RES 06035 - Laserfiche WebLink

Draft Environmental Impact Report Bernal Property Phase II Specific Plan EI R center of the roadway, which would exceed those recommended (open space and wetlands) and considered "normally compatible" (agriculture) with the proposed land uses. These land uses would be considered "normally acceptable" at distances farther than 500 feet from the center of the freeway. Multi-story commercial uses are planned as part of Phase I for the large parcel between 1- 680 and the existing residences to the east of Valley Avenue. With the development of these structures, noise levels generated by freeway traffic would be mitigated at noise sensitive uses east of Valley Avenue (potential child-care facility in sub-area 5). 1-680 Western Exposure. Substantial acoustical shielding from 1-680 traffic noise is provided to areas west of 1-680. North of the Laguna Creek Lane/ UPRR Overpass, noise levels are 60 dBA Ldn or less at distances of about 220 feet or farther from the centerline of the roadway (about 100 feet from the edge of the berm) and noise levels do not exceed 65 dBA Ldn, even in areas directly adjacent to the berm. Open space uses (sub-area 11) proposed on the western side of the freeway and shielded by the berm would be exposed to traffic noise levels of less than 70 dBA Ldn and would be considered acceptable. Adjacent to the overpass, where 1-680 is elevated (sub-area 16), ambient traffic noise levels are higher because acoustical shielding is not provided in this area. Similarly to the eastern exposure, without additional noise reduction measures, agricultural land uses proposed for sub-area 16 would exceed 70 dBA Ldn and would be considered "conditionally compatible" within 500 feet of the center of the freeway. At distances farther than 500 feet from the center of 1-680, this land use would be considered "normally acceptable". Union Pacific Railroad. Potential land uses to be located along the UPRR (sub-areas 2, 7, 8, 9,10, 16; an elementary school has already been built in sub-area 8) include agricultural uses, open space areas, trails, and a pre-treatment marsh. Based on measurements made along the tracks, railroad operations are calculated to generate noise levels of about 63 to 69 dBA Ldn at a distance of 50 feet from the tracks, depending on the number of train passbys occurring over the course of the 24-hour period. Assuming a typical Ldn noise level of about 66 dBA Ldn at 50 feet from the tracks, noise levels would be about 65 dBA Ldn at approximately 60 feet from the tracks and about 60 dBA Ldn at approximately 120 feet from the tracks. Noise sensitive outdoor uses at Hearst Elementary School (sub-area 8) would be considered "normally acceptable" at a setback of 120 feet or greater from the tracks, trails and outdoor recreational facilities such as tennis courts (sub-area 2) would be considered "normally acceptable" at a setback of 60 feet, and agricultural, open space, and industrial land uses (sub-areas 7, 9, 10, and 16) would be compatible at setback of 30 feet. Bernal Avenue. Future traffic noise levels generated along Bernal Avenue were modeled based on traffic volumes supplied by Dowling Associates, Inc. West of 1-680 (sub-areas 12 and 13), noise levels would be 70 dBA Ldn at a distance of about 60 feet from the centerline of the roadway and would be 60 dBA Ldn at a distance of about 250 feet from the centerline of the roadway. The potential Environmental Education Center would be considered 106