2017-046 - Approving Addendum Nos. 1 and 2

Home Browse Search

Santa Ana/Garden Grove Fixed Guideway Project Addendum #2 increases in delay at other locations. However, in no instance would the minor increase in delay result in a new significant impact, or increase in the seventy of an impact. All intersections would continue to operate at an acceptable LOS. Table 3-8 summarizes the delay and corresponding LOS for 2035 Streetcar Conditions, with and without the transit signal priority adjustments, and using Intersection Capacity Utilization (ICU) Methodology. As shown in Table 3-8, the application of Traffic Signal Priority to all of the affected intersections would not result in any deterioration of LOS from acceptable to unacceptable. Based on this supplemental traffic impact analysis of 60% design modifications, no new significant traffic impacts and no increase in the seventy of an impact would result as compared to the originally approved Project as evaluated in the EIR. No additional traffic impacts would occur and the conclusion that the Project would result in a less than significant traffic impact as identified in the EIR remains accurate. Noise and Vibration A Noise and Vibration Technical Addendum was prepared to address the potential noise and vibration impacts associated with the proposed design modifications (see Appendix D). Decrease in Speed Reducing the maximum speed within the PE ROW from 45 mph to 44 mph would have no effect on the streetcar vibration levels. Centerline Re -Alignment (Alignment Shift) The proposed modification at 60% design would shift the railroad alignment within the PE ROW. Table K lists the vibration levels calculated by HDR (June 2016) for the 30% design. Only the receptors included within the affected area (PE ROW) are listed. Table L of the supplement analysis (see Appendix D) lists the distances from the modeled receivers to the 30% design alignment and the distances to the currently proposed 60% design alignment. Table L (see Appendix D) also lists the streetcar operation vibration levels associated with the 30% and 60% design streetcar alignments. The impact threshold for Land Use Category 2 is 72 VdB and for Land Use Category 3 is 75 VdB. As shown in Table L of Appendix D, the vibration levels are belowthe impactthreshold at all receptor locations. Therefore, no minimization design features are required. Traction Power Substation Noise Analysis The 60% design plans move TPSS unit 4 to the Santa Ana Regional Transportation Center (SARTC) on the north side of the parking structure adjacent to Santiago Street. At this location the TPSS unit would be located within 100 feet of the main SARTC structure and 350 feet from the nearest residences. Table M (see Appendix D) shows the predicted noise level at the TPSS sites assuming the units are specified to have a maximum sound level of 50 dBA at a distance of 50 feet from any surface. As shown, by orienting the TPSS units so that the noise from the HVAC units is directed away from the sensitive uses, the noise levels at all receptors closest to the TPSS units would result in no impacts. Air Quality The potential air quality and greenhouse gas emissions (global climate change) impacts associated with both the construction and operation of the proposed Project were evaluated in the EIR. There have been no changes to the air quality environment as evaluated in the EIR. The proposed minor design modifications would change some of proposed improvements within the corridor, however, the general Project construction characteristics as described in the EIR would not be altered in such a manner as to result in an increase in the daily construction emissions, and no new mitigation measures would be required. 101 Page 1170726.1