal
For a number of SO<INF>2</INF> NAAs, including the San Juan and
Guayama-Salinas NAAs, the EPA published an action on November 3, 2020,
effective December 3, 2020, finding that Puerto Rico and other
pertinent states had failed to submit the required SO<INF>2</INF>
nonattainment plan by the submittal deadline. See 85 FR 69504. This
finding initiated a deadline under CAA section 179(a) for the potential
imposition of two sanctions clocks related to new source review offsets
(i.e., ``2-to-1 offsets'') and highway funding, within 18 and 24 months
of the findings, respectively, unless the states and territories
subject to the finding made the necessary complete SIP submittal.
Additionally, this finding initiated a deadline under CAA section
110(c) for the EPA to promulgate a Federal Implementation Plan (FIP)
within two years of the finding unless, by that time, the EPA had
approved the submittal as meeting applicable requirements.
On June 3, 2022, the 2-to-1 offset sanctions took effect within the
Puerto Rico NAAs. Before the highway funding sanctions could go into
effect within the NAAs on December 3, 2022, the Puerto Rico Department
of Natural and Environmental Resources (PRDNER) submitted a
nonattainment plan for the San Juan and Guayama-Salinas NAAs (i.e., San
Juan and Guayama-Salinas SO<INF>2</INF> plan) on November 22, 2022, and
the EPA deemed the PRDNER's submittal administratively and technically
complete on December 2, 2022. As a
[[Page 79831]]
result of the EPA's determination, the 2-to-1 offset sanctions clock
was stopped and the highway sanctions never took effect, per the EPA's
sanctions regulations at 40 CFR 52.31; however, this completeness
determination did not terminate the EPA's FIP obligation that was
triggered by the EPA's November 3, 2020, Finding of Failure to Submit.
Within the San Juan and Guayama-Salinas SO<INF>2</INF> plan,
amendments to Puerto Rico's RCAP were submitted for the EPA's approval.
The RCAP amendments incorporate the SO<INF>2</INF> control measures and
nonattainment provisions of the SO<INF>2</INF> plan and would become
federally enforceable upon final approval by the EPA. The RCAP
amendments consist of revisions to Rule 102, ``Definitions,'' as well
as the adoption of Rule 210, ``Non-Attainment Provisions,'' and Rule
425, ``Provisions for SO<INF>2</INF> Non-Attainment Areas.'' \6\ The
PRDNER's permitting requirements to construct new sources or modify
major sources of emissions of SO<INF>2</INF> and other pollutants in
NAAs, including the San Juan and Guayama-Salinas NAAs, are set forth in
the revisions to Rule 102, ``Definitions,'' and the recently adopted
Rule 210, ``Nonattainment Provisions.'' Finally, the recently
promulgated Rule 425 was adopted to include control measures, emission
limits, test methods and procedures, reporting and recordkeeping
requirements, and contingency measures for the San Juan and Guayama-
Salinas NAAs.
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\6\ The RCAP amendments were approved by the Secretary of the
PRDNER on November 21, 2022, and became effective on the same day.
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D. Puerto Rico's Integrated Resource Plan
The compliance strategy for Puerto Rico's SIP, and the accompanying
RCAP amendments, were developed based on the most recent Integrated
Resource Plan (IRP) approved by the Puerto Rico Energy Bureau
(PREB),\7\ as well as additional updates provided by the PREB, which
considered emission unit retirements within the San Juan and Guayama-
Salinas NAAs following the integration of renewable energy sources.
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\7\ Final Resolution and Order on the Puerto Rico Electric Power
Authority's Integrated Resource Plan, Review of the Puerto Rico
Electric Power Authority Integrated Resource Plan, Case No. CEPR-AP-
2018-0001, August 24, 2020 (``Approved IRP''), available at <a href="https://energia.pr.gov/wp-content/uploads/sites/7/2020/08/AP20180001-IRP-Final-Resolution-and-Order.pdf">https://energia.pr.gov/wp-content/uploads/sites/7/2020/08/AP20180001-IRP-Final-Resolution-and-Order.pdf</a>.
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The IRP is a plan that is required under Puerto Rico law, with the
purpose of providing cost-effective electrical power to meet Puerto
Rico's energy demand over a twenty-year planning period, while
considering energy conservation, resiliency, reliability, efficiency,
transparency, and the environment. Under Act 57-2014,\8\ a Puerto Rico
law known as the Puerto Rico Energy Transformation and RELIEF Act, the
Puerto Rico Electric Power Authority (PREPA), or the electric utility
responsible for the operation of the electric power transmission and
distribution system (currently LUMA Energy), is required to prepare an
IRP for the PREB's approval, which considers reasonable resources to
satisfy energy demand for up to a twenty-year period. Puerto Rico's
electric utility is also responsible for updating the plan at least
every three years to reflect changes in energy market conditions,
regulations, fuel prices, and capital costs. Pursuant to Act 57-2014,
the PREB is responsible for establishing and implementing regulations
to ensure the capacity, reliability, safety, and efficiency of Puerto
Rico's electrical system. This includes evaluating and approving the
IRP, overseeing and ensuring compliance, and implementation.
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\8\ See <a href="https://energia.pr.gov/wp-content/uploads/sites/7/2015/10/AN-ACT-57-20141.pdf">https://energia.pr.gov/wp-content/uploads/sites/7/2015/10/AN-ACT-57-20141.pdf</a>.
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On August 24, 2020, the PREB issued the IRP Final Order, based on
the IRP submitted by PREPA. The Approved IRP included a Modified
Preferred Resource Plan (Action Plan) considering specific power
generation capacity additions and retirements. In the Approved IRP, the
PREB established a schedule for minimum quantities of renewable
resources, and battery energy storage resources to be procured through
the Requests for Proposals processes, to be completed by June 2023. The
Approved IRP also directed PREPA to submit a renewable resource and
battery energy storage procurement plan. Specifically, the Approved IRP
included a program for six tranches of procurement for renewable energy
and battery storage resources that would add 3,750 MW of renewable
sources to the energy grid. Based on the procurement of renewable
resources to be integrated in the Puerto Rico Electric System, the
Approved IRP authorized the retirement of PREPA's older, oil-fired
steam resources, combined cycle turbines and peaking units for the
period between 2021 and 2025.
The PREB provided an updated schedule for emission unit retirements
and the integration of new renewable energy and battery storage
resources via letter to the PRDNER on October 18, 2022, which was
updated on November 15, 2022.\9\ The IRP was scheduled to be revised
and submitted to the PREB by June 28, 2024 by LUMA, the current
operator of Puerto Rico's electrical power transmission and
distribution system.\10\ However, on June 7, 2024, LUMA requested that
the PREB suspend the June 28 deadline, due to modeling delays
associated with its base case scenario.\11\ LUMA requested that the
2024 IRP be filed on May 16, 2025, with an analysis of four
supplemental scenarios proposed to be filed on June 19, 2025.\12\ On
August 20, 2024, the PREB denied LUMA's request for an extension, until
May 16, 2025, for a full IRP.
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\9\ The October 18, 2022 and November 15, 2022 letters are
available in the docket of this rulemaking.
\10\ On June 22, 2020, LUMA entered into an operation and
maintenance agreement under which it will operate the transmission
and distribution system previously operated by PREPA. PREPA
maintains ownership over the transmission and distribution system.
See <a href="https://www.p3.pr.gov/wp-content/uploads/2020/06/executed-consolidated-om-agreement-td.pdf">https://www.p3.pr.gov/wp-content/uploads/2020/06/executed-consolidated-om-agreement-td.pdf</a>.
\11\ See LUMA's Motion in Compliance with Resolution and Order
of June 18, 2024, and Submitting Second Revised IRP Filing Schedule,
dated June 28, 2024, at ] 18, available at <a href="https://energia.pr.gov/wp-content/uploads/sites/7/2024/07/20240628-AP20230004-Motion-in-Compliance-with-Resolution-and-Order-of-June-18-2024-and-Submitting-Second-Revised-IRP-Filing-Schedule.pdf">https://energia.pr.gov/wp-content/uploads/sites/7/2024/07/20240628-AP20230004-Motion-in-Compliance-with-Resolution-and-Order-of-June-18-2024-and-Submitting-Second-Revised-IRP-Filing-Schedule.pdf</a>.
\12\ See id. at ] 27.
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The PREB ordered LUMA to file the Preferred Resource Plan and
``salient components'' of the base case and alternative case scenarios
by no later than November 29, 2024, and ordered LUMA to file certain
transmission and distribution related requirements by no later than
February 28, 2025.\13\
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\13\ See PREB Resolution and Order, dated August 20, 2024,
available at <a href="https://energia.pr.gov/wp-content/uploads/sites/7/2024/08/20240820-AP20230004-Resolution-and-Order.pdf">https://energia.pr.gov/wp-content/uploads/sites/7/2024/08/20240820-AP20230004-Resolution-and-Order.pdf</a>.
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II. What is the EPA proposing?
The EPA is proposing several actions in this rulemaking. First,
under CAA section 179(c), the EPA is proposing to determine that the
San Juan and Guayama-Salinas SO<INF>2</INF> NAAs failed to attain the
2010 1-hour primary SO<INF>2</INF> standard by the statutory attainment
date of April 9, 2023. The EPA's proposed Finding of Failure to Attain
(FFA) determination is based on a weight-of-evidence analysis that
demonstrates that the San Juan and Guayama-Salinas areas failed to
attain the standard by the mandatory attainment date. The EPA's
reasoning for this decision is described in Section III of the
preamble.
Second, the EPA is proposing to approve certain elements of Puerto
Rico's SO<INF>2</INF> plan, which was submitted to demonstrate how the
San Juan and Guayama-Salinas areas would meet the 2010 1-hour
SO<INF>2</INF> standard in the San Juan and Guayama-Salinas NAAs. The
[[Page 79832]]
EPA outlines the requirements for nonattainment plans under CAA section
172(c), and reviews Puerto Rico's plan against these requirements in
Sections IV, V and VI of this preamble.
Although Puerto Rico submitted its plan to satisfy CAA section
172(c) requirements, the EPA is proposing to approve only specific
elements at this time for compliance with the CAA. The elements being
proposed for approval include Puerto Rico's NNSR program and base year
emissions inventory. The EPA is not proposing action on other elements
of the plan, such as the attainment demonstration, RFP, RACM/RACT,
emission limitation as necessary to provide for NAAQS attainment, and
contingency measures. The EPA will address whether Puerto Rico is
meeting its statutory obligations for those elements in a future
rulemaking. Finally, amendments to the RCAP, which Puerto Rico
submitted with the plan, are being proposed for approval, in part, and
conditional approval, in part, based on providing SIP-strengthening.
III. Proposed Determination of Failure To Attain and the Associated
Consequences
A. Applicable Statutory and Regulatory Provisions
Section 179(c)(1) of the CAA requires the EPA to determine whether
a NAA attained an applicable standard by the applicable attainment date
based on the area's air quality as of the attainment date. In
determining the attainment status of SO<INF>2</INF> NAAs, the EPA may
consider ambient monitoring data, air quality dispersion modeling, and/
or a demonstration that the control strategy in the SIP has been fully
implemented.\14\
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\14\ EPA, Guidance for 1-Hour SO<INF>2</INF> Nonattainment Area
SIP Submissions (April 2014) (``2014 SO<INF>2</INF> Guidance''), 49.
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Under the EPA's regulations in 40 CFR 50.17, and in accordance with
40 CFR part 50 Appendix T, the 2010 1-hour annual SO<INF>2</INF>
standard is met when the design value is less than or equal to 75 ppb.
Design values are calculated by computing the three-year average of the
annual 99th percentile daily maximum 1-hour average concentrations.\15\
An SO<INF>2</INF> 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.\16\
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\15\ As defined in 40 CFR part 50, Appendix T section 1(c),
daily maximum 1-hour values refer to the maximum 1-hour
SO<INF>2</INF> concentration values measured from midnight to
midnight that are used in the NAAQS computations.
\16\ See 40 CFR part 50, Appendix T sections 1(c), 3(b), 4(c),
and 5(a).
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A determination of whether an area's air quality meets applicable
standards is generally based upon the most recent three calendar 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.\17\ Data from
ambient air monitors operated by state and local agencies in compliance
with the EPA monitoring requirements must be submitted to AQS.\18\
Monitoring agencies annually certify that these data are accurate to
the best of their knowledge.\19\ All certified SO<INF>2</INF> air
monitoring data are used to calculate design values that are used to
determine the area's air quality status in accordance with 40 CFR part
50, Appendix T.
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\17\ AQS is the EPA's repository of ambient air quality data.
\18\ 40 CFR 58.16.
\19\ 40 CFR 58.15.
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In addition to utilizing ambient monitoring data to make
determinations of attainment by the attainment date, the EPA considers
air quality dispersion modeling and/or a demonstration that the control
strategy in the SIP has been fully implemented. With regard to the use
of monitoring data for such determinations, EPA's 2014 Nonattainment
SO<INF>2</INF> Guidance \20\ specifically notes that if the EPA
determines the air quality monitors located in the affected area are
located in the area of maximum concentration, the EPA may be able to
use the data from these monitors to make the determination of
attainment without the use of air quality modeling data.\21\ In this
case, there are SO<INF>2</INF> monitors within the San Juan and
Guayama-Salinas NAAs; however, there is no evidence indicating that the
monitors are located within the areas of expected maximum
concentration.
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\20\ EPA, Guidance for 1-Hour SO<INF>2</INF> Nonattainment Area
SIP Submissions (April 2014) (``2014 SO<INF>2</INF> Guidance''),
p.49, available at <a href="https://www.epa.gov/sites/default/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf">https://www.epa.gov/sites/default/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf</a>.
\21\ Id., p.50.
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Due to insufficient monitoring data collected for all three years
in the 2020-2022 data period for the SO<INF>2</INF> monitors, the EPA
is unable to determine valid monitor-based 2020-2022 design values. As
a result, the EPA has considered available air modeling data submitted
by the PRDNER with its November 22, 2022, SIP revision, as well as the
designation modeling the EPA used to initially determine that the areas
were in nonattainment, to assess whether the areas attained by the
attainment date.
According to the EPA's Modeling Technical Assistance Document
(TAD),\22\ for the purpose of modeling to characterize air quality for
use in designations, the recommended approach is to use the most recent
3 years of actual emissions data and concurrent meteorological data.
However, the TAD also indicates that it would be acceptable to use
allowable emissions in the form of the most recently permitted
(referred to as PTE or allowable) emissions rate that is federally
enforceable and effective. When relying on a modeling demonstration
based on allowable emissions for purposes of determining attainment by
the attainment date, the EPA looks to whether the emission limit or
limits were adopted and whether the relevant source or sources were
complying with those modeled limits prior to the attainment date. That
is, when determining attainment by the attainment date using air
quality modeling of allowable emissions, the EPA looks to whether the
state/commonwealth has demonstrated that the control strategy in the
SIP has been fully implemented. This is necessary because a modeling
demonstration based on allowable emissions is not itself sufficient
since, without the supporting emissions information reflected in the
control strategy, there would be no way to confirm that the actual
emissions were below the modeled limits within the period under review.
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\22\ See <a href="https://www.epa.gov/so2-pollution/technical-assistance-documents-implementing-2010-sulfur-dioxide-standard">https://www.epa.gov/so2-pollution/technical-assistance-documents-implementing-2010-sulfur-dioxide-standard</a>.
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The EPA would like to clarify that a significant amount of
information is required for the EPA to accurately conduct its own air
quality dispersion modeling to determine attainment by the attainment
date for these two NAAs. This information is not readily available, and
the limited data currently accessible to the Agency raises concerns
about the reliability of new modeling. Specifically, the EPA does not
have access to fuel use data or concurrent meteorological data and
continuous emissions monitoring systems (CEMS) data from the stacks at
the PREPA facilities (the EPA also believes that CEMS provide
acceptable historical
[[Page 79833]]
emissions information). As a result, it is the EPA's position that any
air quality dispersion modeling the EPA would perform for the purpose
of this determination would not be representative of air quality within
the areas. Thus, the EPA is not performing air quality dispersion
modeling to support its determination that the areas have failed to
attain by their attainment dates. The EPA will instead consider the
modeling conducted and provided by the PRDNER in its November 22, 2022,
SIP submission, which shows that controls that PRDNER anticipates will
lead to attainment were not in place prior to the areas' attainment
dates.
As noted earlier in this section, the EPA may also consider whether
the state (or commonwealth) has demonstrated that the control strategy
in the SIP has been fully implemented. That said, the PRDNER's control
strategy has not been implemented, nor has it been approved by the EPA.
As a result, the EPA cannot determine that the subject sources have
achieved compliance with either the PRDNER's control strategy as
submitted to the EPA, or a SIP-approved strategy. To address this, the
EPA is proposing a determination that the areas did not attain by their
attainment date which is based on a technical analysis of various
evidence available (i.e., weight-of-evidence analysis): including the
control strategy timeline Puerto Rico identified and adopted into its
RCAP, which was determined in coordination with the air quality
dispersion modeling submitted within its November 22, 2022 SIP revision
as well as the EPA's designation modeling; Puerto Rico's failure to
implement the control strategy in a timely manner thus far; and the
EPA's review of annual facility-wide emissions data from January 2020
through December 2022 for the PREPA San Juan, PREPA Palo Seco, and
PREPA Aguirre facilities located within the NAAs--as described in
Sections III.B and III.C of this notice. As noted, the determination of
whether the monitors are located in the area of maximum concentration
is not needed here, because a demonstration is not being made that the
NAAs have attained the 2010 SO<INF>2</INF> NAAQS by the April 9, 2023
attainment date.
B. San Juan and Guayama-Salinas SO2 Monitoring Networks and
Considerations
Section 110(a)(2)(B)(i) of the CAA requires states to establish and
operate air monitoring networks to compile data on ambient air quality
for all criteria pollutants. The EPA's monitoring requirements are
specified by regulation in 40 CFR part 58. These requirements are
applicable to state, and where delegated, local air monitoring agencies
that operate criteria pollutant monitors. The regulations in 40 CFR
part 58 establish specific requirements for operating air quality
surveillance networks to measure ambient concentrations of
SO<INF>2</INF>, including requirements for measurement methods, network
design, quality assurance procedures, and the minimum number of
monitoring sites designated as SLAMS.
In sections 4.4 and 4.5 of Appendix D to 40 CFR part 58, the EPA
specifies the minimum requirements for SO<INF>2</INF> monitoring sites
to be classified as SLAMS. SLAMS produce data that are eligible for
comparison with the NAAQS, and therefore, the monitor must be an
approved federal reference method (FRM), federal equivalent method
(FEM), or approved regional method (ARM) monitor, pursuant to section 2
of Appendix C to 40 CFR part 58. Additionally, Appendix A to 40 CFR
part 58 specifies quality assurance requirements for SLAMS monitors.
During the 2020-2022 data period, the PRDNER operated three
SO<INF>2</INF> SLAMS in the San Juan and Guayama-Salinas SO<INF>2</INF>
NAAs. In the San Juan NAA, SLAMS monitors are in operation at
Bayam[oacute]n (AQS Site ID 72-021-0010, Avenue Central Correcional)
and at Cata[ntilde]o (AQS Site ID 72-033-0004, Northwest Street at the
11 Final Street, Las Vegas). In the Guayama-Salinas NAA, a SLAMS
monitor is located at Guayama (AQS Site ID 72-057-0011, Road #3 Cuartel
Vehiculos Hurtados).
C. SO2 Data Considerations and the EPA's Proposed Determination
1. SO<INF>2</INF> Monitor Data
As discussed in Section I.B of this preamble, the applicable
attainment date for the San Juan and Guayama-Salinas areas was April 9,
2023. In accordance with Appendix T to 40 CFR part 50, determinations
of SO<INF>2</INF> NAAQS compliance are based on three consecutive
calendar years of data. To determine the air quality as of the
attainment date in the nonattainment area, the EPA reviewed the
available data collected during the three calendar years immediately
preceding the attainment date for the San Juan and Guayama-Salinas
areas (i.e., January 1, 2020 through December 31, 2022), as well as
SO<INF>2</INF> emissions data that resulted from the burning of fossil
fuels for electricity generation at the PREPA San Juan, PREPA Palo
Seco, and PREPA Aguirre facilities.
The available annual 99th percentile daily maximum 1-hour average
SO<INF>2</INF> data at each monitoring site within the San Juan and
Guayama-Salinas areas for the 2020-2022 period are presented in Tables
1 and 2 below. Moreover, the 1-hour SO<INF>2</INF> design values at the
Bayam[oacute]n, Cata[ntilde]o, and Guayama SO<INF>2</INF> monitoring
sites for the 2020-2022 period are shown in Tables 1 and 2 below.\23\
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\23\ A design value is a statistic that describes the air
quality status of a given location relative to the level of the
NAAQS. SO<INF>2</INF> design values at the Bayam[oacute]n,
Cata[ntilde]o, and Guayama SO<INF>2</INF> monitoring sites for the
2020-2022 period were obtained from the EPA's Air Quality Design
Values web page. See <a href="https://www.epa.gov/air-trends/air-quality-design-values#report">https://www.epa.gov/air-trends/air-quality-design-values#report</a>.
\24\ Monitoring sites must meet the data completeness
requirements listed in Appendix T to 40 CFR part 50 in order to have
a valid design value. Annual 99th percentile daily maximum 1-hour
averages with an asterisk (*) indicate that those values do not meet
these completeness requirements.
Table 1--2020-2022 SO2 Monitor Data for the San Juan Area \24\
----------------------------------------------------------------------------------------------------------------
2020 Annual 2021 Annual 2022 Annual
99th 99th 99th
percentile percentile percentile 2020-2022 SO2
SLAMS monitor AQS site ID daily maximum daily maximum daily maximum design value
1-hour average 1-hour average 1-hour average (ppb)
(ppb) (ppb) (ppb)
----------------------------------------------------------------------------------------------------------------
Bayam[oacute]n................ 72-021-0010 * 35.4 9.8 10.8 Not Valid (NV).
Cata[ntilde]o................. 72-033-0004 * 17.6 * 18.2 * 0.0 NV
----------------------------------------------------------------------------------------------------------------
[[Page 79834]]
Table 2--2020-2022 SO2 Monitor Data for the Guayama-Salinas Area \25\
----------------------------------------------------------------------------------------------------------------
2020 Annual 2021 Annual 2022 Annual
99th 99th 99th
percentile percentile percentile 2020-2022 SO2
SLAMS monitor AQS site ID daily maximum daily maximum daily maximum design value
1-hour average 1-hour average 1-hour average (ppb)
(ppb) (ppb) (ppb)
----------------------------------------------------------------------------------------------------------------
Guayama......................... 72-057-0011 NV * 3.4 * 3.4 NV
----------------------------------------------------------------------------------------------------------------
The attainment date for the areas was April 9, 2023. In order for
the EPA to determine that the areas attained by the April 9, 2023
attainment date based solely on air quality monitoring data, the design
value based upon complete, quality-assured monitored air quality data
from three consecutive years (2020-2022) at each eligible monitoring
site must be equal to or less than 75 ppb for the 1-hour standard, and
air quality modeling would need to show that there was an air quality
monitor located in the area of maximum concentration.
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\25\ Monitoring sites must meet the data completeness
requirements listed in Appendix T to 40 CFR part 50 in order to have
a valid design value. Annual 99th percentile daily maximum 1-hour
averages with an asterisk (*) indicate that those values do not meet
these completeness requirements.
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The EPA has not been provided with nor is the EPA aware of
information indicating that these three monitors are located within the
area of maximum concentration. Therefore, this information alone is
insufficient to support a determination of whether the NAAs attained
the 2010 SO<INF>2</INF> NAAQS by the attainment date.
2. Modeling Data and Control Strategy Timeline
The EPA's Modeling TAD notes that for area designations under the
2010 SO<INF>2</INF> NAAQS, the American Meteorological Society/
Environmental Protection Agency Regulatory Model (AERMOD) modeling
system should be used, unless use of an alternative model can be
justified. As previously stated, the EPA did not conduct its own air
dispersion modeling demonstration with AERMOD and is instead relying on
the air dispersion modeling conducted by the PRDNER, as provided within
its attainment demonstration submitted to the EPA on November 22, 2022.
The PRDNER's attainment demonstration utilized version 21112 of
AERMOD, with default options. Version 21112 of AERMOD was the most
recent version at the time the attainment demonstration modeling was
conducted. Further information pertaining to the PRDNER's modeling,
such as the area of analysis, source characterization, emissions,
meteorology and surface characteristics, geography and terrain, and
background concentrations, can be found in Section V, ``Review of
Modeled Attainment Demonstration,'' of this proposed rulemaking. For
purposes of the FFA, the EPA finds the PRDNER's modeling was conducted
in a technically correct manner, consistent with the EPA's modeling
guidance.
The control strategy the PRDNER identified and modeled to provide
for attainment of the standard relies primarily on the retirement of
PREPA electricity generation units and is based on the integration of
new renewable energy projects (as determined by PREB). However, this
control strategy was not scheduled to start until February 2023,
specifically involving the transition of several units to ultra-low
sulfur diesel fuel. Specifically, the retirement of PREPA units was
scheduled to occur in phases, from June 30, 2023, through December 31,
2025, at PREPA San Juan and PREPA Palo Seco, and from December 31,
2025, through December 31, 2029, at PREPA Aguirre.
The projected attainment dates identified by the PRDNER, via its
modeling of the control strategy were December 31, 2025, for the San
Juan area and December 31, 2029, for the Guayama-Salinas Area. Although
these attainment dates for the control strategy were identified as
being as expeditious as practicable given the integration of renewable
energy sources, they provide for attainment of the standard after the
CAA mandatory attainment date of April 9, 2023. Thus, based on the
PRDNER's own modeling of its control strategy, and unless that control
strategy was implemented in a more expeditious manner than originally
planned, the control strategy did not provide for attainment by the
statutory deadline.
Additionally, the EPA notes that the Round 3 designation modeling
\26\ showed modeled concentrations well in exceedance of the standard
within the San Juan and Guayama-Salinas areas, therefore requiring
significant measures to be implemented to reduce such concentrations.
Since it is the EPA's understanding that the emissions controls
necessary to achieve attainment of the standard were not implemented
(as further discussed in Section III.C.3 of this notice), the EPA
proposes to find that attainment of the standard was not provided by
the mandatory attainment date.
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\26\ The San Juan and Guayama-Salinas areas were designated
nonattainment based on Puerto Rico's modeling, which indicated that
the highest predicted 99th percentile daily maximum 1-hour
concentration (i.e., modeled concentration) within the chosen
modeling domain to be 422 [mu]g/m\3\ (equivalent to 161 ppb) for the
San Juan area and 252 [mu]g/m\3\ (equivalent to 96 ppb) for the
Guayama-Salinas area. These modeled concentrations, which are above
the NAAQS level of 196.4 [mu]g/m\3\ (equivalent to the 2010
SO<INF>2</INF> NAAQS of 75 ppb reflecting a 2.619 [mu]g/m\3\
conversion factor), were based on actual emissions from the
facilities. The TSD for the Round 3 designations is found within the
docket for this rulemaking.
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3. Failure To Implement the Control Strategy
As of the time of signature of this proposed rulemaking, the EPA
has no evidence indicating that the control strategy identified by the
PRDNER and adopted within the RCAP in support of its November 22, 2022
SIP submission has in fact been implemented. Instead, available
evidence indicates that the strategy has not yet been implemented, and
that therefore, emissions reductions expected under the strategy have
not yet been achieved. Although not federally SIP-approved, this
absence of strategy implementation is considered as part of EPA's
weight of evidence analysis.
The control strategy under the PRDNER's SIP submission is based on
the retirement of emission units and the implementation of emission
limits based on the use of ULSD or LNG for units that will continue to
operate and generate electricity at the PREPA San Juan, PREPA Aguirre,
and PREPA Palo Seco facilities. As previously noted, the control
strategy was to begin in February 2023, specifically involving the
transition of several units to ULSD. The PREPA unit retirements were to
occur in phases--from June 30, 2023, through December 31, 2025, at
PREPA San Juan and PREPA Palo Seco, and from December 31, 2025, through
December 31, 2029, at PREPA Aguirre.
At PREPA Palo Seco and PREPA Palo San Juan, several boilers were
required
[[Page 79835]]
to retire by June 30, 2023. Specifically, at PREPA Palo Seco, Boiler 1,
Boiler 2, Power Block 2-2, Power Block 3-1, and Power Block 3-2 had a
retirement compliance date of June 30, 2023. At PREPA San Juan, Boiler
7, Boiler 8, and Boiler 10 were required to retire by June 30, 2023.
Additional retirements are required at PREPA Palo Seco by December 31,
2025 (i.e., Boiler 4), and PREPA San Juan by December 31, 2024 (i.e.,
Boiler 9). PREPA Aguirre units are scheduled to retire beginning
December 31, 2025, through December 31, 2029.\27\
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\27\ Refer to Table 7. PREPA Aguirre SO<INF>2</INF> Emission
Limits under Section V, ``Review of Modeled Attainment
Demonstration'' of this rulemaking for more detailed information
regarding the specific units scheduled to retire from December 31,
2025, through December 31, 2029.
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A more detailed discussion of the retirement of emission units and
the implementation of emission limits for units that will remain in
operation at the PREPA San Juan, PREPA Aguirre, and PREPA Palo Seco
facilities can be found under Section V, ``Review of Modeled Attainment
Demonstration,'' subsection G, of this proposed rulemaking.
As mentioned previously in Section I, ``Background,'' of this
notice, the compliance strategy for Puerto Rico's SIP was developed
based on the most recent IRP approved by the PREB in 2020, as well as
additional updates provided by the PREB in 2022, which considered
emission unit retirements within the San Juan and Guayama-Salinas NAAs
following the integration of renewable energy sources and battery
storage resources. It is the EPA's understanding that the integration
of renewable energy sources has been delayed, including the deployment
of solar projects under Tranche 1, due to renegotiations and legal
challenges pertaining to the use of the land identified for
development.\28\ Tranche 1 was expected to provide at least 1,000 MW
solar PV (or energy-equivalent other renewables) and at least 500 MW
(2,000 MWh or equivalent) battery energy storage; \29\ however, its
delayed implementation has impacted the PREPA's ability to retire units
in accordance with the submitted SIP control strategy since other means
of providing electricity to citizens of the areas is not sufficient.
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\28\ See Section 6.2, ``Inputs and Assumptions'' of the ``Puerto
Rico Grid Resilience and Transitions to 100% Renewable Energy Study
(PR100)'' provided within the docket for this rulemaking.
\29\ See ] 860 of the ``Final Resolution and Order on the
PREPA's IRP'' included within the docket for this rulemaking.
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The transition to renewable energy, which will allow the retirement
of units at PREPA San Juan, PREPA Aguirre, and PREPA Palo Seco, has an
uncertain timeline. As indicated previously, the IRP was scheduled to
be revised and submitted to the PREB in June 2024 by LUMA, but that
process has been delayed to November 29, 2024. The EPA anticipates that
a new IRP \30\ will provide an updated schedule for emission unit
retirements and the integration of renewable energy. Moreover, under
the current IRP,\31\ PREPA will retire units ``based on the
installation schedule and location of new peaking generation, new solar
PV, and energy storage resources to address overall and local resource
adequacy.'' Accordingly, the retirement sequence of the existing PREPA
units is contingent on the timing, amount, and location of replacement
generation, which will further complicate Puerto Rico's ability to
ensure that retirements of emission units occur as provided within its
submitted control strategy timeline.
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\30\ Due to the complexity and coordination required between
stakeholders such as the PREPA, the PREB, and LUMA, it is
anticipated that a revised IRP will not be finalized until late 2026
or 2027 at this point in time.
\31\ See ] 870-873 of the ``Final Resolution and Order on the
PREPA's IRP.''
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The delay in implementing the submitted control strategy and the
extended timeline and uncertainty for transitioning to renewable energy
projects serve as additional evidence that Puerto Rico has not met, and
has fallen well behind, the statutorily required attainment date of
April 9, 2023. Moreover, given that the modeling submitted by PRDNER
did not anticipate the areas would attain the NAAQS until well beyond
the statutory April 9, 2023 attainment date, the EPA proposes to find
that attainment of the standard did not occur by the statutory
attainment date of April 9, 2023.
4. SO<INF>2</INF> Emissions Data
The EPA has compiled information from its Emission Inventory System
(EIS) that details total SO<INF>2</INF> emissions from 2020-2022 across
the three PREPA facilities.\32\ The Emissions Inventory System (EIS)
Gateway was developed to provide registered EPA, state, local, and
Tribal users with access to emissions inventory data.\33\ The EIS helps
the EPA to build the National Emissions Inventory (NEI). Additionally,
the EIS Gateway allows users to manage their profile information to
add, view, and edit facility inventory information for their agency;
extract data by running reports; and access reporting codes. Hourly and
monthly data are not available in the EIS Gateway, so the EPA will
utilize annual emissions from 2020-2022 at the three PREPA facilities
within the discussion regarding annual emission trends in the NAAs
since the designations. That information is as follows:
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\32\ 2021 and 2022 data are preliminary and will be finalized
upon release of the 2023 NEI. The 2023 NEI inventory year is in
progress and will not be published until March 2026. See <a href="https://www.epa.gov/air-emissions-inventories/2023-national-emissions-inventory-nei-documentation">https://www.epa.gov/air-emissions-inventories/2023-national-emissions-inventory-nei-documentation</a>.
\33\ For more information on EIS, refer to <a href="https://www.epa.gov/air-emissions-inventories/emissions-inventory-system-eis-gateway">https://www.epa.gov/air-emissions-inventories/emissions-inventory-system-eis-gateway</a>.
Table 3--Facility-Wide SO2 Emissions of Point Sources in the NAAs From 2020-2022 \34\
----------------------------------------------------------------------------------------------------------------
2020 SO2 2021 SO2 2022 SO2
emissions emissions emissions
Stationary point source Nonattainment area (tons per (tons per (tons per
year) year) year)
----------------------------------------------------------------------------------------------------------------
PREPA San Juan........................ San Juan................ 3,257 1,369 2,740
PREPA Palo Seco....................... San Juan................ 5,272 4,322 4,488
PREPA Aguirre......................... Guayama-Salinas......... 8,829 8,164 5,434
----------------------------------------------------------------------------------------------------------------
\34\ 2021 and 2022 data are preliminary and will be finalized upon release of the 2023 NEI.
The PREPA San Juan facility emitted 3,257 tons of SO<INF>2</INF> in
2020, 1,369 tons of SO<INF>2</INF> in 2021, and 2,740 tons of
SO<INF>2</INF> in 2022. The PREPA Palo Seco facility emitted 5,272 tons
of SO<INF>2</INF> in 2020, 4,322 tons of SO<INF>2</INF> in 2021, and
4,488 tons of SO<INF>2</INF> in 2022. Finally, the PREPA Aguirre
facility emitted 8,829 tons of SO<INF>2</INF> in 2020, 8,164 tons of
SO<INF>2</INF> in 2021, and 5,434 tons of SO<INF>2</INF> in 2022.
[[Page 79836]]
Table 4--Facility-Wide SO2 Emissions of Point Sources in the NAAs From 2013-2015
----------------------------------------------------------------------------------------------------------------
2013 SO2 2014 SO2 2015 SO2
emissions emissions emissions
Stationary point source Nonattainment area (tons per (tons per (tons per
year) year) year)
----------------------------------------------------------------------------------------------------------------
PREPA San Juan........................ San Juan................ 5,307 5,135 6,063
PREPA Palo Seco....................... San Juan................ 5,700 3,128 2,979
PREPA Aguirre......................... Guayama-Salinas......... 9,640 9,261 9,585
----------------------------------------------------------------------------------------------------------------
Notably, as provided within the Round 3 designations,\35\ Table 4
indicates that SO<INF>2</INF> emissions were: (1) 5,307 tons in 2013,
5,135 tons in 2014, and 6,063 tons in 2015 for PREPA San Juan; (2)
5,700 tons in 2013, 3,128 tons in 2014, and 2,979 tons in 2015 for
PREPA Palo Seco; and (3) 9,640 tons in 2013, 9,261 tons in 2014, and
9,585 tons in 2015 for the PREPA Aguirre facility.
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\35\ Modeling of the 2013-2015 emissions data, which showed that
the San Juan and Guayama-Salinas areas did not meet the 2010
SO<INF>2</INF> NAAQS, was a basis for the nonattainment designation.
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While there has been a decrease in emissions at the PREPA San Juan
and PREPA Aguirre facilities, it is important to note that the
thousands of tons of SO<INF>2</INF> emitted by these facilities from
2020 to 2022 are significant. Notably, although emissions at PREPA Palo
Seco appear to have decreased from 2013 through 2015, emissions
increased at the facility from 2015 to 2020. It is the EPA's
understanding, based on the air quality dispersion modeling the PRDNER
provided in its attainment modeling for its SO<INF>2</INF> plan, that
SO<INF>2</INF> emissions from the three PREPA facilities would need to
significantly decrease in order to provide for attainment of the
SO<INF>2</INF> standard. The PRDNER projected that SO<INF>2</INF>
emissions would be 43 tons per year (tpy) at PREPA San Juan and 12 tpy
at PREPA Palo Seco by the PRDNER-projected attainment date of December
31, 2025, as well as 4 tpy at PREPA Aguirre by the PRDNER-projected
attainment date of December 31, 2029.\36\ In contrast, the
SO<INF>2</INF> emissions listed in Table 3 are significantly higher
than the emissions for which the PRDNER modeled to provide attainment.
Thus, since the EPA was unable to conduct its own additional air
quality dispersion modeling, the EPA has no evidence indicating that
the SO<INF>2</INF> emissions at the facilities from 2020-2022 would
provide for attainment of the 2010 1-hour primary SO<INF>2</INF> NAAQS
by the statutory attainment date.
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\36\ The PRDNER's modeling results under the Attainment
Demonstration provided in its November 22, 2022 SIP submission
indicated that these emissions would result in a modeled
concentration of 47.518 [mu]g/m\3\ for the San Juan NAA and 47.191
[mu]g/m\3\ for the Guayama-Salinas NAA. These concentrations are
below what would be required for the NAAs to attain the 2010
SO<INF>2</INF> standard. For additional information on the projected
emissions at the PREPA facilities, see Table 11, ``Projected
Stationary Point Source SO<INF>2</INF> Emissions for 2019-2029''
under Section VI, subsection A, ``Emissions Inventory,'' within this
proposed rulemaking.
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The EPA's emissions assessment focused specifically on the three
PREPA sources: PREPA San Juan, PREPA Palo Seco, and PREPA Aguirre.
These sources were significantly larger in terms of emissions compared
to smaller and more distant sources like Bacardi, Edelcar, and Applied
Energy System (AES). As a result, the smaller emissions from these
distant sources were dwarfed by the impact of the explicitly modeled
PREPA sources.\37\ For example, AES emitted 245 tons of SO<INF>2</INF>
in 2014. The EPA's conclusion was based on this consideration, ensuring
that the emissions assessment accurately reflected the most relevant
contributors to air quality in the vicinity.
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\37\ As discussed within Section V.B., ``Area of Analysis,''
within this notice, based on the magnitude of emissions and distance
relative to the NAAs, the EPA concluded that the smaller and more
distant sources were adequately represented in the monitored ambient
background concentrations. The EPA concluded that these sources were
not expected to have their maximum impacts in the vicinity of PREPA
San Juan, PREPA Palo Seco, and PREPA Aguirre.
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Consequently, the EPA proposes to find that emissions from the
PREPA San Juan, PREPA Palo Seco, and PREPA Aguirre facilities continue
to be significant and provide additional evidence that the San Juan and
Guayama-Salinas areas have not attained the 2010 1-hour primary
SO<INF>2</INF> NAAQS by the statutory attainment date of April 9, 2023.
5. The Weight-of-Evidence Analysis Conclusions and the EPA's Proposed
Determination
The determination of failure to attain for the San Juan and
Guayama-Salinas NAAs is based on a control strategy timeline that does
not provide for attainment by the statutorily required attainment date,
Puerto Rico's failure to implement its adopted control strategy in a
timely manner, and the EPA's review of annual facility-wide emissions
data from January 2020 through December 2022 for the PREPA San Juan,
PREPA Palo Seco, and PREPA Aguirre facilities.
As discussed in this notice, Puerto Rico's control strategy is
deficient in providing for attainment by the mandatory attainment date.
It provided for attainment after the statutory date and it failed to
practicably account for the feasibility of retiring relevant emission
units, resulting in its failure to be timely implemented. The EPA's
assessment of the air quality dispersion modeling that the PRDNER
provided in its November 22, 2022 SIP submittal provides further
support for this determination. Moreover, due to its inability to
obtain valid design values from SO<INF>2</INF> monitors in the San Juan
and Guayama-Salinas areas, the EPA did not utilize monitoring data as
the basis for this determination. The EPA obtained facility-wide
SO<INF>2</INF> emissions from 2020-2022 at PREPA San Juan, PREPA Palo
Seco, and PREPA Aguirre. This emissions data demonstrates that
emissions from the three PREPA facilities continue to be significant
and there is no evidence that they provide for attainment of the
standard.
The EPA proposes to find that this weight-of-evidence analysis is
sufficient to demonstrate that the San Juan and Guayama-Salinas area
failed to attain the standard by the mandatory attainment date. The EPA
therefore proposes to find under CAA section 179(c)(1) that the San
Juan and Guayama-Salinas NAAs failed to attain the 1-hour
SO<INF>2</INF> NAAQS by the required attainment date of April 9, 2023.
D. Consequences for SO<INF>2</INF> NAAs Failing To Attain Standards by
Attainment Date
The consequences for SO<INF>2</INF> NAAs failing to attain the
standards by the applicable attainment date are set forth in CAA
section 179(d). Under section 179(d), a state must submit a SIP
revision for the area meeting the requirements of CAA sections 110 and
172, the latter of which requires, among other elements, a
demonstration of attainment, an NNSR program, the base year emissions
inventory, the requirements for meeting RFP, RACM/RACT, and contingency
measures. In addition, under CAA section 179(d)(2), the SIP revision
must include such additional measures as the EPA may reasonably
prescribe, including all
[[Page 79837]]
measures that can be feasibly implemented in the area, in light of
technological achievability, costs, and any non-air quality and other
air quality-related health and environmental impacts.
In this case, the primary sources of SO<INF>2</INF> emissions in
the San Juan and Guayama-Salinas NAAs are the PREPA San Juan, PREPA
Palo Seco, and PREPA Aguirre facilities. The EPA anticipates that the
PRDNER will collect relevant information on the control measures
necessary to achieve attainment by the required attainment date, as
part of its development of the SIP revision triggered by a final FFA.
The state (or commonwealth) is required to submit the SIP revision
within one year after the EPA publishes a final action in the Federal
Register determining that the NAA failed to attain the SO<INF>2</INF>
NAAQS.
With this proposed rulemaking, the EPA is also proposing to approve
certain elements of the 2010 SO<INF>2</INF> attainment plans for the
San Juan and Guayama-Salinas NAAs, as submitted on November 22, 2022,
for compliance with the CAA and for SIP-strengthening purposes.
Specifically, the EPA is proposing to approve Puerto Rico's NNSR
program and the base year emissions inventory for compliance with the
CAA; as well as proposing to approve, in part, and conditionally
approve, in part, amendments to Puerto Rico's RCAP for SIP-
strengthening purposes. The EPA will not act on Puerto Rico's
previously submitted demonstration of attainment, RACM/RACT, RFP,
emission limitations as necessary to provide for attainment, and
contingency measures, since these elements will be addressed in the
subsequent submittal as a result of the FFA, should it become final.
Under CAA sections 179(d)(3) and 172(a)(2), the new attainment date
for each NAA is the date by which attainment can be achieved as
expeditiously as practicable, but no later than five years after the
EPA publishes a final action in the Federal Register determining that
the NAA failed to attain the SO<INF>2</INF> NAAQS by the applicable
attainment date.
IV. Requirements for SO2 Nonattainment Area Plans
Nonattainment plans for SO<INF>2</INF> must meet the applicable
requirements of the CAA, specifically CAA sections 110, 172, 191, and
192. The EPA's regulations governing nonattainment SIP submissions are
set forth in 40 CFR part 51, with specific procedural requirements and
control strategy requirements codified at subparts F and G,
respectively. Soon after Congress enacted the 1990 Amendments to the
CAA, the EPA issued comprehensive guidance on SIP revisions in the
``General Preamble for the Implementation of Title I of the Clean Air
Act Amendments of 1990'' (``General Preamble'').\38\ Among other
things, the General Preamble addressed SO<INF>2</INF> SIP submissions
and fundamental principles for SIP control strategies.\39\ On April 23,
2014, the EPA issued recommended guidance for meeting the statutory
requirements in SO<INF>2</INF> SIP submissions in a document entitled,
``Guidance for 1-Hour SO<INF>2</INF> Nonattainment Area SIP
Submissions'' (``2014 SO<INF>2</INF> Guidance'').\40\
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\38\ 57 FR 13498 (April 16, 1992).
\39\ Id. at 13548-13549, 13567-13568.
\40\ See <a href="https://www.epa.gov/sites/default/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf">https://www.epa.gov/sites/default/files/2016-06/documents/20140423guidance_nonattainment_sip.pdf</a>.
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In the 2014 SO<INF>2</INF> Guidance, the EPA described the
statutory requirements of CAA section 172(c) for a complete
nonattainment plan, including: an accurate emissions inventory of
current emissions for all sources of SO<INF>2</INF> within the NAA; an
attainment demonstration; a demonstration of RFP; implementation of
RACM (including RACT); new source review; enforceable emission
limitations and control measures; and adequate contingency measures for
the affected area.
For the EPA to fully approve a SIP revision which meets the
requirements of CAA sections 110, 172, 191, and 192, and the EPA's
regulations at 40 CFR part 51, the plan for an affected area must
demonstrate to the EPA's satisfaction that each of the aforementioned
requirements has been met. Under CAA section 110(l), the EPA may not
approve a plan that would interfere with any applicable requirement
concerning NAAQS attainment and RFP, or any other applicable
requirement. Under CAA section 193, no requirement in effect (or
required to be adopted by an order, settlement, agreement, or plan in
effect before November 15, 1990) within any area that is nonattainment
for any of the NAAQS may be modified in any manner unless it ensures
equivalent or greater emission reductions of such air pollutant.
Sections 172(c)(1) and 172(c)(6) of the CAA direct states and
territories with areas designated as nonattainment to demonstrate that
the submitted plan, and the emissions limitations and control measures
in it, provide for attainment of the NAAQS. 40 CFR part 51, subpart G
further delineates the control strategy requirements that plans must
meet, and the EPA has long required that all SIPs and control
strategies reflect four fundamental principles of quantification,
enforceability, replicability, and accountability.\41\ SO<INF>2</INF>
nonattainment plans must consist of two components: (1) emission limits
and other control measures that ensure implementation of permanent,
enforceable, and necessary emission controls, and (2) a modeling
analysis that meets the requirements of 40 CFR part 51, Appendix W and
demonstrates that these emission limits and control measures provide
for timely attainment of the primary SO<INF>2</INF> NAAQS as
expeditiously as practicable, but no later than the attainment date for
the affected area. In cases where the necessary emission limits have
not previously been made a part of the state's SIP or have not
otherwise become federally enforceable, the plan must include the
necessary enforceable limits in an adopted form suitable for
incorporation into the SIP in order for the plan to be approved by the
EPA. In all cases, the emission limits and control measures must be
accompanied by appropriate methods and conditions to determine
compliance with the respective emission limits and control measures and
must be quantifiable (i.e., a specific amount of emission reduction can
be ascribed to the measures), fully enforceable (i.e., specifying
clear, unambiguous, and measurable requirements for which compliance
can be practicably determined), replicable (i.e., the procedures for
determining compliance are sufficiently specific and objective so that
two independent entities applying the procedures would obtain the same
result), and accountable (i.e., source-specific limits must be
permanent and must reflect the assumptions used in the SIP
demonstrations).
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\41\ 57 FR at 13567-13568.
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The EPA's 2014 SO<INF>2</INF> Guidance recommends that emission
limits be expressed as short-term average limits not to exceed the
averaging time for the applicable NAAQS that the limit is intended to
help maintain (e.g., addressing emissions averaged over one or three
hours), but it also describes the option to utilize emission limits
with longer averaging times of up to 30 days, so long as the state/
commonwealth meets various suggested criteria.\42\ The 2014
SO<INF>2</INF> Guidance recommends that, should states/territories and
sources utilize longer averaging times (such as 30 days), the longer-
term average limit should be set at an adjusted level that reflects a
stringency comparable to the 1-hour average limit at the critical
emission value shown to provide
[[Page 79838]]
attainment. Additional discussion of EPA's rationale for approving
longer-term average limits in selected cases has been provided in
several notices of proposed rulemaking. Examples include the Pekin,
Illinois area,\43\ the Steubenville, Ohio-West Virginia area,\44\ and
the Central New Hampshire area.\45\
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\42\ 2014 SO<INF>2</INF> Guidance, at 22-39.
\43\ 82 FR 46434 (Oct. 5, 2017).
\44\ 84 FR 29456 (June 24, 2019).
\45\ 82 FR 45242 (Sept. 28, 2017).
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Preferred air quality models for use in regulatory applications are
described in Appendix A of the EPA's ``Guideline on Air Quality
Models'' (40 CFR part 51, Appendix W (``Appendix W'')).\46\ In general,
nonattainment SIP submissions must demonstrate the adequacy of the
selected control strategy using the applicable air quality model
designated in Appendix W.\47\ However, where an air quality model
specified in Appendix W is inappropriate for the particular
application, the model may be modified or another model substituted, if
the EPA approves of the modification or substitution.\48\ In 2005, the
EPA promulgated the American Meteorological Society/Environmental
Protection Agency Regulatory Model (AERMOD \49\) as the Agency's
preferred near-field dispersion model for a wide range of regulatory
applications addressing stationary sources (e.g., in estimating
SO<INF>2</INF> concentrations) in all types of terrain based on an
extensive developmental and performance evaluation. Supplemental
guidance on modeling for purposes of demonstrating attainment of the
SO<INF>2</INF> standard is provided in Appendix A of the 2014
SO<INF>2</INF> Guidance.
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\46\ The EPA published revisions to Appendix W on January 17,
2017, 82 FR 5182.
\47\ 40 CFR 51.112(a)(1).
\48\ 40 CFR 51.112(a)(2); Appendix W, section 3.2.
\49\ See <a href="https://www.epa.gov/scram/air-quality-dispersion-modeling-preferred-and-recommended-models#aermod">https://www.epa.gov/scram/air-quality-dispersion-modeling-preferred-and-recommended-models#aermod</a>.
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Appendix A of the April 23, 2014, Guidance for 1-Hour
SO<INF>2</INF> Nonattainment Area SIP Submissions provides extensive
guidance on the modeling domain, the source inputs, assorted types of
meteorological data, and background concentrations. Consistency with
the recommendations in the 2014 SO<INF>2</INF> Guidance is generally
necessary for the attainment demonstration to offer adequately reliable
assurance that the plan provides for attainment.
As stated previously, attainment demonstrations for the 2010 1-hour
primary SO<INF>2</INF> NAAQS must demonstrate future attainment and
maintenance of the NAAQS in the entire area designated as nonattainment
(i.e., not just at the violating monitor) by using air quality
dispersion modeling (see Appendix W) to show that the mix of sources
and enforceable control measures and emission rates in an identified
area will not lead to a violation of the SO<INF>2</INF> NAAQS. For the
short-term (i.e., 1-hour) standard, the EPA believes that dispersion
modeling, using allowable emissions and addressing stationary sources
in the affected area (and in some cases those sources located outside
the NAA that may affect attainment in the area) is technically
appropriate. This approach is also efficient and effective in
demonstrating attainment in NAAs because it takes into consideration
combinations of meteorological and source operating conditions that may
contribute to peak ground-level concentrations of SO<INF>2</INF>.
The meteorological data used in the analysis should generally be
processed with the most recent version of AERMET, which is the
meteorological data preprocessor for AERMOD. Estimated concentrations
should include ambient background concentrations, follow the form of
the standard, and be calculated as described in the EPA's August 23,
2010 clarification memorandum.\50\
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\50\ See ``Applicability of Appendix W Modeling Guidance for the
1-hr SO<INF>2</INF> National Ambient Air Quality Standard'' (August
23, 2010), available at <a href="https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/20100823_page_1-hr_so2_naaqs_psd_program.pdf">https://www3.epa.gov/ttn/naaqs/aqmguide/collection/cp2/20100823_page_1-hr_so2_naaqs_psd_program.pdf</a>.
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V. Review of Modeled Attainment Demonstration
The EPA is not at this time proposing action on the attainment
demonstration submitted by the PRDNER that aims to provide for
attainment of the 2010 SO<INF>2</INF> NAAQS. However, the following
discussion addresses various features of the modeling that the PRDNER
used in its submitted attainment demonstration for the San Juan and
Guayama-Salinas NAAs. This discussion may be useful for the PRDNER as
it continues its efforts. Additionally, the modeling was considered by
the EPA in part of the weight-of-evidence analysis for the FFA. The EPA
anticipates acting on an updated attainment demonstration in a future
SIP submission.
A. Modeling Approach
The PRDNER's submitted attainment demonstration utilized the EPA's
preferred model, version 21112 of AERMOD, with default options. Version
21112 of AERMOD was the most recent version at the time the attainment
demonstration modeling was conducted; however, since then, version
23132 of AERMOD has become the regulatory model version. There were no
updates from version 21112 to version 23132 that would significantly
affect the SO<INF>2</INF> concentrations predicted here. Therefore, for
its own purposes, the EPA does not consider the model selection to have
been inappropriate. However, in a future SIP submission, the EPA
expects that the PRDNER would use the version of the model that is
current at the time of the analysis.
The PRDNER examined land use within three kilometers of the
facilities in the two NAAs using the Auer technique, which is a
technique in section 7.2.1.1 of Appendix W for establishing if an area
should be modeled as either an urban or rural source. It was determined
by PRDNER that San Juan should be modeled with urban dispersion
characteristics and Guayama-Salinas should be modeled with rural
dispersion characteristics. The EPA has reviewed the maps and images
provided by the PRDNER and expects that it would be reasonable for the
PRDNER to use these characteristics in future modeling.
B. Area of Analysis
The PRDNER accounted for SO<INF>2</INF> impacts in the modeling
domain through the inclusion of measured background levels and
explicitly modeled emission sources. In the San Juan NAA, the PRDNER
included the largest SO<INF>2</INF> sources in the modeling-PREPA San
Juan and PREPA Palo Seco. The impact from other sources of
SO<INF>2</INF> in the San Juan NAA (contributions from Bacardi U.S.A.,
Inc. (200 PR-165 Cata[ntilde]o, 00962), Edelcar Inc. (CVMQ+FGQ, Calle
B, Guaynabo, 00965), and other minor and distant sources), are included
in the background monitored concentrations, which are added to the
concentrations from the explicitly modeled sources. In the Guayama-
Salinas NAA, the PRDNER included the largest SO<INF>2</INF> source in
the modeling-PREPA Aguirre (State Road No. 3, Int. 705, Salinas,
00751). The impact from the other sources of SO<INF>2</INF> in the
Guayama-Salinas NAA (i.e., Applied Energy System (AES) Puerto Rico, LP
(PR-3 Km. 142.0, Jobos Ward, Guayama, 00784) and other minor and
distant sources) are included in the background monitored
concentrations, which are also added to the concentration from the
explicitly modeled sources.
The PRDNER modeled sources in the NAAs (i.e., PREPA San Juan, PREPA
Palo Seco, and PREPA Aguirre) that could cause or contribute to a NAAQS
violation. The impacts of emissions of SO<INF>2</INF> from smaller and
distant sources are represented by background monitored concentrations
(such as
[[Page 79839]]
Bacardi, Edelcar, and AES). These emissions were dwarfed by emissions
from the three much larger PREPA sources and would not be expected to
have their maximum impacts in the vicinity of the sources of
interest.\51\ However, they may have a smaller impact, which is
measured at the ambient monitor and added to the modeled concentration.
For instance, AES, which is situated in Jobos and within close
proximity to PREPA Aguirre (i.e., less than 5 kilometers away), is a
relatively small source of SO<INF>2</INF> emissions when compared to
the PREPA facility. In 2014,\52\ AES emitted 245 tons of
SO<INF>2</INF>, whereas PREPA Aguirre released a significantly larger
amount of 9,261 tons of SO<INF>2</INF> during the same period. Further,
AES is approximately 8.5 kilometers east of PREPA Aguirre and less than
5 kilometers upwind of the Guayama background monitor. Thus, the AES
concentration in the area of PREPA Aguirre is captured by the measured
ambient background monitored concentration and added to PREPA Aguirre's
maximum modeled concentration for a total air quality SO<INF>2</INF>
concentration in the area.\53\
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\51\ When considering other sources to include in the modeling
(other than those that are driving the nonattainment), Appendix W in
section 8.3.3.b states that all sources expected to cause a
significant concentration gradient in the vicinity of the source of
interest should be explicitly modeled and that the number of such
sources is expected to be small except in unusual cases.
\52\ Data from 2014 was representative of the emissions data
that was used for the designations of the SO<INF>2</INF> NAAs in
Puerto Rico. Furthermore, the PRDNER used 2014 as the base year for
emissions inventory preparation. The base year inventory establishes
a baseline that is used to evaluate emission reductions achieved by
the control strategy.
\53\ See the Technical Support Document, Chapter 36, Final Round
3 Area designations for the 2010 1-Hour SO<INF>2</INF> Primary
National Ambient Air Quality Standard for Puerto Rico, available at
<a href="https://www.epa.gov/sites/default/files/2017-12/documents/36-pr-so2-rd3-final.pdf">https://www.epa.gov/sites/default/files/2017-12/documents/36-pr-so2-rd3-final.pdf</a>.
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Based on the magnitude of emissions and distance relative to the
NAAs, the EPA expects that the smaller and more distant sources would
not have their maximum impacts in the vicinity of PREPA San Juan, PREPA
Palo Seco, and PREPA Aguirre. Accordingly, the EPA expects that in
future modeling, those sources could be adequately represented in the
monitored ambient background concentrations, and that the PRDNER's
future attainment demonstration could account for them in this way.
Additionally, the EPA believes that the background levels could
reasonably account for other sources influencing air quality within the
NAAs because data used to develop background levels include hours
during which those sources may have impacted the monitors. However, the
EPA acknowledges that conditions pertaining to ambient background level
concentrations of these smaller and distant sources could be different
in the future.
C. Receptor Grid
Within AERMOD, air quality concentration results are calculated at
discrete locations identified by the user; these locations are called
receptors. The PRDNER used a coarse grid to determine the maximum 1-
hour SO<INF>2</INF> concentrations and the extent of the significant
impact area. A denser refined grid was placed around the areas of
maximum 1-hour concentration and discrete receptors were placed around
the facility fence lines.
For the San Juan NAA, a coarse receptor grid with 250-meter spacing
covers areas with violating receptors and the extent of the significant
impact area. Two refined 50-meter spacing receptor grids cover the two
areas with maximum 1-hour SO<INF>2</INF> concentrations around PREPA
San Juan and PREPA Palo Seco.
For the Guayama-Salinas NAA, a coarse grid with 1000-meter spacing
extending out to 50 kilometers from the source is used to determine the
significant impact area. Two refined 50-meter spacing receptor grids
cover the area with the maximum 1-hour SO<INF>2</INF> concentration and
another area approximately five miles northwest of the facility. Beyond
the 50-meter refined grid around the facility, a 250-meter spacing grid
is also placed around the facility area to ensure that any significant
concentrations are identified.
The EPA expects that the receptor network could be sufficient to
identify maximum impacts from all the facilities in consideration for
characterizing the NAAs in the PRDNER's future submission.
D. Meteorological Data
The PRDNER utilized onsite meteorological data from both the PREPA
San Juan and PREPA Aguirre meteorological stations, which was collected
and provided by PREPA. The PRDNER utilized concurrent Upper Air data
measured at the San Juan National Weather Service located at the San
Juan Airport. The PRDNER provided confirmation that PREPA collected the
meteorological data and conducted quality assurance/quality control
(QA/QC) procedures on the data in accordance with EPA's meteorological
guidance.\54\ The PRDNER further reviewed the data for relevance and
quality assurance, as per the EPA's guidelines, prior to processing it
for use within AERMOD. Since there was one year that satisfied the
EPA's data completeness requirements, the PRDNER utilized only one year
of meteorological data from 2013 for the San Juan NAA. In the Guayama-
Salinas NAA, the PRDNER used three years of meteorological data from
2014-2016, since multiple years of data were available.
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\54\ See ``Meteorological Monitoring Guidance for Regulatory
Modeling Applications'' (Feb. 2000), available at <a href="https://www.epa.gov/sites/default/files/2020-10/documents/mmgrma_0.pdf">https://www.epa.gov/sites/default/files/2020-10/documents/mmgrma_0.pdf</a>.
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The EPA observed that the temperature data at both stations was
measured at three meters above the rooftop and could be possibly
influenced by other radiation sources. The concurrent San Juan National
Weather Service data was used as a substitute only for the temperature
data. Additionally, since the wind sensor was switched during the data
collection period, the EPA requested that the PRDNER perform additional
analysis on the data collected at PREPA Aguirre. The new sensor has a
higher wind threshold compared to the older sensor. The EPA recommended
that the PRDNER perform two separate AERMET runs, one with the older
sensor threshold and another with the new sensor threshold, and then
combine the files for use in AERMOD. The PRDNER followed this
recommendation to process the data and used it for the AERMOD runs for
the Guayama-Salinas NAA.
The PRDNER used AERMOD's meteorological data preprocessor AERMET
(version 21112) with the ADJ_U* option (with no turbulence data
included), and Upper Air meteorological data from the San Juan National
Weather Service site, to process the data in AERMOD. The PRDNER used
AERSURFACE (version 20060) using land cover data from the National Land
Cover Database 200 (NLCD 2001) to estimate the surface characteristics
(albedo, Bowen ratio, and surface roughness length).
E. Source Characterization
The EPA also reviewed the PRDNER's source characterization in its
modeling assessment, including source types, use of accurate stack
parameters, and inclusion of building dimensions for building downwash.
The EPA expects that the PRDNER would use these in its future
submission.
[[Page 79840]]
F. Emissions Data
The PRDNER used maximum allowable 1-hour emissions from PREPA San
Juan and PREPA Palo Seco for the San Juan NAA, and from PREPA Aguirre
for the Guayama-Salinas NAA. The modeling included the certified
SO<INF>2</INF> emission rates as provided by PREPA. The modeling
demonstration considers unit retirements at the PREPA facilities as
discussed in Section V, subsection G below. The PRDNER did not include
start-up and shut-down emissions in the modeling due to their
infrequent occurrence of up to 2-3 times a year.
G. Retirements and Emission Limits
The PRDNER's attainment modeling in both the San Juan and Guayama-
Salinas NAAs is based on the retirement of emission units and the
implementation of emission limits for units that will remain in
operation for electricity generation at the PREPA San Juan, PREPA
Aguirre, and PREPA Palo Seco facilities through requiring fuel
switching to ULSD (Ultra Low Sulfur Diesel) fuel and LNG (Liquified
Natural Gas). The PRDNER noted in its SIP narrative and Rule 425 of the
RCAP that the retirement dates for the plan were provided by the PREB
based on the projected integration of renewable energy to the
generation grid.\55\ The PRDNER noted that this compliance strategy is
consistent with the existing approved IRP, as it considers the addition
of power generation and emission unit retirements within the PREPA
fleet.
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\55\ The PREB provided a projected schedule for emission unit
retirements and the integration of new renewable energy and battery
storage resources via letter to the PRDNER on October 18, 2022,
which was updated on November 15, 2022. These letters are available
in the docket of this rulemaking.
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Table 5 summarizes the SO<INF>2</INF> emission limits (lb/hr) and/
or other requirements, including fuel to be fired (0.0015% by weight
(15 ppm) ULSD) and retirements, for emission units at the PREPA Palo
Seco facility.
Table 5--PREPA Palo Seco SO2 Emission Limits
------------------------------------------------------------------------
SO2 emission limit
Emission unit and/or other Compliance date
requirements
------------------------------------------------------------------------
Boiler 1........................ Retire............ June 30, 2023
Boiler 2 \56\................... Retire............ June 30, 2023
Boiler 3........................ Retire............ December 31, 2024
Boiler 4........................ Retire............ December 31, 2025
Power Block 1-1, 1-2............ 0.5 lb/hr, ULSD... February 1, 2023
Power Block 2-1................. 0.5 lb/hr, ULSD... February 1, 2023
Power Block 2-2 \61\............ Retire............ June 30, 2023
Power Block 3-1................. Retire............ June 30, 2023
Power Block 3-2 \61\............ Retire............ June 30, 2023
FT8 MobilePac 1................. 0.4 lb/hr, ULSD... February 1, 2023
FT8 MobilePac 2................. 0.4 lb/hr, ULSD... February 1, 2023
FT8 MobilePac 3................. 0.4 lb/hr, ULSD... February 1, 2023
------------------------------------------------------------------------
Table 6 summarizes the SO<INF>2</INF> emission limits (lb/hr) and/
or other requirements, including fuel to be fired (0.0015% by weight
(15 ppm) ULSD and 1 gram/100 dscf LNG) and retirements, for emission
units at the PREPA San Juan facility.
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\56\ Palo Seco Boiler 2, Power Block 2-2, and Power Block 3-2
were permanently shut down and out of service on November 9, 2022
(to generate netting credits for three MobilePac units in Palo
Seco).
\57\ The Gas Turbines SJ 5&6 have been operating as dual-fuel
units since late 2019. The PRDNER required the units to switch to
ULSD by February 1, 2023. As of February 1, 2023, the SJ 5&6
emission units have been subject to a maximum sulfur content of
0.0015% by weight (15 ppm) (which is equivalent to an SO<INF>2</INF>
emission rate of 5.1 lb/hr under ULSD firing), as well as a separate
SO<INF>2</INF> limit of 9.8 lb/hr under LNG firing. As listed in
Table 2 above, the PRDNER utilized the more conservative rate under
LNG firing load for the attainment demonstration. More information
pertaining to this can be reviewed on page 59 of the Modeling
Protocol included in the docket for this rulemaking.
Table 6--PREPA San Juan SO2 Emission Limits
------------------------------------------------------------------------
SO2 emission limit
Emission unit and/or other Compliance date
requirements
------------------------------------------------------------------------
Gas Turbines SJ 5 & 6 \57\...... 9.8 lb/hr, ULSD/ February 1, 2023
LNG.
Boiler 7........................ Retire............ June 30, 2023
Boiler 8........................ Retire............ June 30, 2023
Boiler 9........................ Retire............ December 31, 2024
Boiler 10....................... Retire............ June 30, 2023
------------------------------------------------------------------------
Table 7 summarizes the SO<INF>2</INF> emission limits (lb/hr) and/
or other requirements, including fuel to be fired (0.0015% by weight
(15 ppm) ULSD) and retirements, for emission units at the PREPA Aguirre
facility.
Table 7--PREPA Aguirre SO2 Emission Limits
------------------------------------------------------------------------
SO2 emission limit
Emission unit and/or other Compliance date
requirements
------------------------------------------------------------------------
AG1............................. Retire............ December 31, 2025
AG2............................. Retire............ December 31, 2026
Gas Turbine CC1-1HRSG........... Retire............ December 31, 2028
Gas Turbine CC1-2HRSG........... Retire............ December 31, 2028
Gas Turbine CC1-3HRSG........... Retire............ December 31, 2028
Gas Turbine CC1-4HRSG........... Retire............ December 31, 2029
Gas Turbine CC2-1HRSG........... Retire............ December 31, 2029
Gas Turbine CC2-3HRSG........... Retire............ December 31, 2029
------------------------------------------------------------------------
As indicated earlier in this section, the PRDNER's control strategy
is based on the retirement of emission units and the implementation of
emission limits for units that will remain in operation at the PREPA
San Juan, PREPA Aguirre, and PREPA Palo Seco facilities through
requiring fuel switching to ULSD and LNG. There is no intention and/or
indication of an intention to implement longer-term averaging limits
within the PRDNER's submission, and therefore, no
[[Page 79841]]
discussion regarding longer-term averaging limits is warranted.
Rule 425 of the RCAP provides requirements for the SO<INF>2</INF>
plan, including providing emission reductions through an interim
remedy. Under the ``Interim Plan,'' as detailed within Sections II,
``Emission Limitations for PREPA San Juan and PREPA Palo Seco'' and
III, ``Emission Limitations for PREPA Aguirre'' of Rule 425, certain
emission units located at the PREPA facilities in Palo Seco, San Juan,
and Aguirre are prohibited from burning any fuel oil above a maximum
sulfur content of 0.0015 percent by weight (15ppm) after February 1,
2023. To clarify, while the interim plan requiring ULSD provides for
significant SO<INF>2</INF> emission reductions, there is no indication
that the reductions are enough to provide for attainment of the NAAQS.
The PRDNER has provided a schedule of retirements for the PREPA
steam generating units based on the integration of renewable energy
into the system. According to Section II(B) and Section III(B) of Rule
425, the emission units from the PREPA San Juan, PREPA Palo Seco, and
PREPA Aguirre facilities shall be retired as early as the dates
provided in tables 5-7 above, unless an alternative date is authorized
by the PREB. This alternative date shall be no later than December 31,
2025, for PREPA San Juan and Palo Seco, and no later than December 31,
2029, for PREPA Aguirre.\58\ If an alternative date is requested, PREPA
would be required to submit to the PRDNER a revision to the
construction and operation emission source permits, a copy of the
PREB's alternative retirement date authorization, and an explanation
for the necessity of the alternative date.
---------------------------------------------------------------------------
\58\ Apart from Palo Seco Boiler 2, Power Block 2-2, and Power
Block 3-2, the EPA is not aware of any other retirements that have
been made according to the proposed schedule in the tables herein.
---------------------------------------------------------------------------
The EPA is not acting on Section II(B) and Section III(B) of Rule
425 since the EPA anticipates these provisions will be revised
following the EPA's final action on the FFA, which will require the
PRDNER to submit a subsequent SIP revision. The EPA further evaluates
the approvability of Rule 425 within Section VI of the preamble for
this notice of proposed rulemaking, entitled, ``The EPA's Evaluation of
Rule 425.''
H. Background Concentrations
The PRDNER developed background concentrations for the NAAs using
hourly SO<INF>2</INF> measurements from 2007-2009 at the Guayama
SO<INF>2</INF> monitor, Air Quality System (AQS) number 72-057-
0009.\59\ Other SO<INF>2</INF> monitors, such as the Cata[ntilde]o (AQS
ID 72-033-0004) or Bayam[oacute]n (AQS ID 72-021-0010) monitors, are
likely to be impacted by the PREPA facilities discussed here. This
would result in double-counting of the impacts from those emissions,
since the impacts from PREPA are modeled and the measured ambient data
are added to the modeled impacts for a total concentration, which is
compared to the NAAQS. The Guayama monitor is representative of the
regional background and includes impacts from natural and man-made
sources not explicitly included as sources in the modeling. The PRDNER
used a design value from 2007-2009, since the more recent monitored
data was incomplete and did not satisfy the EPA's data completeness
requirements. The EPA also recommended that for 2007, the PRDNER use
the maximum daily value of 36 ppb, instead of the 99th percentile
concentration of 6 ppb, since there were some missing values in the
second quarter of 2007.
---------------------------------------------------------------------------
\59\ This SO<INF>2</INF> monitor site closed on January 1, 2023.
---------------------------------------------------------------------------
I. Summary of Results
Because a new attainment date will be established upon the EPA's
final determination that the NAAs failed to attain the standard by the
mandatory attainment date of April 9, 2023, the EPA is not proposing
action on the attainment demonstration portion of the PRDNER's November
2022 SIP submission within this rulemaking. Instead, the EPA will
address the PRDNER's revised attainment demonstration following the SIP
revision the PRDNER will be required to submit within 12 months of the
EPA finalizing its determination that the areas failed to attain the
standard.
VI. Review of Other Plan Requirements
A. Emissions Inventory
The emissions inventory and source emission rate data for an area
serve as the foundation for air quality modeling and other analyses
that enable states/territories to: (1) estimate the degree to which
different sources within a NAA contribute to violations within the
affected area, and (2) assess the expected improvement in air quality
within the NAA as a result of the adoption and implementation of
control measures. The state/commonwealth must develop and submit to the
EPA a comprehensive, accurate, and current inventory of actual
emissions from all sources of SO<INF>2</INF> in each NAA, as well as
any sources located outside the NAA that may affect attainment in the
area.\60\
---------------------------------------------------------------------------
\60\ CAA section 172(c)(3), 42 U.S.C. 7502(c)(3).
---------------------------------------------------------------------------
The base year inventory establishes a baseline that is used to
evaluate emission reductions achieved by the control strategy and to
assess RFP requirements. In its submittal, the PRDNER used 2014 as the
base year for emissions inventory preparation. 2014 data was used as
the base year because SO<INF>2</INF> emissions data from this year was
the most recently completed emissions data available for all sectors in
the inventory. Data from 2014 was also representative of the emissions
data that was used for the designations of the two SO<INF>2</INF> NAAs
in Puerto Rico, which were based on emissions data between 2013 and
2015.
The PRDNER considered using 2017 as an emissions base year;
however, it was determined that 2017 was not a representative year for
fuel consumption due to the impacts from Hurricanes Irma and Maria.
These hurricanes caused PREPA power plants, which generate electricity
via the burning of fossil fuels and are the principal sources
contributing to nonattainment in the San Juan and Guayama-Salinas
areas, to be inoperative, or operate at reduced capacity, for several
months. As a result, the PRDNER estimated that electrical generation
was below fifty percent of the normal average in the last quarter of
2017.
The PRDNER utilized SO<INF>2</INF> actual emissions reported for
the principal stationary point sources in the San Juan and Guayama-
Salinas NAAs (i.e., PREPA San Juan, PREPA Palo Seco, and PREPA Aguirre
facilities), which were submitted under the SIP-approved RCAP Rule 410
(Maximum Sulfur Content in Fuels), and as a permit condition, which
requires submission of certified annual reports to the PRDNER by PREPA.
The PRDNER included the emissions calculations used to determine the
actual SO<INF>2</INF> emissions using reported fuel usage data in its
SIP submittal.\61\ The 2014 National Emissions Inventory (2014 NEI) was
used for the other emission inventory sectors.
---------------------------------------------------------------------------
\61\ Included in the appendix of the Baseline Emission Inventory
2014.
---------------------------------------------------------------------------
Table 8 summarizes the 2014 SO<INF>2</INF> base year emission
inventory by sector for the San Juan NAA.
[[Page 79842]]
Table 8--Base Year SO2 Emissions Inventory for the San Juan SO2 NAA
[Tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stationary
Year Stationary nonpoint Stationary Fuel combustion Onroad mobile Nonroad mobile
point sources sources nonpoint events sources sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
2014.............................................. 8,262 37 <1 39 33 437
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 9 summarizes the 2014 SO<INF>2</INF> base year emission
inventory by sector for the Guayama-Salinas NAA.
Table 9--Base Year SO2 Emissions Inventory for the Guayama-Salinas SO2 NAA
[Tons per year]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stationary
Year Stationary nonpoint Stationary Fuel combustion Onroad mobile Nonroad mobile
point sources sources nonpoint events sources sources
--------------------------------------------------------------------------------------------------------------------------------------------------------
2014.............................................. 9,261 4 7 <1 3 <1
--------------------------------------------------------------------------------------------------------------------------------------------------------
As shown in Tables 8 and 9, the majority of SO<INF>2</INF>
emissions in the 2014 base year inventory can be attributed to the
stationary point source category. Emissions for this category are
provided in further detail in Table 10.
Table 10--Base Year Stationary Point Source SO2 Emissions Inventory
------------------------------------------------------------------------
Emissions (tons
Stationary point source Nonattainment area per year)
------------------------------------------------------------------------
PREPA Palo Seco................. San Juan 3,128
PREPA San Juan.................. San Juan 5,135
PREPA Aguirre................... Guayama-Salinas 9,261
------------------------------------------------------------------------
A projected attainment year emissions inventory should also be
included in the SIP submission, according to the 2014 SO<INF>2</INF>
Guidance. This emissions inventory should include, in a manner
consistent with the attainment demonstration, estimated emissions for
all SO<INF>2</INF> sources that were determined to have an impact on
the affected NAA for the projected attainment year.
In addition to the 2014 base year inventory of actual emissions,
the PRDNER's submission included a projected emission inventory for the
PREPA San Juan, PREPA Palo Seco, and PREPA Aguirre facilities that
includes allowable emissions from 2019 through 2029. The emissions
projections represent current permit allowable emissions (2019-2022),
emissions based on an interim remedy relying on the mandatory use of
ULSD for certain units starting in February 2023, and emissions that
provided for attainment of the 1-hour SO<INF>2</INF> NAAQS based on
their final remedy (i.e., emission unit retirements and fuel switching
to ULSD or LNG from 2022-2029). Based on the schedule for enforceable
retirements, the final projected emissions occur through December 31,
2025, for PREPA Palo Seco and PREPA San Juan, and December 31, 2029,
for PREPA Aguirre, which extends beyond the April 9, 2023 attainment
date. The PRDNER did not include an emission inventory for the actual
2023 attainment deadline year.
Table 11 summarizes the PRDNER's projected emissions for the PREPA
San Juan, PREPA Palo Seco, and PREPA Aguirre facilities for 2019-2029.
Table 11--Projected Stationary Point Source SO2 Emissions for 2019-2029
[Tons per year]
----------------------------------------------------------------------------------------------------------------
Base potential Interim PTE Change (base
Stationary point source to emit (PTE) (2023) Final PTE to final)
----------------------------------------------------------------------------------------------------------------
PREPA Palo Seco................................. 17,157 11,013 12 -17,145
PREPA San Juan.................................. 10,215 9,496 43 -10,172
PREPA Aguirre................................... 31,246 19,199 4 -31,242
----------------------------------------------------------------------------------------------------------------
The EPA has evaluated the PRDNER's 2014 base year inventory and the
2019-2029 projection year inventory. The EPA proposes to find the base
year inventory and the methodologies used for its development
consistent with the EPA's guidance. As a result, the EPA is proposing
to determine that the San Juan and Guayama-Salinas SO<INF>2</INF>
nonattainment plan meets the requirements of CAA section 172(c)(3) for
the San Juan and Guayama-Salinas SO<INF>2</INF> NAAs for its 2014 base
year inventory.
As previously stated, the projected emissions inventory includes
estimated emissions for SO<INF>2</INF> emission sources for a projected
attainment year that extends beyond the CAA mandatory attainment date
of April 9, 2023. That said, since a new attainment date will be
[[Page 79843]]
established following the EPA's final determination that the areas
failed to attain the standard, the PRDNER will be expected to update
the projection year emissions inventory in its subsequent SIP revision.
The subsequent SIP revision will be required to be submitted within 12
months of a final determination on the EPA's proposed determination, in
accordance with CAA section 179(d). Consequently, the EPA is not
proposing action on the projection year emissions inventory in this
rulemaking.
B. RACM and RACT and Enforceable Emission Limitations and Control
Measures
CAA section 172(c)(1) states that nonattainment plans should
``provide for the implementation of all reasonably available control
measures as expeditiously as practicable (including such reductions in
emissions from existing sources in the area as may be obtained through
the adoption, at a minimum, of reasonably available control technology)
and shall provide for attainment of the national primary ambient air
quality standards.'' CAA section 172(c)(6) requires plans to ``include
enforceable emissions limitations, and such other control measures [. .
.] as may be necessary or appropriate to provide for attainment of [the
NAAQS].''
The necessary emissions limitations or other control measures in
the PRDNER's 2022 submitted plan for attaining the 1-hour
SO<INF>2</INF> NAAQS in the San Juan and Guayama-Salinas NAAs are based
on emission unit retirements and fuel switching to ULSD. As previously
mentioned, the enforceable control measures established in RCAP Rule
425 were to be implemented from June 30, 2023, through December 31,
2025, in the San Juan NAA, and December 31, 2025, through December 31,
2029, in the Guayama-Salinas NAA.
Rule 425 provides exemptions allowing for alternative retirement
dates, provided they are approved by PRDNER and the PREB, but no later
than December 31, 2025 for the San Juan NAA, and December 31, 2029 for
the Guayama-Salinas NAA. As a result of these exemptions, the EPA
believes the retirement dates listed under Rule 425 would not provide
permanently enforceable measures for major sources of SO<INF>2</INF>.
The EPA anticipates that the PRDNER will remove these exemptions within
the subsequent SIP revision that Puerto Rico will be required to submit
within one year of the final determination of the EPA's proposed
finding that the areas failed to attain the standard by the statutory
attainment date.
Because the San Juan and Guayama-Salinas NAAs will be subject to a
new attainment date, which will be five years following the EPA's final
determination that the areas failed to attain the standard, the EPA is
not proposing action on the PRDNER's RACM/RACT and emissions
limitations or control measures that were submitted in accordance with
CAA sections 172(c)(1) and (6). As a result of this new attainment
date, the EPA expects these elements will be revised within the
subsequent SIP revision that the PRDNER will be required to submit
within one year of the EPA's final finding that the areas failed to
attain the standard. The EPA will act on these elements upon receipt of
the PRDNER's subsequent SIP revision.
C. New Source Review
Part D of title I of the CAA prescribes the procedures and
conditions under which a new major stationary source or major
modification may obtain a preconstruction permit in an area designated
nonattainment for any criteria pollutant. The nonattainment new source
review (NNSR) permitting requirements in section 172(c)(5) and 173 of
the CAA are among ``the requirements of this part'' to be submitted to
the EPA as part of a revised SIP for a nonattainment area within 18
months of the effective date of a designation or redesignation to
nonattainment. The NNSR permitting requirements provide for the
permitting of any proposed major stationary source of SO<INF>2</INF>
located in a NAA under the 2010 SO<INF>2</INF> NAAQS.
The PRDNER submitted its NNSR program's rules for SO<INF>2</INF>
and other future potential nonattainment pollutants in its SIP
submission to the EPA on November 22, 2022. Specifically, the PRDNER
submitted \62\ for SIP approval, Rule 102, ``Definitions,'' as amended,
which includes definitions relevant to nonattainment; and Rule 210,
``Nonattainment Provisions,'' which establishes the requirements
necessary to construct or modify major emission sources of
SO<INF>2</INF> and other pollutants in areas designated as NAAs.
---------------------------------------------------------------------------
\62\ Rule 425, ``Provisions for SO<INF>2</INF> Nonattainment
Areas,'' which contains the emission limits and other control
measures for the PREPA San Juan, PREPA Palo Seco, PREPA Aguirre
facilities, as well as for the San Juan and Guayama-Salinas NAAs, is
evaluated in Section VI.B of this notice.
---------------------------------------------------------------------------
The PRDNER's NNSR program rules are evaluated in Section VII,
``Puerto Rico's New Source Review Program'' of the preamble within this
notice of proposed rulemaking. These rules provide appropriate new
source review for SO<INF>2</INF> sources undergoing construction or
major modification in the San Juan and Guayama-Salinas NAAs, including
meeting the applicable statutory requirements, which include but are
not limited to the installation of Lowest Achievable Emissions Rate
(LAER) control technology and the acquisition of emissions reductions
to offset new emissions of nonattainment pollutant(s). Based on the
EPA's evaluation in Section VII, the EPA is proposing, upon final
approval of the RCAP's Rules 102 and 210, that the new source
requirements have been met for the San Juan and Guayama-Salinas NAAs.
D. Reasonable Further Progress
The EPA's policy that Reasonable Further Progress (RFP) for
SO<INF>2</INF> may be satisfied by ``adherence to an ambitious
compliance schedule'' is based on the fact that ``for SO<INF>2</INF>
there is usually a single `step' between pre-control nonattainment and
post-control attainment.'' \63\ Because a new attainment date will be
promulgated upon the EPA's final determination that the NAAs failed to
attain the standard by the statutory attainment date, and the EPA
expects this element will be revised by the PRDNER with the subsequent
SIP revision required following the EPA's final determination, the EPA
is not proposing action on the requirements listed under CAA section
172(c)(2), to provide for RFP toward attainment in the San Juan and
Guayama-Salinas SO<INF>2</INF> NAAs.
---------------------------------------------------------------------------
\63\ 2014 SO<INF>2</INF> Guidance, at 40.
---------------------------------------------------------------------------
E. Contingency Measures
As discussed in the EPA's SO<INF>2</INF> guidance, section
172(c)(9) of the CAA defines contingency measures as measures in a SIP
that are to be implemented in the event an area fails to make RFP, or
fails to attain the NAAQS, by the applicable attainment date.
Contingency measures are to become effective without further action by
the state/commonwealth or the EPA, where the area has failed to (1)
achieve RFP or (2) attain the NAAQS by the statutory attainment date
for the affected area. These control measures are to consist of other
available control measures that are not included in the control
strategy for the NAA SIP. The EPA's guidance describes special features
of SO<INF>2</INF> planning that influence the suitability of
alternative means of addressing the requirement in section 172(c)(9)
for contingency measures for SO<INF>2</INF>. Because SO<INF>2</INF>
control measures are by definition based on what are directly and
quantifiably necessary emissions
[[Page 79844]]
controls, any violations of the NAAQS are likely related to source
violations of a source's permit terms. Therefore, an appropriate means
of satisfying this requirement for SO<INF>2</INF> is for a state to
have a comprehensive enforcement program that identifies sources of
violations of the SO<INF>2</INF> NAAQS and to undertake an aggressive
follow-up for compliance and enforcement.
For its contingency measures program, the PRDNER indicated it will
continue to operate a comprehensive program to identify sources
violating the SO<INF>2</INF> NAAQS, and that it will undertake
compliance inspections and necessary enforcement actions.
In its submission to the EPA, the PRDNER clarified that it has
authority under Article 9(a)(7) of the Puerto Rico Energy Public Policy
Act (PREPPA) to order persons causing or contributing to a condition
which harms the environment and natural resources, or which poses an
imminent danger for the public health and safety, to immediately
diminish or discontinue their actions. Furthermore, the PRNDER
indicated that Article 9(a)(8) of PREPPA provides the PRDNER with the
authority to issue orders to take the preventative or control measures
necessary.
Accordingly, the PRDNER also included a provision that, upon
notification by the PRDNER that a nearby monitor has four validated
SO<INF>2</INF> concentrations in excess of the standard or has a
monitored SO<INF>2</INF> violation based on the design value, PREPA
would be required to undertake a system audit of emissions units.
Consequently, an audit report would be required for submission by PREPA
to the PRDNER within 90 days of the notification. An audit report would
detail the operating parameters of all emissions units for four 10-day
periods up to and including the date upon which the reference monitor
registered each exceedance, together with recommended SO<INF>2</INF>
emission control strategies, and evidence that the strategies have been
deployed, as appropriate. Upon receipt of the report, the PRDNER would
begin a 60-day evaluation period to diagnose the exceedance, to be
followed by a 60-day consultation period with PREPA to develop and
implement necessary operational changes. The PRDNER indicated that such
changes may include fuel switching, physical or operational reductions,
or other changes that the PRDNER determined to be appropriate.
Additionally, if any new emission limits were deemed necessary, the
PRDNER indicated they would be submitted to the EPA as a SIP revision.
The PRDNER has also provided details on the corrective actions to
occur if emission sources do not comply with required emission limits
and other requirements in Section VI of Rule 425. Specifically, this
includes expedited procedures for establishing enforceable consent
agreements when the adoption of revised SIPs is pending, and subjecting
any source that is found to be in violation of an approved compliance
plan or requirement within such plan to repercussions listed under Rule
115. Additionally, under Rule 425, the PRDNER indicated that if a new
measure or control was determined to be sufficient to address
violations of the SO<INF>2</INF> NAAQS and was promulgated or scheduled
to be implemented at the federal or state level, additional local
measures might be unnecessary following the PRDNER's submission of an
analysis to the EPA demonstrating that such proposed measures were
adequate to return an area to attainment. Under Rule 425, the PRDNER
will also have the authority to require any owner or operator of an
SO<INF>2</INF> emissions source contributing to air pollution to
install, operate, and maintain monitoring devices; as well as maintain
records and file periodic reports to the PRDNER. The PRDNER will also
have the ability under Rule 425 to require the submission of an
``Ambient Air Quality Monitoring Plan'' that complies with the EPA's
guidelines and includes an air quality and meteorological measurement
network which collects accurate SO<INF>2</INF> air quality and
meteorology data within the zone impacted by SO<INF>2</INF> emissions
from a source. Finally, the PRDNER will have authority under Rule 425
to issue additional orders which require that a previously submitted
plan be clarified, updated, corrected, supplemented, or otherwise
amended.
The PRDNER also provided information regarding a proposed
``Attainment Ambient Monitoring Network'' (or AAMN). The PRDNER
proposed that the AAMN would establish 12 SO<INF>2</INF> monitoring
stations, with six in each of the two nonattainment areas. The location
of these proposed stations would be determined based on an analysis
that predicts the maximum concentrations using the EPA-approved AERMOD
model. Additionally, the PRDNER indicated that the proposed
SO<INF>2</INF> monitoring will be subject to 40 CFR part 58
requirements to be used for comparison to the NAAQS. The EPA did not
approve any new SO<INF>2</INF> sites as part of PRDNER's 2023 AMNP.\64\
Based on the preliminary information provided, the EPA does not believe
there is sufficient information to evaluate the appropriateness of the
AAMN as part of the contingency measures for the plan.
---------------------------------------------------------------------------
\64\ See letter dated January 10, 2023, from Richard Ruvo,
Director, EPA Region II, Air and Radiation Division to Ana[iacute]s
Rodr[iacute]guez Vega, Secretary, Puerto Rico Department of Natural
and Environmental Resources.
---------------------------------------------------------------------------
Although Puerto Rico has taken significant steps to develop a
comprehensive program to satisfy the contingency measures requirement
for SO<INF>2</INF>, the EPA's policy is premised on full compliance
with the approvable controls and limits required in the approvable plan
to ensure attainment. However, as previously discussed, the EPA is not
proposing action on related CAA section 172(c) elements of the
attainment plan, including the attainment demonstration, the RFP, and
the RACM/RACT and enforceable emission limitation elements of the SIP,
because Puerto Rico will be required to submit a revised SIP which the
EPA anticipates will contain an updated control strategy based on the
new attainment date that will be established with the EPA's final
determination that the areas failed to attain the standard. Thus, the
EPA is not proposing action on the contingency measures the PRDNER
provided in its submission to satisfy section 172(c)(9), because the
approvability of the contingency measures element depends upon the
approvability of the attainment demonstration.
F. Conformity
Generally, as set forth in section 176(c) of the CAA, conformity
requires that actions by federal agencies do not cause new air quality
violations, worsen existing violations, or delay timely attainment of
the relevant NAAQS. General conformity applies to federal actions,
other than certain highway and transportation projects, if the action
takes place in a NAA or maintenance area (i.e., an area which submitted
a maintenance plan that meets the requirements of section 175A of the
CAA and has been redesignated to attainment) for ozone, particulate
matter, nitrogen dioxide, carbon monoxide, lead, or SO<INF>2</INF>. The
EPA's General Conformity Rule establishes the criteria and procedures
for determining if a federal action conforms to the SIP.\65\
---------------------------------------------------------------------------
\65\ 40 CFR 93.150 to 93.165.
---------------------------------------------------------------------------
With respect to the 2010 SO<INF>2</INF> NAAQS, federal agencies are
expected to continue to estimate emissions for conformity analyses in
the same manner as they estimated emissions for conformity analyses
under the previous NAAQS for SO<INF>2</INF>. The EPA's General
[[Page 79845]]
Conformity Rule includes the basic requirement that a federal agency's
general conformity analysis be based on the latest and most accurate
emission estimation techniques available.\66\ When updated and improved
emission estimation techniques become available, the EPA expects
federal agencies will continue to use these techniques to ensure
projects conform to the SIP.
---------------------------------------------------------------------------
\66\ 40 CFR 93.159(b).
---------------------------------------------------------------------------
The EPA concluded in its 1993 transportation conformity rule that
highway and transit vehicles are not significant sources of
SO<INF>2</INF>. As a result, transportation conformity determinations
are not required in SO<INF>2</INF> nonattainment and maintenance areas.
Therefore, transportation plans, transportation improvement programs,
and projects are presumed to conform to applicable implementation plans
for SO<INF>2</INF>.
VII. Puerto Rico's New Source Review Program
The PRDNER's permitting requirements for the preconstruction review
of new major sources in NAAs are set forth in the revisions to Rule
102, ``Definitions,'' and the newly adopted Rule 210, ``Nonattainment
Provisions.'' The PRDNER's NNSR program applies to the construction and
modification of any major stationary source of air pollution in a NAA,
as required by part D of title I of the CAA. To receive approval to
construct, a source that is subject to these regulations must show that
it will not cause a net increase in pollution with more than a 1:1
offset ratio, will not create a delay in meeting the NAAQS, and will
install and use control technology that achieves the LAER. The
revisions to Rule 102 and the newly created Rule 210 within the RCAP,
which the EPA is proposing to approve into the SIP, incorporate
provisions that are consistent with the current federal requirements
for an approvable nonattainment NSR program in 40 CFR 51.165. Among
these provisions is the prohibition of construction, unless an
effective permit is issued that meets the requirements of Rule 210, and
a certification from the applicant that all existing major stationary
sources owned and operated by the applicant in Puerto Rico are
complying with all applicable emissions standards of the CAA or that
such stationary sources are in compliance with an expeditious schedule
which is federally enforceable or contained in a court decree.
As part of its review of the PRDNER's NNSR submittal, the EPA has
determined that the revisions are consistent with the program
requirements for the preparation, adoption, and submittal of
implementation plans for NNSR, set forth at 40 CFR 51.165.
VIII. The EPA's Evaluation of Rule 425
On November 21, 2022, the PRDNER promulgated the new Rule 425,
``Provisions for SO<INF>2</INF> Non-Attainment Areas.'' The new Rule
425 was included within the November 22, 2022 SIP revision submitted by
the PRDNER.
The EPA is proposing to approve, for SIP-strengthening purposes and
to make federally enforceable, the following sections of Rule 425:
Section I, ``Applicability;'' Section IV, ``Emission Limitations for
San Juan and Guayama-Salinas Non-Attainment Areas,'' Section V,
``Measurement methods and procedures,'' Subsections (A), (B), and (E);
and Section VI, ``Contingency Measures.'' Additionally, the EPA is
proposing to conditionally approve Section II, ``Emission Limitations
for PREPA San Juan and PREPA Palo Seco,'' Subsection (A), Section III,
``Emission Limitations for PREPA Aguirre,'' Subsection (A), Section V,
``Measurement methods and procedures,'' Subsections (C), (D), and (F).
Rule 425 is applicable to the current and future owners or
operators of the PREPA San Juan, PREPA Palo Seco, and PREPA Aguirre
facilities, as indicated under Section I, ``Applicability'' of Rule
425. Additionally, under Section I of Rule 425, any other major sources
in or nearby the NAAs that have not undergone a major modification or
construction of a new emission unit subject to Rule 210 are also
subject to the provisions of Rule 425. The EPA proposes to approve the
applicability provisions listed under Section I of Rule 425 for SIP-
strengthening purposes.
Under Section II, ``Emissions Limitations for PREPA San Juan and
PREPA Palo Seco'' and Section III, ``Emission Limitations for PREPA
Aguirre'' of Rule 425, details are provided regarding compliance start
dates for fuel switching to ULSD of certain emission units, retirement
schedules for emission units not being converted to ULSD, and emission
limits for units using ULSD or LNG at the PREPA San Juan, PREPA Palo
Seco, and PREPA Aguirre facilities. The EPA is proposing to
conditionally approve the ULSD emission limits for units listed under
Section II(A) and Section III(A) of Rule 425, which prevent the burning
of any fuel oil above a maximum sulfur content of 15 ppm at the three
aforementioned PREPA facilities, since fuel switching of emission units
to ULSD is expected to result in a significant decrease of sulfur
emissions, providing for improved air quality. Details regarding the
conditional approval and revisions the PRDNER has committed to make to
Rule 425 as discussed in its September 2, 2024 commitment letter \67\
are provided in the following paragraphs of this section. In accordance
with section 110(k)(4) of the CAA, this proposed conditional approval
is based on the PRDNER's commitment to make specific revisions to
Section V of Rule 425, which will address concerns the EPA has
regarding the enforceability of emission limits for the specific units
listed under Section II(A) and Section III(A), and to submit such
revisions to the EPA by January 1, 2026 for approval into the SIP for
Puerto Rico.
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\67\ Details regarding the EPA's conditional approval and the
revisions which the PRDNER has committed to make to RCAP Rule 425 by
January 1, 2026, can be found within the commitment letter the
PRDNER submitted to the EPA on September 2, 2024, and which the EPA
has included within the docket for this action.
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The EPA is not proposing to approve and is taking no action on
Section II(B) and Section III(B) of Rule 425, which list the retirement
schedules for emission units and detail emission limits for units at
the three PREPA facilities, since the EPA anticipates these schedules
will be revised by Puerto Rico to conform with the updated control
strategy submitted by the PRDNER in the subsequent SIP submission
required under the CAA following the EPA's final determination that the
areas failed to attain. Additionally, the retirement provisions within
Section II(B) and Section III(B) of Rule 425 allow the PRDNER to
request an alternate date, which provides exemptions to a control
strategy and are therefore not a permanently enforceable control
strategy.
In addition, under Section IV, ``Emission Limitations for San Juan
and Guayama-Salinas Non-Attainment Areas'' of Rule 425, any emission
source (or any nearby sources having a significant impact) within the
boundaries of the San Juan and Guayama-Salinas NAAs, except for PREPA
emission units, shall comply \68\ with all the provisions within
subsection IV(A). Thus, no owner or operator of any combustion units
within the boundaries of the NAAs, or nearby sources having a
significant air quality impact on SO<INF>2</INF>, shall cause or permit
the burning of any fuel oil above a maximum sulfur content of 0.0015
[[Page 79846]]
percent by weight (15 ppm) by no later than April 9, 2023 (Sections
IV(A)(l)-(2) of Rule 425). Under Section IV(B), owners or operators of
stationary sources subject to the limitations of Section IV(A) are
required to certify in writing to the PRDNER that such source complies
with Rule 425. Finally, under Section IV(C), any owner or operator of a
stationary source subject to the limitations of Section IV(A) that
cannot comply with the emission limits established by the date required
under Rule 425 shall create a compliance plan which implements RACT in
accordance with Rule 205 and in compliance with Rule 425. Upon the
PRDNER's approval, a compliance plan must then be implemented and
certified by a responsible official for accuracy. The EPA is proposing
to approve Section IV of Rule 425 for SIP-strengthening purposes, as it
provides for the reduction of SO<INF>2</INF> emissions within the NAAs
and provides air quality benefits.
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\68\ Emission sources are also required to comply with
provisions provided under Rules 401 through 421 of the RCAP.
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Regarding the test methods to be utilized when determining
compliance with the allowable emission limits listed under Rule 425,
the PRDNER requires the use of test methods provided in 40 CFR part 60.
Further detail regarding the test methods and procedures for PREPA to
determine compliance with the allowable emission limit for any fuel
other than coal at the PREPA facilities in San Juan, Palo Seco, and
Aguirre is provided under Section V, ``Measurement methods and
procedures'' of Rule 425. The EPA acknowledges the PRDNER's recommended
on-site fuel sampling of ULSD (and LNG for PREPA San Juan) in
accordance with USEPA Method 19, ASTM D2622, D4294, D5453, D7039, or
other appropriate EPA or ASTM method. The EPA also acknowledges the
requirement for the PREPA facilities to have monitors recording the
amount of each fuel type burned at each emission unit on an hourly
basis and the requirement for PREPA to sample each batch of fuel prior
to use for sulfur content (percent by weight), heat value, and density.
Additional provisions under Rule 425 concern sample submission for
laboratory analysis and maintenance of laboratory analysis records for
a period of at least five years. Under this rule, PREPA will also be
required to maintain monthly records listing (a) the fuel used (hourly
usage and total fuel used for the month), (b) sulfur content of the
fuel, fuel density, fuel heating value, and the basis for the sulfur
content used (fuel analysis showing the date the sample was collected,
type of fuel, sulfur content, and fuel heating value), and (c)
SO<INF>2</INF> emission rates (lb/hr) with the assumption that 100% of
the sulfur in the fuel is converted to SO<INF>2</INF>. Accordingly, the
EPA proposes to approve Subsections (A), (B), and (E) of Section V
under Rule 425 for SIP-strengthening.
Furthermore, under the current Section V of Rule 425, the PREPA San
Juan, PREPA Palo Seco, and PREPA Aguirre facilities (and any owner or
operator of an SO<INF>2</INF> emission source subject to Rule 425) will
be required to retain all data, calculations, and reports from any
performance test or fuel sample developed for the purpose of
demonstrating compliance with the applicable emission limits, emission
tracking requirements, or emission rate limits, for a minimum of five
years. Additionally, Section V will require that these records be made
available for inspection to the PRDNER upon its request. Under Rule
425, the PRDNER will also have the authority to issue orders to require
performance testing, fuel sampling, or require record-keeping and
reporting of emission information.
The EPA is proposing to conditionally approve the reporting
provisions under Rule 425, Section V, Subsections (C), (D), and (F),
which only require an owner or operator of an SO<INF>2</INF> emission
source in the NAAs to make records available for inspection purposes
and following the PRDNER's request. Section V of Rule 425 includes
provisions imposing monitoring and recordkeeping obligations on the
relevant sources, such as performance and fuel testing, and retention
of records needed to demonstrate compliance with the relevant emission
limitations; however, the EPA is concerned that the absence of periodic
reporting obligations under Subsections (C), (D), and (F) may interfere
with enforcement of the rule. On September 2, 2024, the PRDNER
submitted a letter committing to revise the reporting provisions under
Subsections (C), (D), and (F) by January 1, 2026, which will require
facilities subject to Rule 425 to submit reports semi-annually (i.e.,
every six months). In accordance with section 110(k)(4) of the CAA, the
EPA may conditionally approve a plan based on a commitment from a
State/commonwealth to adopt specific enforceable measures and submit
the necessary SIP revisions to the EPA by a date certain.
If this conditional approval is finalized as proposed, the
conditionally approved provisions of Rule 425 will become part of the
SIP and will be federally enforceable as of the effective date of the
final conditional approval. If the PRDNER submits the revisions to Rule
425 by January 1, 2026, as committed to in its September 2, 2024
commitment letter, the conditionally approved provisions will remain a
part of the SIP unless the EPA disapproves the revisions to Rule 425
through notice-and-comment rulemaking. If the EPA takes final action
approving the revisions to Rule 425 into the SIP, in the same final
action, the EPA will also convert the conditional approval of Rule 425,
Section V, Subsections (C), (D), and (F), to an approval by making
appropriate revisions to the SIP in the Code of Federal Regulations. If
the EPA disapproves the revisions to Rule 425 intended to satisfy the
PRDNER's commitment, the conditional approval will convert to a
disapproval, and the conditionally approved provisions of Rule 425 will
no longer be a part of the approved SIP for Puerto Rico.
If the PRDNER fails to meet its commitment to submit the necessary
SIP revisions to the EPA by January 1, 2026, or if the PRDNER submits
timely SIP revisions, but the EPA finds the SIP submittal to be
incomplete, this conditional approval will be converted to a
disapproval. In either case, the EPA would notify the PRDNER by letter
that the conditional approval has converted to a disapproval and the
EPA would subsequently publish a document in the Federal Register
announcing that the conditional approval converted to a disapproval.
As previously stated, the EPA is proposing to conditionally approve
the ULSD emission limits described in Section II(A) and Section III(A)
of Rule 425, since the emission limits provide for a significant
decrease in sulfur emissions. The EPA is also proposing to
conditionally approve the reporting provisions which apply to these
limits described in Section V, Subsections (C), (D), and (F). The EPA,
however, is not conditionally approving these sections for compliance
with CAA section 172(c) requirements.
Finally, as previously discussed under Section VI.E, ``Contingency
Measures,'' of this preamble, Section VI, ``Contingency Measures'' of
Rule 425 specifies corrective actions \69\ to be taken if emission
sources do not achieve compliance with emission limits
[[Page 79847]]
established in Rule 425 by the dates specified.
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\69\ These provisions, which are more fully discussed by EPA in
Section VI, subsection E of this proposed rulemaking, include
expedited procedures for establishing enforceable consent
agreements; repercussions for violations; assessing new measures;
monitoring, reporting, and recordkeeping requirements; assessment of
additional local measures; and the PRDNER's ability to require
previously submitted plans to be clarified, updated, corrected,
supplemented, or otherwise amended.
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Moreover, in Section VI. E of this notice of proposed rulemaking,
the EPA has indicated that the Agency is not proposing action on the
contingency measures within the PRDNER's plan. That is because the
EPA's policy is premised on full compliance with approvable controls
and limits required in the approvable plan to ensure attainment.
However, the EPA recognizes that the corrective actions outlined in
Section VI of Rule 425 will have an overall positive impact on air
quality in the San Juan and Guayama-Salinas NAAs. Therefore, the EPA is
proposing to approve Section VI of Rule 425 for SIP strengthening and
not to satisfy the contingency measure requirements of CAA 172(c)(9).
IX. Environmental Justice Considerations
The PRDNER did not provide any information within its November 22,
2022, SIP submittal to the EPA regarding environmental justice (EJ)
considerations within the two NAAs. For informational purposes only,
the EPA evaluated EJ considerations during its review of the PRDNER's
SO<INF>2</INF> SIP submittal. The EPA did not rely on this information
to reach any decisions described in this action. Notably, the CAA and
applicable implementing regulations neither prohibit nor require such
evaluation of EJ. The following information and discussion is provided
for informational purposes only. An informational application of the
White House's Climate and Economic Justice Screening Tool (CEJST) \70\
produced information that indicates that nearly all census tracts (or
95% of the population) within Puerto Rico are considered
disadvantaged.\71\
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\70\ See <a href="https://screeningtool.geoplatform.gov/en/#3/33.47/-97.5">https://screeningtool.geoplatform.gov/en/#3/33.47/-97.5</a>.
\71\ A census tract is considered disadvantaged if it meets the
thresholds for at least one of the tool's categories of burden or it
is on the lands of a federally recognized Tribe. Additional
information on the categories of burden can be found at <a href="https://screeningtool.geoplatform.gov/en/methodology">https://screeningtool.geoplatform.gov/en/methodology</a>.
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The evaluation here of environmental burdens and susceptible
populations is based on screening-level analyses utilizing version 2.2
of the EPA's Environmental Justice Screening and Mapping Tool
(EJScreen).\72\ EJScreen is the EPA's EJ screening and mapping tool
that provides EPA with a nationally consistent dataset and approach for
combining environmental and demographic socioeconomic indicators.
EJScreen is not a detailed risk analysis of EJ issues/concerns; rather,
it is a screening tool that examines some of the relevant issues
related to EJ, and there is uncertainty in the data included.
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\72\ See <a href="https://www.epa.gov/ejscreen">https://www.epa.gov/ejscreen</a>.
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Through its use of EJScreen, the EPA determined that there may be
potential EJ concerns within both SO<INF>2</INF> NAAs and the areas
within a 1-mile radius of the three PREPA facilities. The EJScreen
Community Reports are provided in the docket for this action. The
results of these analyses are being provided for informational and
transparency purposes only.
In using EJScreen, if any of the EJ indices for the areas under
consideration are at or above the 80th percentile nationally, then
further review may be appropriate.\73\ Thus, the EPA's discussion of
EJScreen results will focus on bringing attention to indices at or
above the 80th percentile. As discussed in the EPA's EJ technical
guidance,\74\ people of color and low-income populations often
experience greater exposure and disease burdens than the general
population, which can increase their susceptibility to adverse health
effects from environmental stressors. Underserved communities can also
experience reduced access to health care, nutritional, and fitness
resources, further increasing their susceptibility.
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\73\ For early applications of EJScreen, the EPA identified the
80th percentile filter as the initial starting point for the purpose
of identifying geographic areas that may warrant further
consideration. In other words, an area with any of the 13 EJ Indices
at or above the 80th percentile nationally should be considered as a
potential candidate for further review. See <a href="https://www.epa.gov/ejscreen/how-interpret-ejscreen-data">https://www.epa.gov/ejscreen/how-interpret-ejscreen-data</a>.
\74\ See <a href="https://www.epa.gov/system/files/documents/2023-06/ejscreen-tech-doc-version-2-2.pdf">https://www.epa.gov/system/files/documents/2023-06/ejscreen-tech-doc-version-2-2.pdf</a>.
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Furthermore, the EJScreen tool provides information on 13 EJ
Indices and 13 Supplemental Indices. Out of these, 11 indices have
available data to derive in parts of Puerto Rico. Each index combines
one environmental measure with demographic data \75\ to characterize
potential areas of EJ concern that may warrant further consideration,
analysis, or outreach. The EJ indices help screen for potential EJ
concerns and combine data on low-income and people of color populations
with a single environmental indicator. The supplemental indices offer a
perspective on community-level vulnerability and combine data on
percent low-income, percent linguistically isolated, percent with less
than a high school education, percent unemployed, and low life
expectancy with a single environmental indicator. It is also possible
to compare indices for a given area to other locations within the
nation and a State (or commonwealth). Specific background and source
information on these indices and environmental indicators can be found
in the EPA's ``EJScreen Technical Documentation for Version 2.2.'' \76\
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\75\ Demographic and socioeconomic data utilized within EJS is
obtained from the U.S. Census Bureau's American Community Survey
(ACS) 2017-2021 5-Year Estimates.
\76\ See <a href="https://www.epa.gov/system/files/documents/2023-06/ejscreen-tech-doc-version-2-2.pdf">https://www.epa.gov/system/files/documents/2023-06/ejscreen-tech-doc-version-2-2.pdf</a>.
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The population living within the San Juan NAA has high (for the
purpose of this discussion, at or above the 80th percentile) EJ and/or
Supplemental Index values at the national and/or State (or
commonwealth) level for 9 of the 11 indices available in EJScreen.
These include Diesel Particulate Matter, Toxic Releases to Air, Traffic
Proximity, Lead Paint, Superfund Proximity, RMP Facility Proximity,
Hazardous Waste Proximity, Underground Storage Tanks, and Wastewater
Discharge. While none of these indices have direct implications to
SO<INF>2</INF> emissions, and are not at issue in the SIP submission,
they highlight that there may be some potential EJ concerns within the
area.
The population living within the Guayama-Salinas NAA also has high
(for the purpose of this discussion, at or above the 80th percentile)
EJ and/or Supplemental Index values at the national and/or State (or
commonwealth) level for 6 of the 11 indices available in EJScreen.
These include Air Toxics Cancer Risk, Toxic Releases to Air, Traffic
Proximity, Lead Paint, Superfund Proximity, and Wastewater Discharge.
While none of these indices have direct implications to SO<INF>2</INF>
emissions, and are not at issue in the SIP submission, they highlight
that there may be some potential EJ concerns within the area.
The EPA elected to conduct further analysis of the areas within a
1-mile radius of the three PREPA facilities (and within the NAAs) to
ensure that the areas of maximum impact from emissions at the PREPA
facilities were being considered.
The results in EJScreen for the areas within a 1-mile radius of
both the PREPA San Juan and PREPA Palo Seco facilities indicated that
the populations were in the 96th percentile for People of Color
nationally (99 percent of the population in both of the areas within a
1-mile radius are considered People of Color). The area within a 1-mile
radius of the PREPA San Juan facility is in the 97th percentile
nationally for low income (81 percent of the population within a 1-mile
radius of the PREPA San Juan facility is considered to be low-income),
and the area within a 1-mile radius of the PREPA Palo Seco facility
[[Page 79848]]
is in the 76th percentile (46 percent of the population within a 1-mile
radius of the PREPA Palo Seco facility is considered to be low-income).
The population living within a 1-mile radius of the PREPA San Juan
facility is at or above the 90th percentile for EJ and/or Supplemental
Index values at the national and/or State (or commonwealth) level for
all 11 available indices in EJScreen. The population living within a 1-
mile radius of the PREPA Palo Seco facility is at or above the 80th
percentile for EJ and/or Supplemental Index values at the national/and
or State (or commonwealth) level for 7 of the 10 available indices. In
addition, the population within the Guayama-Salinas NAA, and within a
1-mile radius of the PREPA Aguirre facility, are both in the 98th
percentile nationally for People of Color (with 100 percent of the
population considered People of Color), and in the 96th percentile
nationally for low-income (with 78 percent of the population considered
low-income).
Based on all the screening-level demographic and socioeconomic data
previously detailed, the populations within both NAAs and within a 1-
mile radius of the three PREPA facilities are predominately made up of
people of color and/or low-income individuals. As a result, conditions
that exist prior to this action have the potential to result in
disproportionate and adverse effects on communities with EJ concerns.
The reliability of Puerto Rico's energy infrastructure has been
impacted by a combination of factors, including its vulnerability to
severe storms and an aging fossil fuel-reliant generation fleet. After
Hurricane Maria in 2017, Puerto Rican households experienced the
largest and longest blackout in U.S. history, and the second-longest
blackout in the world, with 80 percent of the island's power lines
leveled.\77\ Moreover, Puerto Rico's fleet of fossil fuel generators is
the oldest in the United States, with an average age of 44 years as
compared with the national average of 18 years.\78\ Notably, although
the poverty rate in Puerto Rico is more than three times the national
average, Puerto Ricans pay an average of almost twice as much for
electricity as U.S. mainland customers.\79\ The average price of
electricity in 2022 across all sectors (residential, commercial, and
industrial) in Puerto Rico averaged 29.63 cents/kWh, which is higher
than every U.S. State except Hawaii (and excluding other U.S.
Territories).\80\
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\77\ See <a href="https://www.fema.gov/disaster/4339">https://www.fema.gov/disaster/4339</a>.
\78\ See Jones, G., The Future of Energy in Puerto Rico: Current
Challenges and Opportunities for a Resilient Power Grid. On Behalf
of the U.S. Environmental Protection Agency, Region 2 Brownfields
Program (2021/12/15), <a href="https://www.bu.edu/rccp/files/2022/01/Energy-Resilience-in-Puerto-Rico.pdf">https://www.bu.edu/rccp/files/2022/01/Energy-Resilience-in-Puerto-Rico.pdf</a>.
\79\ See U.S. Energy Information Administration, ``Puerto Rico,
Territory Profile and Energy Estimates,'' available at https://
www.eia.gov/state/
?sid=RQ#:~:text=Puerto%20Rico%27s%20reliance%20on%20petroleum,
fired%20power%20plant and <a href="https://www.eia.gov/electricity/annual/html/epa_02_10.html">https://www.eia.gov/electricity/annual/html/epa_02_10.html</a>.
\80\ See U.S. Energy Information Administration, ``State Energy
Profiles, Puerto Rico,'' available at <a href="https://www.eia.gov/beta/states/states/RQ/data">https://www.eia.gov/beta/states/states/RQ/data</a>.
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The EPA anticipates that its proposed conditional approval of the
use of ULSD at the three PREPA facilities will not negatively impact
energy reliability for citizens within the NAAs. The lower sulfur
content in ULSD (15 ppm) has the potential to reduce harmful emissions
from nonroad diesel sources by more than 90%.\81\ Thus, the anticipated
significant reduction in sulfur content, compared to the sulfur content
of diesel fuel previously used at the three PREPA facilities, is
expected to result in approximately 15,000 tons of projected
SO<INF>2</INF> reductions annually that will bring the NAAs closer to
attainment of the NAAQS.\82\ At a minimum, this action is not expected
to worsen any existing air quality, and the EPA believes that this
proposed action will provide benefits to communities living within the
NAAs, as it will provide for emission reductions along with ensuring
the continued operation of existing electric generating units at the
PREPA facilities.
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\81\ See <a href="https://www.epa.gov/diesel-fuel-standards/diesel-fuel-standards-and-rulemakings">https://www.epa.gov/diesel-fuel-standards/diesel-fuel-standards-and-rulemakings</a>.
\82\ See docket for projected SO<INF>2</INF> emission
reductions.
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Public participation and community involvement are crucial for
ensuring that decisions affecting human health and the environment
advance environmental justice considerations. Communities affected by
environmental justice issues often face many challenges and barriers
associated with meaningful involvement and adequate representation in
the development, implementation, and enforcement of environmental laws,
regulations, and policies. Consequently, to provide ample time for
meaningful involvement, the EPA will extend its comment period for this
notice of proposed rulemaking (NPRM) from the customary 30 days to 60
days.
Additionally, as previously detailed within this NPRM, to provide
effective and meaningful involvement from community members during the
comment period for this NPRM, the EPA will hold public information
sessions concerning this proposed rulemaking. Given the high percentage
of households whose primary language is Spanish, the EPA intends to
provide all public distributions and supporting and related materials
for this rulemaking that are legally permitted to be translated, in
both Spanish and English, to the best of its ability. A Spanish
translator will also be present at these public information sessions to
ensure participants are able to understand the information provided by
the EPA. The EPA will announce the date, time, and location for each
session on its website. These sessions will allow citizens an
opportunity to learn more about this proposed action, which will
enhance their ability to provide more informed official comments during
the public comment period. See the Supplementary Information section
for additional information regarding the Public Information Sessions.
As previously stated, this analysis of EJ considerations was done
solely for the purpose of providing additional context and information
about this proposed rulemaking to the public and is not a basis for the
action. The EPA is taking action under the CAA and on bases independent
of EJ.
X. The EPA's Proposed Action
First, the EPA proposes, under CAA section 179(c)(1), to determine
that the San Juan and Guayama-Salinas areas failed to attain the 2010
1-hour SO<INF>2</INF> standard by the statutory attainment date of
April 9, 2023. This determination is based upon a weight-of-evidence
analysis, including (1) the control strategy timeline Puerto Rico
identified and adopted into its RCAP and submitted in support of its
air quality dispersion modeling of its November 22, 2022 SIP revision,
which did not provide for attainment by the statutory attainment date;
(2) Puerto Rico's inability to effectively implement the control
strategy it identified and adopted within a timely manner thus far; and
(3) the EPA's review of annual facility-wide emissions data from
January 2020 through December 2022 for the PREPA San Juan, PREPA Palo
Seco, and PREPA Aguirre facilities located within the NAAs.
If the EPA's determination is finalized as proposed, the
Commonwealth of Puerto Rico will be required under CAA section 179(d)
to submit revisions to the SIP for the San Juan and Guayama-Salinas
SO<INF>2</INF> NAAs. The required SIP revision for each area must,
among other elements, demonstrate expeditious attainment of the
standards within the time period prescribed by CAA section 179(d). If
the EPA's determination is finalized as proposed, the SIP revisions
required under CAA section 179(d) will be due for submittal to the EPA
no later
[[Page 79849]]
than one year after the publication date of the final action notice.
Second, the EPA proposes to approve certain but not all elements of
Puerto Rico's SIP submission, submitted to the EPA by the PRDNER on
November 22, 2022. Specifically, the EPA is proposing to approve the
following elements for compliance with the requirements of section
172(c) of the CAA: Puerto Rico's NNSR program, the base year emissions
inventory, and to affirm that the NNSR requirements for the NAAs have
been met. If finalized, this action would incorporate RCAP amendments
under Rules 102 and 210 into Puerto Rico's approved and federally
enforceable SIP.
The EPA is not proposing action on other remaining elements within
Puerto Rico's November 22, 2022 submission, as a result of the
anticipated revisions to the SIP, which Puerto Rico would be required
to submit within one year of the publication date of the final action
pursuant to CAA section 179(d), should the EPA finalize its
determination that the areas failed to meet the attainment date of
April 9, 2023. The EPA is therefore not proposing action on the
PRDNER's attainment demonstration, contingency measures, RACM/RACT and
emission limitations necessary for attainment, as well as the
requirements for meeting RFP toward attainment of the NAAQS.
Additionally, the EPA proposes to approve, in part, and
conditionally approve, in part, and not for compliance with the CAA
section 172(c) requirements, specific amendments to Rule 425 of Puerto
Rico's RCAP, which include control measures, emission limitations, and
reporting requirements for sources in the NAAs. Specifically, the EPA
is proposing to approve for SIP-strengthening, the following sections
of Rule 425: Section I, ``Applicability;'' Section IV, ``Emission
Limitations for San Juan and Guayama-Salinas Non-Attainment Areas;''
Section V, ``Measurement methods and procedures,'' Subsections (A),
(B), and (E); and Section VI, ``Contingency Measures.'' Moreover, the
EPA is proposing to conditionally approve Section II, ``Emission
Limitations for PREPA San Juan and PREPA Palo Seco,'' Subsection (A),
Section III, ``Emission Limitations for PREPA Aguirre,'' Subsection
(A), Section V, ``Measurement methods and procedures,'' Subsections
(C), (D), and (F).
The EPA is soliciting public comments on this proposed action. The
EPA will accept comments from the public on this proposal for the next
60 days and will consider these comments before taking final action.
XI. Incorporation by Reference
In this rule, the EPA is proposing to include in a final EPA rule,
regulatory text that includes incorporation by reference. In accordance
with requirements of 1 CFR 51.5, the EPA is proposing to incorporate by
reference Puerto Rico's RCAP, Rule 102, ``Definitions,'' and Rule 210,
``Non-Attainment Provisions,'' as well as portions of Rule 425,
``Provisions for SO<INF>2</INF> Non-Attainment Areas,'' with a State/
commonwealth effective date of November 21, 2022, and as described in
Sections VI through VIII of this preamble.
Specifically, the EPA is proposing to incorporate by reference the
following sections of Rule 425: Section I, ``Applicability''; Section
II, ``Emission Limitations for PREPA San Juan and PREPA Palo Seco,''
Subsection (A); Section III, ``Emission Limitations for PREPA
Aguirre,'' Subsection (A); Section IV, ``Emission Limitations for San
Juan and Guayama-Salinas Non-Attainment Areas;'' Section V,
``Measurement methods and procedures;'' and Section VI, ``Contingency
Measures.'' These documents are available in the docket of this
rulemaking through <a href="http://www.regulations.gov">www.regulations.gov</a>.
XII. Statutory and Executive Order Reviews
Additional information about these statutes and Executive Orders
can be found at <a href="https://www.epa.gov/laws-regulations/laws-and-executive-orders">https://www.epa.gov/laws-regulations/laws-and-executive-orders</a>.
A. Executive Order 12866: Regulatory Planning and Review, and Executive
Order 14094: Modernizing Regulatory Review
This action is not a significant regulatory action as defined in
Executive Order 12866, as amended by Executive Order 14094, and was
therefore not submitted to the Office of Management and Budget (OMB)
for review.
B. Paperwork Reduction Act (PRA)
This action does not impose an information collection burden under
the PRA because this action does not impose additional requirements
beyond those imposed by State law.
C. Regulatory Flexibility Act (RFA)
I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. This
action will not impose any requirements on small entities beyond those
imposed by State/commonwealth law.
D. Unfunded Mandates Reform Act (UMRA)
This action does not contain any unfunded mandate as described in
UMRA, 2 U.S.C.1531-1538, and does not significantly or uniquely affect
small governments. This action does not impose additional requirements
beyond those imposed by State/commonwealth law. Accordingly, no
additional costs to State, local, or Tribal governments, or to the
private sector, will result from this action.
E. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have
substantial direct effects on the States, on the relationship between
the National Government and the Sates, or on the distribution of power
and responsibilities among the various levels of government.
F. Executive Order 13175: Coordination With Indian Tribal Governments
This action does not have Tribal implications, as specified in
Executive Order 13175, because the SIP is not approved to apply on any
Indian reservation land or in any other area where the EPA or an Indian
Tribe has demonstrated that a Tribe has jurisdiction and will not
impose substantial direct costs on Tribal governments or preempt Tribal
law. Thus, Executive Order 13175 does not apply in this action.
G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
The EPA interprets Executive Order 13045 as applying only to those
regulatory actions that concern environmental health or safety risks
that the EPA has reason to believe may disproportionately affect
children, per the definition of ``covered regulatory action'' in
section 2-202 of the Executive order. This action is not subject to
Executive Order 13045 because it does not impose additional
requirements beyond those imposed by State/commonwealth law.
H. Executive Order 13211: Actions That Significantly Affect Energy
Supply, Distribution, or Use
This action is not subject to Executive Order 13211, because it is
not a significant regulatory action under Executive Order 12866.
I. National Technology Transfer and Advancement Act (NTTAA)
Section 12(d) of the NTTAA directs the EPA to use voluntary
consensus standards in its regulatory activities
[[Page 79850]]
unless to do so would be inconsistent with applicable law or otherwise
impractical. The EPA believes that this action is not subject to the
requirements of section 12(d) of the NTTAA because application of those
requirements would be inconsistent with the CAA.
J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
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 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 PRDNER did not evaluate environmental justice considerations as
part of its SIP submittal; the CAA and applicable implementing
regulations neither prohibit nor require such an evaluation. Consistent
with the EPA's discretion under the CAA, the EPA evaluated the
environmental justice considerations of this action, as is described
above in the section titled, ``Environmental Justice Considerations.''
The analysis was done for the purpose of providing additional context
and information about this rulemaking to the public, and not as a basis
of the 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. In addition, there is no information in
the record inconsistent with the stated goal of E.O. 12898 of achieving
environmental justice for communities with environmental justice
concerns.
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Intergovernmental relations, Sulfur dioxide, Reporting and
recordkeeping requirements.
Authority: 42 U.S.C. 7401 et seq.
Lisa Garcia,
Regional Administrator, Region 2.
[FR Doc. 2024-22466 Filed 9-30-24; 8:45 am]
BILLING CODE 6560-50-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.