31B - CUP - 1901 NORTH FAIRVIEW ST

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City of Santa Ana Environmental Checklist The greatest air pollution impacts in the Basin occur from June through September, and are generally attributed to the large amount of pollutant emissions, light winds, and shallow vertical atmospheric mixing. This condition frequently reduces pollutant dispersion, thus causing elevated air pollution levels. Pollutant concentrations in the Basin vary with location, season, and time of day. Ozone (03) concentrations, for example, tend to be lower along the coast, higher in the near inland valleys, and lower in the far inland areas of the Basin and adjacent desert. Air quality within the basin is regulated by the South Coast Air Quality Management District (SCAQMD or District), which has jurisdiction over an area of approximately 10,743 square miles, including all of Orange County, Los Angeles County except for the Antelope Valley, the non- desert portion of western San Bernardino County, and the western and Coachella Valley portions of Riverside County. The Basin is a sub - region of the SCAQMD jurisdiction. While air quality in this area has improved, the Basin requires continued diligence to meet air quality standards. The SCAQMD has recently completed the Multiple Air Toxics Exposure Study III (MATES 111), an ambient air- monitoring and evaluation study conducted in the Basin. MATES III was a follow up to previous air toxics studies in the Basin and is part of the SCAQMD Governing Board Environmental justice Initiative. Over the past 30 years, substantial progress has been made in reducing air pollution levels in Southern California. For example, compared to previous studies of air toxics in the Basin, MATES III found a decreasing risk for air toxics exposure, with the population weighted risk down by 17% from the analysis in MATES 11. However, although there has been improvement in air quality regarding air toxics, the risks are still unacceptable and are higher near sources of emissions such as ports and transportation corridors. Diesel particulate continues to dominate the risk from air toxics, and the portion of air toxic risk attributable to diesel exhaust is increasing compared to the MATES Il Study. The highest risks are found near the port, central Los Angeles, and transportation corridors. The results from the MATES Ill study underscore that a continued focus on reduction of toxic emissions, particularly from diesel engines, is needed to reduce air toxics exposure. The MATES III study concluded that the average carcinogenic risk throughout the Basin, attributed to toxic air contaminants (TACs), is approximately 1,194 in one million. Mobile sources (e.g., cars, trucks, trains, ships, aircraft, etc.) represent the greatest contributors. About 83.6% of all risk is attributed to diesel particulate matter (DPM) emissions. Data from the closest climate monitoring station— Western Regional Climate Center's (WRCC) Santa Ana Fire Station —was used to characterize project vicinity climate conditions. The average project area summer (August) high and low temperatures are 84.7 and 61.6 °F, respectively; the average winter (January) high and low temperatures are 68.0 and 43.0 °F, respectively. The average annual rainfall is 13.79 inches (WRCC 2012). The closest wind monitoring station is the Anaheim wind monitoring station, which was used to characterize study area wind conditions. Wind patterns in the project vicinity display a nearly unidirectional flow, primarily from the south - southwest and southwest, at an average speed of 8 mph. Calm wind conditions are present 14.73% of the time (SCAQMD 2012). Wind direction is reversed from the stated direction only 2 -3% of the time. The Academy Charter High School 3 14 June 2012 Initial Study/Mitigated Negative Declaration IcF 00914.11 •III