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City of Pleasanton–10x Genomics Project Environmental Checklist and <br />Initial Study/Mitigated Negative Declaration Environmental Evaluation <br /> <br /> <br />FirstCarbon Solutions 111 <br />Https://adecinnovations.sharepoint.com/sites/PublicationsSite/Shared Documents/Publications/Client (PN-JN)/2148/21480024/ISMND/wp/21480024 10x Genomics Project Full Screencheck ISMND.docx <br />worst case noise levels of up to 53 dBA Lmax as measured at the nearest residential property line. All <br />operational noise level calculations are provided in Appendix H. <br />However, the closest sensitive receptor that would have a direct line of sight to the loading areas <br />would be the multi-family residential property at the southwest corner of the Springdale Avenue and <br />Stoneridge Drive intersection, approximately 630 feet from the nearest proposed loading area. At this <br />distance, reasonable worst-case loading and unloading activities could result in intermittent noise <br />levels ranging up to 58 dBA Lmax. Assuming reasonable worst-case conditions of truck loading and <br />unloading activities occurred throughout an entire hour period would result in an hourly average <br />noise level of 50 dBA Leq, as measured at the residential property line of this residential land use. <br />Therefore, noise from these activities would not exceed the City’s most restrictive noise performance <br />standard (the standard for nighttime hours) of 65 dBA Leq as measured at the property boundary of <br />the nearest residential land use that would have a direct line of sight to the nearest loading and <br />unloading area. <br />Combined Operational/Stationary Source Noise Impacts Summary <br />Table 19 provides a summary of the combined stationary source operational noise impacts. <br />Table 19: Stationary Operational Noise Impact Summary <br />Source <br />(Reference Noise Levels) <br />Reasonable Worst- <br />Case Operational <br />Noise Level as <br />Measured at the <br />Nearest Residential <br />Property Line <br />Combined <br />Noise Levels as <br />Measured at <br />the Nearest <br />Residential <br />Property Line <br />City’s <br />Nighttime <br />Noise <br />Performance <br />Threshold <br />Exceed <br />Threshold? <br />(Yes/No) <br />Parking Lot Activities <br />(60 dBA to 70 dBA Lmax at 50 feet) 43 dBA Leq <br />51 dBA Leq 65 dBA Leq No Mechanical Ventilation Equipment <br />(60 dBA Leq at a distance of 25 feet) 41 dBA Leq <br />Truck Loading and Unloading Activities <br />(70 dBA to 80 dBA Lmax as measured at 50 feet) 50 dBA Leq <br />Notes: <br />dBA = A-weighted decibel <br />Lmax = maximum sound level <br />Leq = equivalent continuous sound level <br />Source: FCS 2021. <br /> <br />As shown in the table above, the combined noise levels from project stationary operational noise <br />sources would not result in an exceedance of the City’s most restrictive noise performance threshold <br />(nighttime threshold of 65 dBA Leq) as measured at the exterior of the nearest residential receptor. <br />Therefore, the project stationary operational noise sources would not generate a substantial <br />temporary or permanent increase in ambient noise levels in the vicinity of the project in excess of <br />standards established in the local general plan or noise ordinance; and the impact of stationary <br />operational noise sources to off-site sensitive receptors would be less than significant.