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EFFECTS OF EARLY MORNING 1 NIGHTTIIVIE DSS FACILITY OPERATIONS The noise generation of the DSS facility during early morning/nighttime operations is expected to be essentially similar to current daytime operations noise generation,except that there would likely be considerably less load-out of aggregates during early morning/nighttime hours. Processing Activity Noise Emissions Table 2 indicates that early morning/nighttime processing activities can be expected to generate noise levels of approximately 40 dB Leq at the nearest residences. Because the predicted processing equipment noise emissions of 40 dB Leq would not significantly exceed existing early morning / nighttime noise levels without the prof ect,and because those levels would satisfy the County exterior noise level standard at those residences,no significant noise impacts are identified for early morning /nighttime operation of the processing equipment. Mining Activity Noise Emissions Table 2 indicates that early morning/nighttime processing activities can be expected to generate noise levels of approximately 30-35 dB Leq at the nearest residences with the mining activities taking place in the current mining area. However, as the mining activities progress further to the south,and the distance from those activities to the nearest residences decreases,mining-related noise levels will increase at those residences. Table 3 shows the mining related noise levels predicted when the mining operations are occurring at the closest positions to the nearest residences, as well as the setback distance required to ensure that mining-related noise emissions do not exceed 45 dB Leq at those nearest residences during early morning/nighttime mining operations. Table 3 Predicted Early morning/nighttime Mining Noise Levels at Nearest Residences DSS Quarry-San Joaquin County Reference Level at ResidenceZ Nearest Future Distance Predicted L�at _ Source 100 feet-L, from Source(feet); Receaiver Mining Equipment 65 dB 1 1,500 36 2 800 42 3 400 48 Setback distance from mining activities required to achieve 45 dB Leq= 600 feet 1 - Reference levels obtained from Bollard&Brennan,Inc.noise level measurements conducted at the DSS site on February 21,2002. 2- Residential receiver locations are identified on Figure I. 3- Approximate distance in feet from the effective center of noise source area to receiving location. 4- Levelspredicted at the receiver are based on a noise level reduction of 6 dB per doubling of distance from the source and an additional offset of-5 dB for shielding provided by the existing berm, atmospheric absorption and excess ground attenuation. Environmental Noise Evaluation Proposed DSS Quarry Rescheduled Hours of Operation Page S '�f f—�