RES 211231 Exhibit A - Laserfiche WebLink

Environmental Checklist and City of Pleasanton–10x Genomics Project Environmental Evaluation Initial Study/Mitigated Negative Declaration 38 FirstCarbon Solutions Https://adecinnovations.sharepoint.com/sites/PublicationsSite/Shared Documents/Publications/Client (PN-JN)/2148/21480024/ISMND/wp/21480024 10x Genomics Project Full Screencheck ISMND.docx Operational Carbon Monoxide Hotspot The CO emissions from traffic generated by the proposed project are a concern at the local level. Congested intersections can result in high, localized concentrations of CO. The BAAQMD recommends a screening analysis to determine if a project has the potential to contribute to a CO hotspot. The screening criteria identify when site-specific CO dispersion modeling is necessary. The proposed project would result in a less than significant impact to air quality for local CO if the following screening criteria are met: 1. The project is consistent with an applicable congestion management program established by the county congestion management agency for designated roads or highways, regional transportation plan, and local congestion management agency plans; or 2. The project traffic would not increase traffic volumes at affected intersections to more than 44,000 vehicles per hour; or 3. The project traffic would not increase traffic volumes at affected intersections to more than 24,000 vehicles per hour where vertical and/or horizontal mixing is substantially limited (e.g., tunnel, parking garage, bridge underpass, natural or urban street canyon, below-grade roadway). As indicated by the traffic volume data provided by the City of Pleasanton,22 the proposed project at full buildout would generate an estimated 548 net new AM peak-hour vehicle trips and 400 net new PM peak-hour vehicle trips. As indicated in the Traffic Impact Analysis (TIA) prepared for the proposed project,23 the greatest AM peak-hour traffic volumes under existing plus project conditions would be experienced at the intersection of Hopyard Road and Stoneridge Drive and the greatest PM peak-hour traffic volumes under existing plus project conditions would be experienced at the intersection of the I-680 northbound offramp and Stoneridge Drive. As displayed therein, the AM peak-hour traffic volumes at the intersection of Hopyard Road and Stoneridge Drive would total an estimated 5,176 vehicles and PM peak-hour traffic volumes at the I-680 northbound offramp and Stoneridge Drive would total an estimated 6,585 vehicles. As illustrated in the TIA, the proposed project would not result in a nearby intersection exceeding 44,000 vehicles per hour. Nonetheless, CO hotspots can occur when a transportation facility’s design or orientation prevents the adequate dispersion of CO emissions from vehicles, resulting in the accumulation of local CO concentrations. The design or orientation of a transportation facility which may prevent the dispersion of CO emissions include tunnels, parking garages, bridge underpasses, natural or urban canyons, below-grade roadways, or other features where vertical or horizontal atmospheric mixing is substantially limited. Adjacent roadways that would receive new vehicle trips generated by the proposed project do not include roadway segments where vertical or horizontal atmospheric mixing is substantially limited. Therefore, based on the above criteria, the proposed project would not exceed the CO screening criteria and would have a less than significant impact related to CO. 22 City of Pleasanton. 2009. 2005 Pleasanton Plan 2025, 2. Land Use Element. Adopted July 21. Website: https://www.cityofpleasantonca.gov/civicax/filebank/blobdload.aspx?BlobID=23896. Accessed January 6, 2021. 23 Fehr and Peers. 2021. Draft Final Transportation Impact Analysis. March.