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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, Feldman.Michael@epa.gov. 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, Feldman.Michael@epa.gov. 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) on behalf of the Texas Air Control Board (TACB), 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.
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).
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.
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.
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.” 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.”
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 § 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. 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)).
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.
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. §§ 111.111(a)(1)(B) and 111.153(b) apply during periods of planned MSS.” 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.
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, 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. 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).
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.
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.
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.
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) 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. 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.
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.
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.
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 20, 2020 SIP submittal | Agreed order No. | Texas county |
|---|---|---|
| Southwestern Electric Power Company (SWEPCO) H.W. Pirkey Power Plant (See FN 14) | 2020-0078 | Harrison. |
| Lower Colorado River Authority (LCRA) Sam Seymour Fayette Power Project | 2020-0077 | Fayette. |
| Luminant Generation Company, LLC Martin Lake Steam Electric Station | 2020-0076 | Rusk. |
| NRG Texas Power, LLC Limestone Electric Generating Station | 2020-0075 | Limestone. |
| San Miguel Electric Cooperative, Inc. San Miguel Electric Plant | 2020-0074 | Atascosa. |
| Southwestern Public Service Company (SPS) Harrington Station in Potter County | 2020-0073 | Potter. |
| Texas Municipal Power Agency (TMPA) Gibbons Creek Steam Electric Station (See FN 14) | 2020-0178 | Grimes. |
| Public Service Company of Oklahoma (PSCO) Oklaunion Power Station (See FN 14) | 2020-0072 | Wilbarger. |
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 °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. |
Table 3—Startup Durations and Definitions in AOs
| Facility | Duration of normal startup | Extended startup limitation | Startup begins | Startup ends |
|---|---|---|---|---|
| Gibbons Creek | 2,880 minutes | 600 hr/yr | forced draft fans start | boiler reaches the 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 service | unit reaches a sustained load of 150 megawatts. |
| Sam Seymour | 48 hours | 600 hr/yr | fuel oil igniters are started | Boiler is released to the LCRA Generation Desk for automatic dispatch. |
| Limestone | 2,880 minutes | 600 hr/yr | forced draft fans start | utility boiler 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 (combined on 3 units) | induced draft fans start operation | Boiler reaches stable load and the electrostatic precipitator (ESP) operation has been fully optimized. |
| San Miguel | 2,880 minutes | 600 hr/yr | induced draft fans start operation | lowest sustainable 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 service | lowest sustainable 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 service | lowest sustainable load on lignite for at least 60 consecutive minutes while coal is being fired. |
Table 4—Shutdown Durations and Definitions in AOs
| Facility | Duration of normal shutdown | Extended shutdown limitation | Shutdown begins | Shutdown ends |
|---|---|---|---|---|
| Gibbons Creek | 600 minutes | 600 hr/yr | load drops below LSL following dispatch request for a shutdown | When the boiler water circulating pump manifold temperature reaches 180 degrees Fahrenheit (F). |
| Harrington | 36 hours | when the generator breaker is opened or at the point of main fuel no longer being fired in the boiler, whichever is earlier. | when the generator breaker is open and main fuel is no longer being fired in the boiler. | |
| Sam Seymour | 12 hours | 600 hr/yr | when the LCRA Generation Desk releases control of the boiler to the plant for the purpose of a shutdown | temperature has been reached that allows personnel to enter the structure and conduct maintenance activities. |
| Limestone | 2,880 minutes | 600 hr/yr | when load drops below the lowest sustainable load (LSL) following dispatch request for a shutdown | when the drum metal temperature reaches 200 degrees F. |
| Martin Lake | 24 hours | 900 hr/yr (combined on 3 units) | when the ESP is partially or completely de-energized due to reaching its minimum operating temperature | when a temperature has been reached that allows personnel to enter the structure and conduct maintenance activities. |
| San Miguel | 2,880 minutes | 600 hr/yr | load drops below the LSL following the permit holder's request to dispatch for a shutdown | ends when the average lower drum metal temperature reaches 200 degrees Fahrenheit (F) or when the induced draft fans are removed from service by the plant operators. |
| Oklaunion | 2,880 minutes | when the Boiler has dropped below the lowest sustainable load for at least 30 consecutive minutes | 24 hours after combustion has ceased. | |
| Pirkey | 2,880 minutes | when the Boiler has dropped below the lowest sustainable load for at least 30 consecutive minutes | 24 hours after combustion has ceased. |
Table 5—EJSCREEN Analysis Summary for Affected EGU Facilities Part 1
Table 6—EJSCREEN Analysis Summary for Affected EGU Facilities Part 2