Animats
5 hours ago
Plating operations are a huge headache. They have corrosive plating baths. They have to do some chemical processing on site to neutralize the corrosive chemicals and get them down to a neutral pH.
Some years ago, a plating company in San Jose dumped a plating bath into the sewer system. This was so toxic that it killed the bacteria that reduce organic sludge at the sewerage plant. This knocked the whole plant offline, releasing untreated sewerage into the bay. The lower bay was toxic for a week. It's normally swimmable. San Jose was fined by the EPA. The plating company was heavily fined by San Jose.
It's a good sewerage plant. The output is drinkable, and if you take the tour, you're offered some to drink. Some of the output is used for irrigation. In a severe drought emergency, water could be fed back into the water system. They've never had to do that, but in a big drought a few years ago, things got close to that point.
San Jose, which is more of an industrial city than most people realize, still has plating companies. Here's an inspection report for one of them.[1] This one was releasing too much chromium.
[1] https://19january2017snapshot.epa.gov/www3/region9/water/pre...
fsckboy
3 hours ago
a plating company in San Jose dumped a plating bath into the sewer system. This was so toxic that it killed the bacteria that reduce organic sludge at the sewerage plant. This knocked the whole plant offline, releasing untreated sewerage into the bay. The lower bay was toxic for a week
toxic because of chemicals and toxic because of the release of untreated sewage (bacteria) are sufficiently different that I thought I'd point out that you kind of mix them here. Also, toxic because of high concentrations (e.g. pH) that will dilute vs toxic cumulative forever chemicals are different orders of magnitude altogether.
This incident you describe seems like a one-off and fairly benign compared to long term patterns that lead to superfund sites. Till this company dumped that batch, they weren't dumping batches, i.e. the system was working.
I'm not up on the latest, not a civil engineer or public health authority, but it is generally recommended in many seaside places not to swim at the beach after rainstorms. the influx of large volumes of water into the sewage treatment systems means that they overflow and raw sewage is released. These systems are being improved all the time, but it's a known problem and civilization hasn't collapsed. Some natural creatures like sewage outflow. When Boston moved their outflow pipe from the inner harbor to deeper water in Cape Cod bay, the lobster population collapsed. Maybe we should have called it the lobster poopulation.
nine_k
4 hours ago
Nuclear power plants have secondary and tertiary overflow reservoirs, intended to capture any uncontrolled dangerous outflow if things go wrong.
I wonder if chemical plants have something similar, a way to contain an uncontrolled outflow of toxic stuff if the normal flow of neutralization fails.
BTW this likely means quite a bit of land used up by such a reservoir which is ideally never needed, but must be present.
Animats
4 hours ago
Yes. In Silicon Valley, if you go to Bedwell Bayfront Park, which is behind Meta/Facebook HQ, there is, on the bay side, a small sewerage treatment plant. There's a fenced concrete-lined pond, usually empty. That is a sewerage overflow containment pond. It's next to a hiking trail, so it's easily visible to the public. That whole park, by the way, is a recycled garbage dump. So is the bay side park behind Google HQ.
Wastewater plants have other ponds and tanks which are part of the process, and they're usually full, with liquid moving in and out, accompanied by stirring, air, and chemical injection. A big empty one is a backup system.
Real engineering.[1]
[1] https://www.epa.gov/sites/default/files/2014-09/documents/la...
mikestorrent
an hour ago
Does the area smell, or is that all captured somehow? I've been to the plant in my city many years ago and it only smelled in certain buildings.
overfeed
4 hours ago
> BTW this likely means quite a bit of land used up by such a reservoir which is ideally never needed, but must be present
This is enough to earn chemical plants a spot on a future "BANNED in California 2" article, because it's "clearly" overregulation.