Class 1* Permit Modification for Closure of Waste Vault 45 and Tank 101 at Western Digital Technologies, Inc. (formerly HGST, Inc)
The California Department of Toxic Substances Control (DTSC) approved an Addendum to the previously certified Environmental Impact Report and approved a Class 1* Permit Modification to Western Digital Technologies Inc. (WDT) Hazardous Waste Facility Permit. The purpose of the permit modification is to amend the sampling plan and closure timing specified in the approved closure plan for Waste Vault 45 and Tank 101.
The WDT facility, formerly known as HGST, Inc., is used for designing, developing and manufacturing computer storage devices. The processes utilized in these operations include photolithography, vacuum deposition, electroplating, chemical and vacuum etching, and precision machining. In January 2006, WDT consolidated its operations into the 158-acre central production area of the site (internally referred to as the Core Campus and initiated plans to redevelop the remainder of the previous campus for mixed commercial/residential occupancy (internally referred to as the Redevelopment Area). The environmental impacts of the consolidation and redevelopment were addressed in the Integrated Final Environmental Impact Report (IFEIR) for the Hitachi Campus and Mixed-Use Transit Village Project (State Clearinghouse No. 2004072110). The Waste Vault 45 and Tank 101 will be emptied, cleaned, sampled and physically removed. Additionally, soil and groundwater samples will be taken in several locations under Waste Vault 45. Western Digital, Inc. must submit a certification of closure report in accordance with CCR, title 22, section 66264.115.