Which regulation established the National Contingency Plan?

The National Contingency Plan (NCP) was established under 40 CFR part 300. This regulation provides the framework for the federal government's response to chemical spills and releases of hazardous substances. The NCP outlines the procedures and standards for responding to hazardous substance releases and is integral in coordinating efforts among federal, state, and local agencies during these incidents.

By being detailed in the regulatory framework, 40 CFR part 300 ensures that appropriate methods are used in containment, cleanup, and mitigation processes of environmental disasters. This plan not only addresses response actions but also helps in establishing the roles and responsibilities of various agencies involved in emergency response.

The other choices pertain to different aspects of environmental legislation or regulations. While CERCLA §120 relates to the responsibilities of federal agencies in managing contaminated sites, and Executive Order 12580 outlines delegated authorities regarding hazardous waste, they do not specifically establish or define the National Contingency Plan as comprehensively as 40 CFR part 300 does.