The Tower a.k.a. The Tin Man a.k.a. The Rocket...
This is an Air Stripper. It is used to remove VOCs (Volatile Organic Compounds) from ground water wells located under our campus. In summary, water is pumped to the top of the tower, and then released over 'wiffle balls' to increase the surface area that it flows over. At the same time, a powerful stream of air is sent up the tower, where the high velocities pull the VOC's out of the water. They are then ejected high into the atmosphere, where they evaporate & diffuse immediately. For more information on how the Air Stripper operates, please visit The Air Stripper FAQ Page.
Building 23 Has an Interesting View
Yes, building 23 is right next to the tower, but do not despair. The VOCs are discharged from the air stripper at a very high rate of speed, & they evaporate into the atmosphere immediately. The EPA, the BAAQMD, the RWQCB, the previous owners, and Netscape have & will continue to monitor the processes and the quality of the environment across our entire campus. Similarly, much of the Bay Area, including many residential areas, have ground contamination issues & are undergoing remediation.
What's Down There Anyway?
Primarily Trichloroethene (TCE), and derivatives of that chemical. (TCA, PCE, DCE, DCA, trace amounts of Freon 113, Phenol, Vinyl Chloride, DCB) The area where these are found is approximately a half mile wide and 2 miles long, much of which is covered by Moffet Airfield.
There was a little putting green between the two buildings, and if you were anywhere near it or walking between the buildings you could feel the mist raining town from the tower. The building HVAC intakes buildings were also nearby.
We were moved to building 24 in 1999, and wondered about this hare-brained scheme to rid groundwater of poison by spraying it onto people and into ventilation intakes. Bryn's dad is a PhD chemist, so we asked him about TCE. His opinion was that it was bad stuff and we likely didn't want to be soaking in it. So we asked Netscape for TCE testing of our air quality, but predictably got the runaround. Shrug.
A few years later, tragi-predictably, the EPA reclassified TCE to be far more harmful than they previously had claimed:
The U.S. Environmental Protection Agency will require 10 Silicon Valley high-tech companies that once operated manufacturing plants in Mountain View to conduct -- for the first time -- air-quality testing for a toxic substance inside several offices that were later built on the land.
The same companies are suspected of having leaked into the ground a substance called trichloroethylene, known as TCE, a widely used solvent that cleans machine parts.
Now, the EPA believes TCE might be 60 to 70 times more dangerous to humans than previously thought, and it is concerned that contamination in groundwater is seeping into the air inside office buildings constructed in areas vacated by those companies.
-- old unlinkable merc story
Might be seeping up? Yah right. It was pumped out of the ground and sprayed all over the place, on purpose. Sheesh.
I'm too apathetic about such things to worry over what kind of increased risk of god-knows-what I might have in the future, but if you care check out the TCE blog.