Silicon Valley Chemical Exposure

Groundwater plume map

“Silicon Valley is home to one of the nation’s heaviest concentrations of toxic-waste sites. Even as Silicon Valley positions itself as an eco-friendly clean-technology center, the tech industry’s underbelly continues to scar the region.” [Wall Street Journal: link]

Table of Contents:


​”California’s Santa Clara County, the seat of Silicon Valley, has more federal Superfund sites than anywhere else in the US. According to an NBC Bay Area investigation from 2014, Santa Clara county is also home to hundreds more unofficial toxic waste sites; The NBC team counted 518 chemical spill sites in total.” [Quartz: link

  • “Silicon Valley is One of the Most Polluted Places in the Country,” [The Atlantic, 2019: link]
  • “Silicon Valley’s Success Sits on Toxic ‘Superfund’ Sites,” [India Currents, 2019: link]
  • “0 of 23: An Introduction” (to Santa Clara County’s 23 Superfunds), [Archive 408, 2019: link]
  • “The Superfund Sites of Silicon Valley,” [New York Times, 2018: link
  • “Is Silicon Valley doomed to become the next Detroit?” [Fast Company, 2018: link
  • “Silicon Valley, from ‘heart’s delight’ to toxic wasteland,” [Rappler, 2018: link]
  • “How Silicon Valley industry polluted the sylvan California dream,” [KQED, 2017: link
  • “Silicon Valley is home to more toxic Superfund sites than anywhere else in the country,” [QZ, 2017: link] ​
  • “Toxic-Waste Sites Haunt Silicon Valley,” [Wall Street Journal, 2010: link
  • “High-Tech Hazards Chipping Away at Workers Health,” [MNM, 1986: link]
  • “Storm Clouds Over Silicon Valley: As blind faith in the infallibility of high-tech companies falters, the era of unrestrained growth in the Valley may be over.” [Inc, 1982: link]​
  • “Bay Area tech offices sit on some of the most contaminated land in America, new book claims,” [SF Gate, 2019: link]

“Silicon Valley is not what it seems. The world’s capital of tech innovation prefers to keep its superlatives, good and bad, under wraps. Along its Prius-choked roads, it looks like Anywhere, U.S.A.: single-family-home suburbs south of San Francisco, bordered by chain stores, auto dealerships and corporate parks — lots of beige, boxy corporate parks. Inside these plain vanilla buildings, where C.E.O.s in hoodies and jeans stockpile more money than the G.D.P. of developing countries, newly minted techies complain that “S.V.,” the world’s largest wealth generator, is too expensive and that its exhausting work culture is toxic. So, too, is the land beneath their feet. From its origins as a manufacturer of silicon chips and semiconductors, Santa Clara County is riddled with 23 toxic Superfund sites, more than any county in the country. The issue is no secret — Silicon Valley government officials are well-schooled on the sites and news organizations have written about them. Still, Silicon Valley’s Superfund sites rarely make news. ” [New York Times: link]


  • Cupertino Superfund sites: 12x total, 2x active NPL: AcrianAmpexHewlett PackardIntersilSiemensKaiserSC QuarryTandemTimex,  Zilog Inc, & Zilog corp. [EPA: link
  • “Apple Park” (Intersil EPA Superfund site; TCE, TCA, & PCE cleanup), [US EPAlink] [CA Water Boardslink]
  • “Apple Park” (Siemens EPA Superfund site; TCE & TCA cleanup), [CA Water Boardslink
  • “Apple Park” (HP Superfund/Water Boards clean-up; TCE, arsenic, etc cleanup) [CA Water Boards: link
  • “Infinite Loop” (cleanup site): [CA Water Boards: link & link], [CA DTSC: link] ​
  • Apple Agrees to Pay $450,000 to Settle Hazardous Waste Violations, [CA DTSC, 2016: link
  • “Cupertino cement quarry to pay $7.5 million to settle water pollution violations,” [Mercury News: link
  • “Cupertino area cement quarry won’t be added to Superfund list,” [Mercury Newslink
  • Mercury Spill [EPAlink]

Mountain View

  • Mountain View Superfund site: 29x total; 1x deleted; 6x active [EPAlink
  • “TCE discovery halts Fairchild Drive housing project,” [MV Voicelink
  • “Google and NASA campuses sit on a hazardous waste site with contaminated soil. It’s part of a toxic legacy across Silicon Valley.,” [Business Insider: link]
  • “EPA warning residents about dangers at Superfund sites near local schools,” [Los Altos Onlinelink
  • “I live next to Google – and on top of a toxic site. Don’t let polluters be evil,” [The Guardianlink] ​
  • “Google Employees Face Health Risks From Superfund Site’s Toxic Vapors,” [NBC News, 2013: link
  • “Google workers at Superfund site exposed to TCE,” [SF Gate, 2013: link]  
  • “Google Shoreline Office” (TCE), [Disaster Area, 2021: link]  
  • “Google and NASA campuses sit on a hazardous waste site with contaminated soil. It’s part of a toxic legacy across Silicon Valley,” [Business Insider, 2019: link]  
  • “Google Headquarters, Mountain View, [Disaster Area, 2019: link]  
  • “Settlement reached to clean up groundwater in Mountain View,” [The Mercury News, 2014: link]  
  • “Moffett Field Toxic Plume Subject of EPA Meeting with Mountain View Residents,” [NBC News: link]  
  • “EPA releases plan for toxic Mountain View site,’ [Mercury News: link]  
  • “Middlefield-Ellis-Whisman Superfund site still raises questions, [MV Voice: link
  • “EPA sets plan for cleanup of toxic air in Mountain View’s MEW Superfund site,” [Mercury News: link]  
  • “EPA Superfund Sites Cause New Toxic Plume Concerns,” [NBC News: link
  • “Registry Finds High Cancer Numbers Around Moffett Field Superfund Site,” [NBC Newslink
  • “Are Sewers Source of Toxic Hot Spots in Mountain View?,” [NBC News: link]  
  • “Mountain View, California’s Mystery TCE Hotspots,” [CPEOlink
  • “Cancer spike found near Superfund site,” [MV Voice: link]  
  • “Cleaning up the mess at Middlefield-Ellis-Whisman,” [MV Voice: link]
  • “Residential cancer cluster investigation nearby a Superfund Study Area with trichloroethylene contamination” (Mountain View, California), National Library of Medicinelink

Palo Alto

  • Palo Alto Superfund sites: 38x total; 1x active NPL [EPAlink] ​
  • “Pollution spikes despite years of cleanup,” [Palo Alto Onlinelink
  • “Eshoo opens inquiry into Silicon Valley toxic cleanup,” [Palo Alto Onlinelink]  ​
  • “Menlo Park Facebook Building #23 Tyco Electronics (Raychem),” DTSC Oversight & Land Use Restrictions, [Disaster Arealink
  • “Facebook HQ on Chemical Waste site,” [Disaster Area: link]  
  • DTSC Facebook HQ Memo, [CA DTSClink]
  • “In Search of the Cookie Dough Tree: Silicon Valley is toxic in more ways than one.” [Aaron Greenspan: link
  • “Congress investigating Silicon Valley tech toxin sites,” [Biz Journals: link
  • “Stanford University built housing on a toxic waste site,” [Disaster Area: link
  • “Stanford sues HP companies, Agilent over toxic contamination,” [Palo Alto Onlinelink
  • “Palo Alto teens ask city to test for vapor intrusion,” [Mercury News: link
  • “Decades-old Superfund site still affects Stanford Research Park,” [Stanford Dailylink
  • “Historic California Posts, Camps, Stations and Airfields: Camp Fremont,” [Military Museumlink
  • “Stanford Research Park: An alternative history of Silicon Valley,” [ARCGISlink]  

San Jose & Morgan Hill

  • San Jose Superfund sites: 73x total; 2x active NPL [EPAlink
  • “Toxic Concerns Over Development in San Jose,” [NBC News: link]  
  • “Tracking a toxic trail / Long-closed mine identified as largest source of mercury in San Francisco Bay,” [SF Gatelink]
  • “IBM, Ex-employees Go To Court Over ‘Cancer Cluster,’” [CRNlink
  • “Ten years after toxic plume, Morgan Hill and surrounding communities work to find normalcy,” [Mercury News: link
  • “GE Nuclear Fuel Processing Facility at The Plant Shopping Center” (nuclear radiation, across from the Fairgrounds), [Disaster Area: link
  • “Leaking Chemicals in California’s “Silicon Valley” Alarm Neighbors,” [New York Timeslink
  • “A poison. A metal. A god: Settler Colonialism, Mercury, and the Lethal Legacy of Silicon Valley,” [Archive 408: link
  • “Bay Area’s worst pollution,” [SF Gate: link
  • “Implications of IBM Study on Miscarriages : Workplace: The two chemicals involved have a wide range of uses. But computer companies are downplaying the significance of the report,” [LA Times: link]  

Santa Clara city

  • Santa Clara city Superfund sites: 67x total; 1x closed NPL, 3x active NPL: [EPA: link]
  • “I thought I was dying: My apartment was built on toxic waste” (Ashley Gjovik & the Santa Clara Square Apartments), [SF Bay View: link
  • ​”City Place Santa Clara: Addressing Vapor Instruction in a Massive Landfill Redevelopment,” [CPEOlink]   
  • Zeta Laboratories (Superfund & military defense contractor) [LA Timeslink] [Militarylink] [Superfundlink]
  • “Santa Clara Waste Facility Agrees to Keep Toxic Runoff Out of the Bay” (lawsuit), [Bay Keeperlink
  • “Santa Clara Plating Company Agrees to Keep Toxic Runoff from Polluting the Bay” (lawsuit), [Bay Keeper: link


  • Sunnyvale Superfund sites: 67x total; 5x active NPL [EPAlink] ​​
  • “Silicon Valley’s Toxic Past Haunts Sunnyvale Neighborhood,” [KQED, 2017: link]  ​​
  • “U.S. Navy Conceals Nuclear Weapons Production in California (Mathilda, Sunnyvale – United States Navy and Lockheed Martin),” [Indy Baylink
  • “Building Trust at the Triple Site, Sunnyvale, California,” [CPEO, 2015: link]
  • “EPA Reaches Settlements to Study Indoor Air and Groundwater Contamination in Sunnyvale,” [NBC News: link]
  • “Sunnyvale: EPA shares findings on vapor intrusion,” [Mercury News: link
  • “Sunnyvale: EPA plans on testing indoor air quality for vapor intrusion,” [Mercury News: link
  • “Sunnyvale: EPA steps in for contaminated triple site oversight” (Notice of Deficiency), [Mercury News: link
  • “3 Superfund sites located under 4 schools and 2 daycare centers and over 100 residences in Sunnyvale California,” [Disaster Area: link
  • “The Triple Site: 1, 2, and 3 of 23,” [Archive 408link
  • “Low levels of toxic metal [Chromium 6] found in Sunnyvale’s groundwater,” [Mercury News: link
  • “Sunnyvale debates zoning designation of superfund site,” [Mercury News: link
  • “Public-health assessment for Westinghouse (Sunnyvale Plant), Sunnyvale, Santa Clara County,” [OSTI: link
  • “The Secret History of Silicon Valley Part 13: Lockheed-the Startup with Nuclear Missiles,” [Steve Blanklink
  • “Former Military Bases: Cheap Land, Hidden Hazards,” [Monterey Herald: link]  
  • “Sunnyvale WWII Ordnance Depot & Chemical Laboratory Company (1940s), [Military Museum: link & link]  
  • “Missile defense back on radar (Lockheed), [SF Gate: link
  • “War On Iraq: Bay to Baghdad; Defense: Lockheed Bay Area’s Key Player,”  [SF Gate: link
  • “Onizuka Air Force Station, Sunnyvale,” [EPAlink


“Unbeknownst to even seasoned inhabitants, today’s Silicon Valley had its start in government secrecy and wartime urgency… [The] roots of Silicon Valley sprang not from the later development of the silicon semiconductor but instead from the earlier technology duel over the skies of Germany and secret efforts around (and over) the Soviet Union. World War II, the Cold War and one Stanford professor set the stage for the creation and explosive growth of entrepreneurship in Silicon Valley. The world was forever changed when the Defense Department, CIA and the National Security Agency acted like today’s venture capitalists funding this first wave of entrepreneurship.” [Steve Blank: link]

“Today, the valley is home to more EPA Superfund sites than any other county in the nation, with the most notorious of those sites from a leaking tank at a Fairchild Semiconductor fabrication plant poisoning a well that served the south San Jose neighborhood of Los Paseos. A subsequent study by the state’s Department of Health Services found 2.5 to three times the expected rate of miscarriages and birth defects among pregnant women exposed to the contaminated drinking water, leading to a lawsuit and multimillion-dollar settlement in 1986 with over 250 claimants.” [Salon: link]

  • “The Secret History of Silicon Valley and the Toxic Remnants of the First Computers,” [Gizmodolink]  
  • “If I Told You I’d Have to Kill You: The Story Behind ‘The Secret History of Silicon Valley’”, [Steve Blanklink
  • “SVTC Eco-Maps,” [2003: link]
  • “In Search of Toxic Silicon Valley: The Subterranean Poisoning From High Technology Manufacturing,” [Marquislink
  • “Not Even Silicon Valley Escapes History,” [The Atlanticlink] ​
  • “American Chipmakers Had a Toxic Problem. Then They Outsourced It.” [Bloomberg, 2017: link
  • “Poisons Imperil Silicon Valley’s Clean Image,” [New York Times, 1984: link]   
  • “Poison Valley,” [Salon, 2001: link
  • “The valley’s toxic history / IBM trial is latest round in long-running dispute over the tech industry’s environmental record,” [SF Gate: link] ​
  • “Disaster Area, The Navy Nuked SF,”
  • Santa Clara Center for Occupational Health (SCCOSH) and Silicon Valley Toxics Coalition (SVTC) Collection, [link
  • An Augmented Reality Tour Of Silicon Valley Superfund Sites, [link]
  • The Silicon Valley of Dreams: Environmental Injustice, Immigrant Workers, and the High-Tech Global Economy, [Amazon: link
  • The Code: Silicon Valley and the Remaking of America, [Amazon: link] ​
  • Silicon Valley Toxics Coalition [link]

Mapping & Risk Assessment Tech

  • “Toxic Plumes: The Dark Side of Silicon Valley,” [NBC News: link]  
  • “Applying Information Technology for Stewardship of Groundwater Contamination Plumes,” [YouTube: link]  
  • “Whats Down: Buried Toxics in Silicon Valley,” [YouTube: link]​
  • “At the intersection of tech, climate and the land of Silicon Valley,” [Marketplacelink]  
  • “Climate change impacts are coming to Big Tech’s doorstep,” [Marketplace: link]