11 ATTACHMENT 04 - Laserfiche WebLink

I. Summary of the Findings The noise exposures presented herein 1\'ere evaluated against the noise standards of the City of Pleasanton Noise Element. which utilizes the Day-Night Level (DNL) 24- hour descriptor to define acceptable noise levels for various land uses. The standards specify a limit of 60 dB DNL for multi-family residential exterior areas and 45 dB DNI, for residential interior living spaces. Him ever. when the noise source is a railroad, the exterior noise exposure standard is 70 dB DNL as the noise environment is characterized by few loud events rather than a relatively constant source such as vehicular traffic. Because of the less restrictive exterior noise levels, short-term interior noise limits are applied to bedrooms and other living spaces. The limit for bedrooms is 50 dBA maximum (L,,,,,) while the limit for other living spaces is 55 dBA Ln,,,. Because the noise levels from the train horns would preclude development along the railroad tracks. the City of Pleasanton Planning Department is allowing disregarding of the train horns' noise levels and the City is allowing the use of the maximum noise level from the train (engine) itself. The vibration levels shown in the findings are expressed in units of dB re: 1 x I04' in/sec (peak velocity). The human response to vibration can vary within wide limits, as it depends on the position and inherent motion of the person perceiving the vibration, as well as the physical and psychological makeup of the particular person. The City of Pleasanton does not currently have any quantifiable standards for vibration in residential areas. The vibration analysis presented in this report uses the criteria established by the Federal Transit Administration (FTA). For residences near rail lines that carry fewer 70 trains per day, which is considered infrequent, the FTA recommends a limit of 80 decibels of vibration (VdB) inside the dwelling. The ETA guidelines provide adjustment methodologies to vacant site vibration levels to determine the approximate vibration levels in various floor elevations of residential structures. The noise and vibration levels shown below are without the application of mitigation measures. and represent the noise and vibration environment for the existing site conditions.