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EPA’s electronic mailbox is open for requests from stationary sources until March 31.

By Karl A. Karg, Stacey L. VanBelleghem, and Bruce M. Johnson

In March 2025, the United States Environmental Protection Agency (EPA) announced that it has set up an electronic mailbox to allow stationary sources to request a presidential exemption from certain standards under Section 112 of the Clean Air Act (CAA).

Section 112 requires EPA to establish emission standards for certain stationary sources of hazardous air pollutants. Section 112 also includes a provision that enables the president to exempt stationary sources from compliance with any standard or limitation under Section 112 for up to two years if “the President determines that the technology to implement such standard is not available and that it is in the national security interests of the United States to do so.” 42 U.S.C. § 7412(i)(4). Section 112(i)(4) also provides that such an exemption may be extended “for 1 or more additional periods, each period not to exceed 2 years.”

William Jefferson Clinton Federal Building In Washington DC

EPA will regulate legacy CCR surface impoundments and CCR Management Units for the first time.

By Stacey L. VanBelleghem, Karl A. Karg, Phil Sandick, Jacqueline Zhang, Bruce Johnson, and Samuel Wallace-Perdomo

On April 25, 2024, EPA released its Final Rule to extend certain requirements governing the disposal of coal combustion residuals (CCR) in inactive surface impoundments at inactive power plants (referred to as “legacy CCR surface impoundments” or “legacy ponds”) and CCR Management Units (CCRMU), a…

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A district court has ruled that federal law does not preempt an indirect source rule that targets emissions associated with warehouses in Southern California.

By Joshua Bledsoe, Nick Cox, and Jennifer Garlock

On December 14, 2023, a US federal judge rejected claims that federal law preempts the South Coast Air Quality Management District’s (SCAQMD or the District) adoption of Rule 2305 (Rule), upholding the first-in-the-nation Rule[1] that regulates trucking emissions from warehouses.

Rule 2305 is the Warehouse Indirect Source Rule (ISR) — Warehouse Actions and Investments to Reduce Emissions (WAIRE) Program. As described in this Latham blog post, the WAIRE Program applies to certain warehouses in the South Coast Air Basin and imposes a compliance obligation based on the number of truck visits to that warehouse per year. Warehouse operators can meet that obligation by taking any number of emissions-reducing actions, either from the “WAIRE Menu” or through a custom plan approved by the District.

EPA’s long-awaited proposal would set aggressive emission reduction targets with many different approaches and timelines to achieve them.

By Stacey L. VanBelleghem and Jennifer Garlock

On May 11, 2023, the US Environmental Protection Agency (EPA) released its proposed rule[1] to regulate carbon dioxide (CO2) emissions from electric generating units (EGUs) at power plants under Section 111 of the Clean Air Act (CAA) (the Power Plant GHG Rule or the Proposed Rule).

The Power Plant GHG Rule consists of five proposed actions:

  1. determinations and updates to current CO2 standards of performance (promulgated in 2015) for new and reconstructed stationary combustion turbines (generally natural gas-fired) pursuant to Section 111(b) of the CAA;
  2. determinations and updates to current CO2 standards of performance (promulgated in 2015) for modified fossil fuel-fired steam-generating EGUs (generally coal-fired) pursuant to Section 111(b) of the CAA;
  3. determinations and CO2 emission guidelines for existing fossil fuel-fired steam-generating EGUs (generally coal-fired) pursuant to Section 111(d) of the CAA;
  4. determinations and CO2 emission guidelines for large, frequently used existing fossil fuel-fired stationary combustion turbines (generally natural gas-fired) pursuant to Section 111(d) of the CAA; and
  5. a repeal of the Trump-era Affordable Clean Energy (ACE) Rule.

EPA is also soliciting comment on a number of topics, including potential options and emission guidelines for existing fossil fuel-fired stationary combustion turbines not otherwise covered by the Proposed Rule (generally natural gas-fired units that are either smaller or less frequently used).

The decision will limit EPA’s options for future regulation of existing power plant GHG emissions and may have broader implications for other federal agency rulemakings.

By Stacey L. VanBelleghem, Karl A. Karg, and Malorie R. Medellin

On June 30, 2022, the US Supreme Court issued its long-awaited ruling in West Virginia v. EPA — the consolidated petitions addressing EPA’s authority to regulate existing power plant greenhouse gas (GHG) emissions under Section 111(d) of the Clean Air Act (CAA). In a 6-3 opinion drafted by Chief Justice Roberts, the Court ruled against EPA, holding that EPA’s attempt to force an overall shift in power generation from higher-emitting to lower-emitting sources exceeded EPA’s statutory authority. Indeed, the Court noted that such a sweeping transformation of the nation’s power sector implicated a “major question” requiring explicit congressional authorization, that the Court argued the CAA did not provide.

The decision clears a path for President Biden’s climate priorities, striking down a Trump Administration rule that had repealed the Obama Administration’s power plant greenhouse gas regulations.

By Stacey L. VanBelleghem and Devin M. O’Connor

On January 19, 2021, on the eve of President Biden’s inauguration, in American Lung Association, et al. v. EPA, the US Court of Appeals for the District of Columbia Circuit overturned the Environmental Protection Agency’s (EPA’s) Affordable Clean Energy (ACE) Rule, which sought to replace the Obama Administration’s Clean Power Plan (CPP). Both rules would regulate carbon dioxide (CO2) emissions from existing electric generating units (EGUs) under Section 111(d) of the Clean Air Act (CAA).[1]

The ACE Rule (summarized in this Latham blog post), took three key actions:

  1. It formally repealed the Obama Administration’s CPP, finding that the CPP exceeded the EPA’s statutory authority by employing generation-shifting (shifting electric generation from higher to lower emitting sources) as a Best System of Emission Reduction (BSER). In the ACE Rule, the EPA concluded that the agency’s authority to define BSER is limited to measures that can be applied “to or at” an individual stationary source, that generation-shifting conflicts with the CAA’s unambiguous statutory requirement, and the ACE Rule interpretation is the only permissible reading of the statute.
  2. It established EGU heat rate improvements as the BSER for CO2 emissions, identifying much weaker targets for these existing sources.
  3. It updated the foundational implementing rules for existing source emissions guidelines under Section 111(d) by extending compliance timelines.

A recent federal court decision in Utah renews the question of whether defeat device and tampering prohibitions constitute “an emission standard or limitation”.

By Arthur F. Foerster

A non-profit citizen group, Utah Physicians for a Healthy Environment, is seeking nearly US$1.5 million in costs and attorneys’ fees after successfully prosecuting a citizen action in Utah federal court for violations of the defeat device and tampering provisions of the Clean Air Act (CAA, or the Act).[i] Section 304 of the CAA authorizes persons to enforce compliance with “an emission standard or limitation” or an “order” issued by the US Environmental Protection Agency (EPA) or a state with respect thereto, after notice is provided and so long as the EPA or state is not already litigating an action to require compliance with the standard, limitation, or order.[ii]

In a significant and potentially precedent-setting action, EPA terminates the Clean Power Plan, narrows the scope of required controls to the regulated unit, and axes previously available compliance options.

By Stacey L. VanBelleghem and Robert A. Wyman

On June 19, 2019, the US Environmental Protection Agency (EPA) released its final Affordable Clean Energy (ACE) Rule to replace the Obama Administration’s Clean Power Plan (CPP). Both rules would regulate carbon dioxide (CO2) emissions from existing electric generating units (EGUs) pursuant to Section 111(d) of the Clean Air Act (CAA).[i] EPA made few changes from its 2018 proposal (summarized in this prior Latham post), with the notable exception of EPA’s decision to proceed with a separate rulemaking to finalize its proposed revisions to New Source Review (NSR) rules for power plants.

EPA Rulemakings

EPA’s recent notice announcing the final ACE Rule identifies three actions, which EPA characterizes as “separate and distinct rulemakings.”

Webcast addresses recent EPA and DOJ policy developments with important implications for permitting, enforcement, and litigation.

By Joel C. Beauvais, Julia A. Hatcher, Karl A. Karg, Claudia M. O’Brien, and Stacey L. VanBelleghem

Latham’s Environment, Land & Resources Department hosted a 60-minute webcast on March 29, “New Trump Administration Policies on Environmental Enforcement, Settlements, and Clean Air Act Implementation.” Partners provided an overview of important policy clarifications and changes arising in recent months — including the…