Industrial uses before and during the operation of the Naval Air Station left toxics in the area. The Navy identified toxic sites and began clean-up efforts that are overseen by three regulatory agencies: US Environmental Protection Agency, California Dept. of Toxic Substances Control, and the California Water Quality Control Board. A city-hired environmental consultant reviews cleanup decisions on behalf of the city, and the community Restoration Advisory Board receives regular reports and offers comments about cleanup.
Most cleanup activities fall under the Superfund law known as the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Cleanup of fuel lines and petroleum contamination is handled through a separate program, as is the cleanup of radiological contamination inside of buildings. The Navy has spent over $500 million on cleanup. Of the 34 Superfund cleanup sites, only three sites await implementation of final cleanup plans. A few of the sites will require a prolonged effort and will delay the transfer of those sites to the city until 2021.