Lili Petersen

Elizabeth “Lili” Petersen joined Dema Law in 2023, bringing more than two decades of experience in environmental law, complex litigation, and class actions. Since 2003, she has served as Special Counsel to the State of New Jersey, representing the New Jersey Department of Environmental Protection in litigation to recover damages for harm to natural resources. Her current work includes cases against DuPont and Chemours related to discharges from four industrial facilities in New Jersey—most notably the Chambers Works site in Deepwater.

Lili played a central role in New Jersey’s $225 million natural resource damages litigation and settlement with ExxonMobil and has litigated environmental claims against corporations including IBM, AT&T/Lucent, Lockheed Martin, Honeywell, and others. She also served as counsel to the Conservation Law Foundation in precedent-setting cases against ExxonMobil, Shell, and Gulf Oil for environmental violations at industrial sites in Massachusetts, Rhode Island, and Connecticut. In settlement of the claims against it, ExxonMobil ultimately discontinued operations at its Everett Terminal and placed a deed restriction on the property precluding the terminalling of hazardous petroleum products in the future.

Lili also served as Special Counsel to the Louisiana Attorney General, helping to develop and litigate the state’s claims related to the Deepwater Horizon oil spill—resulting in more than $8.8 billion in natural resource and economic damage recoveries.

In addition, she has represented private property owners in pollution cases involving contaminated groundwater and surface water, securing multi-million-dollar settlements. These include a $19.5 million class action settlement for residents near a contaminated aquifer (Roeder v. Atlantic), a multi-million-dollar recovery after trial (Guste v. Shell Oil Co.), and a $65 million settlement in a case against Conoco (Samples v. Conoco, Inc.). She also served as co-lead counsel in a class action involving inflated prescription drug prices, achieving a $98 million settlement affirmed on appeal.

Lili is licensed to practice law in Louisiana and has appeared in courts across the country. She earned her J.D. from Tulane Law School, where she received a Certificate in Environmental Law and worked at the Tulane Environmental Law Clinic. She holds a B.A. in English with Distinction from the University of California, Berkeley.