Transcript for 10X10: City Gutters
Note: Episodes of Outside/In are made as pieces of audio, and some context and nuance may be lost on the page. Transcripts are generated using a combination of speech recognition software and human transcribers, and may contain errors.
Taylor Quimby: On an unpleasant day in February I was standing in front of my apartment (barely) …
Taylor Quimby [Standing outside in the rain] : Woop! Almost just slipped and fell.
Which is located right on the edge of downtown Concord…
Taylor Quimby [Standing outside in the rain] : Concord, Capital of New Hampshire. And we were supposed to get a couple of inches of snow tonight, but um….
We got rain. Lots of rain.
Taylor Quimby [Standing outside in the rain] : It’s freezing. It’s gross. And all the snow that we have is melting and making its way down here.
This is the sound of a storm drain - an honest-to-goodness river running under my feet.
And above me, the first tributaries in this unlikely ecosystem: gutters.
The very phrase, “get your mind out of the gutter” assumes it is a filthy place, hardly worthy of serious inquiry. But if you get your mind out of the gutter, and stick your nose instead...
Taylor Quimby [Standing outside in the rain] : I can also smell. [sniff sniff] It smells a little bit like rotten eggs.
[mux]
That eggy smell? That’s hydrogen sulfide… a toxic and flammable gas and might be produced by sulfur-reducing bacteria…
A category of organism known for surviving in extreme environments with little to no oxygen… Thermal vents, acidic and volcanic hot springs, or you know… Pipes, hot water heaters, and storm drains.
Menno Schilthuizen : They’re extreme environments, places where there’s opportunity but there’s also lots of challenges and risks that urban life has to deal with and the gutter is probably a good example of that.
This is Outside/In. I’m Taylor Quimby, in for Sam Evans-Brown. Today, we’ve got a BONUS episode from our series 10X10, where we take a close look at unusual or overlooked ecosystems..
This special episode was sponsored and selected by our lovely donors… who chose between four options, and ultimately decided to send us sifting through city gutters.
Joyce Hwang : I can’t think about the last time anybody asked me about gutters, to be honest!
Gutters, I’ve discovered, can refer to the curbside drainage channels that lead into storm drains… or to the metal or plastic troughs that line some rooftops, or really any low area designed to move water from one place to another. And since we didn’t specify which ones we were talking about, we’re going to cover those first two kinds.
Starting at the curb and working our way up, we’ll find out which creatures take advantage of our waste-water systems…
Doug Hartman : They go into the gutters cause the gutter is like a feeding trough.
Find evidence of extraterrestrial travel in the most mundane places...
Matthew Genge : And he likes gutters because gutters collect dust.
And we’ll look at how gutters function - or not - for the very species that designed them..
Fushcia Hoover : The challenge is being able to have systems that function the way they should for everybody.
[theme]
Ken Belt : I lived in downtown Baltimore growing up. We had these nice front porches for the road houses. And all of a sudden we’d see a possum. And we’d think, how did that thing get here.
Ken Belt : And it’s because they used the storm drains to get from here to there. Coyotes do the same thing... I would go into storm drains and I would find scat from racoons.
[mux]
Ken Belt : Hopefully they’re smart enough to get the hell out when they start hearing rumblings of flow.
This is Ken Belt, a retired engineer and ecologist who worked for two decades in Baltimore’s Department of Public Works.
If you look at a detailed geographic map of streams and rivers, you might notice it looks a little like a roadmap. And in a way, they are. That’s because rivers aren’t just homes for aquatic ecosystems… they’re highways for all sorts of animal life.
Human-engineered water systems - made up of culverts, and sewers and pipes, function in the same way.
And Ken says that gutters and storm drains aren’t just like streams… they are streams. Intermittent headwaters that can change suddenly from dry bed, to raging river, and back again.
Ken Belt: It’s different, but it’s the same.
On a riverbank, you have what’s called the riparian zone Where the water meets dry land, and lots of water-loving trees and plants grow in abundance. Which drop their leaves into the water.
Ken Belt: There’s a lot of litterfall, and that forms the basis for the food web.
In a healthy stream, Ken says, decomposing leaves attract communities of bacteria that break them down and form colonies of slimy biofilm. Those bacteria are eaten by the next step up the food chain. Bugs, which Ken calls shredders.
Ken Belt :A shredder would tear them apart and eat the microbial biofilm on there.
Like stonefly larvae and Caddisfly larvae...
Ken Belt : They literally build nets in the stream, and the nets catch those particles.
Collectively, this food web prevents the carbon in the leaves from turning back into a gas and re-entering the atmosphere - instead, locking it up in a russian nesting doll of itty bitty bug bodies.
But urban streams, like our gutters, Ken says, are battling tough conditions.
With street sweepers removing leaves, there’s little food break down in the gutter.
And the sudden, rapid currents you get during big storms make it impossible for insects like stoneflies to hang on without being washed away.
Until engineers build places for leaves and insects to collect somewhere in our storm drains, Ken says, you won’t see the fully formed food webs you do in the natural world.
Where you do see a thriving gutter food web, Ken says, is under the microscope.
Ken Belt : There’s a lot of microbiology in storm drains and in gutters.
[city SFX]
In 2015, a team of researchers took to the streets of Paris to look for life in the gutters.
They split up among the city's 20 districts, armed with equipment for collecting water, and toothbrushes for scraping up biofilms - microbial cities that form carpets in and around the gutters.
What they found were nearly 5,782 different OTUs… or Operational Taxonomic Units… Genetic samples unique enough to operate as a loose surrogate for species.
That’s nearly 6,000 different kinds of microbes… algae, photosynthesizing sunlight streaming into the city streets. Bacteria. There was a tiny, freshwater species of sponge.
Fungi. A species of mollusk. Multi-celled microbes called Alveolates.
The gutters of Paris and other cities are home to an invisible biome, a complex ecosystem and food web. One that may be functioning a little like the one in wild streams… Cleaning and filtering water, removing carbon from the air and producing oxygen… and maybe… pooping precious metals.
Carlos Goller : So hi nice to meet you, I’m Carlos Goller.
Carlos Goller is a microbiologist at North Carolina State University, and as an assistant professor who likes to search for microbes in unlikely places.
Carlos Goller : I find it really fascinating that you have some microbes that are able to stick to the drain of a kitchen sink.
He’s sent students out looking for microbes in water fountains on campus. In rooftop gutters...
Carlos Goller : Shady versus sunny gutters. They had different microbial populations.
But there is one microbe that Carlos turns to more than others: Delftia acidovorans… His colleagues have joked:
Carlos Goller : Of the millions of microbes out there, Carlos is interested in the one that does not cause disease but does this weird thing.
[mux]
Carlos Goller : It has this unique ability, when exposed to liquid gold, Delftia acidovorans, that’s the name of this organism, has the ability to make a little protein that takes liquid gold and clumps it together into gold nano-particles. And I always describe it as a gold-pooping microbe.
Delftia has been found in lots of places - like common garden soil - or the very uncommon water filter on the International Space Station.
And, no surprise, Carlos’s students have found it in the downspouts of North Carolina State University’s campus building’s gutter systems.
Carlos Goller : Confirmation bias, we said go search for deftia in downspouts and they found it in downspouts and soil…
Now before you go ahead and start trying to test your own gutters for Delftia, this isn’t a feasible get rich quick scheme. These nano-nuggets don’t add up to much.
Carlos Goller : We’re talking tiny, yes!
Measuring in length around 20 to 80 billionths of a meter, nanoparticles of gold are SOOOO tiny they don’t yet behave like metal… Exhibiting different shapes, colors, and properties. So Deltia won’t be replacing the gold in your wedding band any time soon. But they are a great way to get your microbiology students excited about the world around them…
Carlos Goller : It’s a really excellent way of looking at the understudied microbes that we label as ubiquitous that are doing fantastic things for us that we don’t even know about.
[mux]
Deltia acidovorans aside, the microbial life in city gutters isn’t simply a novelty. Science writer Fiona McMillan, in her article about the Parisian gutter study, points out that gutters line 6,000 miles of New York City’s roads.
That’s one-quarter the circumference of the Earth. With a sprawling ecosystem that large, It’s no wonder organisms aren’t merely taking advantage. They’re evolving.
Menno Schilthuizen : So probably there’s very high levels of lead and zinc, and we know from other organisms in urban environments, plants and city pigeons that they adapt to these high levels of heavy metals, and probably the same applies to the life that lives in these gutters.
This is Menno Schilthuizen, an evolutionary biologist, ecologist, and author of Darwin Comes to Town: How the Urban Jungle Drives Evolution..
So, if you’re a bird, or a squirrel...why even attempt life in the city? Why bother risking high levels of heavy metals, or getting run over by an Uber?
The same reasons any species prefers one habitat to another: more food, fewer predators, or better shelter.
Cliff swallows, for examples, traditionally like to build their cute little mud nests on vertical cliff faces.
Menno Schilthuizen : At some point, they drastically shifted to building them on concrete flyovers along highways. So at some point they discovered those flyovers offer a better substrate to attach their nests to, and that behavior was passed on, somehow. I’m not sure if there is evolution involved there, it could simply be learning and culture that takes off.
Cliff swallows and other birds have also been known to occasionally build nests along or underneath gutters… But, again, whatever advantages urban nests offer, there are always trade-offs… The bizarre non-sentient predators of the anthropocene.
Menno Schilthuizen : They’re also exposed to much more traffic deaths than the original populations of cliff swallows was. And the result is that over about 30, 35 years, these cliff swallows nesting there have evolved shorter, broader wings which is probably a result of this constant natural selection by oncoming traffic.
Taylor Quimby [in interview]: That is wild. That is just wild.
Menno Schilthuizen : And also artificial at the same time, yes.
[mux]
Rooftop gutters, like the ones that line our curbs, are also extreme environments: Prone to bake in the sun on a hot summer day, or flush with water when it rains.
But that’s only when they’re working. When gutters break or get clogged… It can have a domino effect.
Doug Hartman : Typical day for me would be squirrels, raccoons, flying squirrels, roof rats, possums, snakes, birds, the unusual can go into bobcats, alligator, black bear, cougar…
This is Doug Hartman, 34 year owner of Covenant Wildlife Management, based in Birmingham, Alabama. Throughout his career, he has seen it all. And while not all of the critters he’s mentioned can fit into a gutter, he says it's the small mammals especially who use them as highways.
Doug Hartman : They go into the gutters cause the gutter is like a feeding trough. You know it’s collecting any nuts and seeds that have fallen off the roof and collected in the gutter, and then you’ve got low spots that are collecting water in the gutter… And then they find that opening, getting into the soffit, they’ve got nice insulation they can use to stay warm, to stay dry. And all they’ve got to do is go onto their front porch and they’ve got food and water for them.
Doug says, the more neglected the gutters - and he guesses that maybe fifty to sixty percent of the ones he sees aren’t well maintained - the more wild they become.
And Once you’ve got nuts and leaves clogging your gutter, it’s only a matter of time before...
Doug Hartman : You’ll see pine trees growing out of gutters, oak trees.
Doug Hartman : They’ve got caught in leaf matter that’s decomposed, so it’s got great compost that it’s growing in, I’ve seen trees probably an inch in diameter and 8 feet tall growing out of gutters.
And once you’ve got plants and mammals - the next domino to fall is predators like or snakes.
Doug Hartman : So I’ve watched them crawl right up the side of a brick house and over the gutter and into the attic, and then I get into the attic and they’re up on a louvre vent chowing down on bats or something like that.
Be it a spring, or a vernal pool, or an aluminum gutter...Wherever water flows or collects, it attracts life. But what about taller buildings? Skyscrapers and high-rises, with roofs too high for leaves or nuts to collect? Gutters that collect nothing but rain, and dust, and starlight?
That’s after a break.
<BREAK>
This is Outside/In, a show about the natural world and how we use it. I’m Taylor Quimby, in for Sam Evans-Brown.
A gutter is a product - and a receptacle if you will - of its surroundings. It fills up with anything and everything that can fall or climb into it.
Water. Acorns. Leaves.
But story by story, as we ascend from the curb and up to the world of mid and high-rise buildings, there are fewer and fewer things liable to clog up the gutters.
By the time we reach the tallest buildings, just about all that’s left is rain and snow, bird poo, and wayward particles of pollution carried on the wind.
And one more thing: space dust. Technically called ‘micro-meteorites’.
Matthew Genge : So these are rocks from outer space, just like their larger cousins. But in this case they are dust particles.
(Mux)
This is Matthew Genge, a planetary scientist at Imperial College in London.
Micro-meteorites are exactly what they sound like - miniature space rocks just two to three hundred microns across… a little bit smaller than the width of the human hair.
Matthew Genge : Some micrometeorites melt as they come through the atmosphere because of the friction with the air as they come through, they enter the atmosphere at such high speeds they form tiny little droplets.
I cannot emphasize this enough - they are beautiful to behold. Blown up, these melted space rocks - look like otherworldly marbles, or the metallic shells of alien mollusks.
You might be under the impression that space is a vast empty vacuum. Compared to our atmosphere, sure, but in actuality there is a bubble surrounding our solar system, called the zodiacal cloud, that’s full of space dust.
From asteroids banging together, from comets. And that cosmic dust is constantly raining on the surface of the Earth… One-hundred metric tons of it every day.
Matthew Genge: You are never more than a few meters away from one of these particles. They are everywhere. They are on our streets, in our homes, even on our clothes.
As Matthew said, they’re incredibly common… but they are also, in a way, exceedingly rare.
Matthew Genge : So the rate they fall is around 6 particles per square meter per year.
Matthew Genge : Your house looks pretty clean, so I can see into your house….
Taylor Quimby [in the interview]: You can see one corner.
Matthew Genge: [laughs] You go onto any windowsill and you will find a healthy accumulation of dust. And just imagine trying to find that one micrometeorite among millions and millions of dust particles.
That’s why scientists who study micrometeorites have pretty much always collected them where there isn’t so much dust and pollution - in Antarctica.
That was, until Jon Larsen showed up.
Matthew Genge : It all began when I got contacted by a chap called Jon Larsen, who told me he had been collecting micrometeorites on his roof.
On his roof… and in his gutter. . It wasn’t the first time someone had reached out to Matthew with a claim like this.
Matthew Genge : And they always found huge numbers of them, impossibly high numbers. And so I always told Jon, no it wasn’t possible. And he just wouldn’t give up.
Jon, by the way, was too busy to be interviewed for this story… which might have to do with the fact that he isn’t your average amateur astronomer… He’s a painter, and acclaimed jazz guitarist. Even played with Chet Baker.
Matthew Genge : Had a big hit in years ago in Norway, he’s famous in Norway.
Matthew Genge : And in the end he sent me a photograph, and I thought, you know… that really does look like a micrometeorite and it was.
[mux]
In the end, Matthew worked with Jon to help him refine his methods… and together they’ve released a number of scientific papers, about how they’ve changed throughout the life of the solar system- and Jon has put out a book on how to find urban micrometeorites on roofs and rooftop gutters…
Matthew Genge : There are now hundreds of people around the planet who are collecting micrometeorites on their roofs.
Matthew Genge : So I feel quite guilty saying I gave him the tools to recognize micrometeorites, since what I really did was try to dissuade him from doing it in the first place.
[mux]
But it’s time to take our head out of the Zodiacal clouds… and start thinking again about what else - aside from cosmic dust - washes down, from our rooftops and into the storm drains. Because of all the species using our gutters, the one we haven’t yet talked about are humans.
Fushcia Hoover : You know, the engineering, and the work behind our water systems is incredible, it’s magical in a lot of ways.
This is Dr. Fuschia Hoover, a postdoc researcher at the National Socio-Environmental Synthesis Center in Annapolis, Maryland.
Fuschia Hoover : I think gutters are a fascinating part of that, right?
[mux]
In a natural setting, rain that falls in a forest may soak into the soil, and slowly filter through the earth for days, years, millennia even, before popping out as a spring, or seeping into the bed of a river.
But in a concrete waterway, everything is streamlined, integrated, and fast.
And that means there is a lot of stuff being collected as that water flows downstream.
Fuschia Hoover : So Salt, especially in our cities…
Fuschia Hoover : Oil or antifreeze, that’s all getting washed into our gutter systems everytime it rains.
Fuschia Hoover : Dog poop.
Again, urban hydrologist, Dr. Fushcia Hoover.
Fuschia Hoover : Another common thing in cities is fertilizer.
Fuschia Hoover : There’s a lot of nutrient concerns… Nitrate, phosphorus.
Fuschia Hoover: Things like, what would be in our medicine cabinet.
Just like micro-meteorites are invisible unless you’re actually looking for them - so aren’t a lot of the dissolved pollutants that build-up as water washes over all of the asphalt and rooftops of a city and into our sewers.
Fushcia Hoover : They’re showing up in the water, and so folks are trying to learn and discover what the impacts are on ecosystem health but also on human health.
In some cases, storm water runoff is being deposited directly into larger water bodies.
But older cities — especially on the East Coast — often rely, in part, on combined systems that mix storm water with waste water.
Fushcia Hoover: That raindrop is going to pop on your roof, travel down your gutters, and if it is a connected downspout, meaning that your gutters on your home directly connect to the sewer system underground, it's going to emerge with with the same waste that's coming out of your toilets. Right. Or your sinks.
In cases like these, all of that water and sewage flows into a treatment facility before being dumped back into the water cycle.
But these systems were only built to handle so much flow. And because cities are home to more people, bigger storms, and more surface area than they were when the sewers were designed these systems have broken down.
Let’s do a little back of the napkin math. Say you have a half-acre lot, and a pretty good bout of rain - one-tenth of an inch.
That’s one-thousand, three hundred and fifty-eight gallons of water flowing into the drain.
Now let’s do New York City, which from a quick google I see has somewhere around 135,000 acres of impervious surfaces.
Let’s say it’s a big storm - 1 inch of rain.
That adds up to…
Three trillion, five-hundred thirty-billion, twenty-thousand gallons of water.
Combined sewer systems can’t handle even a fraction of that much water.
So instead of sending it into treatment facilities… they dump the overflow directly into place like the Bronx River, the East River, the Hudson, Coney island Creek, and Jamaica Bay.
Fushcia Hoover : So it actually is often constructed within the pipes itself, where once the water gets to a certain level, there's like a release. You can kind of think of it like the extra drainage hole in your bathtub, right. Where the water is only allowed to get so high and then it starts running back into the drain so that you can't have an overflow event.
These are called Combined Sewer Overflows. In 2016, New York City had 100 days where they dumped raw sewage directly into waterways.
It adds up to somewhere around 20 billion gallons of contaminated water every year - just in the big apple.
And this is happening in cities all over the United States every week… every month… every year.
Fushcia Hoover : It can also backup into your home, particularly if you have basements and your pipes are connected into the stormwater system. Now it’s not just rainfall that is flooding your streets or your basements. It's also sewage and effluent. And so that's a health hazard risk. And now you're being exposed to an unknown number of potentially dangerous toxins and pollutants.
This is obviously a problem during events like Hurricane Katrina in 2005. But the harms aren’t reserved for occasional disasters - they’re regular, they’re getting more common, and they’re disproportionately affecting marginalized communities that historically have pushed into low-lying urban areas.
Fushcia Hoover 25: There’s a really good report from the Center for Neighborhood Technology in Chicago that looked at this, when there were really intense thunderstorms that hit the city, and the south side of Chicago which is predominantly black had the highest number of claims to FEMA.
Throughout so much of modern history, humans have worked to hide, control, or eliminate aspects of the natural world that don’t fit neatly with ideas of urban life.
Nature is messy. It’s unpredictable, and smelly, and needs maintenance - so we do our best to contain it in dedicated spaces like parks, gardens and zoos.
But what if our human-engineered systems could stand to be a little bit messier? What if instead of separating cities from the natural world, we tried to integrate them more thoughtfully?
Joyce Hwang: One thing - I think well designed buildings actually do have well-designed gutters. Here in Buffalo, there’s a Frank Lloyd Wright building where the gutter is actually beautiful. Well designed, totally integrated into the design of the house. It doesn’t look like a tacked on object.
Joyce Hwang is an associate professor of architecture at the University of Buffalo school of Architecture and Planning.
Joyce has spent a lot of time designing what is sometimes called Habitecture… design that integrates habitat intentionally into the built environment.
I called her because I wanted to see if she, as an architect, had thought much about gutters?
Joyce Hwang : Okay well the gutter is where water is collecting, why not have it drain, part of it becomes a vegetative area so that it becomes like a green roof type thing.
Joyce Hwang : Maybe make it into a planter, so it’s a gutter slash planter!
When we engineer systems designed to flush away our water in the fastest, most efficient ways possible - we miss out on the benefits of the natural systems we’re replacing.
Systems that filter water, or capture carbon, or prevent flooding.
And that’s why there are so many efforts nowadays to reintroduce the color green back into the cityscape.
Fushcia Hoover : Urban forest, street trees….
Fushcia Hoover : Green roofs…
Fushcia Hoover : There are things called rain gardens or bioswales or tree trenches.
All of this is called “green infrastructure” because it uses biology to slow water down … filter it in place… and let it trickle slowly into our rivers and streams.
These are ideas that can and are being implemented at both a systemic and individual level. Every square foot counts. But as Fuschia Hoover points out, even these solutions can wind up benefiting some over others - new developments, for example, that boast green infrastructure but price communities of color out of the neighborhood - a form of green gentrification.
Fushcia Hoover : Which is for me why it’s so important to think about storm water through an environmental justice lense, and thinking about the way environmental racism has made our communities more at risk particularly as climate change increases the intensity of our thunderstorms.The challenge is being able to have systems that function the way that they should for everybody.
[mux]
Cities are human-built environments, built for human habitation. So it makes sense to view them from that lens - how well are urban systems working for human beings? If they’re not working equally - who aren’t they working for, and why?
But there are limits to that perspective.
Joyce Hwang : If an animal is useful, like a bee pollinates,then we give it value, so we give this life value because of its usefulness. And we talk about this in architecture and planning as “ecosystem services”. So what can the ecosystem do for us as humans. And if we stick to that as a way of thinking, we’re basically in trouble.
I like to think of cities as complex ever-changing organisms… composed of organs, tissues, and cells… capable of working together, independently, and occasionally at odds.
When you look at the city from that perspective, you see that every system is connected.
Just like the gutters on our roofs are connected to the gutters on our streets… and the microbiome of our sewers is connected to the health of our communities, rivers, and oceans.
Since human beings in this analogy are the closest thing a city has to executive function, maybe we need to think about our roles as landlords of this shared ecosystem more seriously.
Menno Schilthuizen : I think we should really see ourselves as the major ecological force that we are now, and like all major ecological changes that come with a lot of extinction but it also means that we are creating a new habitat all over the earth that wasn’t there before.
Here again, is evolutionary biologist Menno Schilthuizen.
Menno Schilthuizen : I’m not saying that’s something we should be proud of, but it’s important that we realized we are as you say part of the system. We are one of the species that has become so numerous that it has started to influence the evolution of all other species.
It’s as the author and environmentalist Stuart Brand wrote… “We are as Gods and might as well get good at it.”
Menno Schilthuizen : So yes we are changing life on earth and that has both destructive and creative effects.
Might as well start in the gutter.
[mux and gutter SFX]
This episode of Outside/In was produced by me, Taylor Quimby, Justine Paradis, and Sam Evans-Brown.
Erika Janik is our Executive Producer.
You can learn more about the Parisian gutter study, about combined sewer overflows, and about how you can look for micrometeorites where you live, go to outside/in radio dot org.
A quick note - aside from the sounds I collected on that rainy February day, the sound effects in this episode were largely made using foley and other digital sources. For example, I was not able to actually capture a nut falling into a gutter - that was the sound of a piece of ginger hitting the tin cover from a set of dominos.
If you want to chat with other fans of the show, join our Facebook group. It’s a pretty cool forum for talking about the outdoors or commenting on the latest episode, and we also sometimes run ideas or surveys by the group to help inform our content.
Just search for Outside/In on facebook, and you should find us there.
Music in this episode by Blue Dot Sessions, and Podington Bear.
And a little snippet from Jon Larsen’s band, Hot Club of Norway,
Our theme is by breakmaster Cylinder.
Outside/In is a production of NHPR.