William J. Kassab

William Kassab joined Parkowski, Guerke & Swayze P.A. as an Associate in 2025. Prior to joining Parkowski, Guerke & Swayze, Mr. Kassab was a Deputy Attorney General in the Delaware Attorney General’s Office for 9 years where he primarily represented the Delaware Department of Natural Resources and Environmental Control. Most recently before joining Parkowksi, Guerke & Swayze, Mr. Kassab served as an attorney-advisor to the U.S. Environmental Protection Agency, Region III, where he provided legal guidance on CERCLA and RCRA related matters.

Mr. Kassab concentrates his practice in the areas of administrative and government law, environmental law, regulatory enforcement, commercial law and civil litigation. As a Deputy Attorney General with the Delaware Attorney General’s Office, Mr. Kassab has represented the Department of Natural Resources and Environmental control and other State agencies before the Delaware Supreme Court, the Court of Appeals for the District of Columbia Circuit, the Third Circuit Court of Appeals, the Delaware Superior Court, the Delaware Court of Chancery, the District Court of Delaware, and the Delaware Environmental Appeals Board and Delaware Public Service Commission. Mr. Kassab has also represented the Delaware Department of Natural Resources and Environmental Control on legislative matters before the Delaware General Assembly.

Mr. Kassab has a B.S. in Natural Resources Management and Policy from Paul Smith’s College, located in New York’s Adirondack Park. Mr. Kassab returned to the Mid-Atlantic region to earn his J.D. from Widener University Delaware Law School in 2013. Mr. Kassab is admitted to practice law in the States of Delaware, Pennsylvania, and New Jersey, and Mr. Kassab is admitted to practice before the District Court of Delaware, the Third Circuit Court of Appeals and the Court of Appeals for the District of Columbia Circuit.