SEC. 193. GENERAL SAVINGS CLAUSE.
  Each regulation,  standard, rule,  notice,  order and  guidance
promulgated or issued by the Administrator under this Act, as in
effect  before the  date of  the enactment  of the Clean  Air Act
Amendments of 1990 shall remain in effect according to its terms,
except to the extent otherwise provided under this Act, inconsis-
tent   with  any  provision  of  this  Act,  or  revised  by  the
Administrator. No  control requirement in effect,  or required to
be adopted by an  order, settlement agreement, or plan  in effect
before the date of  the enactment of the Clean Air Act Amendments
of  1990 in any  area which is  a nonattainment area  for any air
pollutant  may  be modified  after such  enactment in  any manner
unless the  modification insures  equivalent or  greater emission
reductions of such air pollutant.
[42 U.S.C. 7515]