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t � <br /> It should be noted that the aggregate stockpiles and pit wails of the mining area are currently <br /> providing substantial shielding of processing and mining noise in the direction of the nearest <br /> residences to the south and east. Table 2 shows the predicted average noise levels at the three <br /> residences identified in Figure 1 for current mining and processing activities. <br /> Y <br /> Table 2 <br /> Existing DSS Facility Noise Levels at Nearest Residences <br /> DSS Quarry-San Joaquin County <br /> Reference Level at Residence Distance from Predicted Lq at <br /> Source 100 feet-L , Source(feet)' Receiver° <br /> Processing Equipment 75 dB 1 3,000 41 <br /> 2 3,000 41 <br /> 3 3,000 41 <br /> Mining Equipment 65 dB 1 2,000 34 <br /> 2 3,000 31 <br /> 3 2,500 32 <br /> 1 - Reference Ievels obtained from Bollard&Brennan,Inc.noise level measurements conducted at the DSS <br /> site on February 21,2002. <br /> 2- Residential receiver locations are identified on Figure 1. <br /> 3 - Approximate distance in feet from the effective center of noise source area to receiving location. <br /> 4- Levels predicted at the receiver are based on a noise level reduction of 6 dB per doubling of distance <br /> from the source and an additional offset of-5 dB for shielding provided by intervening stockpiles, <br /> atmospheric absorption and excess ground attenuation. <br /> As a check on the accuracy of the Table 2 data,Bollard&Brennan,Inc. also conducted noise level <br /> measurements along the southern project property line with the plant processing and mining <br /> operations proceeding normally. <br /> At the southern project property line, the noise emissions of the mining and processing activities <br /> were faintly audible at the southwest corner of the site (nearest Residence 2), to inaudible at the <br /> southeast corner of the site(nearest to residence 3). At those locations,the measured median noise <br /> levels were 42 and 39 dB L50, respectively. These levels show very good agreement with the <br /> predictions contained in Table 2. <br /> Residence 1 is generally located a similar distance from the current plant processing and mining <br /> activities as Residences 2 and 3. As a result, the Table 2 projection at that location is expected to <br /> be reasonably accurate as well. <br /> Environmental Noise Evaluation <br /> Proposed DSS Quarry Rescheduled Hours of Operation <br /> Page 4 �� <br />