Litigation
Environmental
National Leadership in Environmental Litigation, Enforcement, and Regulatory Challenges
A deep bench of partners repeatedly recognized by Chambers for their significant knowledge and expertise, creativity, and pragmatic advice
Tier 1 for Environment: Litigation
– Legal 500 U.S. 2026
2024 Winner of Law360’s “Environmental Practice Group of the Year” award
10 Gibson Dunn lawyers named among Lawdragon’s 500 Leading Environmental Lawyers – 2026
Overview
For more than 30 years, Gibson Dunn has represented clients in their most consequential environmental matters.
Our Environmental Practice handles high-stakes federal and state litigation, administrative and regulatory challenges, government investigations and civil and criminal enforcement actions, climate litigation, environmental toxic and mass torts, and complex contamination, remediation, and cost-recovery matters. Our work frequently tests the limits of enforcement authority, liability theories, and regulatory reach and raises questions of first impression under evolving federal and state environmental laws.
We excel in matters involving significant exposure, novel legal theories, complex scientific and technical issues, and material operational or reputational risk. Across trial and appellate courts and administrative forums, we develop integrated strategies designed to position matters for decisive wins on dispositive motions, at trial, and on appeal, as well as favorable resolutions where appropriate. In complex, coordinated proceedings, we align strategy on issues such as preemption, causation, the scope of liability, and class and aggregate treatment that can drive outcomes across related matters.
Our lawyers combine deep environmental subject-matter experience with Gibson Dunn’s premier trial, appellate, white collar, and regulatory capabilities, allowing us to coordinate seamlessly across litigation, enforcement, and regulatory fronts.
As a full-service environmental practice, we also advise clients on significant regulatory and transactional matters, including environmental diligence, compliance counseling, permitting, Superfund and other remediation matters, and environmental issues arising in major transactions. We help clients navigate environmental considerations that can affect business strategy, operations, investments, and transactions. Our lawyers work seamlessly with other Gibson Dunn practice groups to maximize the Firm’s knowledge base and experience.
Our experience includes:
- High-stakes environmental litigation and administrative and regulatory challenges, including matters involving the Clean Air Act, CERCLA, CEQA/NEPA, federal preemption, and rulemaking;
- Civil and criminal enforcement defense and investigations involving the U.S. Department of Justice, U.S. Environmental Protection Agency, state attorneys general, and environmental regulators; and
- Environmental toxic and mass torts, class and multi-plaintiff actions, and climate litigation in the United States and abroad.
“Gibson Dunn has a unique ability to translate the most complex legal topics into broad spectrum and risk-based advice that in-house counsel can use and business colleagues can understand.”
Chambers USA, client quote
Experience
Representative matters include:
- Daimler Truck North America: Secured a preliminary injunction in October 2025 on behalf of Daimler Truck North America and a coalition of heavy-duty truck manufacturers blocking California officials from enforcing the Clean Truck Partnership and related state-specific emissions requirements, after coordinating the resolution of parallel legal and regulatory challenges across multiple forums. The ruling followed Congress’s revocation of California’s authority to maintain the challenged standards and provided manufacturers a path to sell trucks that comply with federal law nationwide. The decision marked a significant victory on federal preemption in one of the country’s most consequential environmental regulatory disputes.
- Alliance for Automotive Innovation: Representing Auto Innovators and the National Automobile Dealers Association in landmark litigation brought by California and other states challenging federal Congressional Review Act resolutions disapproving EPA waivers for California vehicle-emissions standards, including electric-vehicle mandates. In July 2026, secured a significant Ninth Circuit victory reversing the district court’s denial of intervention as of right for Auto Innovators and NADA, and recognizing the organizations’ protectable interests in preserving the ability to invoke Clean Air Act preemption. Separately, representing Auto Innovators as amicus curiae in D.C. Circuit litigation concerning EPA’s rescission of the Greenhouse Gas Endangerment Finding and related motor-vehicle greenhouse gas standards.
- Various Coffee Industry Companies: Secured a significant victory for Nestlé USA, Starbucks, J.M. Smucker Company, The Kraft Heinz Company, Keurig Dr. Pepper, and over 50 other coffee industry members in a long-running Proposition 65 lawsuit by successfully challenging the need for cancer warnings on coffee products and defending against claims for attorneys’ fees and expert costs, with the California Supreme Court denying further review and final judgment entered for the defendants.
- Lane City Wind (RWECE Clean Energy): Representing Lane City Wind in federal litigation challenging its 201-megawatt Texas wind project under the Endangered Species Act, with the plaintiff seeking to halt the project and block federal tax credits. Gibson Dunn leads the defense and mediation strategy in a dispute implicating environmental review, wildlife regulation, permitting, and more than $500 million in potential project impact.
- Multinational Oil Company: Achieved a complete victory for a multinational oil company in a $1.797 billion civil lawsuit in Indonesia by securing a full dismissal of the plaintiff’s claims and costs of litigation, with subsequent affirmations on appeal and successful dismissals of related follow-on actions.
- General Dynamics Electric Boat: Secured a favorable settlement for General Dynamics Electric Boat under CERCLA, with the U.S. agreeing to cover 75% of the $80 million remediation costs for their Quonset Point Facility, and the client being allowed to submit costs as allowable overhead on government contracts.
Representative matters include:
- Daimler AG (now Mercedes-Benz Group AG) and Mercedes-Benz USA: Represented Daimler AG (now Mercedes-Benz Group AG) and Mercedes-Benz USA in resolving EPA, California Air Resources Board (CARB), DOJ and other government investigations concerning diesel vehicle emissions, negotiating a civil settlement valued at approximately $1.5 billion. The resolution did not require an independent monitor, and the DOJ subsequently closed its related investigation without bringing criminal charges. Gibson Dunn continues to advise Mercedes-Benz on implementation of the consent decree, including emissions testing, warranty matters, and evolving regulatory and statutory requirements for light-duty vehicle emissions.
- Daimler AG (now Mercedes-Benz Group AG) and Mercedes-Benz USA: Secured a comprehensive nationwide settlement on behalf of Mercedes-Benz USA and Mercedes-Benz Group AG, resolving claims brought by attorneys general from all 50 U.S. states and territories alleging violations of consumer protection and environmental laws relating to certain model year 2009–2016 diesel vehicles. The resolution followed the Department of Justice’s closure of its investigation without bringing criminal charges against Mercedes-Benz and a parallel nationwide class settlement with consumers.
- eBay Inc.: Secured complete dismissal of an unprecedented DOJ and EPA enforcement action alleging violations of three federal environmental statutes based on third-party sales on eBay’s online marketplace. The district court held that eBay was not a “seller” under two of the relevant environmental statutes and, separately, that Section 230 of the Communications Decency Act independently barred the government’s claims. The DOJ voluntarily dismissed its Second Circuit appeal in April 2025, leaving the dismissal intact.
- Daimler AG and Mercedes-Benz USA, LLC: Secured dismissal with prejudice of an anti-tampering lawsuit against Daimler AG and Mercedes-Benz USA, LLC brought by the Environmental Protection Commission of Hillsborough County Florida (unanimously affirmed on appeal by the U.S. Court of Appeals for the Eleventh Circuit, upholding the district court’s dismissal).
- Matador Resources Company: Successfully defended Matador Resources Company in a pioneering joint civil enforcement action by the U.S. EPA and the State of New Mexico, resulting in a consent decree with innovative injunctive relief terms, a favorable penalty, and significant investments in environmental improvements and local community projects.
- Marathon Petroleum: Led the negotiation of a settlement resolving an enforcement action against Marathon Petroleum’s predecessor, enabling the transformation of the Martinez Refinery into a renewable fuels plant, with the Western District of Texas approving the settlement, and also previously negotiated a consent decree covering company-wide refining operations.
Representative matters include:
- Drax Group: Representing Drax Group, a UK-based energy company and one of the world’s largest producers of compressed wood pellets, as lead strategic and litigation counsel in two high-stakes lawsuits alleging that emissions from its Mississippi manufacturing facility violated the Clean Air Act and caused health and property impacts in the surrounding community.
- Delta Air Lines: Defending Delta in a novel mass tort action alleging that airborne emissions associated with flight operations have caused personal injuries and property damages to a class of individuals living within five miles of the Seattle airport. Secured interlocutory Ninth Circuit review of threshold federal preemption defenses; the appeal was argued in March 2026 and a decision is pending.
- International Paper: Successfully defended International Paper in multiple PFAS-related lawsuits, leading to the dismissal of a putative class action and a mass action, and securing a complete dismissal with prejudice of a subsequent case involving personal injury and property damage claims.
- Northrop Grumman: Defended Northrop Grumman in a class-action lawsuit over groundwater contamination by securing a court ruling that CERCLA preemption barred the plaintiffs’ claims, leading to a favorable early settlement and avoiding a major potential class action.