[Federal Register Volume 89, Number 170 (Tuesday, September 3, 2024)]
[Proposed Rules]
[Pages 71237-71249]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-19600]


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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R06-OAR-2021-0029; FRL-12218-01-R6]


Air Plan Disapproval; Texas; Control of Air Pollution From 
Visible Emissions and Particulate Matter

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: Pursuant to the Federal Clean Air Act (CAA, the Act), the 
Environmental Protection Agency (EPA) is proposing to disapprove a 
revision to the Texas State Implementation Plan (SIP) submitted by the 
State of Texas through the Texas Commission on Environmental Quality 
(TCEQ) on August 20, 2020. The SIP submittal addresses emissions during 
planned Maintenance, Startup and Shutdown (MSS) activities for certain 
Electric Generating Units (EGUs) and includes requirements intended to 
address visible emissions (opacity) and Particulate Matter (PM) 
emissions during planned MSS activities The requirements are included 
in eight Agreed Orders (AOs) issued by TCEQ to the affected EGUs and 
provided in the SIP revision. EPA is proposing to determine that the 
requirements contained in these AOs do not meet the CAA requirements 
that emission limitations must be practically enforceable and must 
apply on a continuous basis. We are taking this action in accordance 
with section 110 of the Act.

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

ADDRESSES: Submit your comments, identified by Docket No. EPA-R06-OAR-
2021-0029 at https://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. The EPA may publish any 
comment received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. The EPA 
will generally not consider comments or comment contents located 
outside of the primary submission (i.e., on the web, cloud, or other 
file sharing system). For additional submission methods, please contact 
Mr. Michael Feldman, (214) 665-9793, [email protected]. For the 
full EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit https://www.epa.gov/dockets/commenting-epa-dockets.
    Docket: The index to the docket for this action is available 
electronically at www.regulations.gov and in hard copy at the EPA 
Region 6 Office, 1201 Elm Street, Suite 500, Dallas, Texas 75270. While 
all documents in the docket are listed in the index, some information 
may be publicly available only at the hard copy location (e.g., 
copyrighted material), and some may not be publicly available at either 
location (e.g., CBI).

FOR FURTHER INFORMATION CONTACT: Mr. Michael Feldman, Regional Haze and 
SO2 Section, EPA Region 6 Office, 1201 Elm Street, Suite 
500, Dallas, Texas 75270, (214) 665-9793, [email protected]. We 
encourage the public to submit comments via https://www.regulations.gov. Please call or email the contact listed above if 
you need alternative access to material indexed but not provided in the 
docket.

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

Table of Contents

I. Background
    A. Texas Chapter 111--Control of Air Pollution From Visible 
Emissions and Particulate Matter
    B. August 20, 2020 SIP Submittal
II. Applicability of Opacity and PM Limitations in 30 TAC 111
III. Evaluation of Emission Limitations in the SIP Revision
    A. SIP Requirements for Emissions Limitations
    B. Environ. Comm. Fl. Elec. Power v. EPA, 94 F.4th 77 (D.C. Cir. 
2024)
IV. Evaluation of Alternative Emission Limits
    A. EPA Recommendations for Development of Alternative Emission 
Limitations
    B. EPA's Evaluation
V. Proposed Action
VI. Environmental Justice Considerations
VII. Statutory and Executive Order Reviews

I. Background

A. Texas Chapter 111--Control of Air Pollution From Visible Emissions 
and Particulate Matter

    Texas promulgated rules for the control of visible emissions 
(opacity) and particulate matter emissions for inclusion in its SIP on 
January 28, 1972, and EPA first approved those rules into the SIP on 
May 31, 1972 (37 FR 10895) at 40 CFR 52.2270(b). In the original 
codification, Texas' rules concerning visible emissions and emission 
restrictions for particulate matter emissions were contained in TACB 
Regulation I--Control of Smoke, Visible Emissions and Particulate 
Matter, Rule 103.1 and 105.31. In developing these original rules, the 
state has noted that it relied in part on the findings of a study 
conducted by the Radian Corporation (Radian Report) \1\ on behalf of 
the Texas Air Control Board (TACB),\2\ a predecessor state agency to 
the TCEQ. The Radian Report provided information on the steady-state 
performance of electrostatic precipitator (ESPs) that the state used as 
part of establishing the Opacity and PM restrictions in TACB Regulation 
I. The control and performance efficiencies documented in the Radian 
Report for visible emissions and particulate matter for coal fired EGUs 
equipped with ESPs did not consider startup and shutdown periods when 
the EGU boiler exhaust gas is below the minimum temperature required to 
ensure the effective and safe operation of an ESP as a control device 
for particulate matter emissions and opacity.\3\
---------------------------------------------------------------------------

    \1\ Radian Corporation, Technical Basis for Texas Air Control 
Board Particulate Regulations, Delbert Max Ottmers, Jr and Ben R. 
Breed, August 20, 1971 (included in TCEQ's SIP submittal in the 
Docket for this proposed rulemaking).
    \2\ The Texas Air Control Board, abolished by Texas S.B. 2, 72nd 
Leg., 1st C.S., effective September 1, 1993, duties transferred to 
the Texas Natural Resource Conservation Commission which was formed 
from a merger with other state agencies including the Texas Water 
Commission and which was later renamed the Texas Commission on 
Environmental Quality, Agency 582.
    \3\ TCEQ's SIP submittal identifies additional studies conducted 
by the EPA and predecessor agencies as early as 1970 on ESP design 
and operation (available in the docket for this action): An 
Electrostatic Precipitator Systems Study: Final Report to The 
National Air Pollution Control Administration, Southern Research 
Institute, Contract CPA 22-69-73, October 30, 1970; Effects of 
Transient Operating Conditions on Steam-Electric Generator 
Emissions, EPA-600/2-75-022, August 1975; Controlling Particulate 
Emissions from Coal-Fired Boilers, EPA-600/8-79-016, June 1979.

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

[[Page 71238]]

    Since the original EPA approval of Rules 103.1 and 105.31 in 1972, 
there have been several subsequent state rule revision actions and EPA-
approved SIP revisions which renumbered and recodified Rules 103.1 and 
105.31 to what they are today--namely, 30 TAC 111.111 (for opacity) and 
30 TAC 111.153(b) (for particulate matter) of the EPA-approved SIP. See 
74 FR 19144 (April 28, 2009). However, none of the subsequent 
rulemakings and SIP revisions were substantive in nature and the record 
for those actions do not suggest a change to the original scope and 
application of Rules 103.1 and 105.31.
    In 2009, Texas recodified Regulation I, Rules 103.1 and 105.31, in 
a new location, 30 TAC 111.111 (Approved by EPA. April 28, 2009 (74 FR 
19144) effective May 28, 2009, Regulations.gov docket ID NO. EPA-R06-
OAR-2005-TX-0028). Despite the changed numbering, the requirements in 
the rules remain the same. For opacity, 30 TAC 111.111 requires that 
the affected sources ``shall not exceed 30 percent averaged over a six-
minute period'' (for any source on which construction or operation was 
begun on or before January 31, 1972), and ``shall not exceed 20 percent 
averaged over a six-minute period for any source on which construction 
was begun after January 31, 1972.'' \4\ For particulate matter, 30 TAC 
111.153(b) requires that no affected source ``may cause, suffer, allow, 
or permit emissions of particulate matter from any solid fossil fuel-
fired steam generator to exceed 0.3 pound of total suspended 
particulate per million BTU heat input, averaged over a two-hour 
period.'' \5\
---------------------------------------------------------------------------

    \4\ See section 111.111 Requirements for Specified Sources, 
https://texreg.sos.state.tx.us/public/
readtac$ext.TacPage?sl=R&app=9&p_dir=&p_rloc=&p_tloc=&p_ploc=&pg=1&p_
tac=&ti=30&pt=1&ch=111&rl=111, also https://www.epa.gov/sips-tx/current-texas-sip-approved-regulations#1A1.
    \5\ See section 111.153 Emission Limits for Steam Generators, 
https://texreg.sos.state.tx.us/public/
readtac$ext.TacPage?sl=R&app=9&p_dir=&p_rloc=&p_tloc=&p_ploc=&pg=1&p_
tac=&ti=30&pt=1&ch=111&rl=153. See also https://www.epa.gov/sips-tx/current-texas-sip-approved-regulations#1A1. Also, during the state 
comment period (as TCEQ was adopting this source-specific SIP 
revision) TCEQ responded to EPA's request for clarification and 
confirmed that the coal-fired EGUs covered by these AOs are ``solid 
fossil fuel-fired steam generator units'' as the term is used in 30 
TAC Sec.  111.153(b), and the AOs apply specifically to a subset of 
solid fossil fuel-fired steam generators that use coal as fuel 
(i.e., those EGUs that use ESPs as a control device).
---------------------------------------------------------------------------

    On October 30, 2014, EPA received a petition from the Environmental 
Integrity Project and Sierra Club (Petitioners) requesting that the EPA 
object to the title V operating permit issued by the TCEQ to the 
Southwestern Electric Power Company (SWEPCO) H.W. Pirkey power 
plant.\6\ Petitioners claimed, among other issues, that the 2014 
proposed title V permit created ``improper exemptions'' from the 20 
percent opacity limit in Texas's SIP at 30 TAC 111.111(a)(1)(B) and the 
0.3 lb/MMBtu PM limit in Texas's SIP at 30 TAC 111.153(b) specifically 
during planned MSS periods. On May 18, 2015 (after a March 2015 Notice 
of Intent) Petitioners filed a Complaint, seeking an order declaring 
that the EPA Administrator must grant or deny the 2014 petition and 
requiring the Administrator to do so. On December 2, 2015, TCEQ 
submitted to EPA an interpretive letter asserting that the opacity and 
PM emission limitations in the state's rules, adopted in the early 
1970's, were based on the use of ESPs during normal/stable operations 
and thus did not apply during periods of planned maintenance, startup 
and shutdown activities. (30 TAC 111.111 and 30 TAC 111.153(b)).\7\
---------------------------------------------------------------------------

    \6\ October 30, 2014, Environmental Integrity Project (EIP) and 
Sierra Club filed a petition for objection to Southwestern Electric 
Power Company's (SWEPCO) Title V permit for the H.W. Pirkey power 
plant.
    \7\ See letter, from Steve Hagle, Deputy Director, Office of 
Air, TCEQ to Gina McCarthy, Administrator, EPA, dated December 2, 
2015 (setting forth TCEQ's interpretation that the opacity and PM 
emission limitations in 30 TAC 111.111 and 30 TAC 111.153(b) never 
applied to periods of planned MSS activities at coal-fired EGUs 
equipped with ESPs as a control device). In their interpretive 
letter, TCEQ notes that courts give deference to a state's 
interpretation of its own regulations, citing to Florida Power & 
Light Co. v. Costle, 650 F.2d 579,588 (5th Cir. 1981) (``Moreover, 
it must be emphasized that EPA is to be accorded no discretion in 
interpreting state law'').
---------------------------------------------------------------------------

    On February 3, 2016, EPA issued an order granting portions of the 
2014 petition, objecting to the title V permit for the Pirkey power 
plant (Petition Number VI-2014-01) which indicated that the Pirkey 
power plant permit and permit record were unclear as to whether TCEQ's 
rules created an exemption from the opacity and PM limits in Chapter 
111. EPA found that the Petitioners demonstrated that the title V 
permit and permit record were unclear regarding whether the SIP opacity 
and PM limits applicable to the source apply during periods of planned 
MSS, as required. Therefore, the EPA directed TCEQ to revise the title 
V permit to ``ensure that it requires that the opacity and PM limits of 
30 T.A.C. Sec. Sec.  111.111(a)(1)(B) and 111.153(b) apply during 
periods of planned MSS.'' \8\ Subsequent to the order, in 2016, EPA and 
TCEQ met to discuss the Pirkey Petition, the MSS issues raised, and a 
path forward to address issues raised as they relate to MSS.
---------------------------------------------------------------------------

    \8\ Order Granting In Part and Denying in Part Petition for 
Objection to Permit, (February 3, 2016).
---------------------------------------------------------------------------

    In a March 13, 2017 letter from EPA to the TCEQ,\9\ and in light of 
the petitions received and in an effort to resolve issues, EPA and TCEQ 
reached an agreement on a path forward by which TCEQ agreed to amend 
provisions applying to excess emissions during periods of startup and 
shutdown.\10\ Specifically, TCEQ agreed to develop and issue AOs for 
the eight affected coal-fired EGUs equipped with ESPs. These AOs would 
include enforceable opacity and particulate matter emission limitations 
that would apply during planned MSS activities. Once adopted, the state 
indicated that it would submit the AOs as part of a SIP revision to the 
EPA for approval as source-specific SIP provisions of the Texas SIP. 
Upon receipt of the proposed SIP revision, the EPA indicated that it 
would evaluate the SIP submission and proceed to initiate rulemaking as 
required by Section 110 of the CAA. If the revision complied with the 
CAA and were approved by EPA, the AOs would be incorporated into the 
Texas SIP as source-specific requirements found at 40 CFR 52.2270(d).
---------------------------------------------------------------------------

    \9\ Letter from Guy Donaldson, Associate Director, Air Branch, 
Air and Radiation Division, EPA to Steve Hagle, Deputy Director, 
Office of Air, TCEQ, dated March 13, 2017. Included in the docket 
for this action.
    \10\ See March 13, 2017 letter from Guy Donaldson, Associate 
Director, Air Branch, Air and Radiation Division, EPA to Steve 
Hagle, Deputy Director, Office of Air, TCEQ referencing EPA's 2015 
SIP call and SSM Policy published at 80 FR 33840 (June 12, 2015).
---------------------------------------------------------------------------

    As a result of the 2016 meeting and letter exchange, TCEQ submitted 
the August 2020 SIP submittal. In the submittal, Texas reiterated its 
interpretation that the opacity and PM emission restrictions for coal-
fired EGUs equipped with ESPs established in TAC Rule 103.1 and Rule 
105.31 were promulgated by the state on the premise that its rules were 
based on normal (steady state) or routine operations of ESPs, and 
therefore were not applicable during periods of planned MSS at such 
sources.\11\
---------------------------------------------------------------------------

    \11\ Texas further supported its conclusion by referencing the 
State's simultaneous adoption of general rules that implemented a 
separate air control strategy for emissions during MSS activities. 
See (TACB) General Rules 8 and 12.2, adopted on January 26, 1972, 
and effective on March 5, 1972 (the same dates as TACB Rules 103.1 
and 105.31 discussed above). TACB General Rule 8 required sources to 
provide the State a 10-day advanced notification of excessive 
emissions from planned MSS activities while General Rule 12.2 
provided sources a discretionary exemption from having to meet 
allowable emission limits in other rules, such as Rules 103.1 and 
105.31, during reported periods of planned MSS activities.

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

[[Page 71239]]

B. August 20, 2020 SIP Submittal

    The August 20, 2020 submittal is intended to address emissions from 
certain sources during planned MSS events. The state adopted and 
submitted for inclusion in its SIP, AOs for eight coal-fired power 
plants (comprised of thirteen EGUs) \12\ equipped with ESPs as the PM 
control device. The state developed the AOs to impose requirements for 
visible emissions and particulate matter during identified periods of 
planned MSS activities. Although the August 20, 2020 submittal 
references 30 TAC Chapter 111, specifically 30 TAC 111.111 and 30 TAC 
111.153(b), it does not revise the existing language of those two 
provisions. Instead, the state included the AOs in the submittal to 
establish source-specific alternative opacity and PM requirements to 
apply during periods of planned MSS activities. These requirements 
include both operational limits on the duration and frequency of 
planned MSS periods and additional requirements that the state 
characterizes as work practices. The state asserts that these 
provisions of the AOs are the same as the opacity and PM operational 
limitations and work practices already contained in the permits 
addressing emissions during planned MSS activities.\13\ For all other 
periods of operation, the affected sources would remain required to 
comply with the existing emission limitations set forth in 30 TAC 
111.111 and 30 TAC 111.253(b) of the Texas SIP.
---------------------------------------------------------------------------

    \12\ As of the date of this notice: Texas Municipal Power Agency 
(TMPA) Gibbons Creek Steam Electric Station shut down and 
surrendered their permits in 2021; Public Service Company of 
Oklahoma (PSCO) Oklaunion Power Station was sold and converted to 
natural gas in 2022. The permit was amended to authorize the 
conversion; and Southwestern Electric Power Company (SWEPCO) H.W. 
Pirkey Power Plant ceased burning coal and ceased operation in March 
2023, however they have not surrendered or submitted amendments to 
permits. It is unclear whether or not this facility will resume 
operations. TCEQ is currently undergoing actions to formally 
withdraw the consideration of the Gibbons Creek and Oklaunion AOs 
from their SIP submittal.
    \13\ Between 2013 and 2016, these Texas EGUs were issued amended 
title V/PSD permits to authorize the existing planned MSS activities 
and associated emissions. TCEQ states in the SIP submittal that, 
``although these planned MSS activities and emissions occurred after 
facilities began operation, they had not necessarily been fully 
authorized in an NSR permit prior to these permit amendments.'' TCEQ 
goes on to explain that these are existing emissions and the permit 
amendments did not involve any physical modifications or changes in 
method of operation.
---------------------------------------------------------------------------

    The state, through the submittal, seeks to include the eight 
source-specific AOs into the Texas SIP through incorporation by 
reference into 40 CFR 52.2770(d), together with a notation in 40 CFR 
52.2270(c) to the effect that the requirements of 30 TAC 111.111(a)(1) 
and 30 TAC 111.153(b) apply to all affected sources during all periods 
of operation, with the exception of the sources covered by the eight 
AOs that would be incorporated into 40 CFR 52.2270(d).
    The eight affected sources, which are all EGUs, and their county of 
location are listed in Table 1 below.\14\
---------------------------------------------------------------------------

    \14\ Since the August 20, 2020 submittal, we note that some of 
these eight affected power plants with coal-fired EGUs have either 
shutdown/no longer operating or have converted to natural gas as 
fuel for power generation. As of the date of this proposal, Texas 
has not provided a written request to withdraw these portions of the 
August 2020 SIP revision. However, TCEQ informed EPA that they do 
plan to submit a request after undergoing the necessary state 
administrative processes.

 Table 1--The Affected Power Plants, Agreed Order Number, and the Texas
                                 County
------------------------------------------------------------------------
  Affected power plants per August    Agreed order
       20, 2020 SIP submittal              No.           Texas county
------------------------------------------------------------------------
Southwestern Electric Power Company       2020-0078  Harrison.
 (SWEPCO) H.W. Pirkey Power Plant
 (See FN 14).
Lower Colorado River Authority            2020-0077  Fayette.
 (LCRA) Sam Seymour Fayette Power
 Project.
Luminant Generation Company, LLC          2020-0076  Rusk.
 Martin Lake Steam Electric Station.
NRG Texas Power, LLC Limestone            2020-0075  Limestone.
 Electric Generating Station.
San Miguel Electric Cooperative,          2020-0074  Atascosa.
 Inc. San Miguel Electric Plant.
Southwestern Public Service Company       2020-0073  Potter.
 (SPS) Harrington Station in Potter
 County.
Texas Municipal Power Agency (TMPA)       2020-0178  Grimes.
 Gibbons Creek Steam Electric
 Station (See FN 14).
Public Service Company of Oklahoma        2020-0072  Wilbarger.
 (PSCO) Oklaunion Power Station
 (See FN 14).
------------------------------------------------------------------------

    As stated earlier, if approved, this SIP revision would amend the 
SIP to provide that the sources subject to the 8 AOs in this SIP 
revision are required to comply with the stated visible (opacity) and 
PM emissions restrictions of 30 TAC 111.111 and 30 TAC 111.153(b) 
during all periods of operation except periods of MSS during which time 
the requirements of the AOs would apply. Any other sources subject to 
30 TAC 111.111 and 30 TAC 111.153(b), not addressed with AOs in this 
SIP revision, would be required to comply with 30 TAC 111.111 and 30 
TAC 111.153(b) at all times including during periods of MSS.
    Each of the AOs is comprised of two main sections titled 
Stipulation and Ordering Provisions. The Stipulation section of the AOs 
describes the State air agency's authority for regulating the quality 
of the State's air and preparing and developing a general, 
comprehensive plan for the control of the State's air pollution. It 
also explains that under 42 U.S.C. 7410, Texas is required to submit 
SIP revisions to EPA for review and approval and that such SIP 
revisions cannot interfere with any applicable provision concerning 
attainment or any other applicable requirement of the CAA. The Ordering 
Provisions section of the AOs state that emissions from the boiler(s), 
during each planned MSS, shall comply with the opacity limit in 30 TAC 
Sec.  111.111(a)(1) and the PM limit in 30 TAC Sec.  111.153(b), or the 
requirements listed in detail and tailored for planned MSS activities. 
Each of the AOs is signed by the responsible corporate official and 
TCEQ representatives.

II. Applicability of Opacity and PM Limitations in 30 TAC 111

    As an initial matter, we acknowledge TCEQ's interpretation of its 
regulations is that the existing SIP approved limitations on opacity 
and PM contained in 30 TAC 111.111(a)(1) and 30 TAC 111.153(b) do not 
apply to the sources subject to this SIP revision during periods of 
planned MSS. However, as written, these rules do not contain exemptions 
or any other textual indication that they do not apply during periods 
of MSS. We do note that the ESPs that are the existing control measures 
for PM on these sources have technical constraints that prohibit safe 
and effective operations until sufficient temperatures are reached 
therefore it is highly improbable that these sources could have met the 
limitations required by the rules during MSS as historically

[[Page 71240]]

configured, over the past fifty years. Texas has employed a number of 
approaches over the years to address emissions from these sources 
during MSS events, including discretionary exemptions, affirmative 
defenses, amending the facility permits to authorize the emissions 
during MSS events, and now the 2020 SIP submission. While the state's 
approaches (and explanations) have changed over time, we are not aware 
of any instance that Texas has taken an explicit action to require 
companies to meet the requirements set forth in 30 TAC 111.111(a)(1) or 
30 TAC 111.153(b) during periods of MSS. In particular, Texas has not 
taken an enforcement action against these sources for failure to comply 
with the 30 TAC 111 limits during MSS and that called for any of these 
sources to upgrade their controls to comply with the limits in the 
future. EPA has never taken enforcement action with respect to the 
limitations in 30 TAC 111.111(a)(1) and 30 TAC 111.153(b) for emissions 
during MSS periods. In the 2020 submission, TCEQ states that these 
existing SIP approved rules do not apply to emissions during MSS 
periods but that it now intends to address such emissions through the 
eight new source specific AOs.

III. Evaluation of Emission Limitations in the SIP Revision

A. SIP Requirements for Emissions Limitations

    CAA section 302(k) provides, in relevant part, that ``the terms 
`emission limitation' and `emission standard' mean a requirement 
established by the State or the Administrator which limits the 
quantity, rate, or concentration of emissions of air pollutants on a 
continuous basis, including any requirement relating to the operation 
or maintenance of a source to assure continuous emission reduction, and 
any design, equipment, work practice or operational standard 
promulgated under this chapter.'' Further, CAA Section 110(a)(2)(A) 
requires that SIPs include ``enforceable emission limitations and other 
control measures, means, or techniques (including economic incentives 
such as fees, marketable permits, and auctions of emissions rights), as 
well as schedules and timetables for compliance, as may be necessary or 
appropriate to meet the applicable requirements of this chapter.'' In 
light of these two provisions, EPA's position is, and has been, that 
emissions limitations contained in SIPs must be continuous. Because 
emission limitations must be continuous, they cannot include gaps or 
periods during which sources are not required to limit their emissions 
and thus, for example, cannot include exemptions for emissions during 
periods of operation such as MSS. While emission limits need to be 
continuous, EPA also believes that SIP emission limitations: (i) do not 
need to be numerical in format; (ii) do not have to apply the same 
limitation (e.g., numerical level) at all times; and (iii) may be 
composed of a combination of numerical limitations, specific 
technological control requirements and/or work practice requirements, 
with each component of the emission limitation applicable during a 
defined mode of source operation.

B. Environ. Comm. Fl. Elec. Power v. EPA, 94 F.4th 77 (D.C. Cir. 2024)

    As noted, the SIP submission at issue in this action raises issues 
related to emissions during MSS. The term MSS has considerable overlap 
with the events EPA refers to as startup, shutdown, and malfunction 
(SSM).\15\ Issues associated with SSM are discussed at length in a SIP 
Call that EPA issued to states in 2015 (the 2015 SSM SIP Action).\16\ A 
number of parties challenged the 2015 SSM SIP Action on various 
grounds. On March 1, 2024, the D.C. Circuit Court of Appeals issued a 
decision in Environ. Comm. Fl. Elec. Power v. EPA, 94 F.4th 77. The 
case was a consolidated set of petitions for review of the 2015 SSM SIP 
Action. The Court granted the petitions in part, vacating the 2015 SSM 
SIP Action with respect to specific SIP provisions that the EPA 
identified as automatic exemptions, director's discretion provisions, 
and affirmative defenses that are functionally exemptions, and denied 
the petitions as to other provisions that the EPA identified as 
overbroad enforcement discretion provisions or affirmative defense 
provisions that would preclude or limit a court from imposing relief in 
the case of violations.
---------------------------------------------------------------------------

    \15\ The term SSM refers to startup, shutdown or malfunction at 
a source. It does not include periods of maintenance at such a 
source. An SSM event is a period of startup, shutdown or malfunction 
during which there may be exceedances of the applicable emission 
limitations and thus excess emissions. Id. at 33843.
    \16\ See 80 FR 33840 (June 15, 2015).
---------------------------------------------------------------------------

    Specific to this action, EPA notes that the Court vacated the 2015 
SSM SIP Action with respect to SIP provisions that contain automatic 
exemptions for emissions during SSM events, and that EPA had considered 
automatic exemptions for emissions during other modes of operation such 
as maintenance to pose the same legal deficiency. In the 2015 SSM SIP 
Action, EPA found that certain SIP provisions were inconsistent with 
CAA 110(a)(2)(A) and 302(k). CAA 110(a)(2)(A) requires SIPs to 
``include enforceable emission limitations and other control measures, 
means, or techniques . . . as may be necessary or appropriate to meet 
the applicable requirements of this chapter.'' Because the automatic 
exemption provisions excluded applicability of emission limitations 
during SSM periods, the emission limitations at issue no longer 
operated on a ``continuous basis'' as required by CAA 302(k).
    Significantly, the Court vacated the 2015 SSM SIP Action as to 
automatic exemptions, because the Agency did not first determine that 
the particular SIP provisions at issue were ``emissions limitations'' 
as defined by CAA 302(k), or that it was ``necessary or appropriate'' 
that these provisions be such an emission limitation under CAA section 
110(a)(2)(A). The court's opinion stated that while emission 
limitations must be continuous, SIPs can contain ``other control 
measures, means, or techniques'' per CAA 110(a)(2)(A), and such other 
measures, means, or techniques do not need to meet the CAA's definition 
of an ``emission limitation,'' including the requirement that it apply 
on a continuous basis. The Court therefore took issue with EPA's SIP 
call for SIP provisions with automatic SSM exemptions, on the basis 
that ``EPA's rationale breaks down if the measure need not qualify as 
an `emission limitation' in the first place,'' and therefore such 
measure would need not meet the continuity requirement.\17\
---------------------------------------------------------------------------

    \17\ Environ. Comm. Fl. Elec. Power v. EPA, 94 F.4th 77, 99 
(D.C. Cir. 2024).
---------------------------------------------------------------------------

    In light of the court's decision, EPA is evaluating the nature of 
the SIP provisions at issue in this action. Based on the language of 
the existing SIP provisions and the SIP submission at issue in this 
action, EPA finds that 30 TAC 111.111(a)(1) and 30 TAC 111.153(b) are 
emissions limitations as contemplated under 110(a)(2)(A) and 302(k), 
and thus are required to be continuous. Texas, in its submittal, 
confirms that it adopted the AOs for these eight sources to ensure that 
the SIP provisions are emission limitations that apply continuously. 
From the SIP submission in the Executive Summary, ``[t]he proposed SIP 
revision would make certain operational limits and work practices for 
periods of planned MSS at the listed EGUs federally enforceable so that 
emission limitations apply on a continuous basis (at all times of 
operation) (see FCAA, Sec.  110(a)(2)(A)--SIP must contain emission 
limits, measures, etc. and

[[Page 71241]]

Sec.  302(k)--emission limits apply on a continuous basis to assure 
continuous emission reduction). The SIP revision, through the AOs, 
would establish a SIP limitation for those periods when the SIP limits 
for PM and opacity contained in Sec.  111.111 and Sec.  111.153 do not 
apply due to the technical limitations of the ESPs at the power plants 
that will be subject to the AOs.'' Thus, TCEQ indicated that it 
specifically submitted the SIP revision with the AOs to ensure that the 
emission limitations apply on a continuous basis, including during MSS 
periods. EPA agrees that these SIP limits for PM and opacity are 
emissions limitations that must be continuous under CAA Sec.  302(k). 
We also note that the state originally submitted these rules as part of 
the initial Texas SIP intended to provide for the attainment and 
maintenance of the NAAQS, and EPA originally approved them for this 
purpose (See 37 FR 10896), further confirming that these specific rules 
should be considered emission limitations and ``necessary and 
appropriate to meet the requirements of this chapter,'' in this case 
attainment and maintenance of the NAAQS.

IV. Evaluation of Alternative Emission Limits

A. EPA Recommendations for Development of Alternative Emission 
Limitations

    As previously discussed, Texas has identified 30 TAC 111.111(a)(1) 
and 30 TAC 111.153(b) as emission limitations, and EPA agrees with this 
description. Accordingly, the rules must be continuous and cannot have 
exemptions. The state indicated that it specifically submitted the SIP 
revision with the AOs to ensure that the emission limitations apply on 
a continuous basis, including during MSS periods.
    The revision submitted by Texas takes the form of new Alternative 
Emission Limitations (AELs) intended to apply during MSS periods. The 
EPA interprets the CAA (80 FR 33913, June 12, 2015) to allow SIP 
provisions to include AELs that apply to sources during specific modes 
of operation during which the source cannot meet an otherwise 
applicable emission limitation, such as may be the case during MSS 
periods. An AEL, whether a numerical limitation, technological control 
requirement, or work practice requirement, would apply during a 
specific mode of operation as a component of the continuously 
applicable emission limitation. All components of the resulting 
emission limitation must meet the substantive requirements applicable 
to the type of SIP provision at issue, must meet the applicable level 
of stringency for that type of emission limitation, and must be legally 
and practically enforceable.\18\
---------------------------------------------------------------------------

    \18\ 80 FR at 33913.
---------------------------------------------------------------------------

    EPA has longstanding guidance for AELs, which it reiterated and 
restated in the 2015 SSM SIP Action. For the AELs to be approvable 
(i.e., meet CAA requirements), alternative requirements applicable to 
the source during MSS should be narrowly tailored and take into account 
considerations such as the technological limitations of the specific 
source category and the control technology that is feasible during 
startup and shutdown.\19\ As articulated in the 2015 SSM SIP Action, 
the EPA recommends giving consideration to the following seven specific 
criteria for states when developing AELs in SIP provisions that apply 
during modes of operation such as MSS: \20\ (1) The revision is limited 
to specific, narrowly defined source categories using specific control 
strategies; (2) Use of the otherwise applicable control strategy for 
this source category is technically infeasible during specific modes of 
operation such as startup or shutdown; (3) The AEL requires that the 
frequency and duration of operation in MSS mode are minimized to the 
greatest extent practicable; (4) As part of its justification of the 
SIP revision, the state analyzes the potential worst-case emissions 
that could occur during MSS based on the applicable AEL; (5) The AEL 
requires that all possible steps are taken to minimize the impact of 
emissions during MSS on ambient air quality; (6) The AEL requires that, 
at all times, the facility is operated in a manner consistent with good 
practice for minimizing emissions and the source uses best efforts 
regarding planning, design, and operating procedures; and (7) The AEL 
requires that the owner or operator's actions during MSS periods are 
documented by properly signed, contemporaneous operating logs or other 
relevant evidence.
---------------------------------------------------------------------------

    \19\ Id.
    \20\ June 12, 2015 (80 FR 33980).
---------------------------------------------------------------------------

    We also note that AELs applicable during modes of operation such as 
startup and shutdown cannot allow an inappropriately high level of 
emissions or an effectively unlimited or uncontrolled level of 
emissions, as those would constitute impermissible de facto exemptions 
for emissions during certain modes of operation.\21\ EPA notes that in 
order to be continuous, an emission limitation cannot have periods 
during which a source's emissions are uncontrolled, and this would 
include modes of operation during which the ostensible method of 
controlling emissions merely consists of imposing a time limit, i.e., 
an exemption allowing effectively uncontrolled emissions for a shorter 
period of time remains an exemption.
---------------------------------------------------------------------------

    \21\ June 12, 2015 (80 FR 33980).
---------------------------------------------------------------------------

B. EPA's Evaluation

    After reviewing the information in the Texas SIP submittal, EPA has 
identified the following concerns:
1. No Limit on Frequency of Startup or Shutdown Events
    The requirements in the AOs limit the duration of a normal (as 
opposed to an extended) planned startup or shutdown to a number of 
hours per event (48 hours for all units with the exception of Martin 
Lake units which are limited to 24 hours per normal startups) but 
provides no limit on the frequency of these events. During these times, 
the only requirements that apply are the work standards concerning 
placing the ESP in service as soon as practicable during startup or 
keeping the ESP in service as late as practicable during shutdown. 
There is no requirement for the sources to limit emissions during such 
events in any other way. PM emissions during these events can be much 
higher than normal emissions and there is no limitation on the number 
of times during the year a boiler can go through a planned startup or 
shutdown. The SIP provides no discussion on the historical frequency of 
these events or why there is no limitation on the total number of hours 
a year, or times per year, these events may occur.\22\ This is of 
particular concern as utilization of coal-fired power generation has 
become more variable and planned startup and shutdown events may occur 
more frequently.\23\ In EPA's view, the approach adopted by the state 
in the SIP revision would in effect constitute exemptions from the 
opacity and PM

[[Page 71242]]

limits in the existing rules, by creating periods of time during which 
the emissions from these sources would be otherwise uncontrolled. The 
form of work practices that the state has imposed, e.g., that the 
source operates the ESP in accordance with manufacturer's instructions, 
does not effectively reduce emissions during such periods.
---------------------------------------------------------------------------

    \22\ We note however, the total amount of incremental time that 
extended startups or shutdowns exceed the duration of a normal 
startup or shutdown is limited to a number of hours per year, 
providing some limitation on the frequency and duration of these 
extended events.
    \23\ National Emission Standards for Hazardous Air Pollutants: 
Coal- and Oil-Fired Electric Utility Steam Generating Units Review 
of the Residual Risk and Technology Review, 89 FR 38534 (May 7, 
2024), ``While coal-fired EGUs have historically provided baseload 
generation, they are being dispatched much more as load following 
generating sources due to the shift to more available and cheaper 
natural gas and renewable generation. As such, traditional 
generation assets--such as coal-fired EGUs--will likely continue to 
have more startup and shutdown periods, more periods of transient 
operation as load following units, and increased operation at 
minimum levels, all of which can produce higher PM emission rates.''
---------------------------------------------------------------------------

2. Consideration of Additional Steps and Practices To Minimize 
Emissions
    With respect to factors 5 and 6, AELs should require that all 
possible steps are taken to minimize the impact of emissions during 
modes of operation such as MSS on ambient air quality and to require 
that, at all times, the facility is operated in a manner consistent 
with good practice for minimizing emissions and the source uses best 
efforts regarding planning, design, and operating procedures. We 
propose to find that the Texas SIP submittal and AOs do not address the 
feasibility or availability of any specific measures to minimize 
emissions during startup or shutdown. The only requirement is a work 
practice that consists of placing the ESP into service as soon as 
practicable or remove the ESP from service as late as possible. Nothing 
in the August 20, 2020 submittal indicates that technological or 
economic limitations prevent affected sources from using additional 
measures to limit emissions during planned MSS events that would 
address requirements to minimize emissions during such periods and be 
practically enforceable. This omission is particularly concerning, when 
planned MSS is an intentional, predictable event and within the control 
of the source. Because of the predictability of these events, 
alternative means of limiting emissions appear to be available such as 
use of natural gas or other cleaner burning fuels as auxiliary fuel to 
the maximum extent possible during startup operations until the 
required operating temperatures of the ESP are met and the ESP can be 
engaged. In addition, the submittal contains no analysis indicating 
that the use of another control device for PM emissions (for example, 
fabric filter baghouse) is not feasible, either.
    Furthermore, to the extent that these sources already do utilize 
fuel oil or natural gas in the start-up process, there is no discussion 
in the SIP submission or requirement in the AOs that addresses the use 
of alternative fuels during startup and when coal combustion can begin 
with respect to operation of the ESPs. PM emissions are likely highest 
when coal is introduced into the boiler but the ESP has not yet been 
engaged. Utilizing natural gas (or fuel oil when natural gas is not an 
available fuel) to the maximum extent possible to bring equipment to 
temperature would serve to minimize emissions during startup and could 
allow for ESPs to reach necessary conditions for operation at the time 
coal is introduced into the boilers. In fact, EPA's Mercury and Air 
Toxics Standards (MATS) rule for power plants published February 16, 
2012, and amended on May 7, 2024, contains additional requirements for 
particulate control for these units. Specific to periods of startup and 
shutdown, the MATS requirements include work practice standards that 
requires sources to have sufficient clean fuel capacity to startup and 
warm the facility to the point where the primary PM controls (e.g., 
ESPs) can be brought online at the same time as the addition of the 
coal to the EGU.
3. Enforceability of the AELs
    Clean Air Act Section 110(a)(2)(A) requires that SIPs include 
enforceable emission limits. As discussed previously, Texas stated that 
the AELs are designed to provide continuously effective limits on PM 
and opacity through all modes of operation, with chapter 111 
requirements to apply during routine operations and the AELs to apply 
during MSS periods. SIP provisions, including emission limitations 
under Section 110(a)(2)(A), must be both legally and practically 
enforceable.
    One EPA concern with the state's approach in the AOs is that it 
does not provide for adequate monitoring, recordkeeping and reporting. 
The monitoring and recordkeeping requirements in the AOs are not 
sufficient to ensure that all the data necessary for demonstrating 
compliance is recorded and available for review. The AOs require 
recordkeeping to identify periods of planned MSS, the opacity measured 
by the continuous opacity monitoring system (COMS) for the duration of 
the planned MSS activities, and the work practices followed during the 
planned MSS activities. However, they do not specifically identify and 
require recordkeeping of the parameters used to identify when startup 
or shutdown periods end or begin, such as temperature, unit load or ESP 
operating parameters, nor do they specifically require recordkeeping of 
the parameters monitored (e.g. air heater outlet temperature, drum 
metal temperature, when solid fuel is burned) to determine when the ESP 
should be placed into or removed from service during these MSS periods. 
These specific records are necessary to determine compliance with the 
definitions of when startup and shutdown periods begin or end and 
compliance with the AO requirements on timing of when the ESPs are 
placed into or removed from service. In addition, the AOs only require 
facilities to provide records upon request by the TCEQ or any other air 
pollution control agency with jurisdiction. The AOs do not require 
sources to make any other periodic report related to compliance with 
the AO provisions. EPA cannot determine the enforceability of these 
rules due to these monitoring, recordkeeping, and reporting gaps. Thus, 
we are proposing disapproval and taking comment on whether there is 
other relevant information or analysis that would show that these 
limits are enforceable notwithstanding the lack of monitoring, 
recordkeeping, and reporting in the AOs.
    EPA also proposes to find that the state's conditions in the AOs 
are too subjective to provide for practical enforceability. The AELs 
must be accompanied by appropriate methods and conditions to determine 
compliance that are fully enforceable (specifying clear, unambiguous, 
and measurable requirements for which compliance can be practicably 
determined) and replicable (the procedures for determining compliance 
which are sufficiently specific and non-subjective so that two 
independent entities applying the procedures would obtain the same 
result). Moreover, the work practices that apply during MSS events must 
be practically enforceable and it must be clear when the units are in 
MSS mode, and thus not subject to the otherwise applicable numerical 
limits specified in TAC Ch. 111.
a. Work Practices
    The AOs contained in Texas' submittal all include a requirement 
that the sources must comply with the boiler and ESP manufacturer's 
operating procedures or the owner/operator's written Standard Operating 
Procedures (SOP) manual and to operate in a manner consistent with 
those procedures to minimize opacity.\24\ It is unclear what procedures 
should be followed if requirements in the SOP are inconsistent with the 
manufacturer's operating procedures. It is likely that the lengthy 
operating experience at these units has resulted in the refinement of 
operating procedures over the many

[[Page 71243]]

years since the manufacturers designed the equipment and developed 
their recommended operating procedures. Furthermore, as the owner/
operator's SOP can be modified over time, the required work practices 
cannot be considered permanent and enforceable. For a measure to be 
relied on as an emission limitation, it must be permanent which means 
it cannot be revised absent following the SIP revision process. Thus, 
the AOs need to contain more specific conditions to identify what steps 
must be followed to engage and operate the ESPs during these events.
---------------------------------------------------------------------------

    \24\ As a reminder, several of these sources, as of the time of 
this notice, have ceased operation. See FN 14.
---------------------------------------------------------------------------

    As summarized in Table 2, the AOs vary in the specificity and 
conditions for when the ESPs should be placed into service. The 
Oklaunion AO specifies that the ESP should be placed into service 
during planned startups ``once the outlet gas temperature to the ESP is 
greater than 300 [deg]F.'' This is a clear, unambiguous and measurable 
requirement and compliance can be verified by reviewing the outlet gas 
temperature and when the ESP is brought online. The AOs for the other 
seven facilities lack this level of specificity and are not practically 
enforceable because they require the ESP to be placed into service ``as 
soon as practical.'' For Gibbons Creek, Sam Seymour, Limestone and San 
Miguel, the ESP is to be placed into service as soon as practical after 
the air heater outlet temperature is within a specified 100 degree F 
range. It is unclear why a range is specified rather than a minimum 
temperature or if there are other measurable parameters, such as flow 
rate or drum metal temperature, that are being evaluated to determine 
when it would be ``practical'' to place the ESP into service. 
Similarly, the AO for Harrington specifies that the ESP be placed into 
service as soon as practical after solid fuel is being burned. It is 
unclear what other measurable parameters, such as ESP inlet 
temperature, is being evaluated to determine when it would be 
``practical'' to place the ESP into service. Finally, for Martin Lake 
and Pirkey, there is no additional specification for when the ESP is 
placed into service other than ``as soon as practical.''
    The AOs also vary in the specificity and conditions for when the 
ESPs should be removed from service. For Harrington, the AO specifies 
that the ESP should be kept in service while the unit is burning solid 
fuel. For Sam Seymour, San Miguel, Oklaunion and Pirkey, the AOs 
provide no specificity to the conditions that determine when the ESP 
should be removed from service and only require that the ESP be removed 
from service ``as late as possible.'' For Gibbons Creek, Limestone and 
Martin Lake, the ESP is to be removed from service as late as possible 
after the air heater outlet temperature is within a large, specified 
temperature range. It is unclear why a range is specified rather than a 
minimum temperature or if there are other measurable parameters, such 
as flow rate or drum metal temperature, that are being evaluated to 
determine when the ESP should be removed from service. The AOs for 
these facilities lack specificity and are not practically enforceable.

 Table 2--Summary of Requirements for Placing ESP Into and Removing ESP
                              From Service
------------------------------------------------------------------------
           Facility                           Requirements
------------------------------------------------------------------------
Gibbons Creek................  placing the ESP into service as soon as
                                practical during planned startups or
                                removing the ESP from service as late as
                                possible during planned shutdowns, once
                                the air heater outlet temperature is
                                between 200 and 300 degrees F, but not
                                longer than the durations during
                                startups identified in Paragraph 12.A.
Harrington...................  When solid fuel is being burned, place
                                the ESP into service as soon as
                                practical during planned startups, but
                                not longer than the durations identified
                                in Paragraph 12.A. and keep the ESP in
                                service while the unit is burning solid
                                fuel.
Sam Seymour..................  placing the ESP into service as soon as
                                practical during planned startups once
                                the ESP inlet temperature (air heater
                                outlet temperature) is between 150 and
                                250 degrees F and removing the ESP from
                                service as late as possible during
                                planned shutdowns, but not longer than
                                the durations identified in Paragraph
                                12.A.
Limestone....................  placing the ESP into service as soon as
                                practical during planned startups or
                                removing the ESP from service as late as
                                possible during planned shutdowns, once
                                the air heater outlet temperature is
                                between 200 and 300 degrees F, but not
                                longer than the durations identified in
                                Paragraph 12.A.1.
Martin Lake..................  placing the Boilers into service as soon
                                as practical during planned startups,
                                but not longer than the durations
                                identified in Paragraph 12.A.1. During
                                shutdown, Luminant will operate in a
                                manner consistent with the Procedures to
                                minimize opacity by removing the ESP
                                from service as late as possible during
                                planned shutdowns, once the air heater
                                outlet temperature is between 180 and
                                260 degrees F, but not longer than the
                                durations identified in Paragraph
                                12.A.2.
San Miguel...................  placing the ESP into service as soon as
                                practical during planned startups once
                                the prime inlet air heater is between
                                250 and 350 degrees F and removing the
                                ESP from service as late as possible
                                during planned shutdowns, but not longer
                                than the durations identified in
                                Paragraph 12.A.
Oklaunion....................  placing the ESP into service during
                                planned startups once the outlet gas
                                temperature to the ESP is greater than
                                300 [deg]F, or removing the ESP from
                                service as late as possible during
                                planned shutdowns.
Pirkey.......................  placing the ESP into service as soon as
                                practical during planned startups or
                                removing the ESP from service as late as
                                possible during planned shutdowns.
------------------------------------------------------------------------

b. Duration of Startup
    The AO requirements for these facilities provide definitions for 
when the startup period ends that lack specificity such that it is not 
clear when the units are in startup mode and when they should be 
complying with the otherwise applicable numerical emission limitations 
in TAC Chapter 111. The definitions for when startup ends lack clear, 
unambiguous and measurable requirements by which compliance could be 
practicably determined.

[[Page 71244]]



                                Table 3--Startup Durations and Definitions in AOs
----------------------------------------------------------------------------------------------------------------
                                  Duration of normal   Extended startup
            Facility                    startup           limitation        Startup begins       Startup ends
----------------------------------------------------------------------------------------------------------------
Gibbons Creek...................  2,880 minutes.....  600 hr/yr.........  forced draft fans   boiler reaches the
                                                                           start.              lowest
                                                                                               sustainable load
                                                                                               (LSL) and
                                                                                               maintains that
                                                                                               load (or greater
                                                                                               load) for 60
                                                                                               consecutive
                                                                                               minutes and ESP
                                                                                               operations have
                                                                                               been optimized.
Harrington......................  48 hours..........  300 hr/yr.........  Fans placed into    unit reaches a
                                                                           service.            sustained load of
                                                                                               150 megawatts.
Sam Seymour.....................  48 hours..........  600 hr/yr.........  fuel oil igniters   Boiler is released
                                                                           are started.        to the LCRA
                                                                                               Generation Desk
                                                                                               for automatic
                                                                                               dispatch.
Limestone.......................  2,880 minutes.....  600 hr/yr.........  forced draft fans   utility boiler
                                                                           start.              reaches 400
                                                                                               megawatts (MW)
                                                                                               and maintains
                                                                                               that load (or
                                                                                               greater load) for
                                                                                               60 consecutive
                                                                                               minutes and ESP
                                                                                               operations have
                                                                                               been fully
                                                                                               optimized.
Martin Lake.....................  24 hours..........  900 hr/yr           induced draft fans  Boiler reaches
                                                       (combined on 3      start operation.    stable load and
                                                       units).                                 the electrostatic
                                                                                               precipitator
                                                                                               (ESP) operation
                                                                                               has been fully
                                                                                               optimized.
San Miguel......................  2,880 minutes.....  600 hr/yr.........  induced draft fans  lowest sustainable
                                                                           start operation.    load (LSL) and
                                                                                               maintains that
                                                                                               load (or greater
                                                                                               load) for 60
                                                                                               consecutive
                                                                                               minutes and ESP
                                                                                               operations have
                                                                                               been fully
                                                                                               optimized.
Oklaunion.......................  2,880 minutes.....  18,000 minutes....  fans are placed in  lowest sustainable
                                                                           service.            load on lignite
                                                                                               for at least 60
                                                                                               consecutive
                                                                                               minutes while
                                                                                               coal is being
                                                                                               fired.
Pirkey..........................  2,880 minutes.....  18,000 minutes....  fans are placed in  lowest sustainable
                                                                           service.            load on lignite
                                                                                               for at least 60
                                                                                               consecutive
                                                                                               minutes while
                                                                                               coal is being
                                                                                               fired.
----------------------------------------------------------------------------------------------------------------

    The AOs for Gibbons Creek and San Miguel define the end of startup 
as when the ``boiler reaches the lowest sustainable load (LSL) and 
maintains that load (or greater load) for 60 consecutive minutes and 
ESP operations have been optimized.'' The AO for Martin Lake defines 
the end of startup as when the ``[b]oiler reaches stable load and the 
electrostatic precipitator (ESP) operation has been fully optimized.'' 
However, what constitutes the LSL or stable load is not specified in 
the requirements. In addition, the startup event does not end until the 
ESP operations have been optimized, but there is no additional 
specificity to determine when the ESP would be considered optimized. 
One can imagine that ESP operations with emissions above the Chapter 
111 numerical levels would be considered non-optimized. For Martin 
Lake, the AO also fails to identify what constitutes a stable load so 
it is unclear what duration of operation at that load level is 
considered stable, such that the startup would be deemed to have ended. 
Similarly, the AOs for Oklaunion and Pirkey define the end of startup 
as ``lowest sustainable load (LSL) on lignite for at least 60 
consecutive minutes while coal is being fired'' but do not define the 
LSL. We also note that it is not clear how the LSL ``on lignite'' 
applies to the Oklaunion unit that has historically burned 
subbituminous coal. While the AO for Harrington does define the 
necessary load level (150 MW) it also does not identify what duration 
of operation at that load level is to be considered ``sustained.'' The 
AO for Limestone specifies both the load level (400 MW) and the 
duration (60 minutes) but also requires that the ESP operations are 
``fully optimized'' before the startup event is considered ended. The 
AO for Sam Seymour defines the end of startup as when the ``the boiler 
is released to the LCRA generation desk for automatic dispatch.'' The 
AO provides no additional details to identify the conditions such as 
sustained load to identify when the boiler would be released for 
dispatch to demonstrate that this condition is consistent with the goal 
of minimizing the duration of the event and startup emissions. In 
addition, while all other AOs define the beginning of startup as when 
the fans are placed into service, the AO for Sam Seymour defines the 
beginning of startup when the fuel oil igniters are placed in service. 
It is not clear what limits the source is required to meet when the 
fans are brought online before the igniters are placed into service.
c. Duration of Shutdown
    The AO requirements for these facilities provide definitions for 
when the shutdown period begins that lack specificity such that it is 
not clear when the units are in shutdown mode or when they should be 
complying with the otherwise applicable numerical emission limitations 
in TAC Chapter 111. The definitions for when shutdown begins lack 
clear, unambiguous and measurable requirements by which compliance 
could be practicably determined.

                               Table 4--Shutdown Durations and Definitions in AOs
----------------------------------------------------------------------------------------------------------------
                                  Duration of normal   Extended shutdown
            Facility                   shutdown           limitation        Shutdown begins      Shutdown ends
----------------------------------------------------------------------------------------------------------------
Gibbons Creek...................  600 minutes.......  600 hr/yr.........  load drops below    When the boiler
                                                                           LSL following       water circulating
                                                                           dispatch request    pump manifold
                                                                           for a shutdown.     temperature
                                                                                               reaches 180
                                                                                               degrees
                                                                                               Fahrenheit (F).
Harrington......................  36 hours..........  ..................  when the generator  when the generator
                                                                           breaker is opened   breaker is open
                                                                           or at the point     and main fuel is
                                                                           of main fuel no     no longer being
                                                                           longer being        fired in the
                                                                           fired in the        boiler.
                                                                           boiler, whichever
                                                                           is earlier..

[[Page 71245]]

 
Sam Seymour.....................  12 hours..........  600 hr/yr.........  when the LCRA       temperature has
                                                                           Generation Desk     been reached that
                                                                           releases control    allows personnel
                                                                           of the boiler to    to enter the
                                                                           the plant for the   structure and
                                                                           purpose of a        conduct
                                                                           shutdown.           maintenance
                                                                                               activities.
Limestone.......................  2,880 minutes.....  600 hr/yr.........  when load drops     when the drum
                                                                           below the lowest    metal temperature
                                                                           sustainable load    reaches 200
                                                                           (LSL) following     degrees F.
                                                                           dispatch request
                                                                           for a shutdown.
Martin Lake.....................  24 hours..........  900 hr/yr           when the ESP is     when a temperature
                                                       (combined on 3      partially or        has been reached
                                                       units).             completely de-      that allows
                                                                           energized due to    personnel to
                                                                           reaching its        enter the
                                                                           minimum operating   structure and
                                                                           temperature.        conduct
                                                                                               maintenance
                                                                                               activities.
San Miguel......................  2,880 minutes.....  600 hr/yr.........  load drops below    ends when the
                                                                           the LSL following   average lower
                                                                           the permit          drum metal
                                                                           holder's request    temperature
                                                                           to dispatch for a   reaches 200
                                                                           shutdown.           degrees
                                                                                               Fahrenheit (F) or
                                                                                               when the induced
                                                                                               draft fans are
                                                                                               removed from
                                                                                               service by the
                                                                                               plant operators.
Oklaunion.......................  2,880 minutes.....  ..................  when the Boiler     24 hours after
                                                                           has dropped below   combustion has
                                                                           the lowest          ceased.
                                                                           sustainable load
                                                                           for at least 30
                                                                           consecutive
                                                                           minutes.
Pirkey..........................  2,880 minutes.....  ..................  when the Boiler     24 hours after
                                                                           has dropped below   combustion has
                                                                           the lowest          ceased.
                                                                           sustainable load
                                                                           for at least 30
                                                                           consecutive
                                                                           minutes.
----------------------------------------------------------------------------------------------------------------

    The duration of shutdown events are limited in the AOs to a 
specific amount of time, however, the time periods vary between the 
facilities from 10 hours to 48 hours. There is no discussion as to how 
the duration of the allowed shutdown period was determined nor 
justification for how a shutdown period lasting up to 48 hours is 
consistent with the goal of minimizing the duration of the event and 
associated emissions.
    The AOs for Gibbons Creek, Limestone and San Miguel define the 
start of a shutdown as when the ``load drops below LSL following 
dispatch request for a shutdown'' and the AOs for Oklaunion and Pirkey 
define the start of a shutdown as when the boiler ``has dropped below 
the lowest sustainable load for at least 30 consecutive minutes.'' 
However, what constitutes the LSL is not specified in the requirements. 
For Martin Lake, the AO defines the start of shutdown as ``when the ESP 
is partially or completely de-energized due to reaching its minimum 
operating temperature'' but does not identify the minimum operating 
temperature. For Sam Seymour, the AO defines shutdown as beginning when 
the LCRA Generation Desk releases control of the boiler to the plant 
for the purpose of a shutdown but provides no additional details to 
identify the conditions such as sustained load to identify when the 
boiler would be released for shutdown. For Harrington, the AO defines 
shutdown as beginning when the generator breaker is opened or at the 
point of main fuel no longer being fired in the boiler, whichever is 
earlier, but provides no additional details to identify the conditions 
when the breaker is to be opened. In sum, to be legally and practically 
enforceable, the AOs should clearly define the moment when the 
requirements switch from compliance with 30 TAC 111.111(a)(1) and 30 
TAC 111.153(b) to compliance with the alternative emission limitations 
that apply during shutdown in the AOs.
d. EPA's Conclusion on the Enforceability of AELs
    In sum, to be legally and practically enforceable, the AOs should 
contain enforceable limitations on the duration of start-up and 
shutdown emissions and clearly define the moment when the requirements 
switch from compliance with the alternative emission limitations for 
such modes of operation in the AOs to compliance with 30 TAC 
111.111(a)(1) and 30 TAC 111.153(b). These AO restrictions as written, 
however, are not practically enforceable. Instead, the AOs, due to 
various ambiguities as discussed above, are unclear as to the 
procedures an operator must follow to be in compliance and at what 
point in the startup or shutdown process, the facility must switch from 
compliance with the AO to compliance with 30 TAC 111.111(a)(1) and 30 
TAC 111.153(b) as required for routine operation.
4. Planned Offline and Online Maintenance Activities
    In addition to the work practices and operational limits for 
planned startup and shutdown, the AOs contain provisions specific to 
planned online or offline maintenance activities, such as boiler 
general maintenance, de-slagging, combustion optimization, and flue gas 
conditioning.\25\ However, unlike the provisions for startup and 
shutdown, the AOs do not include any work practices that the sources 
are required to apply during these periods. For these activities, the 
AOs ``authorize'' periods of opacity greater than 20% for a number of 
hours per year (e.g., 535 hrs/year for each unit at Martin Lake). The 
only ostensible requirement during maintenance periods appears to be 
that the source operate the boiler and its ESP in accordance with good 
air pollution control practices, safe operating practices, and 
protection of the facility and associated air pollution control 
equipment. The generic general duty that an owner or operator shall 
operate a source consistent with safety and good air pollution control 
practices for minimizing emissions is not sufficient to identify what 
these specific practices might be across the range of maintenance 
activities to which the AOs apply, and thus such general duty clauses 
are not practically enforceable as a limitation on emissions during 
these activities.\26\ The AOs and SIP submission contain no discussion 
of the potential emissions from these activities, or consideration of 
other forms of alternative emission limitations

[[Page 71246]]

such as alternative numerical opacity limits that could potentially 
apply during these maintenance periods that would provide for a 
quantifiable and more practically enforceable limitation. Furthermore, 
EPA notes that the AOs contain no limitations as to the duration or 
frequency of individual events, the result being that it is possible 
that no opacity limitation could apply for a period of several hundred 
hours.
---------------------------------------------------------------------------

    \25\ For example, See AO for Martin Lake, provision 12.C.1-8.
    \26\ See 80 FR at 33,889-890, 33,893, and 33,903-904 for 
additional rationale describing why general duty clauses cannot 
operate on their own to fill exemptions in otherwise applicable 
emission limitations.
---------------------------------------------------------------------------

    As stated in EPA's June 12, 2015 SSM policy, states may not create 
SIP provisions that contain automatic or discretionary exemptions from 
otherwise applicable emission limitations during periods such as 
``maintenance,'' ``load change,'' ``soot blowing,'' ``on-line operating 
changes'' or other similar normal modes of operation. Like startup and 
shutdown, the EPA considers all of these to be modes of normal 
operation at a source, for which the source can be designed, operated 
and maintained in order to meet applicable emission limitations and 
during which the source should be expected to control and minimize 
emissions. Excess emissions that occur during planned and predicted 
periods should be treated as violations of applicable emission 
limitations. Accordingly, exemptions for emissions during these periods 
of normal source operation are not consistent with CAA requirements.
    It may be appropriate for an air agency to establish an alternative 
numerical limitation or other form of control measure that applies 
during these modes of source operation, as for startup and shutdown 
events, but any such alternative emission limitation should be 
developed using the same criteria that the EPA recommends for 
alternative emission limitations applicable during startup and 
shutdown. Similarly, any SIP provision that includes an emission 
limitation for sources that includes alternative emission limitations 
applicable to modes of operation such as ``maintenance,'' ``load 
change,'' ``soot blowing'' or ``on-line operating changes'' must also 
meet the applicable level of stringency for that type of emission 
limitation and be practically and legally enforceable.\27\ So EPA finds 
that the general duty provisions that apply during Maintenance 
activities in the AOs are not practically enforceable and thus cannot 
be approved.
---------------------------------------------------------------------------

    \27\ See 80 FR at 33978.
---------------------------------------------------------------------------

V. Proposed Action

    For the reasons discussed in this notice, the EPA is proposing to 
disapprove a revision to the Texas SIP submitted by TCEQ on August 20, 
2020 (concerning opacity and PM emissions during planned MSS activities 
for certain EGU sources equipped with ESPs as the PM control device). 
These EGUs are the Southwestern Electric Power Company (SWEPCO) H.W. 
Pirkey Power Plant; the Lower Colorado River Authority (LCRA) Sam 
Seymour Fayette Power Project; the Luminant Generation Company, LLC 
Martin Lake Steam Electric Station; the NRG Texas Power, LLC Limestone 
Electric Generating Station; the San Miguel Electric Cooperative, Inc. 
San Miguel Plant; the Southwestern Public Service Company (SPS) 
Harrington Station; the Texas Municipal Power Agency (TMPA) Gibbons 
Creek Steam Electric Station; and the Public Service Company of 
Oklahoma (PSCO) Oklaunion Power Station.
    The effect of this disapproval, if finalized, is that the Agreed 
Orders will not be incorporated into the SIP. There will be no 
sanctions or FIP clocks started by this action if finalized.

VI. Environmental Justice Considerations

    Information on Executive Order 12898 (Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations, 59 FR 7629, February 16, 1994) and how EPA defines 
environmental justice (EJ) can be found in the section, below, titled 
``VII. Statutory and Executive Order Reviews.'' For informational and 
transparency purposes only, the EPA is including additional analysis of 
environmental justice associated with this proposed action for the 
purpose of providing information to the public.
    EPA conducted screening analyses using EJSCREEN, an environmental 
justice mapping and screening tool that provides EPA with a nationally 
consistent dataset and approach for combining various environmental and 
demographic indicators.\28\ The EJSCREEN tool presents these indicators 
at a Census block group (CBG) level or a larger user-specified 
``buffer'' area that covers multiple CBGs.\29\ An individual CBG is a 
cluster of contiguous blocks within the same census tract and generally 
contains between 600 and 3,000 people. EJSCREEN is not a tool for 
performing in-depth risk analysis, but is instead a screening tool that 
provides an initial representation of indicators related to 
environmental justice and is subject to uncertainty in some underlying 
data (e.g., some environmental indicators are based on monitoring data 
which are not uniformly available; others are based on self-reported 
data).\30\ To help mitigate this uncertainty, we have summarized 
EJSCREEN data within larger ``buffer'' areas covering multiple block 
groups and representing the average resident within the buffer areas 
surrounding the sources. We present EJSCREEN environmental indicators 
to help screen for locations where residents may experience a higher 
overall pollution burden than would be expected for a block group with 
the same total population. These indicators of overall pollution burden 
include estimates of ambient particulate matter (PM2.5), 
ozone, nitrogen dioxide, and diesel particulate matter concentration, a 
score for traffic proximity and volume, percentage of pre-1960 housing 
units (lead paint indicator), and scores for proximity to Superfund 
sites, risk management plan (RMP) sites, and hazardous waste 
facilities.\31\ EJSCREEN also provides information on demographic 
indicators, including percent low-income, unemployment, communities of 
color, linguistic isolation, and education.
---------------------------------------------------------------------------

    \28\ The EJSCREEN tool is available at https://www.epa.gov/ejscreen.
    \29\ See https://www.census.gov/programs-surveys/geography/about/glossary.html.
    \30\ In addition, EJSCREEN relies on the five-year block group 
estimates from the U.S. Census American Community Survey. The 
advantage of using five-year over single-year estimates is increased 
statistical reliability of the data (i.e., lower sampling error), 
particularly for small geographic areas and population groups. For 
more information, see https://www.census.gov/content/dam/Census/library/publications/2020/acs/acs_general_handbook_2020.pdf.
    \31\ For additional information on provides details on the data 
and methods used to create the indicators and indexes in EJSCREEN, 
see ``EJSCREEN Environmental Justice Mapping and Screening Tool: 
EJSCREEN Technical Documentation'' at https://www.epa.gov/ejscreen/technical-information-and-data-downloads.
---------------------------------------------------------------------------

    The EPA prepared EJSCREEN reports covering a buffer area of 
approximately 6-mile radius around each affected EGU. Tables 5 and 6 
present a summary of results from the EPA's screening-level analysis 
for the areas surrounding the affected EGUs in Texas compared to the 
U.S. as a whole. The full, detailed EJSCREEN report is provided in the 
docket for this rulemaking.

[[Page 71247]]



                                          Table 5--EJSCREEN Analysis Summary for Affected EGU Facilities Part 1
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Values for buffer areas (radius) for each affected EGU and the U.S. (percentile
                                                                                                 within U.S. where indicated)
                             Variables                              ------------------------------------------------------------------------------------
                                                                         Fayette       Gibbons Creek      Harrington         Pirkey            U.S.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pollution Burden Indicators:
    Particulate matter (PM2.5), annual average.....................  8.32 [mu]g/m\3\  8.38 [mu]g/m\3\  5.91 [mu]g/m\3\  8.89 [mu]g/m\3\  8.45 [mu]g/m\3\
                                                                           (56%ile)         (58%ile)          (5%ile)         (72%ile)             (--)
    Ozone, annual average of the top ten 8-hour daily maximums.....        61.1 ppb         63.1 ppb         59.6 ppb         56.3 ppb         61.8 ppb
                                                                           (53%ile)         (63%ile)         (46%ile)         (29%ile)             (--)
    Nitrogen dioxide, annual average...............................         4.9 ppb          4.3 ppb          7.7 ppb          3.7 ppb          7.8 ppb
                                                                           (22%ile)         (17%ile)         (51%ile)         (11%ile)             (--)
    Diesel particulate matter......................................   0.0603 [mu]g/    0.0553 [mu]g/     0.172 [mu]g/     0.105 [mu]g/     0.191 [mu]g/
                                                                               m\3\             m\3\             m\3\             m\3\             m\3\
                                                                           (12%ile)         (10%ile)         (55%ile)         (30%ile)             (--)
    Toxic releases to air score *..................................              74               82              260            10000            4,600
                                                                           (21%ile)         (22%ile)         (36%ile)         (93%ile)             (--)
    Traffic proximity and volume score *...........................          27,000           12,000          520,000          110,000        1,700,000
                                                                            (8%ile)          (5%ile)         (40%ile)         (18%ile)             (--)
    Lead paint (percentage pre-1960 housing).......................           0.26%           0.037%            0.44%            0.17%             0.3%
                                                                           (54%ile)         (23%ile)         (70%ile)         (45%ile)             (--)
    Superfund proximity score *....................................               0                0            0.015           0.0065             0.39
                                                                            (0%ile)          (0%ile)         (56%ile)         (56%ile)             (--)
    RMP proximity score *..........................................            0.12            0.012              1.4             0.19             0.57
                                                                           (36%ile)         (28%ile)         (87%ile)         (43%ile)             (--)
    Hazardous waste proximity score *..............................               0                0             0.45            0.096              3.5
                                                                            (0%ile)          (0%ile)         (32%ile)         (17%ile)             (--)
    Underground storage tank proximity score *.....................           0.073            0.022             0.82             0.27              3.6
                                                                           (32%ile)         (29%ile)         (49%ile)         (39%ile)             (--)
    Wastewater discharge score *...................................           2,400               64             0.57               31          700,000
                                                                           (80%ile)         (51%ile)         (19%ile)         (45%ile)             (--)
    Drinking water noncompliance, points...........................             8.5             0.15             0.97             0.87              2.2
                                                                           (92%ile)         (74%ile)         (77%ile)         (77%ile)             (--)
Demographic Indicators:
    People of color population.....................................             15%              19%              72%              26%              40%
                                                                           (30%ile)         (36%ile)         (79%ile)         (44%ile)             (--)
    Low-income population..........................................             15%              17%              55%              29%              30%
                                                                           (27%ile)         (32%ile)         (86%ile)         (53%ile)             (--)
    Unemployment rate..............................................              2%               3%               4%               4%               6%
                                                                           (36%ile)         (44%ile)         (51%ile)         (56%ile)             (--)
    Linguistically isolated population.............................              0%               2%              10%               7%               5%
                                                                            (0%ile)         (62%ile)         (85%ile)         (79%ile)             (--)
    Population with less than high school education................              4%              10%              35%              12%              11%
                                                                           (30%ile)         (58%ile)         (94%ile)         (64%ile)             (--)
    Population under 5 years of age................................              3%               3%               7%               6%               5%
                                                                           (34%ile)         (34%ile)         (70%ile)         (62%ile)             (--)
    Population over 64 years of age................................             31%              17%              11%              11%              18%
                                                                           (89%ile)         (54%ile)         (29%ile)         (27%ile)             (--)
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The traffic proximity and volume indicator is a score calculated by daily traffic count divided by distance in meters to the road. The Superfund
  proximity, RMP proximity, and hazardous waste proximity indicators are all scores calculated by site or facility counts divided by distance in
  kilometers. The underground storage tank proximity indicator is the weighted count within a 1,500-foot block group. The toxic releases to air
  indicator is the modeled toxicity-weighted concentration. The wastewater discharge indicator is the modeled toxicity-weighted concentrations divided
  by distance in meters.


                                          Table 6--EJSCREEN Analysis Summary for Affected EGU Facilities Part 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Values for buffer areas (radius) for each affected EGU and the U.S. (percentile
                                                                                                 within U.S. where indicated)
                             Variables                              ------------------------------------------------------------------------------------
                                                                        Limestone       Martin Lake       Oklaunion        San Miguel          U.S.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pollution Burden Indicators:
    Particulate matter (PM2.5), annual average.....................  8.13 [mu]g/m\3\  8.8 [mu]g/m\3\   6.94 [mu]g/m\3\  8.38 [mu]g/m\3\  8.45 [mu]g/m\3\
                                                                           (49%ile)         (69%ile)         (17%ile)         (58%ile)             (--)
    Ozone, annual average of the top ten 8-hour daily maximums.....          61 ppb         56.9 ppb         57.2 ppb         61.7 ppb         61.8 ppb
                                                                           (53%ile)         (32%ile)         (33%ile)         (56%ile)             (--)
    Nitrogen dioxide, annual average...............................         3.7 ppb          3.2 ppb          3.6 ppb          2.9 ppb          7.8 ppb
                                                                           (11%ile)          (8%ile)         (11%ile)          (6%ile)             (--)
    Diesel particulate matter......................................   0.0574 [mu]g/    0.0572 [mu]g/    0.0496 [mu]g/    0.0384 [mu]g/     0.191 [mu]g/
                                                                               m\3\             m\3\             m\3\             m\3\             m\3\
                                                                           (11%ile)         (11%ile)          (8%ile)          (4%ile)             (--)
    Toxic releases to air score *..................................             320             9400               32               92            4,600
                                                                           (39%ile)         (92%ile)         (14%ile)         (23%ile)             (--)
    Traffic proximity and volume score *...........................          12,000            9,900           59,000           28,000        1,700,000
                                                                            (5%ile)          (4%ile)         (13%ile)          (8%ile)             (--)
    Lead paint (percentage pre-1960 housing).......................          0.061%            0.12%            0.51%            0.08%             0.3%
                                                                           (29%ile)         (38%ile)         (74%ile)         (32%ile)             (--)
    Superfund proximity score *....................................               0            0.014                0                0             0.39
                                                                            (0%ile)         (56%ile)          (0%ile)          (0%ile)             (--)
    RMP proximity score *..........................................            0.14             0.18             0.32            0.084             0.57
                                                                           (39%ile)         (42%ile)         (53%ile)         (30%ile)             (--)
    Hazardous waste proximity score *..............................           0.058            0.055                0                0              3.5
                                                                           (15%ile)         (15%ile)          (0%ile)          (0%ile)             (--)
    Underground storage tank proximity score *.....................           0.022             0.18             0.11         0.000039              3.6
                                                                           (29%ile)         (36%ile)         (34%ile)         (26%ile)             (--)

[[Page 71248]]

 
    Wastewater discharge score *...................................              52               50             0.35               14          700,000
                                                                           (50%ile)         (49%ile)         (18%ile)         (38%ile)             (--)
    Drinking water noncompliance, points...........................             2.7              9.9              2.2             0.86              2.2
                                                                           (87%ile)         (92%ile)         (87%ile)         (77%ile)             (--)
Demographic Indicators:
    People of color population.....................................             21%              33%              43%              44%              40%
                                                                           (37%ile)         (51%ile)         (60%ile)         (61%ile)             (--)
    Low-income population..........................................             33%              28%              41%              15%              30%
                                                                           (60%ile)         (52%ile)         (72%ile)         (29%ile)             (--)
    Unemployment rate..............................................              3%               4%               5%               9%               6%
                                                                           (45%ile)         (55%ile)         (62%ile)         (79%ile)             (--)
    Linguistically isolated population.............................              1%               0%               4%               0%               5%
                                                                           (59%ile)         (56%ile)         (71%ile)         (57%ile)             (--)
    Population with less than high school education................             11%               8%              30%              29%              11%
                                                                           (60%ile)         (50%ile)         (91%ile)         (91%ile)             (--)
    Population under 5 years of age................................              4%               9%               5%               0%               5%
                                                                           (47%ile)         (80%ile)         (54%ile)         (13%ile)             (--)
    Population over 64 years of age................................             27%              17%              17%              35%              18%
                                                                           (83%ile)         (53%ile)         (55%ile)         (92%ile)             (--)
--------------------------------------------------------------------------------------------------------------------------------------------------------
* See Table 5 footnote.

    Communities in close proximity to and/or downwind of these EGUs may 
be subject to environmental impacts of emissions. Short- and/or long-
term exposure to air pollution has been associated with a wide range of 
human health effects including increased respiratory symptoms, 
hospitalization for heart or lung diseases, and even premature 
death.\32\ Emissions during planned MSS may be higher than emissions 
under normal steady-state operations. The EPA believes the human health 
or environmental risk addressed by this action will not have potential 
disproportionately high and adverse human health or environmental 
effects on minority, low-income or indigenous populations. This action 
merely proposes to disapprove a SIP submission as not meeting the CAA.
---------------------------------------------------------------------------

    \32\ See https://www.epa.gov/air-quality-management-process/managing-air-quality-human-health-environmental-and-economic#what 
(accessed dated 02/05/2024).
---------------------------------------------------------------------------

    We therefore propose to determine that this rulemaking action, if 
finalized as proposed, will not have disproportionately high or adverse 
human health or environmental effects on communities with environmental 
justice concerns.

VII. Statutory and Executive Order Reviews

    Under the Act, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, EPA's role is to approve state choices, 
provided that they meet the criteria of the Act. Accordingly, this 
action proposes to disapprove the SIP submittal as not meeting 
applicable requirements of the CAA.
    Additional information about these statutes and Executive Orders 
can be found at https://www.epa.gov/laws-regulations/laws-and-executive-orders.

A. Executive Order 12866: Regulatory Planning and Review, Executive 
Order 13563: Improving Regulation and Regulatory Review, and Executive 
Order 14094: Modernizing Regulatory Review

    This action is not a significant regulatory action as defined in 
Executive Order 12866 (58 FR 51735, October 4, 1993), as amended by 
Executive Order 14094 (88 FR 21879, April 11, 2023), and was therefore 
not subject to a requirement for Executive Order 12866 review.

B. Paperwork Reduction Act (PRA)

    This action does not impose an information collection burden under 
the PRA (44 U.S.C. 3501 et seq.) because it does not contain any 
information collection activities.

C. Regulatory Flexibility Act (RFA)

    This action is certified to not have a significant economic impact 
on a substantial number of small entities under the RFA (5 U.S.C. 601 
et seq.). This action will not impose any requirements on small 
entities.

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 imposes no enforceable duty on any 
State, local, or tribal governments or the private sector.

E. Executive Order 13132: Federalism

    This action does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999). It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

F. Executive Order 13175: Coordination With Indian Tribal Governments

    This proposed action has no tribal implications as specified in 
E.O. 13175 (65 FR 67249, November 9, 2000). This action will neither 
impose substantial direct compliance costs on federally recognized 
tribal governments, nor preempt tribal law. This action will not impose 
substantial direct compliance costs on federally recognized tribal 
governments because no actions will be required of tribal governments. 
This action will also not preempt tribal law as it does not have 
applicable or related tribal laws.

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

    EPA interprets Executive Order 13045 (62 FR 19885, April 23, 1997) 
as applying only to those regulatory actions that concern environmental 
health or safety risks that EPA has reason to believe may 
disproportionately affect children, per the definitions of ``covered 
regulatory action'' in section 2-202 of the Executive Order. Therefore, 
this action is not subject to Executive Order 13045

[[Page 71249]]

because it merely proposes to disapprove a SIP revision. Furthermore, 
the EPA's Policy on Children's Health does not apply to this action.

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

    This action is not subject to Executive Order 13211 (66 FR 28355, 
May 22, 2001), 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 unless to do so would 
be inconsistent with applicable law or otherwise impractical. This 
action is not subject to the requirements of section 12(d) of the NTTAA 
(15 U.S.C. 272 note) 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 Population

    Executive Order 12898 (Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations, 59 FR 7629, 
Feb. 16, 1994) directs Federal agencies to identify and address 
``disproportionately high and adverse human health or environmental 
effects'' of their actions on minority populations and low-income 
populations to the greatest extent practicable and permitted by law. 
EPA defines environmental justice (EJ) as ``the fair treatment and 
meaningful involvement of all people regardless of race, color, 
national origin, or income with respect to the development, 
implementation, and enforcement of environmental laws, regulations, and 
policies.'' EPA further defines the term fair treatment to mean that 
``no group of people should bear a disproportionate burden of 
environmental harms and risks, including those resulting from the 
negative environmental consequences of industrial, governmental, and 
commercial operations or programs and policies.''
    The air agency 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. The EPA performed an environmental justice analysis, 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, 
not as a basis of the action. Due to the nature of the action being 
taken here, this action is expected to have no impact on the air 
quality of the affected area. In addition, there is no information in 
the record upon which this decision is based inconsistent with the 
stated goal of E.O. 12898 of achieving environmental justice for people 
of color, low-income populations, and Indigenous peoples.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Hydrocarbons, Incorporation by reference, Intergovernmental relations, 
Lead, Nitrogen dioxide, Particulate matter, Sulfur dioxide, Reporting 
and recordkeeping requirements, Volatile organic compounds.

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

    Dated: August 27, 2024.
Earthea Nance,
Regional Administrator, Region 6.
[FR Doc. 2024-19600 Filed 8-30-24; 8:45 am]
BILLING CODE 6560-50-P