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California. All areas of the state are currently designated as attainment for the state lead standard(EPA does not <br /> designate areas for the national lead standard). Although the ambient lead standards are no longer violated, lead <br /> emissions from stationary sources still pose"hot spot"problems in some areas. As a result,ARB identified lead as <br /> a TAC. <br /> Monitoring Station Data and Attainment Area Designations <br /> Criteria air pollutant concentrations are measured at several monitoring stations in the SJVAB. There are three <br /> stations in San Joaquin County,two in Stockton and one in Tracy. The Hazelton Street station in Stockton, <br /> approximately 10 miles north of the project site measures ozone,NO2,PMIo, and PM2.5. Table 4.3-1 summarizes <br /> the air quality data from this station for the most recent 3 years,2003 through 2005. The data is not necessarily <br /> representative of the project site,because of the distance from the monitor to the site. <br /> Table 4.3-1 <br /> Summary of Annual Ambient Air Quality Data (2004-2006)—Hazelton Station <br /> 2004 2005 2006 <br /> Ozone <br /> Maximum concentration(1-hr/8-hr,ppm) 0.096/0.080 0.099/0.086 0.109/0.92 <br /> Number of days state standard exceeded(1-hr) 1 3 6 <br /> Number of days national standard exceeded(1-hr/8-hr) 0/0 0/1 0/3 <br /> Nitrogen Dioxide(NO2) <br /> Maximum concentration(1-hr,ppm) 0.079 0.087 0.072 <br /> Number of days state standard exceeded(1-hr) 0 0 0 <br /> Annual Average(ppm) 0.017 0.017 0.018 <br /> Fine Particulate Matter(PM2.5) <br /> Maximum concentration(gg/m3)National/Californial 41/41 63/70 47/53 <br /> Number of days national standard exceeded(measured) 0 0 0 <br /> State annual average(gg/m3) 13.23 12.5 13.1 <br /> Respirable Particulate Matter(PMIo) <br /> Maximum concentration(µg/m) 176/61 79/84 82/85 <br /> Number of days state standard exceeded(calculated2) 18 46 63 <br /> Number of days national standard exceeded(calculated) 1 0 0 <br /> Notes: <br /> ppm=parts per million;Ng/m3=micrograms per cubic meter <br /> State and national statistics may differ for the following reasons:State statistics are based on California approved samplers,whereas <br /> national statistics are based on samplers using federal reference or equivalent methods.State and national statistics may therefore be <br /> based on different samplers.State statistics are based on local conditions National statistics are based on standard conditions.State criteria <br /> for ensuring that data are sufficiently complete for calculating valid annual averages are more stringent than the national criteria. <br /> 2 Measured days are those days that an actual measurement was greater than the level of the state daily standard or the national daily <br /> standard.Measurements are typically collected every 6 days.Calculated days are the estimated number of days that a measurement would <br /> have been greater than the level of the standard had measurements been collected every day.The number of days above the standard is <br /> not necessarily the number of violations of the standard for the year. <br /> 3 The state annual standard was exceeded in 2004 and 2006. <br /> Source:ARB 2007a <br /> Both ARB and the U.S. Environmental Protection Agency(EPA)use this type of monitoring data to designate <br /> areas according to attainment status for criteria air pollutants established by the agencies. The purpose of these <br /> designations is to identify those areas with air quality problems and thereby initiate planning efforts for <br /> EDAW Manteca WQCF and Collection System Master Plans EIR <br /> Air Quality 4.3-6 City of Manteca <br />