A sign is displayed outside of the Google headquarters in Mountain View. (Justin Sullivan/Getty Images) A sign is displayed outside of the Google headquarters in Mountain View. (Justin Sullivan/Getty Images)

MOUNTAIN VIEW (CBS SF) — One of Silicon Valley’s dirty secrets is coming back to haunt Google with toxic vapors.

TCE, or trichloroethylene vapors were detected at the company’s offices in Mountain View.

Google’s buildings QD6, and QD7, which sit on North Whisman road sit on top of what used to be Fairchild Semiconductor, Intel, Raytheon, and other computer chip makers.

The problem began when those chip makers dumped thousands of gallons of the toxic solvent into the ground, contaminating the water.

When Google moved in, they installed state of the art filters, and conducted rigorous air quality testing.