11 ATTACHMENT 04 - Laserfiche WebLink

- 17 _ The noise exposures at measurement Location 3. 75 fl. from the centerline of the UPRRJACE rail tracks were calculated to he 70. 73 and 74 dB DNL on days 1. 2 and 3. In the most impacted rear yards along the rail line. 57 ft. from the tracks, the noise exposures were calculated to be 72, 75 and 76 d13 DNL on days 1. 2 and 3. respectively. Thus. the noise exposures are up to 6 dB in excess of the 70 dB DNL railroad noise standard of the City of Pleasanton Noise Element. B. Interior Noise Exposures and Noise Levels Noise Exposures To determine the interior noise exposures. a 15 dB reduction was applied to the exterior noise exposures at the minimum building setbacks to represent the attenuation provided by a typical building shell under cn nua!-ureruge conditions. The annual- overage condition assumes that residential dwellings have single-pane windows of single- strength glass that are kept open 50% of the time for natural ventilation. The interior noise exposures in living spaces of homes closest to Stanley Boulevard will be 47 and 50 dB DNL under existing and future traffic conditions. respectively. Thus. the interior noise exposures will exceed the City of Pleasanton standard of 45 dB DNL by up to 5 dB. The interior noise exposures in the most impacted living spaces of homes closest to the railroad tracks will be up to 61 dB DNI.. Thus, the noise exposures will be up to 16 dB in excess of the 45 dB DNL standard of the City of Pleasanton Noise Element. Noise Levels To determine the interior L,ra, noise levels. a 10 dB reduction was applied to the exterior L,,,x values at the minimum building setbacks to represent the attenuation provided by a typical building shell under an open it ndow condition. The open window condition assumes that residential dwellings have single-pane windows of single-strength glass that are open during train passbys.