Pennsylvania has joined 20 other states in a federal lawsuit seeking to force the U.S. EPA to reinstate climate pollution rules for power plants, bringing the plaintiff coalition to 21 states, according to the Pennsylvania Capital-Star report.

The suit targets federal greenhouse gas standards covering electric generating units. The suing states argue EPA was obligated to keep the climate rule in place rather than weaken it, framing the action as a statutory authority challenge under the Clean Air Act.

Why power-plant climate rules touch circular operations

Power plant climate standards cover more than coal and natural gas. Waste-to-energy (WTE) facilities, refuse-derived fuel (RDF) boilers, and biomass-cofired units all sit inside the same Clean Air Act category of affected electric generating units. Any reinstatement of the federal greenhouse gas framework therefore resets compliance obligations for operators that combust municipal solid waste, demolition wood, agricultural residues, or landfill gas as fuel.

The practical hooks for circular-economy operators include:

• Title V permit renewals — CO₂ limits, monitoring, and reporting conditions flow into renewed operating permits
• New Source Review applicability — major modifications at WTE or RDF facilities trigger BACT review against the reinstated standard
• State Implementation Plan revisions — a final ruling forces state air agencies to update their SIPs to reflect the restored rule
• Carbon capture and biogas investment — operators that have already invested in CCS, landfill gas-to-energy, or RIN-qualifying renewable generation see those compliance pathways either strengthened or undercut depending on the outcome

What the coalition signals

Pennsylvania's entry adds a state with active coal retirements and a continuing natural gas buildout to a multistate litigation bloc. The 21-state lineup mixes attorneys general from states with aggressive power-sector decarbonization mandates and states where the legal theory centers on EPA exceeding its statutory authority by weakening the existing rule rather than strengthening it.

The geographic breadth of the coalition — and the dual-pronged legal pressure it puts on EPA's climate rulemaking — points to a protracted docket. Similar challenges to EPA greenhouse gas actions have produced both preliminary injunctions and merits decisions in recent years, with the outcome often turning on procedural compliance under the Administrative Procedure Act.

What to watch on the docket

The next milestone for operators is the court's case management order. Plaintiffs in parallel EPA climate challenges have routinely filed preliminary injunction motions to halt the rule rollback pending merits review. Operators should track four dates:

• Scheduling order — sets the briefing calendar and oral argument date
• Preliminary injunction ruling — decides whether the weakened rule is paused during litigation
• Merits decision — determines whether the rule stays weakened, gets reinstated, or gets sent back to EPA for revision consistent with the Clean Air Act
• SIP submission deadline — triggers state air agency revisions once a final order issues

For WTE operators, RDF combustors, and biomass-cofired plants, the compliance horizon ultimately depends on the same judicial outcome that decides the rule for coal and gas. The court order will determine whether current CO₂ limits remain weakened, snap back to the original standard, or move to a replacement rule — and that decision flows directly into permit conditions, control-technology investments, and fuel-supply contracts at every affected facility.