Walter Byrd remembers the first time sewage came bubbling out of his toilet like it was yesterday.
“It was just pumping up through there,” Byrd says. “One of the bathrooms was so full of waste, at least 4 inches high in there. It smelled just like a hog pen.”
He sopped up the murky, foul-smelling water and doused the floor with bleach. But the sewage kept coming. On rainy days, it overflowed from drainage ditches into his yard, carrying wads of toilet paper and human waste.
The eight-bedroom home in Cahokia Heights, Illinois, had been a source of pride for Byrd when he first built it in 1996. He spent a lot of time outside, caring for his vegetable garden and watching wildlife wander through the backyard. But trying to stop the sewage backups quickly became his main focus, consuming countless hours and thousands of dollars of his savings.
“It was a dream house, until the floods came,” says Byrd, now 67. “That house broke me down.”
Byrd’s is one of hundreds of homes in this small community that has experienced sewage backups for years. The southern Illinois city, which sits just across the Mississippi River from St. Louis, has struggled with declining population sizes in recent decades. The majority of residents are Black and over 40% live in poverty.
At a town hall meeting in 2021, Illinois Senator Tammy Duckworth said that communities of color, like Cahokia Heights, have had to “bear the burden” of sewage backups and other environmental issues for far too long.
“No one should be forced to live with a public health crisis in their backyard, no matter their zip code, the color of their skin or how much money they make,” Duckworth said.
How Sewage Ends Up In Homes
In cities across the United States, complex networks of underground pipes carry drinking water, sewage, and stormwater from place to place. In all, millions of miles of pipes crisscross the country, including 800,000 miles of public sewer lines. The average age of these water and sewer pipes is nearly 50 years, but in some cities, pipes are more than a century old.
Though the issue is particularly severe in Cahokia Heights, residential sewage backups are common across the country. The causes vary, depending on how each city’s sewer and stormwater systems are designed. In Cahokia Heights, persistent sewage backups can be traced to outdated, poorly maintained systems that are unable to handle current demand.
The city’s stormwater and sewer systems were originally designed to be separate. The low-lying region relies on a network of drainage ditches and pumps to funnel stormwater to nearby waterways, including the Mississippi River. But the pumps, some up to 70 years old, struggle to keep up during intense rainstorms. Meanwhile, many stormwater pipes are cracked or blocked with sludge and tree roots.
When the pumps and pipes can’t keep up with rainfall, stormwater pools on the streets, says Shawn Sullivan, who works with the St. Louis District of the Army Corps of Engineers. From there, it can enter sanitary sewers through manholes, creating a “mixing and blending” between the two systems, he says. The influx of stormwater sends water in the sewage system “back upstream” through pipes, and into people’s homes through bathtub drains, toilets, and kitchen sinks.
Climate change is exacerbating the issue, driving more intense and frequent rainstorms that inundate the city. During heavy rain events, fast-moving floodwaters have turned streets into rivers and even trapped residents in their homes. Emergency crews rescued dozens of people from their homes by boat in 2015, after 4 feet of floodwater inundated one neighborhood.
But civil rights attorney Kalila Jackson says the root cause of sewer backups in Cahokia Heights is prolonged infrastructure neglect, not climate change. Jackson works with Equity Legal Services, a nonprofit representing some residents affected by sewage backups in two ongoing lawsuits against the city.
“This was completely preventable,” Jackson says. “This is not a situation where people moved into a flood zone. They didn’t move into the path of the Mississippi. This is what happens after decade, after decade, after decade of someone failing to maintain a system.”
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Residents dealing with sewage backups may also face health risks, as human waste carries bacteria, viruses and parasites. One ongoing study has found parasites in stool samples collected from residents, including tapeworms and protozoa. Some residents have also tested positive for Helicobacter pylori, a common bacterium that infects the stomach lining. In some cases, it can cause painful gut inflammation, ulcers, and even certain stomach cancers, says Dr. Theresa Gildner, an assistant professor of biological anthropology at Washington University in St. Louis who is leading the study.
Pathogens and parasites like these tend to be more common in developing countries, says Gildner, and are often underappreciated by US researchers and medical professionals. But infections can have health consequences, she adds, especially in lower-income areas.
“It is the most vulnerable who experience this and it can really compound existing issues, like not having access to healthcare, not having access to nutritious food or clean drinking water,” Gildner says.
Sewage Overflows By Design
Deteriorating infrastructure is not the only cause of sewage overflows.
Many US cities have combined sewer systems, where stormwater and sewage flow through a single set of pipes. When it rains, stormwater flows into the system through storm drains. To prevent the system from backing up into basements and streets during storms, there are specific points where pipes can release a mixture of sewage and stormwater into waterways, in what’s known as a combined sewer overflow.
There are more than 700 communities in the US with combined sewer systems, mostly in the Northeast and Midwest, including New York City, Chicago, and St. Louis. When introduced in the 1850s, these systems were hailed as a major improvement over the open ditches and cesspools of human waste that were common at the time and caused frequent disease outbreaks. Eventually, newer cities started building completely separate sewage and stormwater systems.
But cities that still have combined sewer systems are facing a new challenge: Their capacity can no longer handle current demand. In some places, urban population growth and higher water usage have increased the amount of water going into sewer systems. Moreover, intense rainstorms can rapidly overwhelm combined sewer systems. Sewer overflows that were meant to function as release valves in times of extreme flooding are now sending sewage into rivers and creeks more regularly. According to a 2004 estimate from the Environmental Protection Agency, combined sewer systems release 850 billion gallons of raw sewage into waterways every year. (Many cities and towns have reduced their sewage overflows since then, but the EPA has not released updated data.)
A Path Forward
Some cities, like Minneapolis, have worked to separate the sewage and stormwater systems into different pipes. But that approach can be very expensive. Officials in other cities, like Cincinnati, are working to add capacity to their system instead, building storage tanks to temporarily hold the excess sewage and stormwater until the treatment plant can handle it.
Another solution is “green infrastructure,” in which stormwater is directed into waterways through mostly natural means instead of via pipes and pumps. The Lick Run Greenway in Cincinnati has been lauded as an example of “daylighting” a stream that had been buried in a pipe over a century ago. The stream now handles most of the stormwater from the surrounding low-income neighborhood that once faced persistent sewer backups and combined sewer overflows.
Other US cities are updating their stormwater and sewer infrastructure, fixing broken pipes and pumps. In Cahokia Heights, crews are working to shore up miles of pipes using a technique known as cured-in-place-pipelining. Workers feed resin-soaked fabric and fiberglass tubes into broken pipes and blast hot steam inside, hardening the resin and creating a pipe within a pipe. Though considerably cheaper and faster than digging up and replacing pipes, the installation process has been linked to health problems for residents and workers elsewhere in the US.
Nearly $50 million in state and federal funding has been set aside for the work, which could take at least a decade to complete. Whether the funding will be enough to fully fix the city’s sewage issues remains unclear. Cahokia Heights officials did not make anyone available for an interview or respond to specific questions for this story.
After grappling with sewage backups for years, residents are impatient for the issue to be fixed.
Walter Byrd’s home has had a growing list of issues related to the sewage backups, from a persistent mold problem to rotting floorboards. He estimates he’s spent tens of thousands of dollars over the years on repairs, replacing drywall and flooring, tearing out bathrooms, rerouting pipes, and replacing flood-damaged appliances.
Byrd hopes the government will buy out his home, so he can afford to move somewhere else and have something to leave to his grandkids one day. “We’re just tired of this,” he says. “We ain’t young no more. Do something for us now, because we ain’t gonna be here forever.”
This article was written by Shahla Farzan. Additional reporting by Becca Costello.
Further Reading
- Listen to “Backed Up: A Crappy podcast by Cincinnati Public Radio” by Becca Costello and Ella Rowen.
- See a map of where combined sewage overflow outfalls are located, via the EPA.
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Segment Guests
Shahla Farzan
Shahla Farzan is a science journalist, PhD ecologist, and editor with American Public Media, where she helps produce science podcasts for kids. She loves showcasing the many weird and wonderful aspects of science—and encouraging young, curious thinkers to question and explore the world around them.
Becca Costello
Becca Costello is a reporter at WVXU in Cincinnati, Ohio.
Segment Transcript
SOPHIE BUSHWICK: This is Science Friday. I’m Sophie Bushwick. As we head toward election day, we’ve been hearing about a lot of national issues, but wastewater has not been one of them, despite a sewage crisis in many American cities. Science Friday’s John Dankosky is here with more. Hi, John.
JOHN DANKOSKY: Hey, Sophie. As I’m sure you know, in most US cities when you flush the toilet or wash your hands, that water and whatever else is in it, it flows through the pipes in your house, down to public sewer lines. If you can believe it, there are more than 800,000 miles of these pipes crisscrossing the US. And these pipes, they’re getting pretty old.
A lot of these pipes and the systems that rely on them were installed in decades or even more than a century ago. So these pipes are starting to crack. Others are getting blocked up with lots of gunk. In this kind of broken water infrastructure, it can create smelly, expensive problems, sometimes sending raw sewage into yards, streams and even into people’s homes.
Here to talk with us about this is Shahla Farzan. She’s a science journalist and editor with American Public Media. Shahla, it’s great to have you back.
SHAHLA FARZAN: Thanks for having me.
JOHN DANKOSKY: OK, so we’ve got sewage ending up where it shouldn’t be. Take us to some places where this is happening.
SHAHLA FARZAN: Yeah, I mean, sewage backups are pretty common in the US, so they happen everywhere from Massachusetts to Iowa to South Dakota. But one place that’s been really struggling with these backups for years is a small city in Southern Illinois called Cahokia heights, about a 10-minute drive from downtown St. Louis
And just for context, most of the residents there are Black, and about 40% live in poverty. And that’s where I met Walter Byrd. Walter is in his late 60s, and back in 1996, he built what he calls his dream house.
[AUDIO PLAYBACK]
– I like the area because there was like a lot of wildlife around there, rabbits, squirrels. Everything was there. And it was wonderful.
You might find some deers in the yard in the morning. They’d just be looking at. So yeah, it was real nice. And then had my garden and all this stuff.
I had squash. I had corn. I had peppers. I had– oh man, I had nice, real nice garden.
[PLAYBACK ENDS]
SHAHLA FARZAN: So the house itself had eight bedrooms, a master bath for him and his wife with a big Whirlpool tub. It was basically everything Walter wanted. And then things kind of started falling apart.
JOHN DANKOSKY: Oh, boy. So what happened?
SHAHLA FARZAN: So along the road to Walter’s house are these drainage ditches. I mean, they’re essentially trenches. And he discovered that when it rained, these ditches would fill up with water and flood his yard.
So he bought a pump to try to keep the floodwater away from his house. But then water started showing up inside his house, and it wasn’t floodwater this time. It was sewer water. And it was coming up through the toilet. Here’s Walter.
[AUDIO PLAYBACK]
– One of the bathrooms was full, so full of waste, at least about 4 inches high in there with toilet paper waste backed up, back up in there. And when I got the door open, the door seemed like the door swelled up a little bit. I tried everything. And you could still smell that smell in that house, ooh.
[PLAYBACK ENDS]
SHAHLA FARZAN: He said it smelled like a hog pen. This happened again and again. And it wasn’t just Walter’s house. He figured out his neighbors also had sewage coming up into their homes, out of basement drains, bubbling up out of toilets and bathtubs. And in some cases, when the water finally went down, you’d have inches of this thick, black, smelly sludge left behind.
JOHN DANKOSKY: Oh, it sounds terrible, but it also sounds like it’s a pretty serious health problem.
SHAHLA FARZAN: Oh, definitely. I mean, raw sewage is just full of all different kinds of things that can make us sick– bacteria, viruses, parasites. Theresa Gildner is an assistant professor of biological anthropology at Washington University in Saint Louis, and her research team has found people in Cahokia heights are infected with different parasites that spread through sewage, like tapeworms.
Plus up to 43% of residents, they’ve tested have had this specific bacteria that infects the stomach lining. It’s usually asymptomatic, but it can make people pretty sick. Here’s Theresa.
[AUDIO PLAYBACK]
– So it can cause things like gastritis. That’s kind of like inflammation in the gut that can be really painful. It might cause malnutrition. If you’re having a lot of pain, maybe you’re not eating as much, or the way you’re digesting food is different.
So in kids, that could cause growth delays. So it can have these long-term consequences. It has been linked with things like stomach ulcers and even certain types of cancers in very rare but extreme cases.
[PLAYBACK ENDS]
SHAHLA FARZAN: And it’s important to mention here that sewage isn’t just backing up into people’s homes, which would be bad enough. It’s also flowing out into yards and parks and rivers. So it’s contaminating the environment, too.
JOHN DANKOSKY: Shahla, let’s circle back to what’s causing this issue. We’ve been talking about rainstorms and flooding. So I don’t know. This has got to be connected to climate change, right?
SHAHLA FARZAN: Well, yes and no. So we know that storms are getting more frequent and more severe because of climate change. And Cahokia heights is right at the base of these steep bluffs. When it rains, water flows down those bluffs and floods the city.
So yes, big rain events really do matter here. But climate change is just one part of the story because people are getting sewage in their homes even during relatively light to moderate rain events when the system should be able to handle it. And that’s because the sewer and floodwater systems have been neglected here for decades.
JOHN DANKOSKY: What kind of neglect exactly?
SHAHLA FARZAN: Well, to understand what exactly is happening here, you have to know a little bit about how the system was supposed to work. So in this city have two separate systems.
You’ve got your stormwater system that’s supposed to take rainwater and then funnel it out of the city into waterways, like the Mississippi. Then you’ve got your sewer system, which is a totally separate set of pipes that take sewage and sends that out to a water treatment plant.
JOHN DANKOSKY: Yeah, and this makes sense. If you keep these systems separate, then when it rains a lot, that water goes back out into the river. And the city then is just paying to treat the sewage.
SHAHLA FARZAN: Yeah, exactly. I mean, that’s exactly how the system is supposed to work. But the problem is in this city, the stormwater and sewer systems are not separate anymore. And that’s because the physical infrastructure, so the things like the pipes and the pumps, just haven’t been maintained.
So stormwater pipes are cracked or blocked up with sludge and tree roots. And then on top of that, some of the pumps that are supposed to be pumping floodwater out of the city are really old. We’re talking 60, 70 years old in some cases.
So they don’t work as well. Or they don’t work at all. And then the city floods.
And we’re not just talking about an inch or two of water here. Sometimes it can be waist deep in the streets. I mean, Walter’s had to get his boat out during some of the worst storms. I talked with Shawn Sullivan about what exactly is causing this here. He’s with the St. Louis district of the Army Corps of Engineers.
[AUDIO PLAYBACK]
– So storm sewers are undersized, unable to really accommodate the volume of inflow coming into them, whether they’re either broken or whether they’re blocked or whether the pipe diameters are just too small to handle some of the high-intensity rain conditions that we’re seeing. And therefore, that surcharge stormwater that now is ponding on the surface is also getting into the sanitary sewer network through manholes. And then it starts to, in essence, back upstream, we’ll call it, back up through the pipe to the point where it has to overflow into places we don’t want it.
[PLAYBACK ENDS]
JOHN DANKOSKY: OK, let me make sure I understand this. Because the stormwater drains and the pumps aren’t working, then water starts to pool on the streets, which then, I guess, flows down the manholes, which are connected to this other system, the sewer system. And then that system gets overwhelmed, and it’ll start to back sewage up into the homes.
SHAHLA FARZAN: Yeah, that’s exactly right.
JOHN DANKOSKY: Oh, so you mentioned that this is an issue that’s happening in other cities. Are the reasons there similar?
SHAHLA FARZAN: That’s a really good question. And to answer it, I want to bring in Becca Costello. She’s a local government reporter at WVXU in Cincinnati, and she’s also the cohost of a new podcast called Backed Up about the sewer issues there.
JOHN DANKOSKY: Hi, Becca. I love the name of the podcast, by the way. It sounds like Cincinnati might be dealing with some of its own sewage backups.
BECCA COSTELLO: Yeah, John, that’s exactly right. The symptoms here in Cincinnati are pretty much the same as what Shahla is describing in Illinois. And in Cincinnati, of course, we have that sewage and stormwater mixing together.
But here, even though the symptom is the same, the cause isn’t because of neglect. It’s because the system was actually designed that way. And that’s because Cincinnati has something called a combined sewer system.
That’s where the wastewater and the stormwater all go through the same set of pipes to the treatment plant. But during heavy rain, it overwhelms that system. It backs up into homes. It backs up into creeks and rivers.
But these systems are actually really common in lots of cities, especially older cities. According to the EPA, there’s about 700 communities in the US with these combined sewer systems. That includes cities like Saint Louis, New York, Chicago, Philadelphia. And it’s really common in Europe, too. This, by the way, is why the Seine River in Paris got so much attention for water-quality issues during the Summer Olympics just recently.
JOHN DANKOSKY: I remember that story, Becca. Yeah, we covered that. So how long ago did these cities put in these combined source systems? And I don’t know. Why did so many places build them like this?
BECCA COSTELLO: So it’s most common in cities established at least 150 years ago. They have these combined sewer systems because it’s what made sense at the time. Now, we have to remember that these were replacing open sewers in ditches and cesspools, which were causing a lot of public health problems. They also smelled terrible, of course.
It was way cheaper to build a system that took everything you needed to get away from the people away from the people and do it at the same time. So this was the stormwater that was causing flooding and the sewage that was causing health concerns. Now, this was cutting-edge science at the time. It was a huge improvement over these cesspools but, obviously, causing a lot of problems today.
JOHN DANKOSKY: Yeah, it seems like an improvement over cesspools. But still, I mean, for these combined systems, climate change, I assume, is more of an issue because there’s just more water going into the system right now.
BECCA COSTELLO: Absolutely. So with combined sewer systems, they really are directly tied to heavy rainstorms because it’s just pouring down in a short period of time. And that is happening more often because a warmer climate means more moisture in the atmosphere.
Now, it’s important to remember this is not necessarily about the total amount of rain. It could rain every day for a year and not necessarily overwhelm the sewer system. But in Cincinnati, for example, the average rainfall intensity has gone up by more than half an inch over the past 50 years, which half an inch doesn’t sound like a whole lot, but this can absolutely overwhelm the system.
And when that happens, the systems are designed to overflow into waterways, and this is a way to prevent it from backing up into streets and into homes. And when all this rain comes at once, the sewage can overflow and back up into basements. So you often see both of these problems happening together.
SHAHLA FARZAN: Right. And I mean, when we’re talking about sewage going into waterways, we don’t actually have great data on how much is flowing into rivers and streams from these combined sewers. But the most recent EPA estimate that we have was about 850 billion gallons per year. And John, that’s enough sewage to fill 1.3 million Olympic-sized swimming pools every year going into rivers and streams.
But– and this is a big but– that estimate is from 2004. So it’s 20 years old. Lots of cities have cut down on sewage overflows since then. So the EPA says the total amount of sewage going into waterways could be half that amount. But again, we just– we don’t have updated data from them, so we don’t know.
JOHN DANKOSKY: I can’t believe we don’t have more updated data. But let’s get back to Cincinnati. So Becca, is the city trying to separate their sewer and stormwater systems now?
BECCA COSTELLO: Well, some cities have gone that separation route. Minneapolis is the best example. They’ve actually almost completely separated their combined sewer system.
But here in Cincinnati, it’s too expensive and involved to actually separate the system because it means building a whole new set of pipes, which is a lot of money and a lot of construction. Instead, in Cincinnati, they’re building mostly just bigger capacity, so bigger tanks, more storage so that when all that rain comes, they can store it for a short period of time until the treatment plants are able to treat all of that sewage and stormwater.
The city’s also trying to reduce how much water gets into the system in the first place. And they’re doing that with what’s called green infrastructure projects. And the Lick Run Greenway is the best example. It’s actually kind of been used as a national model. So the Lick Run was a stream that 100 years ago got put into a big underground pipe. And that neighborhood became one of the worst for sewer backups and combined sewer overflows.
But what the city did is they returned that from a pipe back to an open stream now, and it can handle most of the stormwater from heavy rain, meaning the stormwater never has to mix with sewage. It can go straight to the Mill Creek, which ends up in the Ohio River. But it’s important to say all of this is still extremely expensive.
It’s a multibillion dollar effort over several decades. It’s paid for by ratepayers. It’s just not as expensive as it would have been to separate the systems.
JOHN DANKOSKY: How about in Cahokia Heights, Shahla? Are they trying to do something similar to fix the problem there?
SHAHLA FARZAN: In Cahokia Heights, what they’re trying to do is basically repair and replace a lot of this broken infrastructure, so like the broken pipes and pumps that I was talking about. And around $50 million in state and federal funding has been set aside to fix these issues. But I mean, this is a big job. We’re talking about 90 miles of sewers in just this one city. And on top of that, a lot of the system hasn’t even been fully mapped yet. So this is just a huge undertaking.
JOHN DANKOSKY: I don’t know. I’m no engineer, Shahla, but 90 miles of pipe and only $50 million to pay for it. I mean, I don’t know. Is that really enough to fix this problem?
SHAHLA FARZAN: Yeah, it’s a good question, John. And honestly, it’s hard to know. I reached out to the mayor’s office and the sewer department, but they didn’t make anyone available for an interview. So as far as the total cost of how much it would take to completely fix this, that’s kind of still a question mark.
But what I can say is that they’ve started the work of repairing the system, which includes fixing pipes using this technique called cured-in-place pipe lining. So basically workers have these kind of long, fabric-like tubes that look sort of like socks. And those tubes are soaked in resin.
So the workers feed them into the broken pipes, inflate them. And then they blow really, really hot steam inside, which hardens the resin inside those fabric tubes. So that’s why it’s called pipelining because it essentially creates a pipe inside of a pipe. The advantage with this technique is that it’s a lot cheaper and faster than physically replacing the pipes. But it’s just a temporary fix. And we should mention that the process of installing them has been linked to health problems for workers and residents elsewhere in the country.
JOHN DANKOSKY: So it sounds like this isn’t a perfect solution, to say the least. So how are residents feeling about all this?
SHAHLA FARZAN: Not surprisingly, residents are just really tired of dealing with this. In some cases, they’ve had raw sewage coming up into their homes regularly for decades. And many of these people are elderly, and they’re just worried that this isn’t going to be fixed in their lifetimes.
JOHN DANKOSKY: Let’s get back to Walter. He’s the resident that you talked to in the beginning of our story. Is he still living in this dream home of his?
SHAHLA FARZAN: Well, Walter does still own that house that he built, but he doesn’t live there anymore. He can’t get rid of the sewage smell no matter what he does. And the house also has a mold problem at this point.
He says he’s hoping the city will just buy him out so he could afford to buy a different house and maybe have something to leave to his grandkids someday. I asked him where he’d want that new house to be.
[AUDIO PLAYBACK]
– I’m going to be like a bird. I’m going go to the high spot. Y’all will see– y’all will see me living on a mountain somewhere. [LAUGHS] I know. They said, why that– why that house is on top of that hill right there? Because I’m going to be the only one way up there. I say, I ain’t going to have this problem no more.
[PLAYBACK ENDS]
JOHN DANKOSKY: Oh my goodness. I hope he’s able to find that higher ground that he’s looking for. Shahla, thanks so much for bringing us the story. I really appreciate it.
SHAHLA FARZAN: Thanks so much for having me.
JOHN DANKOSKY: Shahla Farzan is a reporter and editor with American Public Media. She was joined by Becca Costello, local government reporter at WVXU in Cincinnati. Becca is cohost of a new podcast called Backed Up. It’s about the sewer issues in Cincinnati.
And if you’d like to read more about the story and for a link to Becca’s great podcast, you can go to sciencefriday.com/sewers. That’s sciencefriday.com/sewers. I’m John Dankosky.
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Meet the Producers and Host
About John Dankosky
John Dankosky works with the radio team to create our weekly show, and is helping to build our State of Science Reporting Network. He’s also been a long-time guest host on Science Friday. He and his wife have three cats, thousands of bees, and a yoga studio in the sleepy Northwest hills of Connecticut.
About Shahla Farzan
@ShahlaFarzanShahla Farzan is a science journalist, PhD ecologist, and editor with American Public Media, where she helps produce science podcasts for kids. She loves showcasing the many weird and wonderful aspects of science—and encouraging young, curious thinkers to question and explore the world around them.