SU0004098 - Laserfiche WebLink

Home Browse Search

San Joaquin County Community Environmental Setting, Impacts,and Mitigation Measures _ Development Department Noise ■ Year 2027 with Project. The model includes the shielding effects of the berm proposed along the east side _ of the project site and the raised edges of the Delta-Mendota Canal. Thresholds of Significance Criteria for determining the significance of noise impacts under CEQA are based _ on the State CEQA Guidelines, local noise planning, and noise ordinance standards. Implementation of the proposed Project is considered to result in a significant noise impact if: ■ existing noise-sensitive land uses in the project area would be exposed to construction noise in excess of standards specified in the County of San Joaquin's noise ordinance, i.e., construction noise exceeding 50 dBA Leq(lh) between the hours of 9:00 p.m. and 10:00 p.m. or 45 dBA Leq(lh)between the hours of 10:00 p.m. and 7:00 am; ■ existing noise-sensitive land uses in the project area would be exposed to noise from stationary sources in excess of 50 dBA Leq (lh)between the hours of 7:00 a.m. and 10:00 pm,or 45 dBA Leq(1h)between the hours of 10:00 _ p.m. and 7:00 a.m.; or ■ existing noise-sensitive land uses in the project area would be exposed to future Project-related traffic noise levels in excess of the standards for — exterior noise exposure specified in the San Joaquin County General Plan noise element(i.e., 65 dB L&) and a perceptible Project-related increase in noise(i.e., greater than 3 dB above future no-Project conditions). — Note: The County noise ordinance also limits maximum (Lmax) sound levels. Given the nature of noise-generating activity on the project site,Lmax sound levels _ are not predicted to be more than about 5 dB greater than Leq values. Because the I. limits in the noise ordinance are 20 dB greater than the Leq limits,the Leq limits are more conservative than the Lmax limits and therefore govern the significance conclusions. Accordingly,the I.limits are not used in the — significance thresholds. As discussed above,high ambient noise levels (minimum values of 57 dBA — during daytime hours and 54 dBA during nighttime hours)occur at the area located north of SR 132. In accordance with County practice, the noise standard in this area is the ambient noise level plus 3 dB. Accordingly, the daytime and — nighttime significance thresholds for this area are modified to levels of 57 dBA Leq(lh)and 60 dBA Leq(lh)respectively. DeSilva Gates Quarry Project — Draft Environmental Impact Report U-8 As 05105.05