No State law or State program in effect on November 5, 1979, or which may become effective thereafter, shall be superseded by any provision of this chapter, or any rule, regulation, or order thereunder, except insofar as such State law or State program is in conflict with any such provision of section
8513 or
8521 of this title (or any rule, regulation, or order under this subchapter relating thereto) in any case in which measures have been implemented in that State under the authority of section
8513 or
8521 of this title (as the case may be).