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<br /> <br />Red Morton Community Park Sports Lighting Initial Study <br />City of Redwood City 28 June 2015 <br />4.3 AIR QUALITY <br /> <br />4.3.1 Setting <br /> <br />4.3.1.1 Background <br /> <br />Air quality and the concentration of a given pollutant in the atmosphere are determined by the <br />amount of pollutant released and the atmosphere’s ability to transport and dilute the pollutant. The <br />major determinants of transport and dilution are wind, atmospheric stability, terrain , and for <br />photochemical pollutants, sunshine. The project area (i.e., the City of Redwood City) is within the <br />southwestern portion of the San Francisco Bay Area Air Basin. The Bay Area Air Quality <br />Management District (BAAQMD) is the regional government agency that monitors and regulates air <br />pollution within the air basin. <br /> <br />4.3.1.2 Topography and Climate <br /> <br />The proximity of San Mateo County to both the Pacific Ocean and San Francisco Bay has a <br />moderating influence on the climate. Northwest winds and northerly winds are most common in the <br />project area, reflecting the orientation of the Bay and the San Francisco Peninsula. <br /> <br />The South Bay has significant terrain features that affect air quality. The Santa Cruz Mountains and <br />Diablo Range on either side of the South Bay restrict horizontal dilution. This alignment of the <br />terrain also channels winds from the north to south, carrying pollution from the northern San <br />Francisco Bay Peninsula toward Santa Clara County. <br /> <br />4.3.1.3 Regional and Local Criteria Pollutants <br /> <br />Major criteria pollutants, listed in “criteria” documents by the U.S. Environmental Protection Agency <br />(USEPA) and the California Air Resources Board (CARB) include ozone, carbon monoxide, <br />nitrogen dioxide, sulfur dioxide, and suspended particulate matter (PM). These pollutants can have <br />health effects such as respiratory impairment and heart/lung disease symptoms. Ozone also damages <br />leaf tissue in trees and other plants. <br /> <br />Violations of ambient air quality standards are based on air pollutant monitoring data and are judged <br />for each air pollutant. The Bay Area as a whole does not meet State or Federal ambient air quality <br />standards for ground level ozone or State standards for PM10 and PM2.5. The area is considered <br />attainment or unclassified for all other pollutants. <br /> <br />4.3.1.4 Local Community Risks/Toxic Air Contaminants and Fine Particulate Matter <br /> <br />Besides criteria air pollutants, there is another group of substances found in ambient air referred to as <br />Toxic Air Contaminants (TACs). These contaminants tend to be localized and are found in relatively <br />low concentrations in ambient air; however, they can result in adverse chronic health effects if <br />exposure to low concentrations occurs for long periods. <br /> <br />Fine Particulate Matter (PM2.5) is a complex mixture of substances that includes elements such as <br />carbon and metals; compounds such as nitrates, organics, and sulfates; and complex mixtures such as <br />8.A. - Page 45