the area's design value as of the attainment date, whether the area
attained such standard by December 31, 1991. If the Administrator
determines that the area attained the standard, the Administrator
shall require, as part of the order, the State to submit a maintenance
plan for the area within 12 months of such determination. If the
Administrator determines that the area failed to attain the standard,
the Administrator shall, by June 30, 1992, designate the area as
nonattainment under section 107(d)(4).
"SEC. 185B. NOx AND VOC STUDY.
"The Administrator, in conjunction with the National Academy of
Sciences, shall conduct a study on the role of ozone precursors in
tropospheric ozone formation and control. The study shall examine the
roles of NOx and VOC emission reductions, the extent to which NOx
reductions may contribute (or be counterproductive) to achievement of
attainment in different nonattainment areas, the sensitivity of ozone
to the control of NOx, the availability and extent of con-
trols for NOx, the role of biogenic VOC emissions, and the basic
information required for air quality models. The study shall be
completed and a proposed report made public for 30 days comment within
1 year of the date of the enactment of the Clean Air Act Amendments of
1990, and a final report shall be submitted to Congress within 15
months after such date of enactment. The Administrator shall utilize
all available information and studies, as well as develop additional
information, in conducting the study required by this section.".
SEC. 104. ADDITIONAL PROVISIONS FOR CARBON MONOXIDE NONATTAINMENT
Part D of title I of the Clean Air Act is amended by adding the
following new subpart at the end:
"Subpart 3-Additional Provisions for Carbon Monoxide Nonattainment
"Sec. 186. Classifications and attainment dates.
"Sec. 187. Plan submissions and requirements.
"SEC. 186. CLASSIFICATION AND ATTAINMENT DATES.
"(a) Classification by Operation of Law and Attainment Dates for
Nonattainment Areas.-(1) Each area designated nonattainment for carbon
monoxide pursuant to section 107(d) shall be classified at the time of
such designation under table 1, by operation of law, as a Moderate
Area or a Serious Area based on the design value for the area. The
design value shall be calculated according to the interpretation
methodology issued by the Administrator most recently before the date
of the enactment of the Clean Air Act Amendments of 1990. For each
area classified under this subsection, the primary standard attainment
date for carbon monoxide shall be as expeditiously as practicable but
not later than the date provided in table 1:
Area classification Design value Attainment date
Moderate........... 9.1-16.4 ppm.............. December 31, 1995
Serious............ 16.5 and above............ December 31, 2000
"(2) At the time of publication of the notice required under