RES 201131 - Laserfiche WebLink

Facts in Support of Finding: The following facts and mitigation measures indicate that the impact will be reduced to less than significant. 1. Remaining and/or previously unidentified contamination may be present on or below the ground surface within the area of the Project. Encountering contaminated soil, surface water, or groundwater without taking proper precautions during site remediation within the Project could result in the exposure of construction workers to hazardous materials and consequently result in associated significant adverse human health and environmental impacts. 2. Implementation of Mitigation Measures 4.E-7 and 4.E-8 set forth in Table 5-1 of the Final SEIR and listed in the RMMRP will ensure that Impact 4.E-5b would be reduced to a less than significant level and is hereby incorporated by reference and described below. Mitigation Measure 4.E-7: Soil and Groundwater Plan. For proposed development on all sites within the EDZ undergoing or requiring remediation of contaminated soil or groundwater, and prior to issuance of a building or grading permit,the project developer shall demonstrate that its construction specifications include implementation of a Soil and Groundwater Plan(SGP)prepared by a qualified environmental specialist(geologist or engineer) and reviewed and approved by the agency or agencies with oversight over cleanup (San Francisco Regional Water Quality Control Board [RWQCB] and/or State Department of Toxic Substances Control [DTSC]). The SGP shall describe requirements for excavation, stockpiling, and transport of soil and disturbance of groundwater. The SGP shall also include a contingency plan to respond to the discovery of previously unknown contamination. In addition,all construction activities shall require written approval by either RWQCB or DTSC prior to commencement. The SGP shall be present on site at all times as ensured by the construction lead, and readily available to site workers and City staff as needed. Site(s) affected: All sites within the area of the Project undergoing or requiring remediation of contaminated soil or groundwater. Mitigation Measure 4.E-8: Soil Vapor Barriers. For proposed development on all sites within the EDZ undergoing or requiring remediation of contaminated soil or groundwater, where residual contamination includes volatile components (such as the chlorinated solvent TCE), and prior to issuance of a building or grading permit, the project developer shall demonstrate to the City either that the building plans include vapor barriers reviewed and approved by San Francisco Regional Water Quality Control Board(RWQCB) or State Department of Toxic Substances Control (DTSC)to be installed beneath foundations for the prevention of soil vapor intrusion, or that RWQCB or DTSC has determined that installation of vapor barriers is not necessary.