ARCHIVED REPORTS_DRAFT ENVIRONMENTAL IMPACT REPORT

Home Browse Search

D o Table 4.3-2 p Ambient Air Quality Standards and San Joaquin County Attainment Status Designations Averaging California National Standards, Pollutant Time 23 Attainment s,s s,s Attainment Standards Status 4 Primary Secondary Status 7 Extinction coefficient of 0.23 per kilometer—visibility of 10 miles or Visibility-Reducing more(0.07 30 miles or more for Particle Matter 8-hour Lake Tahoe)because of particles U when the relative humidity is less than 70%. 1 National standards(other than ozone, PM,and those based on annual averages or annual arithmetic means)are not to be exceeded more than once a year.The ozone standard is attained when the fourth highest 8-hour concentration in a year,averaged over 3 years,is equal to or less than the standard.The PM10 24-hour standard is attained when 99%of the daily concentrations,averaged over 3 years,are equal to or less than the standard.The PM2.5 24-hour standard is attained when 98%of the daily concentrations,averaged over 3 years,are equal to or less than the standard.Contact the EPA for further clarification and current federal policies. 2 California standards for ozone,CO(except Lake Tahoe),SO2(1-and 24-hour),NO2, PM,and visibility-reducing particles are values that are not to be exceeded.All others are not to be equaled or exceeded.CAAQS are listed in the Table of Standards in Section 70200 of Title 17 of the California Code of Regulations. 3 Concentration expressed first in units in which it was promulgated[i.e.,parts per million(ppm)or micrograms per cubic meter(Ng/m3)]. Equivalent units given in parentheses are based upon a reference temperature of 25°C and a reference pressure of 760 torr. Most measurements of air quality are to be corrected to a reference temperature of 25°C and a reference pressure of 760 torr;ppm in this table refers to ppm by volume,or micromoles of pollutant per mole of gas. ° Unclassified(U):a pollutant is designated unclassified if the data are incomplete and do not support a designation of attainment or nonattainment. w Attainment(A):a pollutant is designated attainment if the state standard for that pollutant was not violated at any site in the area during a 3-year period. Nonattainment(N):a pollutant is designated nonattainment if there was a least one violation of a state standard for that pollutant in the area. Nonattainment/Transitional(NT): is a subcategory of the nonattainment designation.An area is designated nonattainment/transitional to signify that the area is close to attaining the standard for that pollutant. 5 National Primary Standards:The levels of air quality necessary,with an adequate margin of safety,to protect the public health. � s National Secondary Standards:The levels of air quality necessary to protect the public welfare from any known or anticipated adverse effects of a pollutant. CD ' Nonattainment(N):any area that does not meet(or that contributes to ambient air quality in a nearby area that does not meet)the national primary or secondary ambient air quality standard for n the pollutant. Attainment(A):any area that meets the national primary or secondary ambient air quality standard for the pollutant. n Unclassifiable(U):any area that cannot be classified on the basis of available information as meeting or not meeting the national primary or secondary ambient air quality standard for the pollutant. CL $ This concentration effective May 17,2006. 9 The 1-hour ozone NAAQS was revoked on June 15,2005. m 10 ARB has identified lead and vinyl chloride as toxic air contaminants with no threshold of exposure for adverse health effects determined.These actions allow for the implementation of control � measures at levels below the ambient concentrations specified for these pollutants. C 11 Designation for San Joaquin County;the designation is different for one or more other counties in the SJVAB � z m The EPA has revoked the annual standard for PM10;the revocation will be effective December 18,2006. 13 On October 17,2006,the EPA finalized redesignation to Attainment. n acn�i ° The 24-hour standard for PM2.5 has been reduced from 65 pg/mato 35 pg/m3,effective December 18,2006. cg 15 The CAAQS were amended on February 22,2007,to lower the 1-hour standard to 0.18 ppm and establish a new annual standard of 0.03 ppm.These changes become effective after regulatory 0 changes are submitted and approved by the Office of Administrative Law,expected later this year. n1 cn 6M Sources:SJVAPCD 2006a,2006b;ARB 2006c,2007b; EPA 2006b