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Impact 4.J-10 Development facilitated by the General Plan Amendment and rezonings could potentially locate residential uses or mixed-use buildings near an existing highway, arterial, or collector roadway, exposing future residents to excessive exterior and interior traffic noise exposure. The SEIR evaluates the impact of the proposed project related to the exposure of residents to excessive exterior and interior noise resulting from locating potential residential or mixed-use buildings near existing highways, arterials, or collector roadways. Significance Before Mitigation: Significant Significance After Mitigation: Less than Significant Finding: Changes or alterations have been required in or incorporated into the Project that would avoid or substantially lessen the significant environmental effect as identified in the SEIR. Mitigation Measures 4.J-5b and 4.J-5c which are required in or incorporated into the Project, will reduce the significant environmental impact to a less than significant level. Facts in Support of Finding: The following facts and mitigation measures indicate that the impact will be reduced to less than significant. 1. Noise exposure at the closest project housing sites to Interstates 580 and 680 (i.e., Sites 1, 2, and 7) is expected to be as-high-as 85 dB Ldn given future increases in traffic volumes (without significant decreases in speed) and elevated receiver locations (e.g., upper-floor building facades). Future traffic noise exposure at project sites along Owens, West Las Positas, First, Stanley, Bernal, and Sunol may be as-high-as 61-67 dB Ldn (setback of 100 feet from center of roadway). Upper-floor building facades at these sites could experience traffic noise as-high-as 71 dB Ldn (4 dB above that at the ground-floor) at these locations. This exterior noise exposure would be expected to exceed the City's 65 dB Ldn exterior noise exposure limit for multi-family residential uses. 2. Implementation of Mitigation Measures 4.J-5b and 4.J-5c, listed above under Impact 4.J-5, set forth in Table 6-1 of the Final SEIR and listed in the MMRP will ensure that Impact 4.J-10 would be reduced to a less than significant level and are hereby incorporated by reference and described below. 4.J-5b: Any residential or office buildings shall be built to California's interior- noise insulation standard so that interior traffic noise exposure does not exceed 45 dB Ldn. Before building permits are issued, the project applicant shall be required to submit an acoustical analysis demonstrating that the buildings have been designed to limit interior traffic noise exposure to a level of 45 dB Ldn/CNEL or less. 4.J-5c: Any locations of outdoor activity for sensitive uses associated with the project site shall be designed so that the noise exposure from traffic does not