Matthew Z. Leopold

Matt advises and defends clients across industries with the strategic insights as former General Counsel for the US Environmental Protection Agency, former General Counsel for the Florida Department of Environmental Protection and a former environmental litigator at the US Department of Justice.

Clients look to Matt to provide pragmatic and strategic solutions to complex regulatory, litigation and enforcement challenges facing their operations. Matt provides his clients with in-depth experience and knowledge respecting the pivotal recent changes in environmental regulation. As EPA General Counsel, he counseled on the development and defense of virtually every significant regulation proposed by EPA since 2017 and was personally involved in the highest profile environmental cases during that time, including two precedent setting environmental cases in the Supreme Court, County of Maui v. Hawaii Wildlife Fund and Atlantic Richfield Co. v. Christian. At EPA, Matt helped draft the Affordable Clean Energy Rule (the repeal and replacement of the Clean Power Plan) and the Navigable Waters Protection Rule (the new definition of the Waters of the United States (WOTUS)), the Clean Water Act Section 401 Certification Rule, the Safe Affordable Fuel-Efficient (SAFE) Vehicles Rule (regulating tailpipe emissions from passenger cars and light duty trucks), and other rulemakings. Additionally, Matt served as the chief attorney at the Florida Department of Environmental Protection advising on state policy and regulatory matters in regard to air, water, waste and public lands for the Department Secretary and the Governor’s Office. In light of this experience, Matt is able to provide deep insight into the regulatory processes of federal and state agencies in advising clients in permitting, compliance, and enforcement defense matters.

Matt has experience in an array of major federal environmental statutes, including the Clean Air Act, the Clean Water Act, the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), the Resource Conservation and Recovery Act (RCRA), the Toxic Substances Control Act (TSCA), and the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), as well as the National Environmental Policy Act (NEPA) and the Endangered Species Act (ESA). In the chemical regulation space, he assisted in implementing the new TSCA framework, working on the first set of chemical risk evaluations required under the new statute, and he counseled on major pesticide registration decisions, litigation and ESA consultations under FIFRA. Matt also assisted on EPA’s recent per- and polyfluoroalkyl substance (PFAS) action plan, to chart a course on regulatory actions to address issues with respect to manufacturing, cleanup, and drinking water protection. With this experience, Matt is regarded as a strategic advisor to Fortune 500 clients offering advice to help advance their business objectives while limiting exposure and risk to the company.

Matt also has significant experience as a litigator for the government and in the private sector, with particular knowledge in developing expert testimony. At the Department of Justice, he was a member of the trial team for the largest civil enforcement in history. In state government, he led the first enforcement action related to hydraulically fractured oil and gas extraction in the southwest Florida region and successfully argued an appeal in the 11th Circuit in the long running Everglades case. In private practice, he represented the State of Florida, in a water rights dispute with the State of Georgia before the US Supreme Court, resulting in a month long trial before a court appointed special master. Matt presented and examined expert witnesses, including developing testimony on the potential sea level rise impacts of climate change. He also successfully represented an industry leading chemical company in litigation over a Clean Water Act Total Maximum Daily Load in an interstate water body. Matt has worked on incident response teams and understands the delicate interplay between responsiveness and brand preservation. 

Based on his experience in both public service and private practice, Matt is particularly well versed in the legal ramifications and the changing climate of environmental regulations affecting the oil & gas, mining, chemical, and renewable energy industries.

Matt is admitted to practice before the Supreme Court of the United States.

• Recommended for Environment: Regulatory and Environment: Litigation, Legal 500 United States, 2022-2024
• Recognized as a Leader in Environment, District of Columbia, Chambers USA, 2023-2024
• Recognized as 2021 Environmental Group of the Year, Law360, January 2022

• Selected as a member of the Lawdragon Top 500 Environmental and Energy Lawyers (2021) and Lawdragon Green 500: Leaders in Environmental Law (2023, 2024)

• 2021 Chambers USA Environment Law Firm of the Year

• Appointed by US Senators Marco Rubio and Bill Nelson to Florida Federal Judicial Nominating Commission, 2015–2017
• Florida Trend Magazine, Florida Legal Elite, 2015
• Assistant Attorney General’s Award for Excellence for the Deepwater Horizon Litigation Team, 2011
• Assistant Attorney General’s Award for Excellence for Providing Legal Advice Related to Border Fence Land Acquisition Project, 2008