Sometimes I forget how filthy the bay is.

AlexB that's really fascinating appreciated you sharing that. 

Q: the removed source material, where does THAT end up??  Hopefully not in the south bay 

The stuff we sucked out of the ground during ERH treatment was just filthy... It was a mix of HOT groundwater, steamy soil vapor, petroleum hydrocarbons (primarily a compound called stoddard solvent - really smelly but not terribly toxic), volatile organic compounds like PCE/TCE/DCE/VC/etc, and smelly black biomass (basically the dead bodies of bacteria that had been munching on this mess until we boiled them alive).

This filthy mix then passed through an extravagant treatment system. First the mix was cooled down to a reasonable temperature, which allowed us to separate the liquid phase (heavily contaminated groundwater with a layer of hydrophobic floating chemicals on top) from the vapor phase (air and chemical vapors). The liquid phase first went through a "product separator" to remove the "free phase" chemicals (the floating portion), clay bed filter to remove small droplets of chemicals, air stripper to remove dissolved volatile compounds, activated carbon remove what the air stripper missed, and finally micro filtered to remove any contaminated activated carbon "dust" that leaked from the carbon beds. After all that, the water was quite clean, and we were able to discharge it to the EBMUD sanitary sewer system (we had a permit to do this, and were required to test the water frequently).

The vapor phase was treated in a similar manner using several very large activated carbon filters. Rather than hauling the "spent" carbon off site as a waste material each time it reached it's treatment capacity, we "regenerated" the carbon every few days by passing steam through it to strip the contaminants from the carbon. What we were left with was ~300 gallon tote after tote after tote of essentially purified/distilled chemicals we had removed from the ground. This stuff looked a lot like vegetable oil, but it would knock you right on your ass if you were to smell it (all staff working directly with that stuff wore respirators at all times).

Long story short, all of the funk we pulled from the ground was separated from the groundwater and soil vapor, concentrated into a pure liquid form, and transported to a Clean Harbors facility Aragonite, Utah where it was blended with other flammable liquieds/fuels and incinerated to generate energy. 

The whole time this was going on, we were monitoring the air quality around the perimiter of the site in real time using a mobile on-site lab (GS/MS) plumbed to ~15 different air sampling points. This ensured that we didn't put the surrounding community at risk.

very interesting stuff. Thanks for sharing that!

Groundwater discharges into the bay, correct?

Groundwater discharges into the bay, correct?

Correct.


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If you ever feel like getting grossed out, check out the Water Board’s GeoTracker tool online. You can search any area of California and see a map with most (not all) contaminated sites identifies. You can also find information about what was spilled, when, and what’s been done to investigate and/or remediate it.

The state is just peppered with sites... Old gas stations, old dry cleaners, old manufacturing hubs, semiconductor industry, etc, etc, etc... Humans have really made a mess of things.

https://geotracker.waterboards.ca.gov


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