Leaky sewer lines delivered TCE to homes

Trail of contamination "almost a smoking gun"

A report commissioned by the city is boosting suspicions that early semiconductor companies spread pollution throughout northeastern Mountain View by dumping toxics into leaky sewer lines.

A sewer line that runs through the city's Moffett Gateway site leaked the Trichloroethylene (TCE) pollution found in the soil and groundwater there, the report concludes, and points to dumping into leaky sewer lines for causing other "hot spots" of TCE contamination in soil and groundwater on Leong Drive and Evandale Avenue.

"It's the most detailed information I've seen thus far" about the hypothesis that sewer lines created the mysterious hot spots located away from a 1.5-mile long regional plume left behind by early silicon chip makers along the east side of Whisman Road, said Lenny Siegel, director of the Center for Public Environmental Oversight.

The four hot spots include the one at the Moffett Gateway site and two recently found among homes on Evandale Avenue. Another had been discovered years prior in the parking lot of a hotel on Leong Drive, though recent sampling found surprisingly high levels there in the soil and groundwater. "It's a very plausible explanation for all four hot spots." Siegel said.

"What's really striking are the maps that show where the sewer lines are," Siegel said. "I had thought, 'Gee, wouldn't it be funny if (the sewer line) zig-zagged and went by the other two hot spots (at the hotel and Moffett Gateway site)?' That would be almost a smoking gun. And it does. It's not just in the general area it's right there."

The city-commissioned report by Bureau Veritas concludes, "The direct correlation between distinct areas of high concentration of TCE in groundwater along the sanitary sewer line in areas of no known historical TCE use strongly suggests that historical discharges of TCE-containing wastes into the sanitary sewer may have occurred and then leaked at various locations both on the (Moffett Gateway) site and off-site, resulting in impacts to groundwater."

An ongoing investigation by the EPA has yet to come to a conclusion, but EPA project manager Alana Lee told residents on Nov. 12 that there was no other plausible explanation for the hot spots on Leong and Evandale. "It appears to be coming down the sewer," she said, adding that the dumping stopped years ago when semiconductor manufacturers left the area.

Fairchild Semiconductor had been caught by the city dumping acid and other toxics into the sewer and storm drains that run to Stevens Creek in the late 1970s, according to several news reports from the time. Fairchild's corporate descendant, Schlumberger Corp., is paying to clean up the two Evandale Avenue hot spots, along with the two Evandale Avenue homes where TCE vapors were found above EPA limits for risk of cancer and birth defects -- but has refused to take legal responsibility for the contamination.

The EPA has sampled the indoor air in over 95 homes in the Evandale Avenue and Leong Drive area and a total of six were found with TCE vapors inside, though four were under EPA action levels.

Looking at a map of the numerous interconnected sewer lines under every street in the area, it's hard to not ask, as a resident did at the Nov. 12 meeting, "Are we sampling enough to know we haven't missed some (hot spots)?"

"He's not the first person to ask that question," Siegel said after the meeting.

A number of groundwater samples on far-flung residential streets -- such as Easy Street and Tyrella Avenue -- have turned up with low levels of TCE along sewer lines. Siegel and others wonder if those samples might just be the tip of the iceberg.

As for the Moffett gateway site, it could be developed with office space and a hotel within a year or two, with or without a site clean-up, said Dennis Drennan, property manager for the city. He said that unless a polluter is held accountable by the EPA, the city may end up paying for a toxic cleanup of the largest of two Moffett Gateway hot spots.

A smaller hot spot on the site appears to have come from the county's use of the site as a vector control yard.

"We have a very keen interest in having this plume cleaned up at some point," Drennan said. "In an ideal world we would find a responsible party and we would clean it up very quickly."

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3 people like this
Posted by dig it out
a resident of Old Mountain View
on Nov 21, 2013 at 3:48 pm

Mountain View's toxic cesspool has been leaking for decades. The city knows it is there but is doing little to clean it up. Meanwhile, people are living on top of it and how many cases of cancer has it caused? What the city needs to do is clear the land and dig out all of the toxics once and for all. This can be done much more quickly than the cheapskate decades long process that has been going on so far. Yes, the people living there now will be inconvenienced if the land is stripped, but better that than die of cancer, right?

3 people like this
Posted by jane
a resident of North Whisman
on Nov 21, 2013 at 4:52 pm

Hi Dig it out,
The city is not the responsible polluting party. The way this works is that the polluters pay for the clean-up. The decades-long leaking i.e. the MEW Site, is a contained plume and the nine responsible polluting parties pay for the clean-up. The newly-discovered contamination is logically the result of these same parties disposing of the chemicals into the sewers. It seems like it should be an easy answer of digging out the toxics once and for all, but water tables/hydrology and other factors complicate such a solution. Sigh.

3 people like this
Posted by Mike
a resident of Bailey Park
on Nov 21, 2013 at 6:09 pm

I agree, more testing please. And I'm sure the guilty parties can team up with a developer and homeowners and come up with a sensible solution i.e. rebuild from the ground up.

3 people like this
Posted by dig it out
a resident of Old Mountain View
on Nov 21, 2013 at 8:10 pm

The 9 companies may be financially responsible, but the city is responsible to its citizens. The company accountants are encouraging the companies to do whatever is cheapest, hence the cleanup is dragged out for decades. The city should just take over and use whatever method will clean up the toxics the quickest, then send the companies the bill. How many cancer cases has this mess caused already? Don't tell me zero, that is not believable.

5 people like this
Posted by member
a resident of another community
on Nov 22, 2013 at 7:58 am

Sadly enough when I was a teenager, I worked for C&Z Circuits - long since gone now. It was at the site where the adult education facility now stands on Moffett. The owners used to make us clean circuit boards with TriClor and then dump our used chemical outside the roll up bay doors and directly in to the sewer grate. Last I heard the owners fled the state, filing bankruptcy on the way out.

3 people like this
Posted by Mark T.
a resident of Old Mountain View
on Nov 22, 2013 at 9:24 am

dig it out, tell me what you know about the remediation of chlorinated solvents. I actually worked in this area of TCE and DCE remediation in the 1990's and find your comments about "Just dig it up" astoundingly ignorant of the process.
I think this is one of those "Better to be silent and thought the fool than to speak up and remove all doubt" situations.

3 people like this
Posted by @Mark T
a resident of Monta Loma
on Nov 22, 2013 at 11:04 am

Do you have any better solution, at least dig it up is offering some type of solution. Or should we wait till more deaths and cancers happen because of this?

I lived on Whisman back in the early 80s and I had a brain tumor the size of a baseball. Coincidence?

Before you put someones comment down, how about offering better solutions.

3 people like this
Posted by Mark T.
a resident of Old Mountain View
on Nov 22, 2013 at 4:15 pm

First of all, if its just dug up, it vents uncontrolled to atmosphere, so yah, that's not a bright idea bulb popping over someone's head, and its dangerous to suggest.

Without seeing any specifics at all (apparently supported here):
Air stripping in conjunction with carbon filters would be the most neighborhood friendly method IMO for large scale areas.
Soil venting is an option, but I don't like the idea if they do not treat the VOCs before venting to atmosphere.
For the smaller pockets, Bio-remediation, though still new technology, could prove very beneficial, of an air well, again only of not left to vent untreated.

3 people like this
Posted by Mark T.
a resident of Old Mountain View
on Nov 22, 2013 at 4:22 pm

Oh and besides apologies for the typos, apologies if I didn't go into detail about the technologies and how they work, but that info is readily available to you via a Google search. Its actually pretty interesting. There's probably even newer tech now-a-days.

3 people like this
Posted by Liz S.
a resident of another community
on Mar 7, 2014 at 10:13 pm

Well the EPA told a group of military families in a meeting they held, April 2013, that we did not have to worry about getting cancer because we wouldn't live here long enough, and just PCS out in a few years anyway. That's not true for people in the Guard. Certain Nasa official were ordered not to go to the meeting, and no one from the housing office showed up either.

Some of us feel trapped by the situation and live in fear of what it's doing to our health. There's a lot of short term effects of TCE that no one seems to be mentioning, and some of us feel like we may be living with them. We don't trust the EPA to look out for us and do the right thing. And most of us just don't feel plain good enough to do much about anything. So we suffer in silence, mostly, and pray we won't regret living at Moffett Air Field.

Posted by Name hidden
a resident of Bailey Park

on Sep 25, 2017 at 9:00 pm

Due to repeated violations of our Terms of Use, comments from this poster are automatically removed. Why?

Sorry, but further commenting on this topic has been closed.

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