Henry’s practice focuses on client counseling and participation in administrative and judicial proceedings under the Clean Air Act, the Clean Water Act, and the National Environmental Policy Act. For more than 35 years, he has represented clients before EPA, state regulatory agencies and the courts on a broad range of environmental regulatory and enforcement related matters.

Henry has been admitted to practice before the United States Supreme Court, all federal circuit courts of appeals, the District Court for the District of Columbia, the District Court for the Northern District of California and the District of Columbia Court of Appeals.


  • Participated in virtually every significant rulemaking under the Clean Air Act, including those involving new source permitting, hazardous air pollution, ambient air quality standards, new source performance standards, noncompliance penalties, visibility protection, tribal air programs, and greenhouse gas regulation.
  • Briefed and argued environmental law cases in federal circuit courts of appeals and federal district courts throughout the country.
  • Developed national environmental compliance and permitting strategies for industrial and utility clients.
  • Defended major Clean Air Act enforcement cases and negotiated complex settlements.
  • Advised major oil company on a range of US and International policy and regulatory matters aimed at addressing climate-change risks.


Honors & Recognitions

  • Recognized as 2021 Environmental Group of the Year, Law360, January 2022
  • 2021 and 2017 Chambers USA Environment Law Firm of the Year
  • “Best Lawyer,” Environmental Law, The Best Lawyers in America, 2001-2020, 2023-2024
  • Recognized as a Leader in Environment Law, District of Columbia, Chambers USA, 2003-2020
  • “Super Lawyer,” Environmental Law, Washington DC Super Lawyers, 2007-2019
  • Who’s Who Legal, The International Who’s Who of Business Lawyers – Environment, 2014 



  • Member, American Bar Association
  • Member, Federal Bar Association
  • Member, District of Columbia Bar Association


Blog Posts



JD, The George Washington University Law School, Editorial Board, The George Washington Law Review, Order of the Coif, 1968

BA, Government, University of Virginia, 1965


District of Columbia

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