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BENDER READY -MIX CONCRETE MANUFACTURING PROJECT Initial Study /Mitigated Negative Declaration Table 4.3.1 Construction Air Emissions JULY 2011 Naturally Occurring Asbestos Asbestos is a term used for several types of naturally occurring fibrous minerals that are a human health hazard when airborne. The most common type of asbestos is chrysotile, but other types such as tremolite and actinolite are also found in California. Asbestos is classified as a known human carcinogen by State, Federal, and international agencies and was identified as a toxic air contaminant by the California Air Resources Board in 1986. Asbestos can be released from serpentinite and ultramafic rocks when the rock is broken or crushed. At the point of release, the asbestos fibers may become airborne, causing air quality and human health hazards. These rocks have been commonly used for unpaved gravel roads, landscaping, fill projects, and other improvement projects in some localities. Asbestos may be released to the atmosphere due to vehicular traffic on unpaved roads, during grading for development projects, and at quarry operations. All of these activities may have the effect of releasing potentially harmful asbestos into the air. Natural weathering and erosion processes can act on asbestos bearing rock and make it easier for asbestos fibers to become airborne if such rock is disturbed. According to the Department of Conservation Division of Mines and Geology, A General Location Guide for Ultrarnafrc Rocks in California — Areas More Likely to Contain Naturally Occurring Asbestos Report (August 2000), serpentinite and ultramafic rocks are not known to occur within the project area. Thus, there would be no impact in this regard. OPERATIONAL EMISSIONS Mobile Source Long -term air quality impacts consist of mobile source emissions generated from project- related traffic and from stationary source emissions. The project would result in on -site aesthetics, drainage /water quality, and safety improvements required for CUP compliance. These improvements would not alter or expand existing concrete manufacturing operations at the facility. Although there would be no new or increased long -term operational emissions, existing operational emissions have been quantified. Project operations generate approximately 88 daily trips (accounting for 12 employees and assuming 20 truck loads per day). 4.3 -4 i A I u [I I'] t 1 1 J r] AIR QUALITY I NIL s - ! .ice:: 1#*? Unmitigated Emissions 3.19 27,70 14.55 0.01 2.05 1.24 Mitigated Emissions2 3.19 27.70 14.55 0.01 1.79 1.24 SCAQMD Thresholds 75 100 550 150 150 55 Is Threshold Exceeded? No No No No No No ROG = reactive organic gases; NOx = nitrogen oxides; CO = carbon monoxide; S02 = sulfur dioxide; PMio = particulate matter up to 10 microns; PM2.5 = particulate matter up to 2.5 microns Notes: 1. Emissions were calculated using the URBEMIS 2007 version 9.2.4 Computer Model, as recommended by the SCAQMD. 2. Mitigated emissions refer to the inclusion of SCAQMD Rule 403 (Fugitive Dust), which requires exposed soils to be watered twice daily. Refer to Appendix A, Air Quality /Greenhouse Gases Data, for model output sheets. JULY 2011 Naturally Occurring Asbestos Asbestos is a term used for several types of naturally occurring fibrous minerals that are a human health hazard when airborne. The most common type of asbestos is chrysotile, but other types such as tremolite and actinolite are also found in California. Asbestos is classified as a known human carcinogen by State, Federal, and international agencies and was identified as a toxic air contaminant by the California Air Resources Board in 1986. Asbestos can be released from serpentinite and ultramafic rocks when the rock is broken or crushed. At the point of release, the asbestos fibers may become airborne, causing air quality and human health hazards. These rocks have been commonly used for unpaved gravel roads, landscaping, fill projects, and other improvement projects in some localities. Asbestos may be released to the atmosphere due to vehicular traffic on unpaved roads, during grading for development projects, and at quarry operations. All of these activities may have the effect of releasing potentially harmful asbestos into the air. Natural weathering and erosion processes can act on asbestos bearing rock and make it easier for asbestos fibers to become airborne if such rock is disturbed. According to the Department of Conservation Division of Mines and Geology, A General Location Guide for Ultrarnafrc Rocks in California — Areas More Likely to Contain Naturally Occurring Asbestos Report (August 2000), serpentinite and ultramafic rocks are not known to occur within the project area. Thus, there would be no impact in this regard. OPERATIONAL EMISSIONS Mobile Source Long -term air quality impacts consist of mobile source emissions generated from project- related traffic and from stationary source emissions. The project would result in on -site aesthetics, drainage /water quality, and safety improvements required for CUP compliance. These improvements would not alter or expand existing concrete manufacturing operations at the facility. Although there would be no new or increased long -term operational emissions, existing operational emissions have been quantified. Project operations generate approximately 88 daily trips (accounting for 12 employees and assuming 20 truck loads per day). 4.3 -4 i A I u [I I'] t 1 1 J r] AIR QUALITY I