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Facts in Support of Findings: Construction of the Project would generate short-term periodic increases in ambient noise levels at sensitive receptors in the Project vicinity. With implementation of Mitigation Measure NOI-2, noise from operation of large mobile construction equipment (greater than 80,000 pounds) and loaded trucks would be reduced; and Mitigation Measure NOI-3 is included to require installation of a temporary noise barrier that would be a minimum 11-feet high, constructed of frame - mounted materials such as vinyl acoustic curtains or quilted blankets, and attached to the masonry wall along the eastern Project site boundary or temporary fence posts. In addition, due to the location of existing sensitive receptors, Mitigation Measures NOI-2 and NOI-3 would require a 50-foot setback for use of large mobile construction equipment and require installation of a temporary noise barrier, which would reduce the temporary and intermittent increase in noise from construction to a less than significant level. With implementation of Mitigation Measures NOI-2 and NOI-3 temporary and periodic construction noise level increases at receiver locations would be reduced to below the 10 dBA Leq temporary noise level increase threshold. Therefore, with implementation of mitigation, impacts related to periodic temporary increases in noise would be less than significant. To ensure that the Project's potential impacts relating to temporary increases in ambient noise levels are mitigated to a less than significant level, in addition to Mitigation Measure NOI-2, discussed above, the following mitigation measure has been identified: Mitigation Measure N0I-3: The Project plans and specifications shall include the requirement to install a minimum I I -foot high temporary construction noise barrier along the Project site eastern boundary for the duration of Project construction. The noise control barriers shall have a solid face from top to bottom and shall meet the following height and constructed requirements: • The temporary noise barrier shall provide a minimum transmission loss of 20 dBA (Federal Highway Administration, Noise Barrier Design Handbook). The noise barrier shall be constructed using an acoustical blanket (e.g. vinyl acoustic curtains or quilted blankets) attached to the construction site perimeter fence or temporary fence posts. • The noise barrier shall be maintained, and any damage promptly repaired. Gaps, holes, or weaknesses in the barrier or openings between the barrier and the ground shall be promptly repaired; • The noise control barrier and associated elements shall be completely removed, and the site appropriately restored upon the conclusion of the construction activity. With the implementation of the mitigation measures identified above (MM-NOI-2 and MM-NOI-3), the Project's potential impacts relating to temporary increases in ambient noise levels would be less than significant. (DEIR, pp. 4.8-16 through 4.8-17.) The Modified Project would involve the same types of construction equipment that would be operated in similar locations as the Original Project. However, the building setback along the eastern side of the project site would be 50 feet greater. Thus, construction of building structures would be farther from the residences located to the east of the Project site. However, consistent with the Original Project, Mitigation Measures NOI-2 and NOI-3 would be required to prohibit the use of large mobile equipment and loaded trucks within 50 feet of the residences to the east of the Project site and install a temporary noise barrier to reduce the temporary increase in ambient noise to a less than significant level. No new or greater impacts Resolution No. Page 20 of 76 Certification of the Magnolia at the Park EIR