Greg is a nationally recognized environmental litigator and trial lawyer with more than 25 years of experience. As co-leader of McGuireWoods’ Environmental Litigation practice group, he has successfully handled EPA enforcement actions and CERCLA litigation at over 110 mega sites nationwide, including complex cases involving marine environments on the West Coast, East Coast, and Gulf of Mexico. Greg regularly represents clients in high-stakes environmental disputes, arguing cases before many U.S. Courts of Appeals.
Greg is widely recognized as a leading environmental trial attorney, earning accolades from peers, legal researchers, and journalists. In 2025, Lawdragon named him a Leading Lawyer, and in 2022, Law360 selected him as an Environmental Law MVP—one of only four attorneys nationwide to receive the honor. Greg has been selected as one of the country’s Winning Litigators by The National Law Journal and as one of L.A.’s Most Influential Lawyers by the Los Angeles Business Journal. His work in environmental litigation has earned him the Financial Times Most Innovative Lawyers in North America finalist distinction and The National Law Journal’s Trailblazer Award.
Greg’s work and commentary has been featured in The Financial Times, Newsweek, Bloomberg, The New York Times, The American Lawyer, The National Law Journal, The Wall Street Journal and The Washington Post. He has also authored and published several articles on public policy, legislation and environmental law.
A seasoned appellate advocate, Greg has successfully argued groundbreaking cases before the U.S. Court of Appeals for the 5th, 9th and 10th Circuits, including Asarco v. Atlantic Richfield Company, which secured recovery of past and future cleanup costs at the East Helena Superfund Site.
Greg is deeply committed to community service and pro bono advocacy, serving as a trustee for Catholic Charities of Los Angeles. He serves on the University of Notre Dame President’s Council, held board leadership roles with the San Francisco YMCA, The Constitutional Rights Foundation, and Public Counsel Law Center.
Overcoming adversity drives Greg forward in all aspects of his professional and personal life. Following the tragic loss of his 14-year-old daughter, Katherine, due to a sudden arrhythmia—and his difficulty placing a wireless 911 call—Greg has been a dedicated advocate for improving wireless communications infrastructure nationwide, including through his national representation of Verizon Wireless. A leader within McGuireWoods, Greg has played a key role in the firm’s growth and governance. He was elected to the Board of Partners in 2018 and re-elected for a consecutive term in 2022. He also serves on the firm’s Political Action Committee.
Before joining McGuireWoods, Greg was an equity partner at Milbank, completed a Fellowship with the U.S. Department of Justice in Washington, D.C., and served as Deputy Counsel to the National Coalition for the Homeless in Washington. Greg has completed 12 marathons, and he is an avid equestrian.
Experience
- Public Service Enterprise Group (PSE&G). Greg currently serves New Jersey’s investor owned public utility as its lead lawyer in all federal enforcement and litigation related to the Diamond Alkali Superfund Site including the Passaic and Hackensack rivers and Newark Bay.
- Verizon Communications & Verizon Wireless. Greg serves Verizon nationally on environmental, land use and communications facility deployment matters.
- RCF Management. Greg co-chaired a successful international arbitration to obtain the recovery of over $130 million from Chubb and Zurich Insurance under a policy providing political risk coverage. Greg and his team proved that the government of Armenia expropriated a gold mine under development. He successfully countered arguments that environmental risks justified the government’s expropriatory conduct.
- Devon Energy. Greg represents Devon Energy in numerous climate change cases filed in federal and state courts throughout the United States.
- Hilton Hotels. Greg represents Hilton Hotels in environmental cases filed throughout the United States.
- Americas Smelting and Refining Corporation, Incorporated.
Greg currently serves copper mining giant ASARCO as its primary outside litigation counsel on all environmental issues. Greg has represented Asarco since 2005. - Grupo Mexico. Greg represents Grupo Mexico in the United States related to its railroad and mining operations in the United States, Mexico and Peru.
- California
- U.S. Supreme Court
- U.S. Court of Appeals for the Second Circuit
- U.S. Court of Appeals for the Fifth Circuit
- U.S. Court of Appeals for the Seventh Circuit
- U.S. Court of Appeals for the Eighth Circuit
- U.S. Court of Appeals for the Ninth Circuit
- U.S. Court of Appeals for the Tenth Circuit
- U.S. Court of Appeals for the D.C. Circuit
- U.S. District Court for the Central District of California
- U.S. District Court for the Eastern District of California
- U.S. District Court for the Northern District of California
- U.S. District Court for the Southern District of California
- U.S. District Court for the Western District of Texas
- U.S. District Court for the District of Colorado
Selected for inclusion in “Lawdragon Green 500: Leading U.S. Environmental Lawyers,” Lawdragon, 2023, 2024, 2025
Selected for inclusion in “Legal 500 United States,” Environment: Litigation; Product liability, mass tort and class actions – toxic tort – defense, 2024
Named an “Environmental Law MVP,” Law360, 2022
Selected for inclusion in “500 Leading U.S. Environmental & Energy Lawyers” list, Lawdragon, 2021
Selected for Inclusion, Daily Journal, “Top Verdicts,” 2020
Named a “Leader in Law“, Los Angeles Business Journal, 2019
Named a “Winning Litigator,” The National Law Journal, 2019
Named an “Energy & Environmental Trailblazer,” The National Law Journal, 2018
Named “Most Influential Attorneys,” Los Angeles Business Journal, 2018 Named an Environmental MVP, Law360, 2017 and 2021
Selected as a “Leading Lawyer,” General Commercial Disputes, 2017; Energy Litigation: Oil and Gas, 2018; California, Legal 500 US
Named, “Star Lateral,” American Lawyer, 2009 Profiled, Wall Street Journal, 2005
Profiled, Daily Journal (statewide, California), 2005
Selected for Inclusion, “45 Under 45,” American Lawyer, 2003
Recipient, “Wiley Manual Award for Pro Bono Service,” California State Bar, 2001 Recipient, Dean’s Award for Social Justice, University of Notre Dame, 1989 Research Editor, Notre Dame Journal of Law, Ethics & Public Policy, 1988-89 Commencement Speaker, University of California, Berkeley, Graduate School, 1986
- Author, EPA Announces Major Shift in Enforcement Priorities for Energy Sector, McGuireWoods Legal Alert, March 20, 2025
- Author, EPA Reconsiders NESHAPs: Key Changes and Industry Impacts for the HON Rule, McGuireWoods Legal Alert, March 13, 2025
- Author, EPA Announces 31 Sweeping Regulatory Reforms, McGuireWoods Legal Alert, March 13, 2025
- Author, Contaminants Compass: March 2024 Edition, McGuireWoods Legal Alert, March 18, 2024
- Co-author, "Allocating Remedial Expenditures at the East Helena Smelter Complex, MT USA," Environmental Claims Journal, June 25, 2021
- Author, State Environmental Enforcement Policies During COVID-19 and Response to EPA “Discretion” Policy, McGuireWoods Legal Alert, April 2, 2020
- Author, EPA Indicates that It May Relax Enforcement Measures for Narrow Categories of Environmental Legal Obligations Occurring After March 13, 2020, if Pandemic Causes Inability to Comply, McGuireWoods Legal Alert, March 30, 2020
- University of Notre DameJD1989
- University of California, BerkeleyMA1986
- University of Southern CaliforniaBS1984
Member, McGuireWoods LLP Political Action Committee
Trustee, Catholic Charities of Los Angeles
U.C. Berkeley, School of Social Welfare
Board of Directors, Constitutional Rights Foundation Board of Directors
Board of Directors, YMCA of San Francisco
- Spanish