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Acoustics Audiovisual Telecommunications Security 130 Sutter Street 536 St. John Street Residences Environmental Noise and Vibration Study 1 July 2016 Page 2 of 50 dB in bedrooms at night and 55 dB in other rooms and bedrooms during the day. We have used the more stringent criterion for this analysis (e.g., Lmax30)• The City considers outdoor noise levels in residential locations below DNL 60 dB to be "normally acceptable ". Noise levels between DNL 60 dB and 75 dB are considered "conditionally acceptable" and noise levels above DNL 75 dB are considered "normally unacceptable ". These standards do not apply to private backyards. Ground -Borne Vibration Due to Rail Although not a City guideline, the Federal Transit Administration (FTA)4 lists ground -bome vibration (GBV) criteria according to several use categories and various frequencies of events. Table 1, below, includes the FTA general assessment criteria for ground -borne vibration. Table 1: FTA Criteria Land Use Category Category 2: Residences and buildings where people normally sleep GBV Impact Levels (VdB re 1 ii-in /sec) Frequent Events Occasional Events Infrequent Events 72 VdB 75 VdB 80 VdB "Frequent" events are defined as more than 70 vibration events of the same source per day. "Occasional" events are defined as between 30 and 70 vibration events of the same source per day and "Infrequent" events are fewer than 30 vibration events of the same source per day. The Altamont Corridor Express (ACE) has 8 trains per day that pass the site. While freight trains also pass by the site, they are unscheduled and irregular, but we would not expect there to be enough passbys to exceed 30 vibration events in total for the day. Based on the frequency of these events, the criteria of 80 VdB is applicable at the residences. NOISE ENVIRONMENT The project site is located in the City of Pleasanton and is bounded by St. John Street, Union Pacific Rail Road Tracks, and Peters Avenue. The major noise sources affecting the project site are vehicular traffic along St. John Street, Peters Avenue, and trains. The train tracks are approximately 180 feet away from the project site, which results in more noise exposure at the site from this noise source. It is likely that there will be higher noise levels at upper floors due to the trains. To quantify the existing noise environment at the project site, we conducted continuous noise measurements between 14 and 18 June 2016. We placed two long -term noise monitors (LT -1 and LT -2) at locations around the site. The monitors were at a height of approximately 12 -feet F oor 5 Son Fronc co CA 94 104 r Federal Transit Administration, "Transit Noise and Vibration Impact Assessment ", May 2006. T 415 3970442 F 415 3970454 �• �.�•: c mxr lei corn Charles ,AA Salter ASSOCI'TUS It1C