Aaron represents clients in regulatory matters before the US Environmental Protection Agency and the White House and in litigation before the federal appellate and district courts. Aaron has represented utilities and trade associations in nearly every significant regulatory and litigation proceeding involving EPA’s regional haze program. His climate change practice has addressed each element of EPA’s program to regulate greenhouse gas emissions, including its controversial Clean Power Plan. Aaron also oversees the firm’s practice with respect to the National Ambient Air Quality Standards for environmental protection and has led industry’s regulatory and litigation response to those policies.
Aaron has extensive government and policy experience from his previous roles as a legal advisor to the US Congress and a lawyer for the White House on environmental and natural resources law and science policy. His representative clients include electric generating utilities and other major companies and trade associations in the energy, mining and transportation industries.
Aaron is admitted to practice before the US Supreme Court and the US Courts of Appeals for the Third, Fourth, Fifth, Sixth, Eighth, Ninth, Tenth, and DC Circuits. He is also admitted to the US District Court for the District of Columbia.
- Regional Haze. Aaron has extensive experience with EPA’s Regional Haze Program. He has represented clients in rulemaking proceedings related to visibility regulation for nearly every state. Most significantly, he has represented four western utilities in major challenges to EPA’s visibility rules in the Ninth and Tenth Circuit courts. For utilities in the eastern part of the country, Aaron is defending regulations that allow the utility industry to rely on compliance with the Cross-State Air Pollution Rule to satisfy regional haze requirements in proceedings before the Fourth, Sixth, and DC Circuits. In addition, he advises clients on what to expect during the Regional Haze Program’s second implementation period, which extends from 2018 to 2028 and is likely to apply the program to new industries.
- National Ambient Air Quality Standards (NAAQS). Aaron has represented the utility industry before EPA in every NAAQS revision proceeding since joining Hunton & Williams LLP in 2007. He represents clients before the DC Circuit and the Supreme Court in litigation related to the standards. In particular, Aaron has led industry efforts challenging the establishment of new secondary NAAQS. Most significantly, in the DC Circuit, Aaron helped to successfully defend EPA’s decision not to set unprecedented standards for nitrogen and sulfur oxides to protect water bodies. Similarly, representing clients before EPA and the White House Office of Management and Budget, Aaron helped to protect his clients from becoming subject to secondary standards for particulate matter and ozone.
- Climate Change. Aaron’s climate change practice for the firm began with his representation of industry in EPA’s Endangerment Finding proceedings. In that role, Aaron was instrumental in developing the consensus industry position on how to address climate change science. Since that time, Aaron has been involved in each of EPA’s rulemaking proceedings involving greenhouse gas regulations, including its controversial Clean Power Plan for existing electric generating facilities. In particular, Aaron advises clients on how states can develop plans to comply with the Clean Power Plan and advises on how those plans might be defended against EPA disapproval. Similarly, Aaron advises clients regarding compliance with state and regional greenhouse gas regulatory programs, such as the Regional Greenhouse Gas Initiative in the Northeast and AB 32 in California.
- Fuels and Fuel Producers. Aaron’s practice also focuses on EPA’s fuel regulations. He has represented industry in litigation in the DC Circuit related to EPA’s waiver for fuel ethanol content and related misfueling standards (Alliance of Auto. Manufacturers, et al. v. EPA) and in litigation related to EPA’s new source performance standards (NSPS) and hazardous air pollutant (HAP) regulations for oil and gas producers (Delaware Department of Natural Resources v. EPA, and American Petroleum Institute v. EPA).
- White House Experience. Prior to joining Hunton & Williams LLP Aaron worked as a lawyer for the White House Office of Science and Technology Policy (OSTP), from 2006 to 2007, where he served as legal counsel for the Science Advisor to the President of the United States. At OSTP, Aaron was responsible for climate change issues, issues related to the major environmental statutes, and a broad range of matters related to the intersection of science and the law. In particular, Aaron sat on the White House’s Ag-Biotech Working Group, which coordinates regulation of genetically modified organisms by EPA, the Food and Drug Administration, and the Department of Agriculture. He also represented OSTP in numerous regulatory review meetings conducted by the Office of Management and Budget and in meetings of the Committee for Foreign Investment in the United States (CFIUS).
- Congressional Experience. From 2003 to 2006, Aaron served as a legal advisor to the members and committees of the US Congress, working as a legislative attorney for the Congressional Research Service. In that role, Aaron served as Congress’ nonpartisan legal authority on all matters related to environmental and energy law. Working with individual congressional offices and committee staff, Aaron assisted in the development of numerous pieces of legislation, including the Energy Policy Act of 2005, and was recognized for his work on climate change, liquefied natural gas (LNG) regulation, public lands policy, military base closure and property redevelopment (BRAC), and offshore and onshore oil, gas, and renewables development.