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City of Pleasanton 475 and 493 St. John Street Mixed-Use Project 52 Groundborne Vibration Operation of the project would not include substantial vibration sources. Thus, construction activities would have the greatest potential to generate ground-borne vibration affecting nearby receivers, especially during grading and paving of the project site. The greatest vibratory source during construction would be a vibratory roller. Neither blasting nor pile driving would be required for construction of the proposed project. Table 9 shows typical vibration levels for various pieces of construction equipment used in the assessment of construction vibration (FTA 2018). Table 9 Typical Vibration Levels for Construction Equipment Equipment PPV (in/sec) at 25 Feet Vibration Damage (VdB) at 25 Feet Single family Residence at 493 St. John Street 65 feet Multi-family residential to the west 110 feet Commercial to the east 110 feet PPV VdB PPV VdB PPV VdB PPV VdB Vibratory Roller 0.21 94 0.050 75 0.023 82 0.023 75 Large Bulldozer 0.089 87 0.021 68 0.010 75 0.010 68 Loaded Trucks 0.076 86 0.018 67 0.008 74 0.008 67 Small Bulldozer 0.003 58 0.001 39 0.000 46 0.000 39 Sources: FTA 2018 Project construction may require operation of vibratory equipment such as a vibratory roller within approximately 65 feet of the existing on-site residential building to the southwest of the project site along St. John Street from the center of construction activity. A vibratory roller would create approximately 0.210 in/sec PPV and 94 VdB at 25 feet (FTA 2018). This would equal a vibration level of 0.050 in/sec PPV and 82 VdB at a distance of 65 feet. This would be lower than the non- engineered timber and masonry building threshold of 0.2 in/sec PPV and 94 VdB. Therefore, temporary vibration impacts associated with the vibratory roller (and other potential equipment) would be less than significant. The project would not generate significant stationary sources of vibration, such as manufacturing or heavy equipment operations. No operational vibration impact would occur. Operational Noise MECHANICAL EQUIPMENT The primary on-site operational noise source from the project would be HVAC units for the residential and commercial buildings. There would be three HVAC units on each of the proposed commercial buildings within the project site. Specific planning data for the future HVAC systems are not available at this stage of project design; however, this analysis assumes the use of a typical HVAC system for commercial uses, which has a sound power level of 85 dBA that is equivalent to a sound pressure level (SPL) of 77 dBA at 3 feet. The unit used in this analysis is a 16.7-ton Carrier 38AUD25 split system condenser (see Appendix F for manufacturer’s specifications). The project would contain three HVAC units located in a rooftop mechanical area on each commercial building, which has a combined noise level of 82 dBA. In addition, each residential unit is assumed to have one ground-mounted HVAC unit on each of the proposed residential buildings. For purposes of this analysis, a typical HVAC system for residential uses (2.5-ton Carrier 24ABA4030) was analyzed, which has a sound power level of 73 dBA that is