Reso 2004-069 - Laserfiche WebLink

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Pn'I~F:1'l IALI,Y PO"IFyI~InL1.Y SIG~rICAAT LESSTIIAA 1SSUE5 slcvIEIC4~T t ~Llas slc~lElca,~T ISSLF:S \1ITIG.4TIOS 1>1PACr I\CORPnK,1 rE.D A~ ~ SOCRCES I\1P4CT umant nr air S. AIR QUALITY. Where available, the significance crtterla esta~usnea oy Inc eNNi~cauic a~~ y,.a~~v ~~~°~~~b~••~-••- ~- --- ollution control district may be relied u on to make the follovvin determinations. Would the ro'ect: a. Conflict with or obstruct implementation of the X ~ a licable air uality tan'? b. Violate any air quality standard or contribute X ~ substantially to an existing or projected air ualit violation? c. Result in a cumulatively considerable net X ~ increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard (including releasing emissions which exceed quantitative thresholds for ozone recursors)'? d. Expose sensitive receptors to substantial X 1, 7 pollutant concentrations'? e. C-reate objectionable odors affecting a X ~ substantial number of en le'? EaPLANATION: a-d) The dredged material characteristically has a high water content that precludes and limits its dust generation potential. However, the project could generate substantial amounts of dust through truck movement on unpaved roads on the site. Dust generation could also occur due to any spillage from the trucks along paved haul routes which would subsequently become "resuspended" by other vehicular traffic. Mitigation measures proposed as part of the project would reduce this effect to below a level of significance. The San Francisco Bay Area Air Basin is in non-attainment for PI`~110 (for not achieving the State ambient air quality standard for PMlO). Exceedances of the state standard occur relatively frequently in Alameda County. The climate in the area is marine. with prevailing winds from the west and northwest. Major sources of PM 10 are vehicle movements over paved and unpaved roads and construction and demolition activities. Under CEQA significance criteria (Appendix G[x]), any project would have a significant aIr quality impact if the project would cause or contribute substantially to an excess of ambient air quality standards. The project would involve substantial truck movement on paved and unpaved roads which would generate large amounts of PM 10 (Fugitive dust). Generation of PM 10 from truck travel over unpaved roads depends on several factors including vehicle speed, silt content of unpaved road surface material, vehicle weight and number of wheels, accidental spillage onto paved roads and the prevailing climate. With high truck vehicle speeds, PM10 fugitive dust emissions could be substantial and these emissions could substantially contribute to ambient PM ] 0 concentrations in the project vicinity. As anon-attainment area, maximum background concentrations already exceed the standards. Prevailing winds from the west and northwest could potentially transport dust from truck traffic onto adjacent residential areas. Thus, without mitigation, project air quality effects could be significant. As noted in the Project Description, the project incorporates mitigation measures including use of water trucks on unpaved haul roads and examining trucks as they leave the site. These measures would reduce PM10 emissions, but additional measures are recommended to reduce this effect below a level of significance. Additional recommended measures include: 1) limiting truck speeds on unpaved surfaces to 15 mph, 2) assigning a monitor (project inspector) to oversee and coordinate the dust abatement program, 3) ensuring that truck tires do not carry dirt onto the paved roads, 4) keeping the paved road segments adjacent to the site free of dust through sweeping, and 5) covering truck with tarps on an as-needed basis. e) Dredged material would be uncontaminated soil material and would not create objectionable odors. San Leandro Dredged Material Management Site Sediment Remaval Project March / 2004