Peterson was also a dedicated environmentalist and the guiding force behind the Coastal Zone Act of 1971. This act protected Delaware's inland bays and waterways by banning heavy industry from a two-mile-wide strip of Delaware's 115 mile coastline, about 20% of the state. The major consequence of the Act was preventing Shell from building a $200m oil refinery. This piece of legislation has since been used by other states to protect their shorelines. During his tenure as governor Peterson chaired the Education Commission of the States from 1970 to 1971. When Maurice Stans, the Secretary of Commerce under Richard Nixon complained to Peterson that the Act harmed America's security and prosperity, Peterson listed a dozen ways in which companies could continue their work without harming Delaware's coastline. The Act was unsuccessfully challenged in court, and Peterson led the environmental movement in Delaware by sporting a badge on his lapel that said "To Hell with Shell!"