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Grand Avenue Widening Project Environmental Impact Report Section 3.0 <br />TABLE 3.6-8 <br />NOISE LEVELS AT 50 FEET FROM ROAD CENTERLINE <br />AND CHANGES IN NOISE LEVELS IN THE FUTURE <br />Road Segment <br />Noise Levels at 50 Feet From the Road Centerline in dB CNEL <br />Exist ng <br />2020 Under <br />2020 Under <br />Change Due <br />Change Due <br />the No <br />the With <br />to Growth <br />to the Project <br />Project <br />Project <br />Alternative <br />Scenario <br />On Grand Avenue From <br />69.5 <br />70.3 <br />70.3 <br />0.8 <br />0.0 <br />Seventeenth Street to <br />Santa Ana Boulevard. <br />Santa Ana Boulevard to <br />70.4 <br />71.2 <br />71.2 <br />0.8 <br />0.0 <br />Fourth Street <br />Fourth Street to First <br />70.2 <br />71.0 <br />71.0 <br />0.8 <br />0.0 <br />Street <br />I-5 at Grand Avenue <br />84.6 <br />1 86.5 <br />865-1 <br />1.9 <br />0.0 <br />Source: BridgeNet Consulting Services (2001). <br />Traffic on I-5 is also expected to increase in the future due to normal growth. However, there is <br />no expected change in projected traffic volumes on I-5 as a result of the proposed Grand Avenue <br />widening itself. There are existing noise barriers along this segment of I-5 and, therefore, the <br />projected noise from I-5 is assumed to be mitigated by these noise walls. <br />The results in Table 3.6-8 also show that there will be no change in noise levels as a result of the <br />widening alternative along the entire project segment of Grand Avenue. The 2020 with project <br />noise levels will be the same as under the No Project Alternative, as shown on Table 3.6-8. <br />As discussed in detail elsewhere in this EIR, the widening of Grand Avenue under Alternative 1 <br />will require the acquisition of some properties directly adjacent to Grand Avenue. The acquisition <br />of residential units will remove the first row of structures adjacent to Grand Avenue between <br />Seventeenth Street and Northbound I-5 off -ramp at Grand Avenue, thereby exposing the second <br />row of residences to increased noise levels associated with traffic on Grand Avenue. The second <br />row of residences is currently largely screened from traffic noise by the structures, fences and walls <br />associated with the first row of residences. The removal of the first row of residences homes will <br />result in an increase of approximately three to five dBA in noise to the second row of dwellings <br />next to Grand Avenue. In some cases, the 2020 with project traffic noise level at the second row <br />of homes will exceed the City of Santa Ana exterior noise standard, and rear and side yards of <br />these unit will require mitigation. Other properties proposed to be acquired by the City include <br />the first row of single family residences adjacent to Grand Avenue between Santa Ana Boulevard <br />and First Street. The removal of the first row of residences in this area will result in an increase <br />of approximately seven to 10 dBA in noise at the second row of residences on this segment of <br />Grand Avenue. The removal of the first row of homes will result in a significant increase in <br />noise to the existing second row of homes located nearest to Grand Avenue. <br />The exterior noise standard for the City of Santa Ana is 65 dB CNEL. Therefore, noise sensitive <br />land uses subject to traffic noise levels in excess of 65 dB CNEL as a result of the widening of <br />F.•IPROJ-EWGrand eirlNew Text - GrandlSection 3 SplitlSection 3.6.doc Page 3.6-36 <br />