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0� OCTA I Santa Ana/Garden Grove Fixed Guideway Project <br />Noise and Vibration Technical Analysis Re-evaluation in Support of Minor Design Modifications <br />situation. Consistent with 49 CFR Part 222, the local jurisdiction - City of Santa Ana - will be <br />responsible for completing the quiet zone creation process in accordance with FRA's Train Horn <br />Final Rule. Table H lists the train noise levels after the horn sounding exemption measure has <br />been implemented. As shown, receivers R10 and R13 are reduced to a moderate impact after <br />the implementation of the proposed mitigation measure. This measure was previously identified <br />in the 2015 EA/EIR, and this analysis demonstrates that the proposed minor modification does <br />not change the previously -adopted mitigation measure. <br />Table H: Modified Project — After Horn Sounding Exemption Mitigation' <br />NSA <br />Rec. <br />Land <br />Use <br />Cat. <br />Existing <br />Noise Level <br />(d BA) <br />Predicted Project Only Noise Level <br />Ldn or Lday (d BA) <br />Impact <br />Overall <br />Streetcar Warning Project <br />Ops Horn Crossing O&M Noise <br />3 <br />R7 <br />2 <br />50 <br />64 N/A N/A N/A 64 <br />Severe Impact <br />6 <br />R10 <br />2 <br />53 <br />58 0 51 N/A 59 <br />Moderate Impact <br />7 <br />R12 <br />2 <br />50 <br />59 0 49 N/A 60 <br />Severe Impact <br />8 <br />R13 <br />2 <br />55 <br />58 0 44 N/A 58 <br />Moderate Impact <br />10 <br />R14 <br />2 <br />58 <br />55 N/A N/A 63 64 <br />Severe Impact <br />Source: URS (February 2012) and HDR (June 2016). <br />1. Horn Sounding Exemption Mitigation previously adopted as part of the 2015 EA/EIR. No changes to this <br />measure are required as part of the minor project modification. <br />Summary of Noise Impacts with Noise Attenuation Measures and Implementation of <br />Previously -Adopted Mitigation (2015 EA/EIR) <br />Table I lists the combined noise levels after implementing all of the mitigation measures <br />discussed above. As shown, all severely impacted receivers are reduced to moderate or no <br />impact after the implementation of proposed mitigation. Eliminating the horn sounding at <br />receptors R10 and R13 would reduce the noise impact from severe to moderate. Therefore, no <br />barriers are recommended at those locations. <br />Table I: Summary of Noise Impacts for Modified Project — With Noise Attenuation <br />Measures and Previously -Adopted Mitigation (2015 EA/EIR) <br />NSA <br />Rec. <br />Land <br />Use <br />Cat. <br />Existing <br />Noise Level <br />(d BA) <br />Predicted Project Only Noise Level <br />Ldn or Lday (d BA) <br />Impact <br />Streetcar Warning <br />Ops Horn Crossing O&M <br />Overall <br />Project <br />Noise <br />3 <br />R7 <br />2 <br />50 <br />59 <br />N/A N/A N/A <br />59 <br />Moderate Impact <br />6 <br />R10 <br />2 <br />53 <br />58 <br />0 51 N/A <br />59 <br />Moderate Impact <br />7 <br />R12 <br />2 <br />50 <br />54 <br />0 49 N/A <br />55 <br />Moderate Impact <br />8 <br />R13 <br />2 <br />55 <br />58 <br />0 44 N/A <br />58 <br />Moderate Impact <br />10 <br />R14 <br />2 <br />58 <br />53 <br />N/A N/A 59 <br />60 <br />Moderate Impact <br />Source: URS (February 2012) and HDR (June 2016). <br />V%] <br />