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Claremont monitoring station. IN addition, the eight-hour standards wrre exceeded one day in 1978 at the Ham Lane station in Lodi. Violations of the federal and state CO standards occurred as recently as 1986 at the Hazelton Street and Claremont stations. There were no recorded violations of the CO standards during 1984 and 1985. As a consequence of the recorded violations of the federal ozone and CO standards, San Joaquin County has been designated as a "nonattainment area"with reWct to ozone and CO. The standards described above are "primary" air quality standards, r1' standards are those levels of air quality necessary to protect public health with an adequate margin of safety. The nonattainment designation indicates that, in the nonattainment area, the level of air quality for ozone and CO is not sufficient to protect public health with an adequate margin of safety. Emissions Table 13-3 lists the sources of emissions that contribute to ozone and CO problems. The data shown in Table 13-3 include estimates of current year emissions and projections of future year emissions. The data are disaggregated by emission source category. Chawtedgia Ozone, the main component of photochemical smog, is primarily a summer/fall period pollution problem. Ozone is not emitted directly into the air, but is formed through a complex series of chemical reactions involving other compounds that are directly emitted. the directly emitted pollutants involved in this reaction are hydrocarbons (HC) and nitrogen oxides (NOx). HC are sometimes measured as reactive organic gases (ROG). These directly emitted pollutants are known as precursors. The time period required for these reactions allows the reacting compounds to become spread over a large area, producing a regional pollution problem. Ozone problems are the cumulative result of regional development patterns, rather than the result of a few significant emission sources. The San Joaquin County Air Quality Management Plan identifies the mqior contributors to regional ozone problems as motor vehicle emissions and pesticides (San Joaquin County Planning Division 1982b). The plan predicts a general reduction in ozone levels through 1987. 7Ws predicted reduction is due to improved controls on motor vehicle emissions. 7he plan currently projects attainment of federal air quality standards by the 1987 deadline. 7here are, however, some concerns about actually attaining the ozone standards by the 1987 deadline (Keranen pens. comm.). Carbon Monoxide. CO is primarily a winter period pollution problem. Motor vehicle emissions are the dominant source of CO in most areas. As a directly emitted pollutant, CO is transported away form the emission source accompanied by dispersion and reduced pollutant concentrations. Consequently, CO problems are usually localized, often the result of a combination of high traffic volumes and significant traffle congestion. 16