EXHIBIT 4-1_55A_BRISTOL WIDENING EIS-EIR

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Currently, the background one -hour carbon monoxide concentration (18.0 ppm) is below the state and federal standards. However, the eight -hour average background concentration (11.7 ppm) presently exceeds both state and federal standards. Year 2006 one -hour background concentrations (14.06 ppm) are projected to be well below the relevant state and federal standards. Ambient eight -hour CO levels in the year 2006 (9.5 ppm) are expected to exceed both state and federal standards (9.0 ppm; see the Appendix in the separate Bristol Street Widening Technical Studies for methodology). At present, sensitive receptors in the project vicinity appear to experience carbon monoxide levels that exceed state and federal standards. Under future conditions with the project, sensitive land uses adjacent to the intersections analyzed will be setback far enough from the intersections to allow dispersion of pollutants and significantly reduce the number of receptors exposed to high concentrations of carbon monoxide. Since only "worst case" conditions were considered in Table 15, carbon monoxide concentrations during conditions which are more likely to occur should be less than those shown. - ° The 1989 Revision of the AQMP includes projections of future carbon monoxide levels in the South Coast Air Basin. At the pollution monitoring station in Anaheim, located within a few miles of the project site, it is predicted that carbon monoxide levels will average above 10 ppm by the year 2010, without the implementation of AQMP attainment strategies. Assuming that the AQMP *' attainment strategies are put into effect, future background concentrations would range from one to five ppm, a figure low enough to indicate a significant reduction in the number of days exceeding the eight -hour standard in the ' project • vicinity. The 1989 AQMP assumes a level of growth in population and employment consistent with the SCAG -88 Growth Management Plan forecasts, which are .. based on a local jurisdiction's General Plan and implementation of regional jobs /housing balance strategies. The project proposal is consistent with the Circulation Element of the General Plan for Santa Ana; therefore, the project appears to be consistent with the AQMP. Moreover, the project will not adversely impact regional ambient air quality. It will improve several circulation performance characteristics which are instrumental in determining vehicle emission rates and thus air pollutant emissions. I The higher speeds resulting from more efficient traffic movement reduces CO emissions from each vehicle. .a w, A IV -18