EPA Superfund site
he Site was formerly identified as two properties: 901 Thompson Place and 902 Thompson Place. These properties have been re-developed and now have a single address: 875 East Arques Avenue, Sunnyvale, California (see site location map). Land use in this area is primarily industrial and commercial. The 901-902 Thompson Place property was formerly occupied by Advanced Micro Devices, Inc. (AMD) to manufacture integrated semiconductor circuits between 1969 and 1992. Two below-ground acid neutralization system (ANS) tank vaults were located at the northern and southern ends of the 901 and 902 Thompson Place buildings, respectively. The ANS tanks for both 901 and 902 Thompson Place were constructed of coated concrete and were used to contain acidic industrial wastewater that was neutralized by adding caustics before discharging to the sanitary sewer. The wastewater also contained volatile organic compounds (VOCs).
Soil and groundwater investigations were conducted by AMD in 1983 and 1984 to assess the impact of releases from both ANS structures. The results of these investigations indicated the presence of VOCs in soil and groundwater samples collected from the area near the ANS structures. Both ANSs and surrounding VOC-affected soils were removed between 1983 and 1992. Groundwater extraction and treatment was conducted from 1983 until December 2002. In situ biological treatment of VOCs in groundwater and saturated soil has been conducted since 2002 and is ongoing.
Soil impacted primarily by VOCs was excavated from source areas ANS-901 and ANS-902 over three separate excavation events.
The relatively low VOC concentrations in monitoring wells within the uppermost water bearing zone (approximately 10 to 20 feet bgs), where TCE concentrations have generally been less than 100 g/L down-gradient of the former ANS-901 source area, suggest that no substantial source for TCE exists in unsaturated zone soil at the Site.
In 2007, Summit Commercial Properties, Inc. (Summit) the current owner of the Site, demolished the building and built a rental storage facility in its place.
Deed Restriction / Land Use Covenant
SITE MANAGEMENT REQUIREMENTS
ACTIVITIES PROHIBITED WHICH DISTURB THE REMEDY AND MONITORING SYSTEMS WITHOUT APPROVAL, DAY CARE CENTER PROHIBITED, ELDER CARE CENTER PROHIBITED, HOSPITAL USE PROHIBITED, LAND USE COVENANT, MAINTAIN MONITORING OF GROUNDWATER, NO EXCAVATION OF CONTAMINATED SOILS WITHOUT AGENCY REVIEW AND APPROVAL, NO GROUNDWATER EXTRACTION AT ANY DEPTH WITHOUT APPROVAL, NOTIFY PRIOR TO DEVELOPMENT, NOTIFY PRIOR TO SUBSURFACE WORK, ONLY EXTRACTION OF GROUNDWATER FOR SITE REMEDIATION PERMITTED, PERFORM H&S PLAN PRIOR TO SUBSURFACE WORK, PUBLIC OR PRIVATE SCHOOL FOR PERSONS UNDER 21 PROHIBITED, RAISING OF FOOD PROHIBITED, RESIDENCE USE PROHIBITED
POTENTIAL CONTAMINANTS OF CONCERN
VOLATILE ORGANIC COMPOUNDS
Post Closure Site Management Requirements
|ACTIVITIES PROHIBITED WHICH DISTURB THE REMEDY AND MONITORING SYSTEMS WITHOUT APPROVAL|
DAY CARE CENTER PROHIBITED
ELDER CARE CENTER PROHIBITED
HOSPITAL USE PROHIBITED
LAND USE COVENANT
MAINTAIN MONITORING OF GROUNDWATER
NO EXCAVATION OF CONTAMINATED SOILS WITHOUT AGENCY REVIEW AND APPROVAL
NO GROUNDWATER EXTRACTION AT ANY DEPTH WITHOUT APPROVAL
NOTIFY PRIOR TO DEVELOPMENT
NOTIFY PRIOR TO SUBSURFACE WORK
ONLY EXTRACTION OF GROUNDWATER FOR SITE REMEDIATION PERMITTED
PERFORM H&S PLAN PRIOR TO SUBSURFACE WORK
PUBLIC OR PRIVATE SCHOOL FOR PERSONS UNDER 21 PROHIBITED
RAISING OF FOOD PROHIBITED
RESIDENCE USE PROHIBITED