2017-046 - Approving Addendum Nos. 1 and 2

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Santa Ana/Garden Grove Fixed Guideway Project Addendum Project alignment, such that no new significant impacts and no increase in the severity of an impact would result as compared to the originally approved Project and as evaluated in the EIR. The proposed modifications that have been determined to have the potential to affect noise and vibration levels and were studied in detail in the Supplemental Noise and Vibration Analysis (Appendix D) include physical improvements and operational modifications. Physical Improvements: Alignment Shift. Repositioning the double track alignment within the PE ROW is proposed. This modification would shift the railroad centerline within the PE ROW to the north. Changes to Special Trackwork. Placement of single crossovers on both sides of the maintenance and storage facility (MSF), changed layout for MSF, added crossovers on both sides of downtown couplet, and replacement of the tail track beyond the SAR Transit Center (SARTC) platform with a double -crossover before the SARTC platform is proposed. Operational Modifications: • Increase in Speed. Increasing the maximum speed within the PE ROW from 35 miles per hour (mph) to 45 mph, and • Traffic Signal Priority. Implementation of traffic signal priority at all traffic signals along the route except for Main Street, Broadway, and Bristol Street is proposed. Noise Analysis of Increased Speed and Alignment Shift As described in Appendix D, the impacts associated with the increase in speed combined with the alignment shift are the same as those for the original Project with the exception of at receivers R1 (located within NSA 1), R4 (located within NSA 2), R7 (located within NSA 3), and R8 (located within NSA 4). With the proposed modifications, receivers R1 and R4 would be exposed to moderate noise impacts. At receiver R7 the noise level would worsen from a moderate impact to a severe impact without mitigation as compared to the original Project. At receiver R8 the noise level improved, as it would be reduced from a severe impact under the original Project, to a moderate impact under the currently modified Project. The February 2012 noise and vibration technical report provided as an appendix to the EIR, recommended the following measures to reduce the severe impacts: 1) wayside noise barriers, 2) horn sounding exemption at grade crossings, and, 3) special trackwork devices. The currently proposed Project plans call for the use of flange bearing frogs at all crossovers. Therefore, no further measures are required for the special trackwork. The 2012 noise analysis evaluation provided in the EIR identified the need for noise barriers for receptor locations R10, R12, R13, and R14. Due to the change in train speed, elevation, and the shift in centerline an additional wayside noise barrier would be required to reduce the noise level in the vicinity of receptor R7 (located in NSA 3). Noise levels at receivers R7 and R14 would be reduced to moderate after the implementation of the proposed design feature, which is consistent with the previously -adopted Mitigation Measure N-3. If a horn sounding exemption is established and approved at each crossing, the required use of warning horns would be exempted and horns would not be sounded except in an emergency situation. Based on the supplemental noise and vibration analysis, noise levels at receivers R10 and R13 would be reduced to a moderate impact after the implementation of the proposed mitigation measure. This measure was previously identified in the EIR, and the supplemental analysis demonstrates that the proposed modification does not change the previously -adopted mitigation measure. 111P age 1170726.1