Former Semiconductor Manufacturing Facility
Livermore, California
Our client, a Fortune 100 chip manufacturer, used this facility in Livermore for chip manufacturing from the early 1980’s, but it has been owned and operated by others since 1995. The facility includes two buildings with basements requiring dewatering to prevent groundwater intrusion; one of these buildings is located directly over the original volatile organic compound (VOC) source and highest groundwater concentrations. Although granted monitored natural attenuation (MNA) status in its 2002 San Francisco Bay Regional Water Quality Control Board (RWQCB) Order, Weiss has continued to implement self-directed remediation, including enhanced in situ bioremediation and targeted groundwater extraction, in the residual source area to reduce potential vapor intrusion (VI) risks and to pursue final site closure.
Weiss used the Johnson & Ettinger (J&E) model in conjunction with California toxicological factors to evaluate potential VI at the facility in 2002 and again in 2007. Based on new California guidance issued in 2011 and 2012, we re-evaluated vapor intrusion in 2012-2013. This evaluation included sub-slab and soil gas sampling following rigorous California guidance, and indoor/outdoor time-integrated air sampling. All these current sampling results provided robust support for our risk evaluation, which indicated no risks for current use and occupancy of the building, and no limitations on future commercial use and/or redevelopment of the property.
Based on follow-up sampling and ongoing aggressive residual source removal, future residential redevelopment may also be approved by the regulatory agencies. Weiss is working with the current owner and the RWQCB to establish a deed restriction limiting future use or disturbance of the shallow groundwater during any future redevelopment.
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