Question

when a toxic waste site is listed by the U.S government who is initially responsible for cleaning up site

Answer 1

Environmental Protection Agency (EPA) uses clean up authorities independently to address clean up situation:
-Under Superfund, or CERCLA, they find companies or the people responsible for contamination and negotiates with them to clean up the site.
-Resource Conservation and Recovery Act (RCRA) provides EPA with enforcements authorities to ensure the sites are clean up.