RES 211231 Exhibit A - Laserfiche WebLink

Environmental Checklist and City of Pleasanton–10x Genomics Project Environmental Evaluation Initial Study/Mitigated Negative Declaration 94 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 a) Violate any water quality standards or waste discharge requirements or otherwise substantially degrade surface or groundwater quality? Less than significant impact. A significant impact may occur if a project discharges water that does not meet the quality standards of agencies that regulate surface water quality and water discharges into stormwater drainage systems. Water quality within the City of Pleasanton is regulated by the San Francisco Bay RWQCB. The proposed project would include ground-disturbing activities such as grading and excavation during project construction. These activities have the potential to result in erosion, sedimentation, and runoff, which could adversely affect water quality during construction. Improperly managed construction activities can lead to substantially accelerated rates of erosion that are considered detrimental to the environment. The NPDES Program was established through the federal Clean Water Act to control and reduce pollutant discharges to surface water bodies. Construction activities, including grading, that would result in the disturbance of 1 acre or more would require compliance with the General Permit for Storm Water Discharges Associated with Construction and Land Disturbance Activity (Construction General Permit). The proposed project is 14.75 acres and would therefore be required to comply with the Construction General Permit. The California State Water Resources Control Board (State Water Board) adopted a requirement for obtaining an NPDES Construction General Permit. To obtain coverage under the Construction General Permit, a project Applicant must submit a Notice of Intent and a SWPPP. Activities subject to the Construction General Permit include clearing, grading, and ground disturbance. The purpose of the SWPPP is to identify the sources of sediment and other pollutants that could affect the quality of stormwater discharges and to describe and implement BMPs to reduce or eliminate sediment and other pollutants in stormwater and non-stormwater discharges resulting from construction activities. As mentioned in Section 2.7, Geology and Soils, the proposed project would comply with the NPDES Program and would obtain coverage under the Construction General Permit and implement a SWPPP and BMPs to control and reduce pollutant discharges to surface water bodies. Additionally, the proposed project would be subject to the RWQCB’s Municipal Regional Permit (MRP), implemented in October 2009 by Order R2-2009-0074, and updated in November 2015 by Order R2-2015-0049. Because the proposed project would include new impervious surfaces greater than 10,000 square feet, the proposed project would be a C.3 Regulated Project. Under the C.3 requirements, the proposed project would be required to prepare and submit a Stormwater Control Plan (SCP) that discusses the design elements and implementation measures necessary to meet the post- construction stormwater control requirements of the MRP. Under the C.3 Permit, the proposed project would include appropriate site design measures and source controls and hydraulically sized stormwater treatment measures, as well as Low Impact Development (LID) measures. Site design measures would include directing runoff onto vegetated areas and maximizing permeability through site design. Source control measures would include signage for inlets, drainage plumbed to storm water treatment facilities, efficient irrigation, minimization of pesticides and fertilizers, and covered trash enclosures. Construction BMPs would include measures such as