EXHIBIT 4-1_55A_BRISTOL WIDENING EIS-EIR

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maintenance, drought - tolerant plant materials, thereby reducing long- term costs for maintenance and water consumption. Su a A detailed air quality impact assessment for this project was prepared by Endo Engineering, under separate cover. That study forms the basis for the following discussion and is available for public review at offices of the City of Santa Ana Public Services Agency. Two types of air pollutant sources must be considered with respect to the .� proposed project: stationary sources and mobile sources. Stationary source considerations include emissions on -site from construction activities, as well as emissions at the power plant associated with the electrical requirements of the project. Mobile source considerations include exhaust emissions resulting from ` short -term construction activities and long -term traffic changes associated with -� the project. Temporary, short-term pollutant emissions will occur during construction of the proposed street improvements, including fugitive dust, construction equipment and vehicle exhaust and construction crew vehicle exhaust. These emissions will vary from day to day as construction levels change, but should be minimal and dispersed without significant impact on sensitive receptors. Long -term carbon - monoxide emissions along the project route would decrease by approximately 3,666 pounds /day by the. year 2006, if the project is implemented. Hydrocarbon emissions would decrease by approximately 376 " pounds /day by 2006, if the proposed improvements are built. Nitrogen dioxide emissions would increase by about 5 pounds /day. No significant change in the levels of sulfur dioxide and particulates would occur with or without the project. -� The reduction in carbon monoxide and total hydrocarbon emissions would result from the reduction in traffic congestion, which would lead to slightly higher speeds and shorter travel times. Higher traffic speeds, however, would also result in increased emissions of oxides of nitrogen from each vehicle. Carbon monoxide concentrations were estimated using the Caline 3 computer model, at four intersections where sensitive receptors are located, for both "project" and "no- project" scenarios, and for both 1987 and estimated year 2006 traffic volumes. The results indicated that, if the project were currently in place, there would be no difference in CO concentrations at the intersections analyzed. Estimates for year 2006 traffic volumes indicated that the proposed IV -8