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City of Pleasanton—Hidden Canyon Residences and Preserve Geology, Soils, and Seismicity Draft EIR 3.6-32 FirstCarbon Solutions https://adecinnovations.sharepoint.com/sites/PublicationsSite/Shared Documents/Publications/Client (PN-JN)/2148/21480016/EIR/3 - Draft EIR/21480016 Sec03-06 Geology.docx building plans to reduce the impacts of expansive soils, in accordance with the CBC. The City Engineer would review and approve the plans prior to issuance of a grading or building permit. With MM GEO-1, the proposed project would not create a substantial risk to life or property from being located on expansive soils and impacts related to expansive soils would be less than significant with mitigation incorporated. Level of Significance Before Mitigation Potentially significant impact. Mitigation Measures Implement MM GEO-1. Level of Significance After Mitigation Less than significant impact. Wastewater Disposal Systems Impact GEO-5: The proposed project would not have soils incapable of adequately supporting the use of septic tanks or alternative wastewater disposal systems where sewers are not available for the disposal of wastewater. Impact Analysis The proposed project is located within the City of Pleasanton. Wastewater infrastructure would be installed along the proposed internal roadways throughout the residential portions of the project site consisting of eight-inch sanitary sewer laterals that would directly connect to eight-inch sanitary sewer laterals underneath Dublin Canyon Road to the north. In addition, stormwater infrastructure would consist of storm drains along internal roadways that would transfer stormwater to three on- site bioretention areas for treatment before connecting to the City’s existing storm drainage system. Since the proposed project would connect to already available wastewater and stormwater systems, no septic tanks or alternative wastewater disposal systems would be installed. Therefore, no direct, indirect or cumulative impact related to soil capability of supporting the use of septic tanks or alternative wastewater disposal would occur. Level of Significance No impact. Destruction of Paleontological Resource or Unique Geologic Feature Impact GEO-6: The proposed project would not directly or indirectly destroy a unique paleontological resource or site or unique geologic feature. Impact Analysis Construction activities associated with the project site include ground-disturbing activities such as grading, trenching, and cutting and filling. The project site is located on colluvium and residual soils at the surface with marine sedimentary bedrock of Miocene-age comprised of sandstone, siltstone, and siliceous shale in the subsurface that are associated with the Claremont member of the