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San Joaquin County Community Environmental Setting,Impacts,and Mitigation Measures <br /> Development Department Noise <br /> Table 3.J-9. Predicted Operations Noise from Stationary Sources, North Pit Stage III <br /> North Pit Stage Ill and Aggregate — <br /> Aggregate Plant, North Pit Stage III, Plant(all stationary sources), <br /> dBA Ley(Ih) dBA Lg(I h) dBA L.,(I h) <br /> Elevation of source,relative 0 0 -30 0 -30 <br /> to existing ground(feet) <br /> P-N1' 54 57 51 59` 56 <br /> P-N2' 55 58 51 60 57 _ <br /> P-N3' 56 59 52 61b` 58` <br /> P-N5' 60 60 55 63b,` 61` <br /> P-N6' 54 53 46 57 55 — <br /> P-N7' 55 54 50 58` 56 <br /> P-N8' 54 53 48 56 55 <br /> P-W 1 49 53 45 54b•` 50` — <br /> P-W2 48 52 45 53b•` 49 <br /> P-W3 49 53 47 54b•` 51` <br /> P-EI 51 53 50 55b,c 540 — <br /> ' Modified thresholds of 60/57 dBA(daytime/nighttime)apply. <br /> b Daytime significance threshold exceeded. <br /> Nighttime significance threshold exceeded. <br /> The applicant's acoustical consultant, Bollard Acoustical Consulting(BAC)has <br /> prepared an independent analysis of predicted noise levels as part of the noise <br /> control plan for the project(refer to Appendix N). Processing noise levels <br /> predicted by BAC are generally 2-3 dB higher for Receivers P-NI through P-N7 <br /> and 2-3 dB lower for Receivers P-N8 through El. These differences are <br /> attributed primarily to differences in assumptions regarding the shielding from <br /> berms and differences in the models used. BAC estimates for mining noise are <br /> lower primarily because the mining source noise level assumed by BAC is 80 — <br /> dBA at 50 feet versus 89 dBA at 50 feet assumed by Jones & Stokes. <br /> The modeling results in Tables 3.J-7 through 3.J-9 above indicate that the — <br /> combined noise levels from mining and processing are predicted to exceed the <br /> daytime and nighttime standards of 60 dBA and 57 dBA at residences north of <br /> SR 132 and the daytime and nighttime standards of 50 dBA and 45 dBA at other — <br /> residences in the area located away from SR 132. This impact is therefore <br /> considered to be significant. <br /> The following mitigation measure that includes noise control features identified <br /> in the BAC report(Appendix N)would reduce this impact to a less-than- <br /> significant level by limiting when certain activities can occur and implementing <br /> physical measures to reduce noise. <br /> DeSilva Gates Quarry Project —' <br /> Draft Environmental Impact Report 3.J-14 <br /> Jas 0510&05 <br />