The project is a redevelopment property within the Teledyne-Spectraphysics (T-S) plume with underlying groundwater probably impacted by the upgradient T-S source properties. The developer plans to construct the building wiht a vapor intrusion mitigation system (VIMS) and water barrier. Indoor air testing will be conducted to verify that the VIMS is working as designed.
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.
The history of the site included industrial usage of the various parcels including Elementis Pigments at 4650 Shellmound Street, McKinley Property at 5500 Shellmound Street, and the Sepulveda Property at 5600 Shellmound Street (Shellmound Properties). Since 1929, Elementis Pigments produced iron oxide for paint pigments and other uses. Sherwin Williams owned the McKinley and Sepulveda properties until 1965 and 1955, respectively. Sherwin Williams operated a lime and sulfur plant and an insecticide and spray plant. Other usages included a sign shop, a photo shop, a machine shop, and commercial offices at the McKinley Property. A truck and trailer storage yard and equipment rentals used the Sepulveda property. The southern portion of the site includes the former Myers Drum site which historically was used for drum cleaning and recycling. Continue reading “Emeryville CA – SOUTH BAYFRONT PROJECT (01890019)”→
The Mora Drive Site was formerly commercial/industrial. It includes several former DTSC sites: PLESSEY #2 (43360131), PLESSEY #3 (43360135), and SYMTRON CORP. (43360124) all of which were determined to require no further action. Lennar conducted sampling in 2015, 2016 and 2017 to confirm that the site has elevated levels of tetrachloroethylene and trichloroethylene in soil gas. Lennar plans to develop the property into residential.
EPA Superfund Site : “The National Semiconductor Corporation (National Semiconductor) previously manufactured electronic equipment at this 50-acre site. Underground storage tanks, sumps, and pipes are the suspected sources for contaminated groundwater and soil in Sunnyvale underneath the site. Beginning in 1982, National Semiconductor closed and removed its leaking tanks and equipment, instituted a groundwater pump and treat system, and removed contaminated soil from selected areas of the facility. The contaminants of concern are primarily chlorinated organic solvents, including trichloloethene (TCE), which, along with other nearby National Priority List (NPL) sites including the Monolithic Memories Superfund Site, have contaminated a common groundwater area. Although these nearby sites are listed separately on the NPL, the cleanup activities at some of the sites are being coordinated as part of an area-wide cleanup approach.”
Deed Restrictions: ACTIVITIES PROHIBITED WHICH DISTURB THE REMEDY AND MONITORING SYSTEMS WITHOUT APPROVAL, LAND USE COVENANT, NOTIFY DAMAGES TO REMEDY AND MONITORING SYSTEMS UPON DISCOVERY
HEWLETT-PACKARD COMPANY (SL720511210) – (Geotracker MAP) Map indicating toxic waste sites in as small square boxes. If you click on each square you will be directed to the State Geotracker page for that toxic waste site.
Groundwater Contamination Map, Toxic Plumes Map Source: The Chemical Legacy of Old Silicon Valley, NBC Bay Area, Map Editor Scott Pham 2019 The red dots represent Daycare centers from 2019. NBC Bay Area had a series of maps that indicated where the toxic waste sites were located and the extent of the damage encompassing vast areas of the community but they took it down. The pollution is in the groundwater so it covers a vast area in Pink.
Envirostor State of California Link: “The EPA added this site to the National Priorities List (NPL) in 1991. This Superfund site is comprised of several former Fairchild Semiconductor Corp facilities spanning 56 acres in Mountain View. The Fairchild Semiconductor Corp – Mountain View site is one of three Superfund or NPL sites that are being cleaned up simultaneously. The other two Superfund sites are the Intel – Mountain View site and the Raytheon site. All three sites are located in the Middlefield-Ellis-Whisman (MEW) Study Area and are being addressed collectively as the MEW SIte. Site investigations at several of these facilities during 1981 and 1982 revealed extensive soil and groundwater contamination, primarily VOCs. Soil cleanup by soil vapor extraction, excavation, and aeration has been completed at all the MEW study area sites. Groundwater remediation is ongoing at the MEW Study Area.”
Apple Computer, Kaiser Permanente Child/ado Psy and Kaiser Permanente – CDRP (Chemical dependency recovery program) are located on the EPA Superfund Tri-Site where there are toxic chemicals in the ground that emerge as toxic vapor and the deed restrictions are present to stop organizations from having hospital facilities on the site. Strange thing is Kaiser Permanente operates two facilities on the site. So I would imagine that each patient must be signing a waver when they visit the facility?
The Teledyne property is part of a two-property Superfund site along with the adjacent Spectra-Physics property.
The responsible parties (RPs) for the Teledyne/Spectra-Physics site completed a Monitored Natural Attenuation (MNA) study in the off-property area north of and downgradient of the site. The MNA study concluded that natural breakdown of the chlorinated volatile organic compounds of concern is occuring naturally and at the same rate as groundwater extraction. As a result, only a few of the off-property downgradient extraction wells were operating mainly to maintain hydraulic control of the plume. The RPs completed a pilot study to test the feasibility of enhanced reductive dechlorination (ERD) and concluded that ERD is feasible with bioaugmentation of the Shallow Zone.
Within the last five years, the RPs detected elevated source areas at the Teledyne property using high resolution technology and continuously logged and screened ERD injection well boreholes. Implementing a full-scale ERD treatability study, they have been and are currently remediating the property with groundwater-CVOC levels dropping from as much as over 80,000 ug/l to low multiples of MCLs. Several rounds of ERD injections successfully cleaned up most of the Shallow Zone at the Teledyne property and the adjacent Spring Street residential area to drinking water standards and the treatability study was even more successful in the underlying Upper and Lower Intermediate Zones.
An on-property IA VI evaluation at a SpectraPhysics property in 2004 indicated no IA-CVOC contamination above the Regional Water Board’s 2008 ESLs. More recently, the RPs also assertively evaluated potential IA VI in the off-property commercial North Bayshore and residential Spring Street areas to conclude that IA VI is not occurring in most of the commercial area and is occasionally occurring in several homes in the residential area. The RPs installed sub-slab depressurization systems in the impacted on-property commercial buildings and offered the affected residents crawl space fans to address the issue.
Nine indicator chemicals were identified from approximately 30 chemicals detected in the Study Area. The nine indicator chemicals are as follows: 1,1-dichloroethane (1,1-DCA) 1.1-dichloroethylene (1,1-DCE) 1.2-dichloroethylene (1,2-DCE) tetrachloroethylene (PCE) toluene 1,2,4-trichlorobenzene (1,2,4-TCB) 1,1,1-trichloroethane (1,1,1-TCA) trichloroethylene (TCE) vinyl chloride (VC
RECORD OF DECISION, TELEDYNE SEMICONDUCTOR AND SPECTRA-PHYSICS, INC. JOINT SUPERFUND SITES MOUNTAIN VIEW, CALIFORNIA MARCH 22, 1991 U.S. ENVIRONMENTAL PROTECTION AGENCY REGION 9 p. 26 https://semspub.epa.gov/work/09/46745.pdf