In this episode, we journey into an unexpectedly aromatic world. Join Dr. Ladner as we revisit a holiday-themed story from season two, but this time with a twist: Dr. Ladner’s family and an old friend join in!
We explore the curious phenomenon of the Turkey aroma at wastewater treatment plants following Thanksgiving. Can millions of gallons of wastewater carry enough Turkey material to scent an entire plant? Dr. Ladner reconnects with his colleague, Manish Kumar, to delve into this aromatic mystery. Together, they ponder whether it’s the grease from Turkey drippings or something else that contributes to this unique phenomenon.
The episode takes an experimental turn as Dr. Ladner and his family visit their local wastewater plant before and after Thanksgiving to conduct an “official smell test.” What will they discover? Tune in to this episode of “The Outfall” for a blend of science, humor, and a dash of holiday spirit, as we unravel the mystery of the Turkey-scented wastewater plant!
Transcript
Dr. Ladner (00:01):
Okay. All right. Come here guys. You wanna hold it for a second? All right. You can hold it.
Child (00:06):
Hello.
Robert (00:09):
Hello, and welcome back. I’m Robert, and you’re listening to the Outfall where we explore water and infrastructure stories hidden beneath the surface of our everyday lives. Today we’re embarking on a special journey, revisiting a holiday highlight from season two, but with a new twist. Dr. Ladd’s family and an old friend are joining the adventure. So get ready to dive back into this mystery story involving Turkey aroma and a wastewater treatment plant.
Dr. Ladner (00:50):
Hello, outfall listeners. Thanksgiving is upon us and it brought back a memory I usually have about this time of year as a grad student. I took a trip down to San Diego to begin a research collaboration with the engineering firm, MWH. And on that trip, I met a guy named Manishh Kumar. He’s a professor at the University of Texas now, but at that time, he was working on a seawater desalination pilot study. A convenient place to build the pilot plant was at a wastewater treatment plant. It was the Point Loma wastewater treatment plant, which is built right on the coast in San Diego. It’s a stone’s throw from the water. Manish told me about surfing during lunch, and he showed me his beautiful view from the operations area. It was just an amazing juxtaposition of wastewater treatment in infrastructure and prime luxury real estate. Now, if memory serves, it was on that trip when Manishh told me for the first time that after Thanksgiving, the whole wastewater treatment plant smells like Turkey. I don’t know if that blows your mind like it did mine, or if it just grosses you out, like it sort of grossed me out at the time. But just think about it, there are millions of gallons of wastewater going through that plant every day. Actually, one source says that the Point Loma treatment plant has 145 million gallons of wastewater every day. And still after Thanksgiving, there is enough Turkey material in that water to give it a high enough concentration to make the whole plant smell like Turkey.
Robert (02:30):
Doctor Dr. Ladner reached out to reconnect with his old friend Manishh. He wanted to verify if his memories were indeed true. Stories are like kudzu. They kind of spread wildly intertwining with time in your mind. But was this an instance of unchecked growth or was this real?
Dr. Ladner (02:49):
Do you remember what I was remembering? And the Point Loma Plant smelled like Turkey after Thanksgiving.
Manish Kumar (02:55):
Yeah, so I’ve heard this in a few places. So, um, the first time I heard it, I think, but I’m not sure, was, uh, when I was doing a tour of the Wastewater Treatment Champion Urbana, it was the first time I think I heard it. And then when I went to Point Loma, my friend and my roommate, uh, who’s also an environmental engineer, uh, and used to work with me, he says the Point Loma Operators told him that. So I, uh, I’ve been on that site on, on, uh, that day and it smelled a little like that. But then after that, when I was in State College, I also asked the operators there and they said, sure. Uh, and State College is a good case study because everything goes to one wastewater treatment plan, right? The whole town. So once I heard from you and I heard your podcast, I also contacted the local, uh, there’s a person who used to work for the city of Austin, uh, uh, water.
Manish Kumar (03:55):
It’s called Austin Water. And, uh, he said he’d never heard of this before. So he contacted a few of his people. So he is retired now. So, uh, so he, he reached out and asked people and he said, uh, many of the people he knows have never been to a plant after Thanksgiving. But somebody sent him an explanation, just like the one that you mentioned, that it must be the grease that people put down the drain that ends up with the smell because, uh, metabolized Turkey may not smell like that. So I started looking online for papers too, and I found some papers on, uh, aroma of cooked Turkey. And if you leave it after being cooked, what transformation happens in the, in the, uh, the VOCs? Uh, so I, I I have no idea, uh, uh, if my recollection is wrong or what, but this is definitely lower in the wastewater, uh, community that, uh, wastewater treatment lines smell like Turkey the day after. So nice. We’ll actually have to go do an experiment someday.
Dr. Ladner (05:05):
So I texted Robert and Amy about this, and Amy had a great question. Do you think it’s just from people dumping the drippings and scraps down the drain or from the poop? And she used a little poop emoji in that text, by the way. So nice use of emoji resources. Amy, I told her I didn’t know, but I think she’s onto something. It could very well be the undigested Turkey that’s the main source of the aroma. So I was kind of curious about this and looked into it a little further. Wanted to find the chemical structure for cooked Turkey smell, and I just didn’t find, find very much information about it. Um, I didn’t find a single compound that is like the quintessential Turkey aroma. I did find an interesting paper on the flavor chemistry of chicken meat, I guess around the world. We eat a lot more chicken than Turkey, so maybe it makes sense that there’s more research on that subject.
Dr. Ladner (05:59):
But it said that chicken meat flavor is supposed to be affected by a number of anti and postmortem factors, is, is what it said. And I thought that was interesting. A chicken’s taste is affected by how it lived and by what happens after it dies. And so the paper had, uh, other discussion about a variety of things that happened to make chicken lose its appropriate flavor, like lipid oxidation and other chemical reactions. For what this made me think about, there must be one or several aroma chemicals that don’t degrade easily. They don’t undergo these oxidative and other chemical reactions, so they keep their chemical form even in the presence of bacteria and all the other stuff in a sewer pipe. So if your house smells like Turkey after dinner, it’s probably those long lasting chemicals that are to blame. Okay? So over the years, I’ve told this story about Turkey aroma at the plant to students in my water and wastewater treatment classes.
Dr. Ladner (06:57):
And it’s come up several times in conversations with other people. And I think a few operators at other treatment plants have confirmed that they indeed smell Turkey like on Black Friday after Thanksgiving at at other treatment plants. Do you know where your local wastewater treatment plant is? If so, are you looking for a fun Black Friday activity drive over to your plant and see if you can smell it. Now, most wastewater treatment plants, they do a pretty good job with odor control. So you’ll probably have to be like, very close to the plant or even ask permission to go onto the grounds or something. Or maybe just buzz into the front gate and ask the operators what they think about this. And, uh, if they don’t run you off and they give you a serious response, it’d be kind of fun. Is it the day before Thanksgiving, grace? Yes. And what are you, oh, wait, don’t, don’t yell. It’s quite so loud. You overwhelm the mic. Okay.
Child (07:54):
got it.
Dr. Ladner (07:56):
Oh, don’t get so close. That’s if I back off. That’s talk.
Child (08:00):
Okay. So it smells like human poop with dog poop, with miss, with mixed with chicken poop, with compost and trash.
Dr. Ladner (08:09):
Oh my goodness. That smells terrible. Then Simon, what does it smell like to you, buddy?
Child (08:15):
It smells like poop and Turkey.
Dr. Ladner (08:18):
Wait, wait, wait, wait, wait, wait, wait, wait. Are you sure It smells like Turkey?
Child (08:23):
Yeah. Yeah,
Dr. Ladner (08:25):
But it’s the day before Thanksgiving. What do you think, Isaac? Does it smell like Turkey?
Child (08:29):
Um,
Child (08:30):
No, I don’t think so. Not very much.
Dr. Ladner (08:33):
So why do you think Simon said it smelled like Turkey?
Child (08:36):
Um, because the whole point of this survey is that we’re coming back the day after Thanksgiving, and we’re gonna see if it smells like Turkey.
Dr. Ladner (08:43):
Okay. So he heard us talking about that, and that’s what’s in his mind, right?
Child (08:47):
Yep.
Robert (08:48):
Let me jump in here. I love that Dr. Leidner took his family to our local wastewater treatment plant even more. I love the fact that he took them back after Thanksgiving for another official smell test. What do you think they found?
Dr. Ladner (09:07):
Simon Grace, come here. I caught a whiff of it right here. Let’s see if it, the wind is kind of swirling around a little bit, so, all right, grace, can you smell anything from the wastewater plant?
Child (09:23):
Yes. It smells steam.
Dr. Ladner (09:25):
. Hey, but grace, oh, right here. Do you think it smells like Turkey though? Wait, come see, you gotta come see it where we can record it. Simon, what do you smell?
Child (09:37):
I smell some poop and pee.
Dr. Ladner (09:40):
Okay. Poop and pee. . What do you smell? Si Isaac,
Child (09:44):
Turkey and all, basically what I smelled last time, plus Turkey.
Dr. Ladner (09:50):
That’s kind of, that’s what I think too. I I definitely smell like a little bit of Turkey over the wastewater smell. You concur?
Child (09:59):
Yeah.
Dr. Ladner (10:00):
Okay. As you’re eating that Turkey dinner this year, remember that whatever you consume, we’ll eventually make it through those pipes and down to the outfall.
