October Term 2013 · Docket 12-1182

Can EPA force states to cut pollution without defining the legal standard?

States challenge EPA's rule requiring them to reduce air pollution. They argue the agency failed to define the legal trigger for these cuts.

Official caption
EPA v. EME Homer City Generation, L.P.
Latest argument session
Latest official Court activity
Latest verified event
Argued
Sources analyzed through
Official Transcript

Verified source milestones

  1. — An official oral-argument transcript was verified.
  2. — An official oral-argument transcript was verified.

The arguments, in order

This case may have been argued more than once. Each entry below uses that session's official transcript. Later arguments do not erase earlier ones.

  1. Argument 1 ·

    What happened at the argument

    Mr. Stewart argued EPA sought to protect public health. He stated the agency struck a fair balance between states.

    Mr. Mitchell argued EPA wrote states out of the Clean Air Act. He claimed the agency left states in the dark about the legal phrase.

    Justice Scalia questioned the statutory basis for EPA's approach. He pressed for a direct answer on the legal provision.

    Justice Roberts used a stabbing analogy to probe the definition of contribution. He asked if any role in a bad result counts as significant.

    Read the official transcript for this argument · Official argument details

    Sources used for this argument breakdown

A citizen's guide to the whole case

What this case is about

The dispute centers on the Clean Air Act. EPA issued a rule requiring upwind states to cut pollution. States argue the rule lacks a clear legal definition. They claim this violates the law's requirements for state action.

Official sources for this section

How the case got here

The Supreme Court heard oral argument in this case on December 10, 2013.

Official sources for this section

What each side wants

EPA wants the rule to stand. It aims to protect public health and balance state interests.

States want the rule struck down. They seek to avoid mandates without a clear legal definition.

Official sources for this section

What each side says

EPA argues the rule strikes a fair balance. It claims the analysis followed three basic steps to protect health.

States argue EPA wrote them out of the law. They claim the agency failed to define the phrase contribute significantly.

Official sources for this section

What the justices asked

Justice Scalia asked which statute provision allows EPA to consider state interests.

Justice Roberts asked if significant contribution means causing a fatal result in any way.

Official sources for this section

Why it matters

This case defines how federal agencies regulate state pollution. It determines the balance between federal power and state autonomy. It sets the standard for defining legal triggers in environmental rules.

Official sources for this section

What happens next

This article currently covers the argument record. Use the official docket link for later case activity.

Official sources for this section

Official Court provenance

Official docket and case history · Official Supreme Court oral-argument detail page

Title and summary sources

Revision history

  1. Revision 1 · Official Transcript ·

    Correction: Rewritten to the concise citizen-facing editorial standard.

  2. Revision 2 · Official Transcript ·

    Correction: Migrated to the dated official Court activity contract without model use.

Download this sanitized case as JSON