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Grand Avenue Widening Project Environmental lmpact Report Section 3.0 Grand Avenue under Alternative 1 will require noise mitigation. As noted above, this includes residences in the second row of residences from Grand Avenue which are within the 65 dB CNEL contour for the 2020 with project scenario. The distances to the 65 dB CNEL noise contour for the 2020 with project scenario under Alternatives 1 and 2 are shown in Figures 3.6-9 and 3.6-10 and as summarized in Table 3.6-7. Noise sensitive land uses within these distances of the centerline of Grand Avenue will require mitigation. As described in the following section, a noise barrier will be necessary to mitigate the noise impacts in the rear and side yards of residences to reduce traffic related noise levels to below the City's exterior noise standard of 65 dB CNEL. Mitigation described later in this Section would substantially mitigate this potentially significant adverse impact under Alternative 1, to below a level of significance. Impacts of Alternative 2 Related to Noise Short Term Construction Impacts Under Alternative 2 Alternative 2 will result in demolition and construction equipment and activities similar to Alternative 1. Therefore, the short term noise impacts under Alternative 2 will be similar to the impacts under Alternative 1. Mitigation measure N-1, provided later in this Section, will substantially reduce short term noise impacts under Alternative 2, but not always to below a level of significance. Long Term Noise Impacts Under .Alternative 2 The potential long term traffic related noise impacts associated with the proposed widening of Grand Avenue under Alternative 2 would be similar to the impacts under Alternative 1. Both Alternatives assume the same traffic volumes, so the 2020 noise contours would be the same, as shown earlier in Tables 3.6-6, 3.6-7 and 3.6-8. In addition, the 2020 noise levels for Alternative 2 would be the same as the noise levels under the No Project Alternative. However, the wider right- of-way for Alternative 2 would result in the acquisition of more residential units, thereby potentially exposing more second row residences to adverse noise levels which exceed the City of Santa Ana exterior noise standard. 3.6.5 MITIGATION RELATED TO NOISE Mitigation Measure for Short Term Noise Impacts N-1 The project specifications shall require project contractors to implement the following during all site preparation, grading and construction: • All site preparation, grading and construction activities shall be limited to between the hours of 7 AM and 7 PM Mondays through Fridays, and between 8 AM and 6 PM on Saturdays. No site preparation, grading or construction shall be allowed on Sundays or federal holidays. F.IPROJ-ENMGrand eirWew Text- Gran&Section 3 SohASection 3.6.doc Page 3.6-37