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4.4 NOISE haul route proposed by the applicant is to bridge the Mokelumne River and extend the roadway to Davis Road, south to Peltier Road and west to the New Hope tract. The extraction and processing of the material would take place 24 hours a day, 7 days a week. The transporting of the material to the levee would only take place on weekdays between the hours of 5:00 AM and 9:00 PM. The material would be excavated from the bottom of the lakes with loaders and transported via a conveyor belt system to the trucks. No blasting or quarrying of the site would occur as part of the excavating process. All of the excavation would be completed prior to occupancy of the new residences. Heavy equipment would be used during excavation of the lake bottoms of the lakes. Maximum noise levels of equipment used in such an operation could be as high as 98 dB at a distance of 50 feet from the noise source (Figure 4.4-2). This would result in maximum noise levels of 62 dB at a distance of 3,000 feet from the source, when terrain variations are not taken into account. Since excavation would occur at the bottom of the lakes, the equipment would be out of the direct line of sight between the residences and the excavation activities. This would provide additional attenuation of the excavation noise. Table 4.4-2 shows average noise levels for excavation processes (U.S.EPA, 1973). As no existing residences are located within 3,000 feet from the excavation site, and are out of sight of the excavation process, average noise levels for the nearest existing residences to the excavation area would range between 35 and 53 dB. The median noise level would be below 50 dB, within the limits recommended by the model noise ordinance. Excavation noise would be audible at the nearest existing residences, but would not significantly impact any nearby residents. Impact 4.4-1 Existing residences along the haul route segments of Davis Road and Ray Road would be impacted by truck traffic transporting excavated material from the site. The maximum number of daily truck trips for transporting excavated material from the site to the levee is estimated to be eight trips per hour, in and out of the site during the excavation period(Omni-Means, 1991). Noise levels at setbacks of existing residences to Davis Road would be 10 dB higher than existing noise levels due to truck traffic on the haul route. Noise levels would increase by 6 dB due to truck traffic on Ray Road, north of Peltier Road. Noise level increases above 5 dB are considered to be significant. 4.4-7