3_Exhibit C_ADDENDUM ONLY - Laserfiche WebLink

City of Pleasanton—Stoneridge Mall Residential Project CEQA Checklist Section 15183 Checklist/15164 Addendum 130 FirstCarbon Solutions Https://adecinnovations.sharepoint.com/sites/PublicationsSite/Shared Documents/Publications/Client (PN-JN)/2148/21480017/Consistency Checklist/21480017 Stoneridge Mall Residential Project Checklist Addendum_Updated.docx Prior EIR Conclusions The Prior EIR found that buildout of the Housing Element could affect drainage patterns and create increased stormwater flows that could exceed existing stormwater drainage system capacities and create new sources of polluted runoff. However, it was determined that compliance with the ACCWP NPDES Permit and implementation of the RWQCB Construction General Permit would require future development under the Housing Element to incorporate BMPs to control sedimentation, erosion, and hazardous materials contamination of runoff during construction. Furthermore, the C.3 provision of the ACCWP NPDES Permit requires that there be no net increase in stormwater rates and runoff at sites proposed for buildout under the Housing Element. These regulations would ensure that there would be no net increase in runoff at future individual development projects. In addition, it was determined that site plans, design, and BMPs would be reviewed and approved by the City and/or the San Francisco Bay RWQCB for compliance with applicable water quality regulations as project proponents apply for development permits and the applicable NPDES permits. Therefore, it was concluded that buildout of the Housing Element would have a less than significant impact. Analysis of Proposed Project As discussed above, the proposed project would be required to prepare a SWPPP incorporating BMPs to control contamination of runoff during project construction. This would minimize any impacts associated with additional sources of pollutants. Additionally, as discussed above, the proposed project would reduce the amount of impervious surfaces on the project site from 239,773 square feet to 220,438 square feet. In addition, the proposed project would construct a new storm drainage system with multiple bioretention areas, inlets, underground piping, and landscaping that would capture, slow down, and cleanse runoff and route it to existing storm drain lines on Stoneridge Mall Road to the south and east of the project site, thus reducing peak runoff rates on the project site (Exhibit 9). The storm drainage system would be required to be designed in accordance with the requirements and specifications of the Pleasanton Municipal Code Chapter 9.14, Stormwater Management and Discharge Control. Additionally, the proposed project would follow the standards established by provision C.3 of the ACCWP NPDES Permit. These measures would ensure that the proposed project does not result in an increase in surface runoff, and therefore would not exceed the capacity of the existing stormwater lines on Stoneridge Mall Road. Impacts would continue to be less than significant, and no mitigation is necessary, consistent with the Prior EIR. There are no proposed changes, new circumstances, or new information that would cause new or more severe impacts. Therefore, there are no environmental effects that are peculiar to the proposed project or the parcels on which the proposed project would be located. Impacts would be less than significant and the proposed project would not result in a new or more severe adverse impact that was not previously identified in the Prior EIR. iv) Impedance or Redirection of Flood Flows