Aaron M. Flynn Partner

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Aaron represents utilities, national trade associations, oil and gas companies, and manufacturers in major environmental litigation and regulatory matters across the country. His practice is focused on reducing and managing his client’s regulatory burdens and liabilities under federal environmental statutes and the Clean Air Act in particular.

Aaron has resolved complex regulatory matters before the EPA, at the White House, and through his extensive litigation experience before the federal courts. Prior to joining the firm, he served as a legal advisor to the US Congress and as an associate general counsel for the White House, where he was responsible for a broad portfolio of environmental matters, including Endangered Species Act and National Environmental Policy Act reform, helping to develop energy legislation, and responding to congressional investigations. That experience allows Aaron to provide companies with insight and practical advice concerning a wide range of issues, particularly related to federal oversight, policies, and processes.

A recognized thought leader on visibility issues, Aaron has been called to testify before the US House of Representatives about implementation of the regional haze program and how it should be changed in the future.  In addition, he has litigated significant visibility rules before numerous federal courts of appeals, arguing most recently before the Ninth and DC Circuits.

Aaron’s climate change work has involved all of the major EPA rulemaking actions since the US Supreme Court’s 2007 decision in Massachusetts v. EPA. He has, for instance, guided clients through creative solutions to problems raised by EPA’s Endangerment Finding, its mobile source rules, and the Clean Power Plan for existing electric generating facilities. Aaron has advised companies in the oil and gas sector on compliance with greenhouse gas reporting requirements and their obligations under EPA’s methane rules.

Aaron’s practice extends to a number of other areas, including environmental permitting on Tribal lands, consultation to address environmental justice issues, litigation in the DC Circuit over fuel regulation, and new source performance standards (NSPS) and hazardous air pollutant (HAP) regulations. He has advised an array of industries on national ambient air quality standards (NAAQS), and has led successful efforts before the DC Circuit and the White House to protect clients from new, unprecedented standards.


  • Advise clients on preparation for the Regional Haze Program’s second implementation period.
  • Representation of energy companies in state and federal permitting proceedings.
  • Represents utility and pipeline industries in rulemaking proceedings involving precedent-setting consideration of environmental justice matters.
  • Advised natural gas project proponent on obligations to respond to public comments addressing environmental justice in environmental analysis conducted under NEPA.
  • Representation of industry participants in DC Circuit litigation supporting EPA’s rule allowing compliance with the Cross-State Air Pollution Rule to satisfy regional haze requirements.
  • Devised a Clean Air Act federal implementation plan providing an alternative to costly emission controls for a facility. Defended that plan as an Intervenor-Respondent in litigation involving extensive discussions and negotiations with impacted tribes, requiring deep knowledge of rules governing energy development on tribal lands.
  • Developed rulemaking comments opposing greenhouse gas reporting rules for pipelines and related facilities and subsequently challenged EPA’s final rule in the DC Circuit.
  • Engaged in litigation challenging New Source Performance Standards and National Emissions Standards for Hazardous Air Pollutants for the oil and gas production sector and negotiated with EPA to revise the standards.
  • Representation of four western utilities in major challenges to EPA’s visibility rules in the Ninth and Tenth Circuit courts.
  • Led industry efforts challenging the establishment of new secondary NAAQS for nitrogen and sulfur oxides, particulate matter, and ozone.
  • Representation of a trade associations in preparing comments on EPA’s proposed Federal Plan and Model Trading Rule to implement the Clean Power Plan.
  • Guided interagency regulation of genetically modified organisms as part of the White House Ag-Biotech Working Group.
  • Representation of the White House Office of Science and Technology Policy (OSTP) in regulatory review meetings and meetings of the Committee for Foreign Investment in the United States (CFIUS).
  • Advise members and committees of Congress on development of the Energy Policy Act of 2005 and drafted key reports on liquefied natural gas (LNG) regulation, public lands policy, military base closure and property redevelopment (BRAC), and offshore and onshore oil, gas, and renewables development.