by the United States government, United States Code — Title 42, Chapter 85…
“ The requirement of paragraph (1) for the use of continuous emission reduction technology may be waived with respect to a particular smelter by the State or the Administrator, after notice and a hearing on the record, and upon a showing by the owner or operator of the smelter that such requirement would be so costly as to necessitate permanent or prolonged temporary cessation of operations of the smelter. ”
