25C - AGMT - OCWD CENTENNIAL PARK

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Section 5 The following analysis is a summary of an Air Quality impact Report prepared for the Mid Basin Centennial Park Injection Well Project by BonTerra/Psornas in October of 2015. The Air Quality Report is presented in its entirety in Appendix B. 5.2.1 Affected Environment The project site is located in the City of Santa Ana and within the South Coast Air Basin (Basin). The Basin consists of Orange County, all of 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 an and environment with little rainfall and abundant sunshine occurring during the summer months. The topography and climate of Southern California combine to make the Basin an area of high air pollution potential. During the summer months, a warm air mass frequently descends over the cool, moist marine layer produced by the interaction between, the ocean's surface and the lowest layer of the atmosphere. The warm upper layer forms a cap over the cooler surface layer and inhibits the pollutants from dispersing upward. Light winds during the summer further limit ventilation. Additionally, abundant sunlight triggers the photochemical reactions that produce ozone and the majority of particulate matter. The region experiences more days of sunlight than any other major urban area in the nation except for the City of Phoenix Attainment Status The EPA and the ARB designate air basins where ambient air quality standards are exceeded as "nonattainment" areas. If standards are met, the area is designated as an "attainment" area. If there is inadequate or inconclusive data to make a definitive attainment designation, they are considered "unclassified." National nonattainment areas are further designated as marginal, moderate, serious, severe, or extreme as a function of deviation from standards. Each standard has a different definition, or 'form' of what constitutes attainment, based on specific air quality statistics. For example, the Federal 8-hour CO standard is not to be exceeded more than once per year. Therefore, an area is in attainment of the CO standard if no more than one 8-hour ambient air monitoring values exceeds the threshold per year. In contrast, the Federal annual PM2r5 standard is met if the 3-year average of the annual average PM2 5 concentration is less than or equal to the standard. The current attainment designations for the Basin are shown in Table 4. The Basin is designated as nonattainment for the state and federal ozone, PM10, and PM2 5, standards. The Basin is also in nonattainment for the state nitrogen dioxide annual standard, based on the 2006-2008 data. Based, on more recent Mid Basin Centennial Park�jnlLProject Final EIR 5-16