Ask me anything about wastewater and sewage

[Guybrush]

Reading all that made me think of that horrific fatberg they found in London a few years ago.

Yeah, they spent like what.. 10 days flushing that thing? might be an exaggeration, but I remember it was supposedly humongous.

Sewer fat is NASTY. The Squamish may not wanna watch this, though it is fascinating:

Heavy metals is an occasional annoyance as it fucks with how our sludge can be treated. If it contains too much of a metal, it becomes hazardous waste.

Do they change thechemical compound from H2O to something else?

They can form salts that dissolve in water that are hard to treat / get out, but the problem we have is in the sludge which is turned into dirt. If it's low in metals, it can eventually be put back into gardens & agriculture (after composting etc). If it contains a lot of, say, lead, that's gonna poison the carrots and so you have to treat it differently.

[jimmy jazz]

Worst thing you've seen?

Are you immune to the smell of shit now?

[Guybrush]

Worst thing you've seen?

Are you immune to the smell of shit now?

My job mostly happens from an office, so I'm not yet immune to poop smells.

I don't lay eyes on that much sewage and worst can be defined in so many ways, but I know what the grimiest job I've seen in sewage is. So quite a few years ago, I was trying to get familiar with the city's fat traps/separators, these installations that separate fat from wastewater that you may find downstream of kitchens in restaurants, cantinas, etc. Some of them are quite big when you're at like a hotel or a McDonald's.

To get familiar with these, I took a ride with an operator for a private contractor who was tasked with emptying these fat traps. That was a dirty job.

The fat in these tanks float on water, so it forms a big, hard, rotting cake of fat at the top of these tanks. To suck this fat up, they would use a high pressure hose to break it up into smaller pieces, then suck those up with a big hose attached to the car. When they start hosing that fat, things stink up bad, especially if you're also in a small technical room underground or in a basement. It was way worse than when, say, hosing down one of our pumping stations. It's a stink that sticks to your skin and probably your eyeballs afterwards.

I'm sure those rooms must also fill up with harmful aerosols and probably dangerous hydrogen sulfide and this guy didn't really wear a mask or any protection, so there was that too.

Other than that, I've seen a full log under a manhole, but that's not so bad. Kind of impressive, really.

[Toy Revolver]

Do you know anyone who got hepatitis or dysentery or any other illness from failing to maintain universal cautions when dealing directly with waste?

[Guybrush]

Do you know anyone who got hepatitis or dysentery or any other illness from failing to maintain universal cautions when dealing directly with waste?

No. In general, our guys are healthy and on average have fewer sick days than the national average. All I've heard people get from exposure to sewage is your basic diarrhea.

Knock on wood

I suspect a lot of would-be pathogens don't survive or stay infective for long after ending up in wastewater which may have the wrong temperature etc. to what they want.

Edit:

The biggest danger about sewage, it seems to me, is that it contains bacteria that produce hydrogen sulfide when there's little oxygen. It smells bad, but it's also very toxic so our guys carry gas detectors with alarms.

If there's a lot of it (like 800 ppm or more), it can have a knockdown effect where you literally just faint and start to die as it ties up all the oxygen in your blood. You don't smell it at that point because your olfactory nerves also get knocked out.

[Psy-Fi]

As far as unusual items being flushed down toilets, is there any particular item which shouldn't be disposed of in a toilet which shows up more frequently than any other? And I'm assuming you were only half-joking about action figures so just out of curiosity, is there any one action figure series which ends up in the sewers more frequently than any other action figure series?

[Guybrush]

As far as unusual items being flushed down toilets, is there any particular item which shouldn't be disposed of in a toilet which shows up more frequently than any other? And I'm assuming you were only half-joking about action figures so just out of curiosity, is there any one action figure series which ends up in the sewers more frequently than any other action figure series?

I haven't actually seen any action figures, but I remember they found one at the wastewater facility in the neighbouring municipality. I am hoping it was Turtles. They'd be the most appropriate, I think.

As for stuff people toss into toilets, most things that are not pee, poo, vomit or toilet paper can cause problems. Here, the biggest problem seems to be wet wipes. Peeps, please - don't toss those suckers in the loo! I understand the temptation, but they don't dissolve in water and will sometimes get stuck inside pumps etc. When a pump starts accumulating wet wipes, it may keep accumulating them until you get this big, hairy lump of shredded wipes that looks more like a drenched, dead dog than anything sold as a hygiene product. In order to get them out and restore normal operation, we need to take those pumps apart. It's expensive and causes frustration as well as pollution.

The second thing I'd say is fat, like cooking oil. Even if it looks liquid in your kitchen, it is likely to turn less viscous and harden once it's in the sewer, at least up here in Norway where it's relatively cold. It collects in the wells in our pumping stations, making them nasty and greasy, and it also creates nasty fat deposits in some of our pipes.

Every now and then, it seems some industry will empty a tank of cleaning chemicals or some real nasty goop rich in metals that will either screw up our ph-regulated sedimentation processes or poison the sludge, turning that into dangerous waste.

[Toy Revolver]

wet wipes

even if they're advertised as flushable?

cooking oil

that's a good way to cause damage to your own sewage as well

pour it in pastic cup - keep in the freeze - when the cup is about half full and the contents cold and hard put it in the trash

still not a fantastic solution but don't put oil into your own plumbing geez

[Psy-Fi]

As far as unusual items being flushed down toilets, is there any particular item which shouldn't be disposed of in a toilet which shows up more frequently than any other? And I'm assuming you were only half-joking about action figures so just out of curiosity, is there any one action figure series which ends up in the sewers more frequently than any other action figure series?

I haven't actually seen any action figures, but I remember they found one at the wastewater facility in the neighbouring municipality. I am hoping it was Turtles. They'd be the most appropriate, I think.

I was also thinking of the Teenage Mutant Ninja Turtles and hoping those figures would be the answer when I posted my question. 

[Toy Revolver]

https://www.theguardian.com/society/2023/feb/17/nhs-unsafe-sewage-leaks

Sewage leak figures prompt warning over state of England's hospitals
Exclusive: freedom of information requests reveal overspill on cancer wards, maternity units and A&E departments

[Guybrush]

Ouch, that sounds pretty bad. Crumbling infrastructure is a problem here too, but my impression is it hasn't become quite that bad yet.

Our general goal for our infrastructure is it should last 100 years. Put kinda stupidly, that means we have to replace 1% of it every year and after 100 years, we will have replaced 100% of it and then the oldest infrastructure should be 100 years old and ready for replacement.

However, our infrastructure very often doesn't last anything close to 100 years and we don't always replace 1% of it either, meaning it's all deteriorating faster than we can mend or replace it.

[Toy Revolver]

Our general goal for our infrastructure is it should last 100 years. Put kinda stupidly, that means we have to replace 1% of it every year and after 100 years, we will have replaced 100% of it and then the oldest infrastructure should be 100 years old and ready for replacement.

i like that - it's obvious after you say it that a hundred year plan means 1% replacement per year but if you hadn't said it i wouldn't have thought of it that way

it's relaxing when a writer tells you something you know but you didn't know you knew, you know?

[Psy-Fi]

Not a question but it's a story related to sewage and waste, so I'll post it here...


A man died after falling into a manure tanker at a New York farm. A second man who tried to help also fell in and died.

[Guybrush]

Not a question but it's a story related to sewage and waste, so I'll post it here...


A man died after falling into a manure tanker at a New York farm. A second man who tried to help also fell in and died.

Yep, hydrogen sulfide is a well known risk in the sewage business. Our guys all have gas detectors and also know not to immediately climb down the manhole to help their dying colleague.

That said, the levels aren't usually very high in our treatment plants, but a manure tanker certainly sounds like it would be very dangerous.

I know quite a few farmers have died this way as well.