The Silicon Valley Toxic Waste Heat Map | Hacker News Reader

The Silicon Valley Toxic Waste Heat Map

plainsite.org

49 pointsthinkcomp20 comments

What's the interpretation of comparing a contaminant level in a monitoring well (in the soil?) with a standard meant for drinking water?

The "total reading" statistic is a bit useless. 5 ug/L here, 10 ug/L there, does NOT make 15 ug/L total.

My understanding is that the monitoring wells measure groundwater so the drinking water standards are relevant.

Yeah, the total is just there because I thought it would be better to make the data visible than not. Overall it's pretty meaningless but it might help in some narrow instances where you're looking at one small area versus another small area in the same timeframe. Sometimes the wells are very close together and different colored icons get overlaid so it's not clear from the map that numbers are even that high.

You're the author? I think you have a parsing issue. I'm looking at barium: apparently the color-coding only looks at the number, discarding the unit (ug vs. mg). The MCL is 1 mg/L; for a measurement of "514 ug/L" (=0.514 mg/L), you code it as >100x Federal Threshold:

http://i.imgur.com/Vd75wlo.png

And for more confirmation, on the sidebar, the 0.220 mg/L measurement maps to the minimum of "0.220" (out of the 2 measurements in the field of view), and the 514 ug/L maps to the maximum "514.000". They should be 0.220 and 0.514 (mg/L).

Your map shows severe Barium pollution over the whole region, but that's just this error repeated many times.

http://i.imgur.com/bDQ3Lie.png

update: And zinc too. The severe zinc pollution all over the map is also an error:

http://i.imgur.com/8RoXpy8.jpg

update: Copper too:

http://i.imgur.com/ZZsm02G.jpg

Good catch. Thanks!

The CA map is interesting too, because it has the cleanup sites with some information on them: http://geotracker.waterboards.ca.gov/map/default.asp?global_...

It seems like gas stations typically leak a lot of gasoline into the ground. Is the burden always on the taxpayer to clean up?

Quite interesting. I would imagine just because of the fact that gas stations are so common & plentiful, they're going to be one of the more common items on that cleanup list.

That, and they're probably fairly easy targets for audits vs. the average co. given the nature of their business (Joe Blow could leak oil into the water for awhile without getting caught, a gas station probably has frequent checks). As for the burden on the tax payer: I don't think any of those are cleanups, just simply gas stations fixing underground leaking tanks. They all appear to be "Leaking Underground Tank (LUST)" cases.

The health burden is upon us all though.

Fairly well centered on Wilson Sonsini? I'm trying not to confuse correlation with causation here.

So how close to one of these indicators do I have to be for it to be hazardous? There's two hot spots very close to my apartment complex (<1000 feet). Now I'm paranoid since I've been living here for 2 years and drinking tap water.

Edit: Zooming out on the south bay it looks like the whole area has issues. I thought the TCE issue was contained to the Moffet Field area. It will be interesting to see the whole bay area when you add other counties. It's amazing to me that these hazardous conditions don't affect home prices.

The presentation of data here seems misleading. The red-green glow around each point seems like it's showing some sort of range of toxicity or something, that anything in the glow is affected somehow. But it's actually just a highlight around the icon. If you zoom in, the glow stays the same relative to the icon, but the range on the map is greatly reduced. If you zoom all the way out, it looks like the whole place in in a red zone, but it's not that way if you zoom in.

Is the data just for Santa Clara County (and really, those specific areas), or are they really that concentrated? Seems hard to believe there are no sites in the rest of the Bay Area.

So far I've only had time to test it out with Santa Clara County. I have all of CA's data but since it's >10GB I'm going to do some optimization and testing first to avoid killing my server.

I wish there were a way to overlay it on Craigslist listings, redfin, etc.

So, I work in one of these zones near Moffet Field. What do I do?

Wear a protection suit to work

I think the biggest concern with the Moffet Field area is trichloroethylene vapors. Trichloroethylene causes cancer.

They claim to be filtering it out of the air at the affected complexes. I don't think there's anything more you as an individual can do.

One way of looking at it is that car exhaust causes cancer, and we don't even attempt to filter that out of the air.

To me this kind of makes the earlier article seem overblown. Okay, so the entirety of silicon valley is a toxic waste dump? Well then.

> Okay, so the entirety of silicon valley is a toxic waste dump?

Yes, notoriously so. Think about where the name Silicon Valley comes from. HP, Shockley, Fairchild Semiconductor, Intel, AMD... Chipmakers. A lot of dangerous chemicals go into silicon chip fabrication, and a lot of them, especially in the bad old days, weren't disposed of (or contained) properly.

https://en.wikipedia.org/wiki/Semiconductor_device_fabricati...

https://en.wikipedia.org/wiki/Health_hazards_in_semiconducto...

http://online.wsj.com/article/SB1000142405274870411170457535...

http://www.epa.gov/region9/cleanup/california.html

Zoom out.

He didn't enter the data for the other regions yet.

Also, TCE is one chemical in a very long list.

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