Electricity
Coal Combustion Residuals Rule
In 2015, EPA promulgated its Coal Combustion Residuals rule under Subtitle D of the Resource Conservation and Recovery Act (RCRA). The rule established numerous requirements for the disposal of coal combustion residuals (CCR) in landfills and surface impoundments, including structural integrity design criteria and safety assessment requirements; liner requirements for new and expanded impoundments and landfills; site restrictions for new landfills and surface impoundments; groundwater monitoring requirements; requirements for closing CCR units; and more.
In 2018, EPA finalized amendments to the 2015 CCR Rule. The amendments permitted EPA (or states with approved programs) to “[s]uspend groundwater monitoring requirements if there is evidence that there is no potential for migration of hazardous constituents to the uppermost aquifer during the active life of the unit and post-closure care … .” They allowed permitting authorities (and not just professional engineers) to certify that facilities comply with the CCR Rule’s requirements. They established risk-based groundwater protection standards (GWPS) for the four constituents in 40 CFR Part 257, Appendix IV, without maximum contaminant levels (MCLs) under the Safe Drinking Water Act. And they extended the deadline by which surface impoundments were required to stop accepting CCR and close if they could not comply with the requirement in 40 C.F.R. § 257.60 to place facilities at least five feet above the upper limit of the uppermost aquifer, or if they are unlined and leaking, causing a statistically significant increase over the GWPS. The 2018 rule was challenged in the United States Court of Appeals for the D.C. Circuit, and ultimately remanded without vacatur for reconsideration.
In August 2018, the D.C. Circuit issued Utility Solid Waste Activities Group v. EPA, 901 F.3d 414 (D.C. Cir. 2018), which granted in part certain environmental organizations’ challenges to the 2015 CCR Rule and remanded certain provisions of the rule at EPA’s request. The court found that the rule’s provisions allowing “existing, unlined surface impoundments to continue operating until they cause groundwater contamination” were “arbitrary and contrary to RCRA” because groundwater contamination would not be “promptly detected,” “promptly stopped,” or remedied “once it occurs.” The court struck down provisions treating clay-lined impoundments as if they were lined with geomembranes, finding those provisions “failed to ensure ‘no reasonable probability’ of adverse effects to the environment, as RCRA requires.” It also struck down the rule’s exemption of “legacy ponds” (“inactive impoundments at inactive facilities”) from its preventative regulations.
The “Part A” Rules
In 2020, EPA finalized a rule (referred to as “Part A”) to respond to the ruling in Utility Solid Waste Activities Group. Among other changes, the rule reclassified clay-lined impoundments as “unlined” impoundments and extended the deadlines in 40 C.F.R. § 257.101(a)(1) and (b)(1)(i) by which unlined impoundments (and those that could not comply with the aquifer location requirement) were required to stop accepting waste and begin closure to “not later than April 11, 2021.” The rule also revised the alternative closure standards in 40 C.F.R. § 257.103 to allow impoundments to continue to receive both CCR and non-CCR waste if the owner or operator demonstrated that there was no alternative disposal capacity on- or off-site and either (1) “it was technically infeasible to complete the measures necessary to obtain alternative disposal capacity … by April 11, 2021”; or (2) the facility was permanently closing a coal-fired boiler. Impoundments qualifying under option (1) could continue to operate until October 2023 or, for impoundments closing because of the Utility Solid Waste Activities Group ruling, October 2024. Impoundments qualifying under option (2) could continue to operate until October 2023 (if 40 acres or smaller) or October 2028 (if larger than 40 acres). In November 2020, several environmental organizations filed a petition for review of the “Part A” rules in the D.C. Circuit in Labadie Environmental Organization v. EPA (Case No. 20-1467), is still, as of October 2024, being held in abeyance while the petitioners review EPA’s decisions on the demonstrations submitted under options (1) and (2), discussed below.
EPA’s website lists 59 facilities that submitted demonstrations under options (1) and (2). In January 2022, EPA announced that it was proposing:
In July 2022, EPA proposed to conditionally approve alternative closure deadlines for Calaveras Power Station (San Antonio, Texas) for its sludge recycling holding pond and Mountaineer Power Plant (Letart, West Virginia) for its bottom ash ponds. In October 2022, EPA proposed to conditionally approve an extension in the deadline to close the ash pond at A.B. Brown Generating Station (Mount Vernon, Indiana). And in July 2023, EPA proposed to deny an extension in the deadline to close the ash ponds at Waukegan Generation Station (Waukegan, Illinois). The only proposed determination that was finalized was the determination for Gavin, which was denied effective November 28, 2022. Fourteen facilities withdrew their extension applications because they stopped receiving waste.
Various affected facilities and the Utility Solid Waste Activities Group filed petitions in the D.C. Circuit for review of EPA’s proposed actions, which were consolidated as Electric Energy, Inc. v. EPA (Case No. 22-1056). A variety of companies and organizations also filed petitions in the D.C. Circuit for review of EPA’s final determination for Gavin, which were consolidated as Electric Energy, Inc. v. EPA (Case No. 23-1035). Both sets of petitions argued that the proposed actions and the final Gavin action effectively amended the existing CCR regulations and imposed new requirements, in violation of RCRA and the Administrative Procedure Act.
On June 28th, the D.C. Circuit issued an opinion dismissing the petitions challenging both the 2022 proposed actions and the final action on the Gavin Plant’s extension request for lack of jurisdiction, finding that both sets of actions were either consistent with the plain language of the 2015 CCR Rule and EPA’s past applications of that rule or permissible interpretations of ambiguous language in the 2015 CCR Rule. In particular, the court rejected disagreed that the proposed actions effectively “announced” a new “prohibition on closing unlined surface impoundments while coal residuals [sit] in contact with groundwater[,]” finding that the 2015 CCR Rule had “[made that prohibition] clear.” It disagreed that the proposed actions introduced a new requirement “to control the post-closure infiltration of liquids not just ‘downward’ through the final cover system, but also from ‘any direction,’” finding that the 2015 CCR Rule was applicable to infiltrations of liquid from any direction. It disagreed that the 2015 CCR rule did not “apply to facilities that stopped receiving coal residuals before EPA promulgated the 2015 Rule,” finding that such impoundments met the clear regulatory definition of “inactive surface impoundment.” And it found that EPA’s proposed findings that Clifty Creek’s “self-supporting concrete settling tank system is a coal residual surface impoundment,” and that Ottumwa’s use of CCR as “fill” for a closing impoundment did not meet the 2015 CCR Rule’s “beneficial use” exception, were merely interpretations of existing law, not amendments of existing law. Similarly, it found that EPA had not announced any new requirements when it denied the Gavin Plant’s extension request on the basis that the water was “‘freely migrat[ing] in and out of the [coal residuals] remaining in the closet [impoundment].’”
The owners of the Gavin facility also filed a complaint in the United States District Court for the Southern District of Ohio (Case No. 2:24-cv-41) challenging the denial of their extension requested. That action was stayed pending resolution of the D.C. Circuit action. The stay was lifted in August. The Gavin Plant’s owners filed an amended complaint on August 30th, and the parties stipulated to an extension of the deadline for EPA’s Answer to October 16th.
The “Part B” Rules
In 2020, EPA also finalized its “Part B” rule, which amended 40 C.F.R. § 257.71(d) to create a process for EPA (or a participating state) to approve an alternate liner for CCR surface impoundments “constructed without a composite liner or alternate composite liner … .” The rule allowed unlined surface impoundments to continue to operate without retrofitting or closing so long as the owner or operator can demonstrate that the unit will pose “no reasonable probability of adverse effects to human health or the environment.” This demonstration required a two-step process. Initially, a facility was required to submit an application that demonstrated the unit met the minimum requirements, including the existence of sufficient monitoring wells. If approved, the facility would then submit a “demonstration package … certified by a qualified professional engineer,” presenting evidence that “there is no reasonable probability that operation of the surface impoundment will result in concentrations of constituents listed in appendix IV to this part in the uppermost aquifer at levels above a groundwater protection standard.”
EPA announced that it received eight applications. Two were withdrawn before the end of January 2023. In January 2023, EPA proposed to deny the remaining applications, because it said the facilities “fail[ed] to demonstrate that the surface impoundments complied with the [location or monitoring] requirements of the CCR regulations” and because there was “[e]vidence of potential releases” from some impoundments. As of October 11th, another four of the applications have been withdrawn. EPA still has not finalized any of the proposed denials.
Legacy Impoundments and CCR Management Units
On May 18, 2023, EPA proposed regulations to respond to the portion of the 2018 Utility Solid Waste Activities Group ruling that struck down the 2015 CCR Rule’s exemption of “legacy ponds.” EPA finalized these regulations on May 8th, and the final rule is effective on November 4th. Under the final rule, “legacy CCR surface impoundments” (“inactive surface impoundments at inactive facilities”) must “comply with the existing regulations in 40 CFR part 257, subpart D applicable to inactive CCR surface impoundments except for the location restrictions at §§ 257.60 through 257.64, and the liner design criteria at § 257.71.” They must also comply with two new requirements: (1) prepare an applicability report that documents each impoundment’s identifying information, location, and site conditions (or complete a closure certification); and (2) develop a site security plan to “prevent the unknowing entry … and to minimize the potential for the unauthorized entry of people or livestock onto the impoundment.”
For most legacy CCR surface impoundments, some requirements go into effect on the final rule’s effective date, such as the requirements to prepare an applicability report and a fugitive dust plan and to develop a site security plan. Other requirements, such as the requirement to conduct initial annual inspections, are required within 3 months of the final rule’s effective date. Yet other requirements go into effect 15 months (e.g., compiling a history of construction), 18 months (completing the initial hazard potential classification, structural stability, and safety factor assessments; and preparing an initial inflow design flood control system plan), 30 months (installing a groundwater monitoring system; developing a groundwater sampling and analysis program; and complying with certain groundwater monitoring requirements), 36 months (preparing closure plans and post-closure care plans), or 42 months after the rules effective date (initiating closure). Legacy CCR surface impoundments are required to complete closure within five years after initiating closure.
The regulations also impose requirements on what EPA calls “CCR management units” (“CCRMU”), which it defines as “any area of land on which any noncontainerized accumulation of CCR is received, is placed, or is otherwise managed, that is not a regulated CCR unit,” such as “inactive CCR landfills and CCR units that closed prior to October 19, 2015.” The definition also includes “other areas where CCR is managed directly on the land.” “[O]wners and operators of active or inactive facilities with a legacy CCR surface impoundment” are required to “conduct a facility evaluation to identify all CCR management units at the facility.” and confirm and document their “presence or absence.” They are required to produce a Facility Evaluation Report in two parts, with the first part due February 9, 2026 and the second part due February 8, 2027. Other, existing CCR requirements would apply to CCR management units, on an extended schedule compared to the requirements for legacy CCR surface impoundments: 42 months (installing a groundwater monitoring system and developing a groundwater sampling and analysis program), 48 months (preparing closure plans and post-closure care plans and initiating closure), or 54 months after the rule’s effective date (initiate closure). And CCR management units, too, are generally required to complete closure within five years after initiating closure.
EPA’s National Enforcement and Compliance Initiative
In late 2023, EPA released its National Enforcement and Compliance Initiatives for Fiscal Years 2024-2027. Among the new initiatives adopted was one directed to “Protecting Communities from Coal Ash Contamination” through enforcement of the RCRA CCR rules. EPA explained that this initiative would “focus[ ] on conducting investigations, particularly at coal ash facilities impacting vulnerable or overburdened communities; taking enforcement action at coal ash facilities that are violating the law; and protecting and cleaning up contaminated groundwater, surface water, and drinking water resources.” As part of this initiative, EPA announced in February that it had reached a settlement with Greenidge that required the company to “assess groundwater contamination from the coal ash impoundment at its facility”; “design and implement a corrective action program to address [any] contamination” found; “update and implement a closure plan for the coal ash impoundment”; and “pay a fine of $105,000.”
State CCR Programs
RCRA § 4005(d) (42 U.S.C. 6945(d)) allows states to submit applications to take over permitting of CCR units located in their states. The statute requires EPA to approve such applications “if the Administrator determines that the [state] program ... requires each [CCR] unit located in the State to achieve compliance with ... the applicable criteria ... in [40 C.F.R. Part 257]” or alternative state criteria that EPA “determines to be at least as protective as” the federal criteria.
In December 2021, the Alabama Department of Environmental Management (ADEM) submitted an application for approval of its CCR program. On June 7th, EPA announced that it had denied Alabama’s application. EPA concluded that “Alabama established State CCR regulations that largely mirror the language in the Federal CCR regulations in almost all respects, and, to the extent the provisions are different, the differences in the State regulations are at least as protective as the Federal CCR regulations.” However, EPA found that Alabama “interprets its closure regulations to impose different requirements than those found in the Federal CCR regulations, and ... has issued permits authorizing closures that are inconsistent with the plain language of the Federal CCR regulations.” EPA also found that ADEM had “repeatedly issued permits that authorize groundwater monitoring systems and corrective actions that do not comply with the Federal CCR regulations.” In particular, EPA concluded that “ADEM issued multiple permits allowing CCR in closed units to remain saturated by groundwater, without requiring engineering measures that will control the groundwater flowing into and out of the closed unit[;] ... approved groundwater monitoring systems that contain an inadequate number of wells, and in incorrect locations, to monitor all potential contaminant pathways and to detect groundwater contamination from the CCR units in the uppermost aquifer[; and] ... issued multiple permits that allow the permittee to delay implementation of effective measures to remediate groundwater contamination ... .”
Interstate Transport of Air Pollution
Clean Air Act § 110(a)(2)(d) (42 U.S.C. § 7410(a)(2)(D)) requires state implementation plans (SIPs) to contain “adequate provisions” to prevent any State’s sources or other emissions activities from contributing significantly to nonattainment with, or interfering with maintenance of, a NAAQS in another state, or interfering with another state’s prevention of significant deterioration (PSD) measures. This is known as the “Good Neighbor” provision of the Clean Air Act.
Disapproval of State Implementation Plans
In 2022, EPA published several Federal Register notices proposing to disapprove almost two dozen states’ SIP submissions for failure to comply with their “good neighbor” obligations under the 2015 ozone NAAQS. In 2023, EPA finalized its disapproval for 19 states (Alabama, Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Texas, Utah, and West Virginia), partially approved the SIP submissions for Minnesota and Wisconsin, and “deferr[ed] final action” on its proposed disapprovals for Tennessee and Wyoming. EPA explained that it had applied a “4-step … framework to evaluate a state’s obligations to eliminate transport emissions under … the ozone NAAQS:
(1) “Identify monitoring sites that are projected to have problems attaining and/or maintaining the NAAQS” in 2023 (i.e., “nonattainment or maintenance receptor[s]”);
(2) “identify states that impact those air quality problems … sufficiently such that the states … warrant further review and analysis”;
(3) “identify the emissions reductions necessary … to eliminate each … upwind state’s significant contribution to nonattainment or interference with maintenance of the NAAQS at the locations identified in Step 1”; and
(4) “adopt permanent and enforceable measures needed to achieve those emissions reductions.”
For step 2, EPA focused on states whose emissions were calculated to contribute at least 1% of the NAAQS (0.70 ppb) “on the days with the highest ozone concentrations at [each problem] receptor based on the 2023 modeling.” And for step 3, “states linked at Steps 1 and 2” were expected to prepare “a multifactor assessment of potential emissions controls” considering cost-effectiveness, total potential emissions reductions, impacts on air quality downwind, and potentially other factors. Applying this framework, EPA disapproved the various states’ SIP submissions. For example, EPA disapproved Ohio’s SIP submission because, among other reasons, Ohio proposed an “alternative definition of maintenance receptors” under Step 1 and “a higher contribution threshold than 1 percent of the NAAQS at Step 2” and failed to properly evaluate “emissions control opportunities” under Step 3.
Dozens of parties filed petitions for review of EPA’s disapproval of the various states’ “good neighbor” SIP submissions and moved for stays of EPA’s disapproval pending review. Several appellate courts granted petitioners’ motions to stay EPA’s disapproval of various SIPs.
Issuance of Federal Implementation Plans
In 2023, EPA published a final rule that included FIP requirements for the 21 states whose SIP submissions were disapproved in whole or in part in February, plus Pennsylvania and Virginia, which failed to submit transport SIPs for the 2015 ozone NAAQS. (Last July, following the Fifth, Sixth, and Eighth Circuits’ issuance of orders staying EPA’s disapproval of the “good neighbor” SIPs for Louisiana, Mississippi, Texas, Arkansas, Missouri, and Kentucky, EPA issued an interim final rule staying the effectiveness of its FIPs for those states.) Starting in 2023, the rule:
- modified the existing FIPs and emissions budgets for the 12 states already in the CSAPR NOx Ozone Season Group 3 Trading Program created by the Revised CSAPR Update (Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia);
- transitioned 7 states currently in the CSAPR NOx Ozone Season Group 2 Trading Program (Alabama, Arkansas, Mississippi, Missouri, Oklahoma, Texas, and Wisconsin) to the Group 3 Program; and
- brought 3 states not currently in any NOx ozone season trading program (Minnesota, Nevada, and Utah) into the Group 3 Program.
The final rule gave EPA the authority to increase states’ budgets if “more current data on the composition and utilization of the EGU [electric generating unit] fleet” allows it to do so. Also, it modified the Group 3 Trading Program so that, “starting with the 2024 control period, the EPA will annually recalibrate the quantity of accumulated banked allowances under the program to prevent the quantity of allowances carried over from each control period to the next from exceeding the target bank level.” EPA also set “backstop daily emissions rates … for coal steam units greater than or equal to 100 MW in covered states.” For units currently without SCRs, the backstop rates were to go into effect in “the second control period in which newly installed SCR controls are operational at the unit, but not later than the 2030 control period.”
EPA also imposed NOx emission limits for certain categories of sources beyond electric generating units in 20 states (Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, and West Virginia), starting with the 2026 ozone season. Of interest to this Section, the covered categories of sources included “reciprocating internal combustion engines in Pipeline Transportation of Natural Gas sources.”
Additionally, on February 16th, EPA published a proposed rule to partially disapprove Arizona, Iowa, Kansas, New Mexico, and Tennessee’s SIP submissions and issue FIPs for those states to address their contribution to downwind nonattainment with, or issues with maintaining, the 2015 ozone NAAQS. The five states would be required to participate in the NOX Ozone Season Group 3 Trading Program starting in 2025. And non-EGUs in Arizona would be required to comply with the NOx limits for non-EGUs, including the limits for reciprocating internal combustion engines used in transporting natural gas.
As with the prior action, dozens of parties filed petitions for review of EPA’s FIPs and moved for stays of EPA’s disapproval pending review. Several Courts of Appeals stayed those petitions for review pending decisions on the earlier petitions for review challenging EOA’s disapproval of the SIPs. Other petitions were transferred to the D.C. Circuit.
In August 2023, several associations, companies, and government agencies, including Hybar, LLC, U.S. Steel, Cleveland-Cliffs, and the Arkansas Department of Energy and Environment, Division of Environmental Quality, filed petitions for reconsideration of the “Good Neighbor” FIPs for Arkansas, Minnesota, and more broadly. On March 27th, EPA Administrator Regan signed a notice and sent out letters partially denying those petitions for reconsideration.
In October 2023, the states of Ohio, Indiana, and West Virginia filed an emergency application for a stay in the United States Supreme Court, arguing that EPA’s FIP rulemaking was flawed and that the Court should stay it while Ohio and other states challenge it in the D.C. Circuit. Among other arguments, the petitioners argued that allowing the FIP rulemaking to go into effect in some states even though it had been stayed in other states, was unfair, unreasonable, and unworkable. Other groups filed similar emergency applications. Surprisingly, the Court scheduled oral argument on the application and directed counsel to “be prepared to address, among other issues related to the challenge … , whether the emissions controls imposed by the Rule are reasonable regardless of the number of states subject to the Rule.” And even more surprisingly, on June 27th, the Supreme Court issued an opinion granting Ohio’s emergency application for a stay. Justice Gorsuch’s five-justice majority opinion held that the challengers were likely to demonstrate that EPA’s action was arbitrary and capricious, because “EPA had determined which emissions-control measures were cost effective at addressing downwind ozone levels based on an assumption that the FIP would apply to all covered states,” and had not explained why removing some states from the FIP would not alter or undermine that cost-effectiveness analysis.
In response, on August 5th, Joe Goffman (Assistant Administrator of EPA’s Office of Air and Radiation) issued a memorandum announcing that “EPA plan[ned] to comply with the Stay Order by administratively staying implementation of the Plan as to all sources in the geography of the Good Neighbor Plan as promulgated.” The memorandum further stated that EPA would not enforce the Plan’s near-term procedural deadlines for non-EGU sources. However, EPA directed EGUs in Illinois, Indiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and Wisconsin to comply with all “emissions monitoring and reporting requirements” under the CSAPR NOx Ozone Season Group 3 trading program that would have applied prior to the issuance of the 2023 final rule.
On August 5th, EPA filed a motion in the D.C. Circuit seeking a partial voluntary remand of the FIP “to enable the Agency to take a supplemental final action addressing the record deficiency preliminarily identified by the Supreme Court ... .” On September 12th, the D.C. Circuit granted that motion and remanded the rulemaking without vacatur, “to permit [EPA] to further respond to comments in the record.”
Mercury and Air Toxics Standards (MATS) Rule
Section 112 of the Clean Air Act, at 42 U.S.C. § 7412(n)(1)(a), required EPA to study the “reasonably anticipated” public health hazards expected to be caused by hazardous air pollutant (HAP) emissions from electric utility steam generating units, and then to regulate those emissions if EPA concluded doing so was “appropriate and necessary.” In 2000, EPA issued a finding that it was “appropriate and necessary” to regulate HAP emissions from coal- and oil-fired electric generating units. And in 2012, EPA issued the Mercury and Air Toxics Standards (MATS) rule, which set limits on mercury and other HAP emissions from those units.
On May 7th, EPA finalized several amendments to the MATS rule. The amendments reduced the fPM (filterable particulate matter) emission standard that existing coal-fired EGUs typically use as a surrogate for compliance with the rule’s non-Hg metal standards from 3.0E-02 lb/MMBtu to 1.0E-02 lb/MMBtu. EPA eliminated the option to use stack tests to demonstrate compliance with that fPM standard, leaving continuous emissions monitoring systems (CEMS) as the only way to demonstrate compliance. It also eliminated the separate mercury emission standard for lignite-fired EGUs, which means lignite-fired EGUs will need to “meet the same Hg emission standard as EGUs firing other types of coal” – 1.2 lb/Tbtu or 1.3E-02 lb/GWh, rather than 4.0 lb/Tbtu or 4.0E-02 lb/GWh. EPA also eliminated the second, alternative definition of “startup” in the MATS rule (“[t]he period in which operation of an EGU is initiated for any purpose[,]” ending “4 hours after the EGU generates electricity that is sold or used for any other purpose …, or 4 hours after the EGU makes useful thermal energy … for industrial, commercial, heating, or cooling purposes …, whichever is earlier.”). And rather than removing the alternative total and individual non-Hg metals emissions limits from the MATS rule, as EPA had originally proposed, it reduced those limits “proportional to the finalized fPM emission limit of 0.010 lb/MMBtu.”
The amendments were effective July 8th. However, affected sources will not need to comply with the new fPM emission standard or the new mercury emission standard for lignite-fired EGUs until July 8, 2027. Moreover, 42 U.S.C. § 7412(i)(3)(B) allows EPA (or a state permitting authority) to “issue a permit that grants an extension [of] up to 1 additional year to comply … .” Affected sources will need to comply with the amendment to the definition of “start-up” starting January 4, 2025, however.
On May 8th, North Dakota and West Virginia joined 21 other states in filing a joint petition for review in the D.C. Circuit (Case No. 24-1119). The D.C. Circuit Court of Appeals, on August 6th, and then the United States Supreme Court, on October 4th (in NACCO Natural Resources Corp. v. EPA, Nos. 24A178, et al., rejected applications to stay the MATS rule pending judicial review.
New Source Performance Standards and Existing Source Emissions Guidelines for Fossil Fuel-Fired Electric Generating Units
Section 111(b) of the Clean Air Act requires EPA to publish, and periodically revise, a “list of categories of stationary sources” that “cause[ ], or contribute[ ] significantly to, air pollution which may reasonably be anticipated to endanger public health or welfare.” EPA must then publish standards of performance for new (and modified) sources in those categories (called New Source Performance Standards or NSPS); review those standards at least every 8 years; and revise the standards “if appropriate.” Section 111(d) of the Act, in turn, requires EPA to establish a process under which states submit plans to establish standards of performance for air emissions from existing sources in those same source categories (though not for air pollutants for which EPA has NAAQS or for source categories regulated under Section 112 of the Clean Air Act). Importantly, for both programs, the “standards of performance” should reflect “the degree of emission limitation achievable through the application of the best system of emission reduction” (BSER) that EPA “determines has been adequately demonstrated.”
In 2023, EPA proposed its replacement to the Obama Administration’s Clean Power Plan and the Trump Administration’s Affordable Clean Energy Rule, neither of which ever went into effect, and to the existing NSPS for new fossil-fuel-fired EGUs. However, EPA withdrew its proposal for existing natural gas combustion turbines. In February, EPA announced that it was “taking a new, comprehensive approach to cover the entire fleet of natural gas-fired turbines, as well as cover more pollutants ... [.]” And on March 26th, EPA announced that it had opened a non-regulatory rulemaking docket “to gather input about ways we can design a stronger, more durable approach to greenhouse gas regulation of the entire fleet of existing gas combustion turbines in the power sector under Clean Air Act Section 111(d).”
On May 9th, EPA published its final GHG rules for the other types of fossil-fuel-fired EGUs. Surprisingly, the final rule backed away from the proposed rule’s reliace on clean hydrogen as a potential BSER, instead relying solely on carbon capture and storage (CCS) technology. In selecting “add-on controls” as BSER, EPA said that it was sticking to the types of technologies it has traditionally selected as BSER in prior Section 111 rulemakings. But selecting CCS as BSER for certain categories of fossil-fuel-fired EGUs has set the agency up for yet another set of legal challenges (discussed below), this time over whether those controls are “adequately demonstrated.”
Existing Fossil Fuel-Fired Steam Generating EGUs
The final BSERs and presumptive standards for existing coal-fired steam generating units vary, depending on when the units’ owners/operators plan to cease operations. There are only two standards, for units ending operations either before or after 2039, with coal-fired units ending operations before 2032 entirely exempt from the regulations. Additionally, EPA moved back the compliance deadline from 2030 to 2032 for coal-fired units that need to implement CCS, to address concerns about grid reliability: