secondary nonattainment area encompassing
General Mitchell International Airport. How-
ever, the EPA declined to reclassify the second-
ary particulate matter nonattainment areas in
Racine and Kenosha Counties on June 23, 1989,
and September 12, 1989, respectively. In doing
so, the EPA cited the DNR's failure to provide
adequate support as to the reasons the TSP
standards were attained in those areas. Thus,
the secondary particulate matter nonattainment
areas as presently delineated in southeastern
Wisconsin are shown on Map 17.
The DNR is presently in the process of
substantiating that the particulate matter emis-
sion reductions in Kenosha and Racine Counties
are real, permanent, and enforceable. It may be
expected, therefore, that the DNR will success-
fully repetition the EPA to reclassify the second-
ary particulate matter nonattainment areas in
those two counties to attainment. However, since
the secondary particulate matter air quality
standards continue to be exceeded in portions of
Milwaukee and Waukesha Counties, the DNR is
unable to seek a reclassification for those areas
at the present time. Given the fact that EPA
generally takes five or more years to act on a
redesignation request, it is probable that the
existing secondary particulate matter nonattain-
ment areas in Milwaukee and Waukesha Coun-
ties will remain unchanged through the
mid-1990s.
Based upon prior exceedances of the ambient air
quality standards, a portion of Milwaukee
County was designated as a sulfur dioxide
nonattainment area in 1981. The boundaries of
this sulfur dioxide nonattainment are shown on
Map 18. No exceedance of any sulfur oxide
ambient air quality standard, however, has been
recorded in the Region since 1979. Accordingly,
in October 1986 the DNR requested the EPA to
reclassify the area to attainment. In May 1990,
the EPA determined to retain the nonattainment
area designation, despite the continued com-
pliance with the sulfur oxide ambient air
quality standard.
A portion of Milwaukee County was designated
a carbon monoxide nonattainment area in 1978.
As noted earlier, however, no violation of the
carbon monoxide ambient air quality standards
have been recorded in the Region since 1984. The
DNR, therefore, has requested the EPA to
reclassify this area to attainment status. The
EPA acted favorably on the requested carbon

monoxide redesignation in July 1990.

The one-hour average ambient air quality stand-
ard for ozone, 0.12 ppm (235 gg/m3), is not to be
exceeded on an average of more than once per
year over a three-consecutive-year averaging
period. Based upon ozone monitoring data for
the years 1986, 1987, and 1988, the DNR has
determined that every county in the Southeast-
ern Wisconsin Region is presently in nonattain-
ment for ozone. The average number of
exceedances for the highest ozone monitoring
site in each county between 1986 and 1988 is
shown in Table 42.
In 1978, when counties in the Region were
initially designated, Walworth and Washington
Counties were declared unclassifiable for ozone
due to a lack of available monitoring data. Since
ozone precursor emissions from these two coun-
ties were suspected of contributing to the
regional ozone problem, however, the DNR
included them in the southeastern Wisconsin
''ozone attainment demonstration area." As
indicated, subsequent air quality monitoring has
confirmed the status of Walworth and Washing-
ton Counties as nonattainment for ozone.
Within an ozone nonattainment area, industrial
development involving any significant volatile
organic compound emissions requires a greater
than one-for-one reduction in emissions from
other sources in the vicinity. As an alternative,
new or expanding industries may purchase
"emission offset credits" from the Wisconsin
Department of Natural Resources or from other
industries which may have acquired "credits"
through the reduction of emissions. Operations
with volatile organic compound emissions of less
than 10 tons during the ozone season (May 1 to
September 30) are not required to provide emis-
sion offsets.
It is apparent from the foregoing that there has
been a general improvement in air quality
conditions in southeastern Wisconsin, with a
reduction in most major pollutants occurring
over the past decade. Ozone remains the most
serious air pollution problem. It is believed that
ozone problems in the Region are attributable in
large measure to precursor emissions from the
large urban areas located to the south and
southeast of the Region. The ozone problem thus
remains largely beyond the control of the Region
and State and can be effectively addressed only
through a multi-state abatement effort. It may
be concluded that, in the preparation of the year

2010 regional land use plan, existing air quality

101