SEC. 192. ATTAINMENT DATES.
  (a) Plans Under Section 191(a).- Implementation plans  required
under section 191(a) shall provide for attainment of the relevant
primary  standard as  expeditiously as  practicable but  no later
than 5 years from the date of the nonattainment designation.
  (b) Plans  Under Section 191(b).- Implementation plans required
under section 191(b) shall provide for attainment of the relevant
primary  national ambient  air  quality standard  within 5  years
after the date  of the enactment of the  Clean Air Act Amendments
of 1990.
  (c) Inadequate Plans.-  Implementation plans for  nonattainment
areas  for sulfur oxides or nitrogen dioxide with plans that were
approved by the Administrator before the date of the enactment of
the  Clean Air  Act Amendments  of 1990  but, subsequent  to such
approval,  were found  by the  Administrator to  be substantially
inadequate, shall provide for  attainment of the relevant primary
standard within 5 years from the date of such finding.
[42 U.S.C. 7514a]