Peter Whitfield

PETER WHITFIELD assists his clients with environmental issues prior to, during, and after project development and operation. He helps companies navigate citizen suits, enforcement actions, regulatory proceedings, and challenges to their environmental clearances. Peter also handles a variety of administrative litigation matters on behalf of clients. With over a decade of experience, Peter has extensive knowledge of the Clean Air Act, National Environmental Policy Act, Endangered Species Act, National Historic Preservation Act, Administrative Procedure Act, Marine Mammal Protection Act, Outer Continental Shelf Lands Act, and numerous other federal and state laws. Peter’s NEPA and regulatory practice is distinguished as he has represented clients on projects that are onshore, offshore, transboundary, and even in outer space.

Peter’s practice also focuses heavily on conventional and renewable fuels regulation. He assists clients with regulatory compliance, transactional advice, advocacy, and litigation under the Renewable Fuel Standard and other fuel regulatory programs. Peter is recognized for his work in Chambers USA, which has ranked him for Environment in District of Columbia (2021–2025). He is also recommended by Legal 500 United States for Environment: Regulatory, featured in the Lawdragon “Green 500: Leaders in Environmental Law” (2023–2024), and was rated by Super Lawyers in 2020 following listings as a “Rising Star” in its 2014–2017 editions.

Prior to joining Sidley, Peter was an environmental lawyer at a large international law firm where he represented clients in the steel, energy, natural resource, and agricultural industries. He also gained significant litigation experience in his role as a trial attorney in the U.S. Department of Justice’s Natural Resources Section, winning the department’s “Outstanding Performance” award in 2010.

Peter has represented the following select matters:

• An offshore renewable energy client with regulatory issues and litigation under the APA, NEPA, ESA, MMPA, and OCSLA.
• Petroleum refining clients in matters alleging violations of the Benzene Waste NESHAP and NSPS QQQ regulations.
• A manufacturing client in negotiating settlement with U.S. EPA and California Air Resources Board over alleged defeat devices.
• A facility in a matter alleging violations of California’s Low Carbon Fuel Standard.
• Petroleum refiners in litigation involving issues under the Renewable Fuel Standard before the D.C. Circuit, 10th Circuit, and U.S. Supreme Court.
• Clients with compliance issues and regulatory advocacy under the Renewable Fuel Standard and other fuels regulations.
• Clients on proposed regulatory actions under the Clean Air Act, ESA, and NEPA.
• An energy infrastructure client in litigation challenging the permitting and environmental review of a transboundary pipeline project. The litigation involved legal issues arising under the APA, NEPA, ESA, and Clean Water Act.
• A foreign country with regulatory issues under the Marine Mammal Protection Act.
• A satellite industry client with environmental review issues for projects requiring FCC approval.
• Railroad industry clients with NEPA review issues before the FRA and STB.
• Clients with NEPA review issues for projects receiving federal funding from the Department of Energy.

• D.C. Bar Energy, Environment, and Natural Resources Section (Steering Committee Member, Energy Committee Co-Chair)
• ABA Section on Environment, Energy and Resources