3B Public Hearing 2009 0720 - Laserfiche WebLink

Home

CORNERSTONE AT SAN LEANDRO CROSSINGS DRAFT MITIGATION MONITORING AND REPORTING PLAN IMPACT _____TMITIGATION MEASURES REQUIRED MONITORING RESPONSIBILITY TIMING Hazards & Hazardous Materials Continued) Mitigation Measure #21 (Continued) Additionally, a groundwater sampling and analysis program will be Community Development and Prior to Issuance of Grading Permit implemented for chemical constituents that could have migrated onto the Sites Environmental Services from off-site upgradient sources, if identified during due diligence. Detection Departments limits for the analytical program will be sufficiently low to allow assessment of risks to human health under construction worker and residential exposure scenarios. If the subsurface investigation programs yield data suggesting that there could be unacceptable risks to future construction workers or residents, a California state environmental regulatory agency will be consulted to provide its opinion on the findings of the subsurface investigations and the assessment of risk. This opinion would be sought prior to initiating construction on either Site. The environmental testing programs have not been completed on either of the Sites. However, there are no chemical source areas known to exist on either Site. The mitigation measures presented below are proposed as means to mitigate potential chemical exposures and associated unacceptable risks to human health should COPCs be found at the Sites at levels of concern in soil, soil gas or groundwater. Mitigation Measure #22 - Pre Development Mitigation Measures: If the subsurface investigation programs yield data suggesting that there could be unacceptable risks to future construction workers or residents and a California state environmental regulatory agency determines that an active remedial response is warranted, the following mitigation measures listed below include methods that may be employed to mitigate unacceptable risks to human health of construction works and future residents. • Remove the impacted soil and dispose of off -Site; • Install a cap to prevent contact with the contamination; • Install a physical barrier for vapors such as a vapor barrier or passive venting system, to prevent the accumulation of vapors in indoor environment; • Stockpile soil and aerate on -Site, or in a staging area as may be appropriate, in compliance with all applicable laws and re mations;