From 1978 to 1991, Kennedy was a scientific support coordinator, providing scientific advice to the U.S. Coast Guard during oil and chemical spills. During this time he coordinated federal scientific response to more than 100 oil and chemical spills, including the Argo Merchant, Amoco Cadiz, IXTOC I oil-well blowout, Presidente Rivera, World Prodigy, and Exxon Valdez.
Kennedy then served as the chief of NOAA’s hazardous materials response and assessment division from 1991 to 1998, working with local, state and federal agencies in coastal states to prepare for and respond to oil and chemical releases.
In 1998 he became director of NOAA's Office of Response and Restoration, leading a multi-disciplinary program to reduce risks to coastal and marine resources from environmental threats, including oil and chemical spills and hazardous waste sites. In this role he directed three divisions: the hazardous materials response division, the coastal protection and restoration division, and the damage assessment center, with 30 regional offices nationwide. His duties also included overseeing the Pribilof Islands Remediation and Land Transfer Project, NOAA’s Marine Debris, Coral Reef Conservation, and Emergency Response programs.
His other work and activities have included serving as a U.S. delegate to the International Maritime Organization’s Conference on Oil Pollution Preparation and Response; chairing the Washington State Legislative Committee on Oil Spill Response; and being a member of the 1990 Program Committee of the National Oil Spill Conference.