{"argument_date":"2006-11-01T00:00:00Z","arguments":[{"argument_date":"2006-11-01T00:00:00Z","heading":"What happened at the argument","official_detail_url":"https://www.supremecourt.gov/oral_arguments/argument_transcript/2006","official_transcript_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","paragraphs":["Sean Donahue argued the Clean Air Act requires a permit for any physical change that increases emissions.","Justice Scalia asked if the case is a regulatory interpretation question rather than a statutory one.","Justice Alito suggested that expert disagreement indicates the regulations are not clear on their face.","Chief Justice Roberts noted that agencies can change interpretations over time if rules are ambiguous."],"reargument":false,"sequence":1,"sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 10, lines 33-49","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 10, lines 33-49"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 12, lines 37-25","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 12, lines 37-25"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 25, lines 43-17","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 25, lines 43-17"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 17-37","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 17-37"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 39-45","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 39-45"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 7-15","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 7-15"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 4, lines 11-21","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 4, lines 11-21"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 5, lines 21-29","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 5, lines 21-29"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 5, lines 47-13","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 5, lines 47-13"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 6, lines 27-31","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 6, lines 27-31"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 6, lines 45-3","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 6, lines 45-3"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 7, lines 43-47","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 7, lines 43-47"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 8, lines 41-7","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 8, lines 41-7"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 8, lines 9-15","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 8, lines 9-15"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 9, lines 31-39","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 9, lines 31-39"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 9, lines 43-7","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 9, lines 43-7"}]}],"caption":"Environmental Defense v. Duke Energy Corp.","case_history":[{"changed_at":"2026-08-29T20:06:28.231136Z","explanation":"An official oral-argument transcript was verified.","status":"argued"}],"case_status":"argued","dek":"Environmental groups and Duke Energy dispute how to measure pollution increases under federal air rules.","dek_sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 12, lines 37-25","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 12, lines 37-25"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 25, lines 43-17","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 25, lines 43-17"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 17-37","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 17-37"}],"dispositions":[],"latest_court_document_date":"2006-11-01T00:00:00Z","maturity":"official_transcript","official_detail_url":"https://www.supremecourt.gov/oral_arguments/argument_transcript/2006","official_disposition_urls":[],"official_docket_url":"https://www.supremecourt.gov/docket/docketfiles/html/public/05-848.html","primary_docket":"05-848","revisions":[{"correction_note":"Rewritten to the concise citizen-facing editorial standard.","created_at":"2026-08-31T21:52:47.703217Z","maturity":"official_transcript","revision_number":1},{"correction_note":"Migrated to the dated official Court activity contract without model use.","created_at":"2026-09-05T03:22:24Z","maturity":"official_transcript","revision_number":2}],"schema_version":"1.1","sections":[{"heading":"What this case is about","paragraphs":["The Clean Air Act requires owners of large pollution sources to get a permit before making changes that increase emissions. The parties disagree on how to measure those increases. Environmental Defense argues the rules require a permit for any physical change that raises output. Duke Energy argues the rules allow changes if the increase stays below a set limit."],"sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 12, lines 37-25","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 12, lines 37-25"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 25, lines 43-17","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 25, lines 43-17"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 17-37","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 17-37"}]},{"heading":"How the case got here","paragraphs":["The Supreme Court heard oral argument in this case on November 1, 2006."],"sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 7-15","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 7-15"}]},{"heading":"What each side wants","paragraphs":["Environmental Defense wants the Court to require a permit for any physical change that raises emissions.","Duke Energy wants the Court to allow changes that stay below a specific emission limit."],"sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 12, lines 37-25","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 12, lines 37-25"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 25, lines 43-17","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 25, lines 43-17"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 17-37","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 17-37"}]},{"heading":"What each side says","paragraphs":["Environmental Defense argues the law defines a modification as any physical change that increases pollution.","Duke Energy argues the regulations allow changes if the increase remains below a set threshold."],"sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 12, lines 37-25","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 12, lines 37-25"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 25, lines 43-17","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 25, lines 43-17"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 17-37","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 17-37"}]},{"heading":"What the justices asked","paragraphs":["Justice Scalia asked if agency opinions existed when the legal challenge began.","Justice Alito asked if expert disagreement shows the rules are unclear on their face."],"sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 10, lines 33-49","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 10, lines 33-49"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 39-45","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 39-45"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 4, lines 11-21","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 4, lines 11-21"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 5, lines 21-29","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 5, lines 21-29"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 5, lines 47-13","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 5, lines 47-13"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 6, lines 27-31","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 6, lines 27-31"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 6, lines 45-3","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 6, lines 45-3"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 7, lines 43-47","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 7, lines 43-47"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 8, lines 41-7","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 8, lines 41-7"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 8, lines 9-15","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 8, lines 9-15"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 9, lines 31-39","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 9, lines 31-39"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 9, lines 43-7","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 9, lines 43-7"}]},{"heading":"Why it matters","paragraphs":["This case defines when power plants must get permits for upgrades. It affects how companies manage pollution controls. It shapes the balance between environmental protection and industrial flexibility. The outcome sets a standard for measuring emission increases nationwide."],"sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 12, lines 37-25","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 12, lines 37-25"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 25, lines 43-17","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 25, lines 43-17"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 17-37","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 17-37"}]},{"heading":"What happens next","paragraphs":["This article currently covers the argument record. Use the official docket link for later case activity."],"sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 10, lines 33-49","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 10, lines 33-49"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 39-45","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 39-45"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 7-15","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 7-15"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 4, lines 11-21","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 4, lines 11-21"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 5, lines 21-29","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 5, lines 21-29"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 5, lines 47-13","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 5, lines 47-13"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 6, lines 27-31","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 6, lines 27-31"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 6, lines 45-3","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 6, lines 45-3"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 7, lines 43-47","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 7, lines 43-47"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 8, lines 41-7","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 8, lines 41-7"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 8, lines 9-15","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 8, lines 9-15"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 9, lines 31-39","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 9, lines 31-39"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 9, lines 43-7","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 9, lines 43-7"}]}],"slug":"2006-05-848-environmental-defense-v-duke-energy-corp","term":"2006","title":"Does a physical change that raises emissions require a new permit?","title_sources":[{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 12, lines 37-25","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 12, lines 37-25"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 25, lines 43-17","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 25, lines 43-17"},{"evidence_type":"Transcript","label":"Official Supreme Court Transcript — file page 3, lines 17-37","official_url":"https://www.supremecourt.gov/pdfs/transcripts/2006/05-848.pdf","page_label":"file page 3, lines 17-37"}],"topics":[],"undated_disposition_date_fallback":null,"updated_at":"2026-09-05T03:22:24Z"}